Port IdentityCredential HAL to AIDL.

This includes add a partial types-only HAL for KeyMaster for
HardwareAuthToken.

Bug: 111446262
Test: atest android.security.identity.cts
Test: VtsHalIdentityTargetTest
Test: android.hardware.identity-support-lib-test
Change-Id: I7a6254d33200bfd62269aed1957cbb2a84b16272

37 files changed, 1502 insertions, 1579 deletions

diff --git a/identity/1.0/Android.bp b/identity/1.0/Android.bp
deleted file mode 100644
index e0a6332f89..0000000000
--- a/identity/1.0/Android.bp
+++ /dev/null
@@ -1,20 +0,0 @@
-// This file is autogenerated by hidl-gen -Landroidbp.
-
-hidl_interface {
-    name: "android.hardware.identity@1.0",
-    root: "android.hardware",
-    vndk: {
-        enabled: true,
-    },
-    srcs: [
-        "types.hal",
-        "IIdentityCredential.hal",
-        "IIdentityCredentialStore.hal",
-        "IWritableIdentityCredential.hal",
-    ],
-    interfaces: [
-        "android.hardware.keymaster@4.0",
-        "android.hidl.base@1.0",
-    ],
-    gen_java: false,
-}
diff --git a/identity/1.0/default/Android.bp b/identity/1.0/default/Android.bp
deleted file mode 100644
index d2b29660d3..0000000000
--- a/identity/1.0/default/Android.bp
+++ /dev/null
@@ -1,43 +0,0 @@
-//
-// Copyright (C) 2019 The Android Open Source Project
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-
-cc_binary {
-    name: "android.hardware.identity@1.0-service.example",
-    init_rc: ["android.hardware.identity@1.0-service.example.rc"],
-    vendor: true,
-    relative_install_path: "hw",
-    cflags: [
-        "-Wall",
-        "-Wextra",
-    ],
-    srcs: [
-        "service.cpp",
-        "IdentityCredential.cpp",
-        "IdentityCredentialStore.cpp",
-        "WritableIdentityCredential.cpp",
-    ],
-    shared_libs: [
-        "android.hardware.identity@1.0",
-        "android.hardware.identity-support-lib",
-        "android.hardware.keymaster@4.0",
-        "libcppbor",
-        "libcrypto",
-        "libbase",
-        "libhidlbase",
-        "liblog",
-        "libutils",
-    ],
-}
diff --git a/identity/1.0/default/IdentityCredential.h b/identity/1.0/default/IdentityCredential.h
deleted file mode 100644
index eb8787b872..0000000000
--- a/identity/1.0/default/IdentityCredential.h
+++ /dev/null
@@ -1,132 +0,0 @@
-/*
- * Copyright 2019, The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef ANDROID_HARDWARE_IDENTITY_IDENTITYCREDENTIAL_H
-#define ANDROID_HARDWARE_IDENTITY_IDENTITYCREDENTIAL_H
-
-#include <android/hardware/identity/1.0/IIdentityCredential.h>
-
-#include <android/hardware/identity/support/IdentityCredentialSupport.h>
-
-#include <map>
-#include <set>
-#include <string>
-#include <vector>
-
-#include <cppbor/cppbor.h>
-
-namespace android {
-namespace hardware {
-namespace identity {
-namespace implementation {
-
-using ::std::map;
-using ::std::string;
-using ::std::vector;
-
-using ::android::hardware::hidl_string;
-using ::android::hardware::hidl_vec;
-using ::android::hardware::Return;
-using ::android::hardware::Void;
-using ::android::hardware::identity::V1_0::IIdentityCredential;
-using ::android::hardware::identity::V1_0::Result;
-using ::android::hardware::identity::V1_0::ResultCode;
-using ::android::hardware::identity::V1_0::SecureAccessControlProfile;
-using ::android::hardware::keymaster::V4_0::HardwareAuthToken;
-
-using MapStringToVectorOfStrings = map<string, vector<string>>;
-
-class IdentityCredential : public IIdentityCredential {
-  public:
-    IdentityCredential(const hidl_vec<uint8_t>& credentialData)
-        : credentialData_(credentialData), numStartRetrievalCalls_(0), authChallenge_(0) {}
-
-    // Parses and decrypts credentialData_, return false on failure. Must be
-    // called right after construction.
-    ResultCode initialize();
-
-    // Methods from ::android::hardware::identity::IIdentityCredential follow.
-
-    Return<void> deleteCredential(deleteCredential_cb _hidl_cb) override;
-    Return<void> createEphemeralKeyPair(createEphemeralKeyPair_cb _hidl_cb) override;
-
-    Return<void> setReaderEphemeralPublicKey(const hidl_vec<uint8_t>& publicKey,
-                                             setReaderEphemeralPublicKey_cb _hidl_cb) override;
-
-    Return<void> createAuthChallenge(createAuthChallenge_cb _hidl_cb) override;
-
-    Return<void> startRetrieval(const hidl_vec<SecureAccessControlProfile>& accessControlProfiles,
-                                const HardwareAuthToken& authToken,
-                                const hidl_vec<uint8_t>& itemsRequest,
-                                const hidl_vec<uint8_t>& sessionTranscript,
-                                const hidl_vec<uint8_t>& readerSignature,
-                                const hidl_vec<uint16_t>& requestCounts,
-                                startRetrieval_cb _hidl_cb) override;
-    Return<void> startRetrieveEntryValue(const hidl_string& nameSpace, const hidl_string& name,
-                                         uint32_t entrySize,
-                                         const hidl_vec<uint16_t>& accessControlProfileIds,
-                                         startRetrieveEntryValue_cb _hidl_cb) override;
-    Return<void> retrieveEntryValue(const hidl_vec<uint8_t>& encryptedContent,
-                                    retrieveEntryValue_cb _hidl_cb) override;
-    Return<void> finishRetrieval(const hidl_vec<uint8_t>& signingKeyBlob,
-                                 finishRetrieval_cb _hidl_cb) override;
-
-    Return<void> generateSigningKeyPair(generateSigningKeyPair_cb _hidl_cb) override;
-
-  private:
-    // Set by constructor
-    vector<uint8_t> credentialData_;
-    int numStartRetrievalCalls_;
-
-    // Set by initialize()
-    string docType_;
-    bool testCredential_;
-    vector<uint8_t> storageKey_;
-    vector<uint8_t> credentialPrivKey_;
-
-    // Set by createEphemeralKeyPair()
-    vector<uint8_t> ephemeralPublicKey_;
-
-    // Set by setReaderEphemeralPublicKey()
-    vector<uint8_t> readerPublicKey_;
-
-    // Set by createAuthChallenge()
-    uint64_t authChallenge_;
-
-    // Set at startRetrieval() time.
-    map<uint16_t, ResultCode> profileIdToAccessCheckResult_;
-    vector<uint8_t> sessionTranscript_;
-    std::unique_ptr<cppbor::Item> sessionTranscriptItem_;
-    vector<uint8_t> itemsRequest_;
-    vector<uint16_t> requestCountsRemaining_;
-    MapStringToVectorOfStrings requestedNameSpacesAndNames_;
-    cppbor::Map deviceNameSpacesMap_;
-    cppbor::Map currentNameSpaceDeviceNameSpacesMap_;
-
-    // Set at startRetrieveEntryValue() time.
-    string currentNameSpace_;
-    string currentName_;
-    size_t entryRemainingBytes_;
-    vector<uint8_t> entryValue_;
-    vector<uint8_t> entryAdditionalData_;
-};
-
-}  // namespace implementation
-}  // namespace identity
-}  // namespace hardware
-}  // namespace android
-
-#endif  // ANDROID_HARDWARE_IDENTITY_IDENTITYCREDENTIAL_H
diff --git a/identity/1.0/default/IdentityCredentialStore.cpp b/identity/1.0/default/IdentityCredentialStore.cpp
deleted file mode 100644
index 9eb1e70751..0000000000
--- a/identity/1.0/default/IdentityCredentialStore.cpp
+++ /dev/null
@@ -1,68 +0,0 @@
-/*
- * Copyright 2019, The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#define LOG_TAG "IdentityCredentialStore"
-
-#include "IdentityCredentialStore.h"
-#include "IdentityCredential.h"
-#include "WritableIdentityCredential.h"
-
-#include <android-base/logging.h>
-
-namespace android {
-namespace hardware {
-namespace identity {
-namespace implementation {
-
-// Methods from ::android::hardware::identity::IIdentityCredentialStore follow.
-
-Return<void> IdentityCredentialStore::getHardwareInformation(getHardwareInformation_cb _hidl_cb) {
-    _hidl_cb(support::resultOK(), "IdentityCredential Reference Implementation", "Google",
-             kGcmChunkSize, false /* isDirectAccess */, {} /* supportedDocTypes */);
-    return Void();
-}
-
-Return<void> IdentityCredentialStore::createCredential(const hidl_string& docType,
-                                                       bool testCredential,
-                                                       createCredential_cb _hidl_cb) {
-    auto writable_credential = new WritableIdentityCredential(docType, testCredential);
-    if (!writable_credential->initialize()) {
-        _hidl_cb(support::result(ResultCode::FAILED,
-                                 "Error initializing WritableIdentityCredential"),
-                 writable_credential);
-        return Void();
-    }
-    _hidl_cb(support::resultOK(), writable_credential);
-    return Void();
-}
-
-Return<void> IdentityCredentialStore::getCredential(const hidl_vec<uint8_t>& credentialData,
-                                                    getCredential_cb _hidl_cb) {
-    auto credential = new IdentityCredential(credentialData);
-    // We only support CIPHERSUITE_ECDHE_HKDF_ECDSA_WITH_AES_256_GCM_SHA256 right now.
-    auto ret = credential->initialize();
-    if (ret != ResultCode::OK) {
-        _hidl_cb(support::result(ret, "Error initializing IdentityCredential"), credential);
-        return Void();
-    }
-    _hidl_cb(support::resultOK(), credential);
-    return Void();
-}
-
-}  // namespace implementation
-}  // namespace identity
-}  // namespace hardware
-}  // namespace android
diff --git a/identity/1.0/default/IdentityCredentialStore.h b/identity/1.0/default/IdentityCredentialStore.h
deleted file mode 100644
index ad7536043f..0000000000
--- a/identity/1.0/default/IdentityCredentialStore.h
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
- * Copyright 2019, The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef ANDROID_HARDWARE_IDENTITY_IDENTITYCREDENTIALSTORE_H
-#define ANDROID_HARDWARE_IDENTITY_IDENTITYCREDENTIALSTORE_H
-
-#include <android/hardware/identity/1.0/IIdentityCredentialStore.h>
-
-namespace android {
-namespace hardware {
-namespace identity {
-namespace implementation {
-
-using ::android::hardware::hidl_string;
-using ::android::hardware::hidl_vec;
-using ::android::hardware::Return;
-using ::android::hardware::Void;
-using ::android::hardware::identity::V1_0::IIdentityCredentialStore;
-using ::android::hardware::identity::V1_0::Result;
-using ::android::hardware::identity::V1_0::ResultCode;
-
-class IdentityCredentialStore : public IIdentityCredentialStore {
-  public:
-    IdentityCredentialStore() {}
-
-    // The GCM chunk size used by this implementation is 64 KiB.
-    static constexpr size_t kGcmChunkSize = 64 * 1024;
-
-    // Methods from ::android::hardware::identity::IIdentityCredentialStore follow.
-    Return<void> getHardwareInformation(getHardwareInformation_cb _hidl_cb) override;
-    Return<void> createCredential(const hidl_string& docType, bool testCredential,
-                                  createCredential_cb _hidl_cb) override;
-    Return<void> getCredential(const hidl_vec<uint8_t>& credentialData,
-                               getCredential_cb _hidl_cb) override;
-};
-
-}  // namespace implementation
-}  // namespace identity
-}  // namespace hardware
-}  // namespace android
-
-#endif  // ANDROID_HARDWARE_IDENTITY_IDENTITYCREDENTIALSTORE_H
diff --git a/identity/1.0/default/WritableIdentityCredential.h b/identity/1.0/default/WritableIdentityCredential.h
deleted file mode 100644
index b1deb16750..0000000000
--- a/identity/1.0/default/WritableIdentityCredential.h
+++ /dev/null
@@ -1,106 +0,0 @@
-/*
- * Copyright 2019, The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef ANDROID_HARDWARE_IDENTITY_WRITABLEIDENTITYCREDENTIAL_H
-#define ANDROID_HARDWARE_IDENTITY_WRITABLEIDENTITYCREDENTIAL_H
-
-#include <android/hardware/identity/1.0/IWritableIdentityCredential.h>
-
-#include <android/hardware/identity/support/IdentityCredentialSupport.h>
-
-#include <cppbor.h>
-
-namespace android {
-namespace hardware {
-namespace identity {
-namespace implementation {
-
-using ::std::string;
-using ::std::vector;
-
-using ::android::hardware::hidl_string;
-using ::android::hardware::hidl_vec;
-using ::android::hardware::Return;
-using ::android::hardware::Void;
-using ::android::hardware::identity::V1_0::IWritableIdentityCredential;
-using ::android::hardware::identity::V1_0::Result;
-using ::android::hardware::identity::V1_0::ResultCode;
-using ::android::hardware::identity::V1_0::SecureAccessControlProfile;
-
-class WritableIdentityCredential : public IWritableIdentityCredential {
-  public:
-    WritableIdentityCredential(const hidl_string& docType, bool testCredential)
-        : docType_(docType), testCredential_(testCredential) {}
-
-    // Creates the Credential Key. Returns false on failure. Must be called
-    // right after construction.
-    bool initialize();
-
-    // Methods from ::android::hardware::identity::IWritableIdentityCredential
-    // follow.
-    Return<void> getAttestationCertificate(const hidl_vec<uint8_t>& attestationApplicationId,
-                                           const hidl_vec<uint8_t>& attestationChallenge,
-                                           getAttestationCertificate_cb _hidl_cb) override;
-
-    Return<void> startPersonalization(uint16_t accessControlProfileCount,
-                                      const hidl_vec<uint16_t>& entryCounts,
-                                      startPersonalization_cb _hidl_cb) override;
-
-    Return<void> addAccessControlProfile(uint16_t id, const hidl_vec<uint8_t>& readerCertificate,
-                                         bool userAuthenticationRequired, uint64_t timeoutMillis,
-                                         uint64_t secureUserId,
-                                         addAccessControlProfile_cb _hidl_cb) override;
-
-    Return<void> beginAddEntry(const hidl_vec<uint16_t>& accessControlProfileIds,
-                               const hidl_string& nameSpace, const hidl_string& name,
-                               uint32_t entrySize, beginAddEntry_cb _hidl_cb) override;
-
-    Return<void> addEntryValue(const hidl_vec<uint8_t>& content,
-                               addEntryValue_cb _hidl_cb) override;
-
-    Return<void> finishAddingEntries(finishAddingEntries_cb _hidl_cb) override;
-
-  private:
-    string docType_;
-    bool testCredential_;
-
-    // These are set in initialize().
-    vector<uint8_t> storageKey_;
-    vector<uint8_t> credentialPrivKey_;
-    vector<uint8_t> credentialPubKey_;
-
-    // These fields are initialized during startPersonalization()
-    size_t numAccessControlProfileRemaining_;
-    vector<uint16_t> remainingEntryCounts_;
-    cppbor::Array signedDataAccessControlProfiles_;
-    cppbor::Map signedDataNamespaces_;
-    cppbor::Array signedDataCurrentNamespace_;
-
-    // These fields are initialized during beginAddEntry()
-    size_t entryRemainingBytes_;
-    vector<uint8_t> entryAdditionalData_;
-    string entryNameSpace_;
-    string entryName_;
-    vector<uint16_t> entryAccessControlProfileIds_;
-    vector<uint8_t> entryBytes_;
-};
-
-}  // namespace implementation
-}  // namespace identity
-}  // namespace hardware
-}  // namespace android
-
-#endif  // ANDROID_HARDWARE_IDENTITY_WRITABLEIDENTITYCREDENTIAL_H
diff --git a/identity/1.0/default/android.hardware.identity@1.0-service.example.rc b/identity/1.0/default/android.hardware.identity@1.0-service.example.rc
deleted file mode 100644
index 1eb7319e14..0000000000
--- a/identity/1.0/default/android.hardware.identity@1.0-service.example.rc
+++ /dev/null
@@ -1,3 +0,0 @@
-service vendor.identity-1-0 /vendor/bin/hw/android.hardware.identity@1.0-service.example
-    class hal
-    user nobody
diff --git a/identity/1.0/default/service.cpp b/identity/1.0/default/service.cpp
deleted file mode 100644
index 839e8030ea..0000000000
--- a/identity/1.0/default/service.cpp
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
- * Copyright 2019, The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#define LOG_TAG "android.hardware.identity@1.0-service"
-
-#include <android-base/logging.h>
-#include <hidl/HidlTransportSupport.h>
-
-#include "IdentityCredentialStore.h"
-
-using android::hardware::joinRpcThreadpool;
-using android::hardware::identity::implementation::IdentityCredentialStore;
-
-int main(int /* argc */, char* argv[]) {
-    ::android::hardware::configureRpcThreadpool(1, true /*willJoinThreadpool*/);
-
-    ::android::base::InitLogging(argv, &android::base::StderrLogger);
-
-    auto identity_store = new IdentityCredentialStore();
-    auto status = identity_store->registerAsService();
-    if (status != android::OK) {
-        LOG(FATAL) << "Could not register service for IdentityCredentialStore 1.0 (" << status
-                   << ")";
-    }
-    joinRpcThreadpool();
-    return -1;  // Should never get here.
-}
diff --git a/identity/1.0/types.hal b/identity/1.0/types.hal
deleted file mode 100644
index 5aedfea4dc..0000000000
--- a/identity/1.0/types.hal
+++ /dev/null
@@ -1,164 +0,0 @@
-/*
- * Copyright 2018 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.hardware.identity@1.0;
-
-/**
- * The ResultCode enumeration is used to convey the status of an operation.
- */
-enum ResultCode : int32_t {
-    /**
-     * Success.
-     */
-    OK = 0,
-
-    /**
-     * The operation failed. This is used as a generic catch-all for errors that don't belong
-     * in other categories, including memory/resource allocation failures and I/O errors.
-     */
-    FAILED = 1,
-
-    /**
-     * The passed data was invalid. This is a generic catch all for errors that don't belong
-     * in other categories related to parameter validation.
-     */
-    INVALID_DATA = 2,
-
-    /**
-     * The authToken parameter passed to IIdentityCredential.startRetrieval() is not valid.
-     */
-    INVALID_AUTH_TOKEN = 3,
-
-    /**
-     * The itemsRequest parameter passed to IIdentityCredential.startRetrieval() does not meet
-     * the requirements described in the documentation for that method.
-     */
-    INVALID_ITEMS_REQUEST_MESSAGE = 4,
-
-    /**
-     * The readerSignature parameter in IIdentityCredential.startRetrieval() is invalid,
-     * doesn't contain an embedded certificate chain, or the signature failed to
-     * validate.
-     */
-    READER_SIGNATURE_CHECK_FAILED = 5,
-
-    /**
-     * The sessionTranscript passed to startRetrieval() did not contain the ephmeral public
-     * key returned by createEphemeralPublicKey().
-     */
-    EPHEMERAL_PUBLIC_KEY_NOT_FOUND = 6,
-
-    /**
-     * An access condition related to user authentication was not satisfied.
-     */
-    USER_AUTHENTICATION_FAILED = 7,
-
-    /**
-     * An access condition related to reader authentication was not satisfied.
-     */
-    READER_AUTHENTICATION_FAILED = 8,
-
-    /**
-    * The request data element has no access control profiles associated so it cannot be accessed.
-    */
-    NO_ACCESS_CONTROL_PROFILES = 9,
-
-    /**
-     * The requested data element is not in the provided non-empty itemsRequest message.
-     */
-    NOT_IN_REQUEST_MESSAGE = 10,
-
-    /**
-     * The passed-in sessionTranscript doesn't match the previously passed-in sessionTranscript.
-     */
-    SESSION_TRANSCRIPT_MISMATCH = 11,
-};
-
-/**
- * A result has a ResultCode and corresponding textual message.
- */
-struct Result {
-    /**
-     * The result code.
-     *
-     * Implementations must not use values not defined in the ResultCode enumeration.
-     */
-    ResultCode code;
-
-    /**
-     * A human-readable message in English conveying more detail about a failure.
-     *
-     * If code is ResultCode::OK this field must be set to the empty string.
-     */
-    string message;
-};
-
-struct SecureAccessControlProfile {
-    /**
-     * id is a numeric identifier that must be unique within the context of a Credential and may be
-     * used to reference the profile.
-     */
-    uint16_t id;
-
-    /**
-     * readerCertificate, if non-empty, specifies a single X.509 certificate (not a chain
-     * of certificates) that must be used to authenticate requests. For details about how
-     * this is done, see the readerSignature paremter of IIdentityCredential.startRetrieval.
-     */
-    vec<uint8_t> readerCertificate;
-
-    /**
-     * if true, the user is required to authenticate to allow requests.  Required authentication
-     * fressness is specified by timeout below.
-     *
-     */
-    bool userAuthenticationRequired;
-
-    /**
-     * Timeout specifies the amount of time, in milliseconds, for which a user authentication (see
-     * above) is valid, if userAuthenticationRequired is set to true.  If userAuthenticationRequired
-     * is true and timout is zero then authentication is required for each reader session.
-     *
-     * If userAuthenticationRequired is false, timeout must be zero.
-     */
-    uint64_t timeoutMillis;
-
-    /**
-     * secureUserId must be non-zero if userAuthenticationRequired is true.
-     * It is not related to any Android user ID or UID, but is created in the
-     * Gatekeeper application in the secure environment.
-     */
-    uint64_t secureUserId;
-
-    /**
-     * The mac is used to authenticate the access control profile.  It contains:
-     *
-     *      AES-GCM-ENC(storageKey, R, {}, AccessControlProfile)
-     *
-     *  where AccessControlProfile is the CBOR map:
-     *
-     *      AccessControlProfile = {
-     *          "id": uint,
-     *          ? "readerCertificate" : bstr,
-     *          ? (
-     *              "userAuthenticationRequired" : bool,
-     *              "timeoutMillis" : uint,
-     *              "secureUserId" : uint
-     *          )
-     *      }
-     */
-    vec<uint8_t> mac;
-};
diff --git a/identity/1.0/vts/OWNERS b/identity/1.0/vts/OWNERS
deleted file mode 100644
index 6969910ce5..0000000000
--- a/identity/1.0/vts/OWNERS
+++ /dev/null
@@ -1,2 +0,0 @@
-swillden@google.com
-zeuthen@google.com
diff --git a/identity/1.0/vts/functional/Android.bp b/identity/1.0/vts/functional/Android.bp
deleted file mode 100644
index 03b49de716..0000000000
--- a/identity/1.0/vts/functional/Android.bp
+++ /dev/null
@@ -1,36 +0,0 @@
-//
-// Copyright (C) 2019 The Android Open Source Project
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-
-cc_test {
-    name: "VtsHalIdentityCredentialTargetTest",
-    defaults: ["VtsHalTargetTestDefaults"],
-    srcs: [
-        "VtsHalIdentityCredentialTargetTest.cpp",
-    ],
-    static_libs: [
-        "android.hardware.identity@1.0",
-        "android.hardware.identity-support-lib",
-        "android.hardware.keymaster@4.0",
-        "libcppbor",
-    ],
-    shared_libs: [
-        "libcrypto",
-    ],
-    test_suites: [
-        "general-tests",
-        "vts-core",
-    ],
-}
diff --git a/identity/1.0/default/OWNERS b/identity/OWNERS
index 6969910ce5..6969910ce5 100644
--- a/identity/1.0/default/OWNERS
+++ b/identity/OWNERS
diff --git a/identity/aidl/Android.bp b/identity/aidl/Android.bp
new file mode 100644
index 0000000000..72b19a1b49
--- /dev/null
+++ b/identity/aidl/Android.bp
@@ -0,0 +1,21 @@
+aidl_interface {
+    name: "android.hardware.identity",
+    vendor_available: true,
+    srcs: [
+        "android/hardware/identity/*.aidl",
+    ],
+    imports: [
+        "android.hardware.keymaster",
+    ],
+    stability: "vintf",
+    backend: {
+        java: {
+            platform_apis: true,
+        },
+        ndk: {
+            vndk: {
+                enabled: true,
+            },
+        },
+    },
+}
diff --git a/identity/aidl/android/hardware/identity/Certificate.aidl b/identity/aidl/android/hardware/identity/Certificate.aidl
new file mode 100644
index 0000000000..5bbc17c133
--- /dev/null
+++ b/identity/aidl/android/hardware/identity/Certificate.aidl
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.identity;
+
+@VintfStability
+parcelable Certificate {
+    /**
+     * encodedCertificate contains the bytes of a DER-encoded X.509 certificate.
+     *
+     * If there is no certificate, this array is empty.
+     */
+    byte[] encodedCertificate;
+}
diff --git a/identity/aidl/android/hardware/identity/CipherSuite.aidl b/identity/aidl/android/hardware/identity/CipherSuite.aidl
new file mode 100644
index 0000000000..20b02a8a08
--- /dev/null
+++ b/identity/aidl/android/hardware/identity/CipherSuite.aidl
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.identity;
+
+/**
+ * Cipher suites that can be used for communication between holder and reader devices.
+ */
+@VintfStability
+@Backing(type="int")
+enum CipherSuite {
+    /**
+     * Specifies that the cipher suite that will be used to secure communications between the reader
+     * is:
+     *
+     * - ECDHE with HKDF-SHA-256 for key agreement.
+     * - AES-256 with GCM block mode for authenticated encryption (nonces are incremented by
+     *   one for every message).
+     * - ECDSA with SHA-256 for signing (used for signing session transcripts to defeat
+     *   man-in-the-middle attacks), signing keys are not ephemeral.
+     *
+     * At present this is the only supported cipher suite and it is mandatory for all
+     * implementations to support it.
+     */
+    CIPHERSUITE_ECDHE_HKDF_ECDSA_WITH_AES_256_GCM_SHA256 = 1,
+}
diff --git a/identity/aidl/android/hardware/identity/HardwareInformation.aidl b/identity/aidl/android/hardware/identity/HardwareInformation.aidl
new file mode 100644
index 0000000000..d67739d94a
--- /dev/null
+++ b/identity/aidl/android/hardware/identity/HardwareInformation.aidl
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.identity;
+
+@VintfStability
+parcelable HardwareInformation {
+    /**
+     * credentialStoreName is the name of the credential store implementation.
+     */
+    @utf8InCpp String credentialStoreName;
+
+    /**
+     * credentialStoreAuthorName is the name of the credential store author.
+     */
+    @utf8InCpp String credentialStoreAuthorName;
+
+    /**
+     * dataChunkSize is the size of data chunks to be used when sending and recieving data
+     * entries. All data chunks for a data item must be this size except for the last.
+     */
+    int dataChunkSize;
+
+    /**
+     * isDirectAccess specifies whether the provisioned credential is available through
+     * direct access. Credentials provisioned in credential stores with this set
+     * to true, should use reader authentication on all data elements.
+     */
+    boolean isDirectAccess;
+
+    /**
+     * supportedDocTypes if empty, then any document type is supported, otherwise
+     * only the document types returned are supported.
+     *
+     * Document types are defined in the relevant standard for the document, for example for the
+     * for Mobile Driving License as defined by ISO 18013-5 the document type is defined to
+     * be "org.iso.18013.5.1.mDL".
+     *
+     */
+    @utf8InCpp String[] supportedDocTypes;
+}
diff --git a/identity/1.0/IIdentityCredential.hal b/identity/aidl/android/hardware/identity/IIdentityCredential.aidl
index 75f6e1843d..10ce4c2867 100644
--- a/identity/1.0/IIdentityCredential.hal
+++ b/identity/aidl/android/hardware/identity/IIdentityCredential.aidl
@@ -14,10 +14,13 @@
  * limitations under the License.
  */
 
-package android.hardware.identity@1.0;
+package android.hardware.identity;
 
-import android.hardware.keymaster@4.0::HardwareAuthToken;
+import android.hardware.identity.Certificate;
+import android.hardware.identity.SecureAccessControlProfile;
+import android.hardware.keymaster.HardwareAuthToken;
 
+@VintfStability
 interface IIdentityCredential {
     /**
      * Delete a credential.
@@ -35,10 +38,9 @@ interface IIdentityCredential {
      * After this method has been called, the persistent storage used for credentialData should
      * be deleted.
      *
-     * @return proofOfDeletionSignature is a COSE_Sign1 signature described above.
+     * @return a COSE_Sign1 signature described above.
      */
-    deleteCredential()
-        generates(Result result, vec<uint8_t> proofOfDeletionSignature);
+    byte[] deleteCredential();
 
     /**
      * Creates an ephemeral EC key pair, for use in establishing a seceure session with a reader.
@@ -46,39 +48,33 @@ interface IIdentityCredential {
      * with the reader.  The reason for generating the key pair in the secure environment is so that
      * the secure environment knows what public key to expect to find in the session transcript.
      *
-     * This method may only be called once per instance. If called more than once, FAILED
+     * This method may only be called once per instance. If called more than once, STATUS_FAILED
      * will be returned.
      *
-     * @return result is OK on success or FAILED if an error occurred.
-     *
-     * @return keyPair contains the unencrypted key-pair in PKCS#8 format.
+     * @return the unencrypted key-pair in PKCS#8 format.
      */
-    createEphemeralKeyPair() generates (Result result, vec<uint8_t> keyPair);
+    byte[] createEphemeralKeyPair();
 
     /**
      * Sets the public part of the reader's ephemeral key pair.
      *
-     * This method may only be called once per instance. If called more than once, FAILED
+     * This method may only be called once per instance. If called more than once, STATUS_FAILED
      * will be returned.
      *
      * @param publicKey contains the reader's ephemeral public key, in uncompressed form.
-     *
-     * @return result is OK on success or FAILED if an error occurred.
      */
-    setReaderEphemeralPublicKey(vec<uint8_t> publicKey) generates (Result result);
+    void setReaderEphemeralPublicKey(in byte[] publicKey);
 
     /**
      * Creates a challenge value to be used for proving successful user authentication. This
      * is included in the authToken passed to the startRetrieval() method.
      *
-     * This method may only be called once per instance. If called more than once, FAILED
+     * This method may only be called once per instance. If called more than once, STATUS_FAILED
      * will be returned.
      *
-     * @return result is OK on success or FAILED if an error occurred.
-     *
-     * @return challenge on success, is a non-zero number.
+     * @return challenge, a non-zero number.
      */
-    createAuthChallenge() generates (Result result, uint64_t challenge);
+    long createAuthChallenge();
 
     /**
      * Start an entry retrieval process.
@@ -92,12 +88,12 @@ interface IIdentityCredential {
      * startRetrieval(), then multiple calls of startRetrieveEntryValue(), retrieveEntryValue(),
      * then finally finishRetrieval()) but if this is done, the sessionTranscript parameter
      * must be identical for each startRetrieval() invocation. If this is not the case, this call
-     * fails with the SESSION_TRANSCRIPT_MISMATCH error.
+     * fails with the STATUS_SESSION_TRANSCRIPT_MISMATCH error.
      *
-     * If the provided authToken is not valid this method fails with INVALID_AUTH_TOKEN.
+     * If the provided authToken is not valid this method fails with STATUS_INVALID_AUTH_TOKEN.
      *
      * Each of the provided accessControlProfiles is checked in this call. If they are not
-     * all valid, the call fails with INVALID_DATA.
+     * all valid, the call fails with STATUS_INVALID_DATA.
      *
      * For the itemsRequest parameter, the content can be defined in the way appropriate for
      * the credential, but there are three requirements that must be met to work with this HAL:
@@ -108,7 +104,7 @@ interface IIdentityCredential {
      *     the example below.
      *
      * If these requirements are not met the startRetrieval() call fails with
-     * INVALID_ITEMS_REQUEST_MESSAGE.
+     * STATUS_INVALID_ITEMS_REQUEST_MESSAGE.
      *
      * Here's an example of ItemsRequest CBOR which conforms to this requirement:
      *
@@ -156,17 +152,18 @@ interface IIdentityCredential {
      * 'x5chain' unprotected header element of the COSE_Sign1 structure (as as described
      * in 'draft-ietf-cose-x509-04'). There will be at least one certificate in said element
      * and there may be more (and if so, each certificate must be signed by its successor).
-     * This is checked and if the check fails the call fails with READER_SIGNATURE_CHECK_FAILED.
+     * This is checked and if the check fails the call fails with
+     * STATUS_READER_SIGNATURE_CHECK_FAILED.
      *
      * The SessionTranscript CBOR is conveyed in the sessionTranscript parameter. It
      * is permissible for this to be empty in which case the readerSignature parameter
-     * must also be empty. If this is not the case, the call fails with FAILED.
+     * must also be empty. If this is not the case, the call fails with STATUS_FAILED.
      *
      * If the SessionTranscript CBOR is not empty, the X and Y coordinates of the public
      * part of the key-pair previously generated by createEphemeralKeyPair() must appear
      * somewhere in the bytes of DeviceEngagement structure. Both X and Y should be in
      * uncompressed form. If this is not satisfied, the call fails with
-     * EPHEMERAL_PUBLIC_KEY_NOT_FOUND.
+     * STATUS_EPHEMERAL_PUBLIC_KEY_NOT_FOUND.
      *
      * @param accessControlProfiles
      *   Access control profiles that are required to retrieve the entries that are going to be
@@ -196,16 +193,11 @@ interface IIdentityCredential {
      *   will succeed (i.e. that the access control profile checks will succeed).  This means that
      *   it's the responsibility of the caller to determine which access control checks will fail
      *   and remove the corresponding requests from the counts.
-     *
-     * @return result is OK on success. If an error occurs one of the values described above
-     *   will be returned.
      */
-    startRetrieval(vec<SecureAccessControlProfile> accessControlProfiles,
-                   HardwareAuthToken authToken,
-                   vec<uint8_t> itemsRequest,
-                   vec<uint8_t> sessionTranscript,
-                   vec<uint8_t> readerSignature,
-                   vec<uint16_t> requestCounts) generates(Result result);
+    void startRetrieval(in SecureAccessControlProfile[] accessControlProfiles,
+        in HardwareAuthToken authToken,
+        in byte[] itemsRequest,
+        in byte[] sessionTranscript, in byte[] readerSignature, in int[] requestCounts);
 
     /**
      * Starts retrieving an entry, subject to access control requirements.  Entries must be
@@ -213,15 +205,15 @@ interface IIdentityCredential {
      *
      * If the requestData parameter as passed to startRetrieval() was non-empty
      * this method must only be called with entries specified in that field. If this
-     * requirement is not met, the call fails with NOT_IN_REQUEST_MESSAGE.
+     * requirement is not met, the call fails with STATUS_NOT_IN_REQUEST_MESSAGE.
      *
-     * If nameSpace or name is empty this call fails with INVALID_DATA.
+     * If nameSpace or name is empty this call fails with STATUS_INVALID_DATA.
      *
      * Each access control profile for the entry is checked. If user authentication
      * is required and the supplied auth token doesn't provide it the call fails
-     * with USER_AUTHENTICATION_FAILED. If reader authentication is required and
+     * with STATUS_USER_AUTHENTICATION_FAILED. If reader authentication is required and
      * a suitable reader certificate chain isn't presented, the call fails with
-     * READER_AUTHENTICATION_FAILED.
+     * STATUS_READER_AUTHENTICATION_FAILED.
      *
      * It is permissible to keep retrieving values if an access control check fails.
      *
@@ -231,38 +223,29 @@ interface IIdentityCredential {
      *
      * @param entrySize is the size of the entry value, if it's a text string or a byte string.
      *     It must be zero if the entry value is an integer or boolean. If this requirement
-     *     is not met the call fails with INVALID_DATA.
+     *     is not met the call fails with STATUS_INVALID_DATA.
      *
      * @param accessControlProfileIds specifies the set of access control profiles that can
      *     authorize access to the provisioned element. If an identifier of a profile
      *     is given and this profile wasn't passed to startRetrieval() this call fails
-     *     with INVALID_DATA.
-     *
-     * @return result is OK on success. Otherwise one of INVALID_DATA, FAILED,
-     *     USER_AUTHENTICATION_FAILED, READER_AUTHENTICATION_FAILED.
+     *     with STATUS_INVALID_DATA.
      */
-    startRetrieveEntryValue(string nameSpace, string name, uint32_t entrySize,
-                            vec<uint16_t> accessControlProfileIds)
-        generates (Result result);
-
+    void startRetrieveEntryValue(in @utf8InCpp String nameSpace, in @utf8InCpp String name,
+                                 in int entrySize, in int[] accessControlProfileIds);
 
     /**
      * Retrieves an entry value, or part of one, if the entry value is larger than gcmChunkSize.
      * May only be called after startRetrieveEntry().
      *
      * If the passed in data is not authentic, can't be decrypted, is of the wrong size, or can't
-     * be decoded, this call fails with INVALID_DATA.
+     * be decoded, this call fails with STATUS_INVALID_DATA.
      *
      * @param encryptedContent contains the encrypted and MACed content.
      *
-     * @return result is OK on success, INVALID_DATA, or FAILED if an error occurred.
-     *
-     * @return content is the entry value as CBOR, or part of the entry value in the case the
+     * @return the entry value as CBOR, or part of the entry value in the case the
      *    content exceeds gcmChunkSize in length.
      */
-    retrieveEntryValue(vec<uint8_t> encryptedContent)
-        generates (Result result, vec<uint8_t> content);
-
+    byte[] retrieveEntryValue(in byte[] encryptedContent);
 
     /**
      * End retrieval of data, optionally returning a message authentication code over the
@@ -273,11 +256,9 @@ interface IIdentityCredential {
      *
      * @param signingKeyBlob is either empty or a signingKeyBlob (see generateSigningKeyPair(),
      *    below) containing the signing key to use to sign the data retrieved. If this
-     *    is not in the right format the call fails with INVALID_DATA.
-     *
-     * @return result is OK on success, INVALID_DATA or FAILED if an error occurred.
+     *    is not in the right format the call fails with STATUS_INVALID_DATA.
      *
-     * @return mac is empty if signingKeyBlob or the sessionTranscript passed to
+     * @param out mac is empty if signingKeyBlob or the sessionTranscript passed to
      *    startRetrieval() is empty. Otherwise it is a COSE_Mac0 with empty payload
      *    and the detached content is set to DeviceAuthentication as defined below.
      *    The key used for the MAC operation is EMacKey and is derived as follows:
@@ -321,23 +302,17 @@ interface IIdentityCredential {
      *        DataItemValue = any
      *
      *
-     * @return deviceNameSpaces the bytes of DeviceNameSpaces.
+     * @param out deviceNameSpaces the bytes of DeviceNameSpaces.
      */
-    finishRetrieval(vec<uint8_t> signingKeyBlob)
-        generates(Result result, vec<uint8_t> mac, vec<uint8_t> deviceNameSpaces);
-
+    void finishRetrieval(in byte[] signingKeyBlob, out byte[] mac, out byte[] deviceNameSpaces);
 
     /**
      * Generate a key pair to be used for signing session data and retrieved data items.
      *
-     * @return result is OK on success or FAILED if an error occurred.
-     *
-     * @return signingKeyBlob contains an encrypted copy of the newly-generated private signing key.
+     * @param out signingKeyBlob contains an encrypted copy of the newly-generated private
+     *     signing key.
      *
-     * @return signingKeyCertificate contains an X.509 certificate for the new signing key, signed
-     *     by the credential key.
+     * @return an X.509 certificate for the new signing key, signed by the credential key.
      */
-    generateSigningKeyPair()
-        generates(Result result, vec<uint8_t> signingKeyBlob,
-                  vec<uint8_t> signingKeyCertificate);
-};
+    Certificate generateSigningKeyPair(out byte[] signingKeyBlob);
+}
diff --git a/identity/1.0/IIdentityCredentialStore.hal b/identity/aidl/android/hardware/identity/IIdentityCredentialStore.aidl
index 118ca6fa9a..23cb1b75a2 100644
--- a/identity/1.0/IIdentityCredentialStore.hal
+++ b/identity/aidl/android/hardware/identity/IIdentityCredentialStore.aidl
@@ -14,10 +14,12 @@
  * limitations under the License.
  */
 
-package android.hardware.identity@1.0;
+package android.hardware.identity;
 
-import IWritableIdentityCredential;
-import IIdentityCredential;
+import android.hardware.identity.IIdentityCredential;
+import android.hardware.identity.IWritableIdentityCredential;
+import android.hardware.identity.HardwareInformation;
+import android.hardware.identity.CipherSuite;
 
 /**
  * IIdentityCredentialStore provides an interface to a secure store for user identity documents.
@@ -98,37 +100,90 @@ import IIdentityCredential;
  * define appropriate encodings, those are used.  For example, X.509 certificates.  Where new
  * encodings are needed, CBOR is used.  CBOR maps are described in CDDL notation
  * (https://tools.ietf.org/html/draft-ietf-cbor-cddl-06).
+ *
+ * All binder calls in the HAL may return a ServiceSpecificException with statuses from the
+ * STATUS_* integers defined in this interface. Each method states which status can be returned
+ * and under which circumstances.
  */
+@VintfStability
 interface IIdentityCredentialStore {
+    /**
+     * Success.
+     */
+    const int STATUS_OK = 0;
+
+    /**
+     * The operation failed. This is used as a generic catch-all for errors that don't belong
+     * in other categories, including memory/resource allocation failures and I/O errors.
+     */
+    const int STATUS_FAILED = 1;
+
+    /**
+     * Unsupported cipher suite.
+     */
+    const int STATUS_CIPHER_SUITE_NOT_SUPPORTED = 2;
+
+    /**
+     * The passed data was invalid. This is a generic catch all for errors that don't belong
+     * in other categories related to parameter validation.
+     */
+    const int STATUS_INVALID_DATA = 3;
+
+    /**
+     * The authToken parameter passed to IIdentityCredential.startRetrieval() is not valid.
+     */
+    const int STATUS_INVALID_AUTH_TOKEN = 4;
+
+    /**
+     * The itemsRequest parameter passed to IIdentityCredential.startRetrieval() does not meet
+     * the requirements described in the documentation for that method.
+     */
+    const int STATUS_INVALID_ITEMS_REQUEST_MESSAGE = 5;
+
+    /**
+     * The readerSignature parameter in IIdentityCredential.startRetrieval() is invalid,
+     * doesn't contain an embedded certificate chain, or the signature failed to
+     * validate.
+     */
+    const int STATUS_READER_SIGNATURE_CHECK_FAILED = 6;
+
+    /**
+     * The sessionTranscript passed to startRetrieval() did not contain the ephmeral public
+     * key returned by createEphemeralPublicKey().
+     */
+    const int STATUS_EPHEMERAL_PUBLIC_KEY_NOT_FOUND = 7;
+
+    /**
+     * An access condition related to user authentication was not satisfied.
+     */
+    const int STATUS_USER_AUTHENTICATION_FAILED = 8;
+
+    /**
+     * An access condition related to reader authentication was not satisfied.
+     */
+    const int STATUS_READER_AUTHENTICATION_FAILED = 9;
+
+    /**
+     * The request data element has no access control profiles associated so it cannot be accessed.
+     */
+    const int STATUS_NO_ACCESS_CONTROL_PROFILES = 10;
+
+    /**
+     * The requested data element is not in the provided non-empty itemsRequest message.
+     */
+    const int STATUS_NOT_IN_REQUEST_MESSAGE = 11;
+
+    /**
+     * The passed-in sessionTranscript doesn't match the previously passed-in sessionTranscript.
+     */
+    const int STATUS_SESSION_TRANSCRIPT_MISMATCH = 12;
 
     /**
      * Returns information about hardware.
      *
-     * The isDirectAccess output parameter indicates whether this credential store
-     * implementation is for direct access. Credentials provisioned in credential
-     * stores with this set to true, should use reader authentication on all data elements.
-     *
-     * @return result is OK on success, FAILED if an error occurred.
-     *
-     * @return credentialStoreName the name of the credential store implementation.
-     *
-     * @return credentialStoreAuthorName the name of the credential store author.
-     *
-     * @return dataChunkSize the maximum size of data chunks.
-     *
-     * @return isDirectAccess whether the provisioned credential is available through
-     *     direct access.
-     *
-     * @return supportedDocTypes if empty, then any document type is supported, otherwise
-     *     only the document types returned are supported.
+     * @return a HardwareInformation with information about the hardware.
      */
-    getHardwareInformation()
-        generates(Result result,
-                  string credentialStoreName,
-                  string credentialStoreAuthorName,
-                  uint32_t dataChunkSize,
-                  bool isDirectAccess,
-                  vec<string> supportedDocTypes);
+    HardwareInformation getHardwareInformation();
 
     /**
      * createCredential creates a new Credential.  When a Credential is created, two cryptographic
@@ -147,16 +202,14 @@ interface IIdentityCredentialStore {
      *     all-zeros hardware-bound key (HBK) and must set the test bit in the
      *     personalizationReceipt (see finishAddingEntries(), in IWritableIdentityCredential).
      *
-     * @return result is OK on success, FAILED if an error occurred.
-     *
-     * @return writableCredential is an IWritableIdentityCredential HIDL interface that provides
-     *     operations to provision a credential.
+     * @return an IWritableIdentityCredential interface that provides operations to
+     *     provision a credential.
      */
-    createCredential(string docType, bool testCredential)
-        generates(Result result, IWritableIdentityCredential writableCredential);
+    IWritableIdentityCredential createCredential(in @utf8InCpp String docType,
+                                                 in boolean testCredential);
 
     /**
-     * getCredential retrieves an IIdentityCredential HIDL interface which allows use of a stored
+     * getCredential retrieves an IIdentityCredential interface which allows use of a stored
      * Credential.
      *
      * The cipher suite used to communicate with the remote verifier must also be specified. Currently
@@ -170,16 +223,17 @@ interface IIdentityCredentialStore {
      *
      * Support for other cipher suites may be added in a future version of this HAL.
      *
+     * This method fails with STATUS_INVALID_DATA if the passed in credentialData cannot be
+     * decoded or decrypted.
+     *
+     * @param cipherSuite is the cipher suite to use.
+     *
      * @param credentialData is a CBOR-encoded structure containing metadata about the credential
      *     and an encrypted byte array that contains data used to secure the credential.  See the
-     *     return argument of the same name in finishAddingEntries(), in IWritableIdentityCredential.
-     *
-     * @return result is OK on success or INVALID_DATA if the passed in credentialData
-     *     cannot be decoded or decrypted.
+     *     return argument of the same name in finishAddingEntries(), in
+     *     IWritableIdentityCredential.
      *
-     * @return credential is an IIdentityCredential HIDL interface that provides operations on the
-     *     Credential.
+     * @return an IIdentityCredential HIDL interface that provides operations on the Credential.
      */
-    getCredential(vec<uint8_t> credentialData)
-        generates (Result result, IIdentityCredential credential);
-};
+    IIdentityCredential getCredential(in CipherSuite cipherSuite, in byte[] credentialData);
+}
diff --git a/identity/1.0/IWritableIdentityCredential.hal b/identity/aidl/android/hardware/identity/IWritableIdentityCredential.aidl
index f26f76349f..483b0c7b6b 100644
--- a/identity/1.0/IWritableIdentityCredential.hal
+++ b/identity/aidl/android/hardware/identity/IWritableIdentityCredential.aidl
@@ -14,12 +14,16 @@
  * limitations under the License.
  */
 
-package android.hardware.identity@1.0;
+package android.hardware.identity;
+
+import android.hardware.identity.Certificate;
+import android.hardware.identity.SecureAccessControlProfile;
 
 /**
  * IWritableIdentityCredential is used to personalize a new identity credential.  Credentials cannot
  * be updated or modified after creation; any changes require deletion and re-creation.
  */
+@VintfStability
 interface IWritableIdentityCredential {
     /**
      * Gets the certificate chain for credentialKey which can be used to prove the hardware
@@ -69,31 +73,23 @@ interface IWritableIdentityCredential {
      *
      * @param attestationChallenge a challenge set by the issuer to ensure freshness.
      *
-     * @return result is OK on success, FAILED if an error occurred.
-     *
-     * @return certificateChain is the X.509 certificate chain for the credentialKey
+     * @return the X.509 certificate chain for the credentialKey
      */
-    getAttestationCertificate(vec<uint8_t> attestationApplicationId,
-                              vec<uint8_t> attestationChallenge)
-        generates(Result result, vec<vec<uint8_t>> certificateChain);
+    Certificate[] getAttestationCertificate(in byte[] attestationApplicationId, in byte[] attestationChallenge);
 
     /**
      * Start the personalization process.
      *
      * startPersonalization must not be called more than once.
      *
-     * @param accessControlProfileCount specifies the number of access control profiles that will be
-     *     provisioned with addAccessControlProfile().
+     * @param accessControlProfileCount specifies the number of access control profiles that will
+     *     be provisioned with addAccessControlProfile().
      *
      * @param entryCounts specifies the number of data entries that will be provisioned with
      *     beginAddEntry() and addEntry(). Each item in the array specifies how many entries
      *     will be added for each name space.
-     *
-     * @return result is OK on success, FAILED if an error occurred.
-     *
      */
-    startPersonalization(uint16_t accessControlProfileCount, vec<uint16_t> entryCounts)
-        generates(Result result);
+    void startPersonalization(in int accessControlProfileCount, in int[] entryCounts);
 
     /**
      * Add an access control profile, which defines the requirements or retrieval of one or more
@@ -103,15 +99,15 @@ interface IWritableIdentityCredential {
      *
      * This method must be called exactly as many times as specified in the startPersonalization()
      * accessControlProfileCount parameter. If this is requirement is not met, the method fails
-     * with INVALID_DATA.
+     * with STATUS_INVALID_DATA.
      *
      * @param id a numeric identifier that must be unique within the context of a Credential and may
      *     be used to reference the profile. If this is not satisfied the call fails with
-     *     INVALID_DATA.
+     *     STATUS_INVALID_DATA.
      *
-     * @param readerCertificate if non-empty, specifies a X.509 certificate (or chain of certificates)
-     *     that must be used to authenticate requests (see the readerSignature parameter in
-     *     IIdentityCredential.startRetrieval).
+     * @param readerCertificate if non-empty, specifies a X.509 certificate (or chain of
+     *     certificates) that must be used to authenticate requests (see the readerSignature
+     *     parameter in IIdentityCredential.startRetrieval).
      *
      * @param userAuthenticationRequired if true, specifies that the user is required to
      *     authenticate to allow requests.  Required authentication freshness is specified by
@@ -121,22 +117,18 @@ interface IWritableIdentityCredential {
      *     authentication (see userAuthenticationRequired above) is valid, if
      *     userAuthenticationRequired is true. If the timout is zero then authentication is
      *     required for each reader session. If userAuthenticationRequired is false, the timeout
-     *     must be zero. If this requirement is not met the call fails with INVALID_DATA.
+     *     must be zero. If this requirement is not met the call fails with STATUS_INVALID_DATA.
      *
      * @param secureUserId must be non-zero if userAuthenticationRequired is true. It is not
      *     related to any Android user ID or UID, but is created in the Gatekeeper application
      *     in the secure environment. If this requirement is not met the call fails with
-     *     INVALID_DATA.
-     *
-     * @return result is OK on success, INVALID_DATA or FAILED if an error occurred.
+     *     STATUS_INVALID_DATA.
      *
-     * @return secureAccessControlProfile is a structure with the passed-in data and MAC created
-     *     with storageKey for authenticating the data at a later point in time.
+     * @return a structure with the passed-in data and MAC created with storageKey for authenticating
+     *     the data at a later point in time.
      */
-    addAccessControlProfile(uint16_t id, vec<uint8_t> readerCertificate,
-                            bool userAuthenticationRequired, uint64_t timeoutMillis,
-                            uint64_t secureUserId)
-        generates(Result result, SecureAccessControlProfile secureAccessControlProfile);
+    SecureAccessControlProfile addAccessControlProfile(in int id, in Certificate readerCertificate,
+        in boolean userAuthenticationRequired, in long timeoutMillis, in long secureUserId);
 
     /**
      * Begins the process of adding an entry to the credential.  All access control profiles must be
@@ -145,7 +137,7 @@ interface IWritableIdentityCredential {
      *
      * This method must be called exactly as many times as the sum of the items in the entryCounts
      * parameter specified in the startPersonalization(), and must be followed by one or more calls
-     * to addEntryValue(). If this requirement is not met the method fails with INVALID_DATA.
+     * to addEntryValue(). If this requirement is not met the method fails with STATUS_INVALID_DATA.
      *
      * @param accessControlProfileIds specifies the set of access control profiles that can
      *     authorize access to the provisioned element.
@@ -155,13 +147,10 @@ interface IWritableIdentityCredential {
      * @param name is the name of the element.
      *
      * @param entrySize is the size of the entry value. If this requirement
-     *     is not met this method fails with INVALID_DATA.
-     *
-     * @return result is OK on success, INVALID_DATA or FAILED if an error occurred.
+     *     is not met this method fails with STATUS_INVALID_DATA.
      */
-    beginAddEntry(vec<uint16_t> accessControlProfileIds, string nameSpace,
-                  string name, uint32_t entrySize)
-        generates(Result result);
+    void beginAddEntry(in int[] accessControlProfileIds, in @utf8InCpp String nameSpace,
+        in @utf8InCpp String name, in int entrySize);
 
     /**
      * Continues the process of adding an entry, providing a value or part of a value.
@@ -171,18 +160,13 @@ interface IWritableIdentityCredential {
      * (see IIdentityCredentialStore.getHardwareInformation()), the caller must provide the
      * value in chunks.  All chunks must be exactly gcmChunkSize except the last and the sum of all
      * chunk sizes must equal the value of the beginAddEntry() entrySize argument. If this
-     * requirement is not met the call fails with INVALID_DATA.
+     * requirement is not met the call fails with STATUS_INVALID_DATA.
      *
      * @param content is the entry value, encoded as CBOR. In the case the content exceeds gcmChunkSize,
      *     this may be partial content up to gcmChunkSize bytes long.
      *
-     * @return result is OK on success, INVALID_DATA or FAILED if an error occurred.
-     *
-     * @return encryptedContent contains the encrypted and MACed content.  For directly-available
-     *     credentials the contents are implementation-defined but must not exceed 32 bytes in
-     *     length.
-     *
-     *     For other credentials, encryptedContent contains:
+     * @return the encrypted and MACed content.  For directly-available credentials the contents are
+     *     implementation-defined. For other credentials, the result contains
      *
      *         AES-GCM-ENC(storageKey, R, Data, AdditionalData)
      *
@@ -196,18 +180,15 @@ interface IWritableIdentityCredential {
      *             "AccessControlProfileIds" : [ + uint ],
      *         }
      */
-    addEntryValue(vec<uint8_t> content)
-        generates(Result result, vec<uint8_t> encryptedContent);
+    byte[] addEntryValue(in byte[] content);
 
     /**
-     * Finishes adding entries and returns a signature that an issuing authority may use to validate
-     * that all data was provisioned correctly.
+     * Finishes adding entries and returns a signature that an issuing authority may use to
+     * validate that all data was provisioned correctly.
      *
      * After this method is called, the IWritableIdentityCredential is no longer usable.
      *
-     * @return result is OK on success or FAILED if an error occurred.
-     *
-     * @return credentialData is a CBOR-encoded structure (in CDDL notation):
+     * @param out credentialData is a CBOR-encoded structure (in CDDL notation):
      *
      *         CredentialData = [
      *              tstr,   ; docType, an optional name that identifies the type of credential
@@ -230,10 +211,10 @@ interface IWritableIdentityCredential {
      *              bstr    ; credentialPrivKey, the private key for credentialKey
      *         ]
      *
-     * @return proofOfProvisioningSignature proves to the IA that the credential was imported into the
-     *     secure hardware without alteration or error.  When the final addEntry() call is made
-     *     (when the number of provisioned entries equals the sum of the items in
-     *     startPersonalization() entryCounts parameter), it a COSE_Sign1 structure
+     * @param out proofOfProvisioningSignature proves to the IA that the credential was imported
+     *     into the secure hardware without alteration or error.  When the final addEntry() call is
+     *     made (when the number of provisioned entries equals the sum of the items in
+     *     startPersonalization() entryCounts parameter), a COSE_Sign1 structure
      *     signed by CredentialKey with payload set to the ProofOfProvisioning CBOR below:
      *
      *          ProofOfProvisioning = [
@@ -266,7 +247,6 @@ interface IWritableIdentityCredential {
      *              "accessControlProfiles" : [ * uint ],
      *          }
      */
-    finishAddingEntries()
-        generates(Result result, vec<uint8_t> credentialData,
-                  vec<uint8_t> proofOfProvisioningSignature);
-};
+    void finishAddingEntries(out byte[] credentialData,
+        out byte[] proofOfProvisioningSignature);
+}
diff --git a/identity/aidl/android/hardware/identity/SecureAccessControlProfile.aidl b/identity/aidl/android/hardware/identity/SecureAccessControlProfile.aidl
new file mode 100644
index 0000000000..01d312d3e6
--- /dev/null
+++ b/identity/aidl/android/hardware/identity/SecureAccessControlProfile.aidl
@@ -0,0 +1,78 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.identity;
+
+import android.hardware.identity.Certificate;
+
+@VintfStability
+parcelable SecureAccessControlProfile {
+    /**
+     * id is a numeric identifier that must be unique within the context of a Credential and may be
+     * used to reference the profile.
+     */
+    int id;
+
+    /**
+     * readerCertificate, if non-empty, specifies a single X.509 certificate (not a chain
+     * of certificates) that must be used to authenticate requests. For details about how
+     * this is done, see the readerSignature paremter of IIdentityCredential.startRetrieval.
+     */
+    Certificate readerCertificate;
+
+    /**
+     * if true, the user is required to authenticate to allow requests.  Required authentication
+     * fressness is specified by timeout below.
+     *
+     */
+    boolean userAuthenticationRequired;
+
+    /**
+     * Timeout specifies the amount of time, in milliseconds, for which a user authentication (see
+     * above) is valid, if userAuthenticationRequired is set to true.  If userAuthenticationRequired
+     * is true and timout is zero then authentication is required for each reader session.
+     *
+     * If userAuthenticationRequired is false, timeout must be zero.
+     */
+    long timeoutMillis;
+
+    /**
+     * secureUserId must be non-zero if userAuthenticationRequired is true.
+     * It is not related to any Android user ID or UID, but is created in the
+     * Gatekeeper application in the secure environment.
+     */
+    long secureUserId;
+
+    /**
+     * The mac is used to authenticate the access control profile.  It contains:
+     *
+     *      AES-GCM-ENC(storageKey, R, {}, AccessControlProfile)
+     *
+     *  where AccessControlProfile is the CBOR map:
+     *
+     *      AccessControlProfile = {
+     *          "id": uint,
+     *          ? "readerCertificate" : bstr,
+     *          ? (
+     *              "userAuthenticationRequired" : bool,
+     *              "timeoutMillis" : uint,
+     *              "secureUserId" : uint
+     *          )
+     *      }
+     */
+    byte[] mac;
+}
+
diff --git a/identity/aidl/default/Android.bp b/identity/aidl/default/Android.bp
new file mode 100644
index 0000000000..2eb0faa034
--- /dev/null
+++ b/identity/aidl/default/Android.bp
@@ -0,0 +1,29 @@
+cc_binary {
+    name: "android.hardware.identity-service.example",
+    relative_install_path: "hw",
+    init_rc: ["identity-default.rc"],
+    vintf_fragments: ["identity-default.xml"],
+    vendor: true,
+    cflags: [
+        "-Wall",
+        "-Wextra",
+    ],
+    shared_libs: [
+        "libbase",
+        "libbinder_ndk",
+        "libcppbor",
+        "libcrypto",
+        "liblog",
+        "libutils",
+        "android.hardware.identity-support-lib",
+        "android.hardware.identity-ndk_platform",
+        "android.hardware.keymaster-ndk_platform",
+    ],
+    srcs: [
+        "IdentityCredential.cpp",
+        "IdentityCredentialStore.cpp",
+        "WritableIdentityCredential.cpp",
+        "Util.cpp",
+        "service.cpp",
+    ],
+}
diff --git a/identity/1.0/default/IdentityCredential.cpp b/identity/aidl/default/IdentityCredential.cpp
index b0a5e568f2..d5b3a0ffee 100644
--- a/identity/1.0/default/IdentityCredential.cpp
+++ b/identity/aidl/default/IdentityCredential.cpp
@@ -18,6 +18,7 @@
 
 #include "IdentityCredential.h"
 #include "IdentityCredentialStore.h"
+#include "Util.h"
 
 #include <android/hardware/identity/support/IdentityCredentialSupport.h>
 
@@ -28,71 +29,24 @@
 #include <cppbor.h>
 #include <cppbor_parse.h>
 
-namespace android {
-namespace hardware {
-namespace identity {
-namespace implementation {
+namespace aidl::android::hardware::identity {
 
-using ::android::hardware::keymaster::V4_0::Timestamp;
+using ::aidl::android::hardware::keymaster::Timestamp;
 using ::std::optional;
 
-Return<void> IdentityCredential::deleteCredential(deleteCredential_cb _hidl_cb) {
-    cppbor::Array array = {"ProofOfDeletion", docType_, testCredential_};
-    vector<uint8_t> proofOfDeletion = array.encode();
-
-    optional<vector<uint8_t>> proofOfDeletionSignature =
-            support::coseSignEcDsa(credentialPrivKey_,
-                                   proofOfDeletion,  // payload
-                                   {},               // additionalData
-                                   {});              // certificateChain
-    if (!proofOfDeletionSignature) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error signing data"), {});
-        return Void();
-    }
-
-    _hidl_cb(support::resultOK(), proofOfDeletionSignature.value());
-    return Void();
-}
-
-Return<void> IdentityCredential::createEphemeralKeyPair(createEphemeralKeyPair_cb _hidl_cb) {
-    optional<vector<uint8_t>> keyPair = support::createEcKeyPair();
-    if (!keyPair) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error creating ephemeral key pair"), {});
-        return Void();
-    }
-
-    // Stash public key of this key-pair for later check in startRetrieval().
-    optional<vector<uint8_t>> publicKey = support::ecKeyPairGetPublicKey(keyPair.value());
-    if (!publicKey) {
-        _hidl_cb(support::result(ResultCode::FAILED,
-                                 "Error getting public part of ephemeral key pair"),
-                 {});
-        return Void();
-    }
-    ephemeralPublicKey_ = publicKey.value();
-
-    _hidl_cb(support::resultOK(), keyPair.value());
-    return Void();
-}
+using namespace ::android::hardware::identity;
 
-Return<void> IdentityCredential::setReaderEphemeralPublicKey(
-        const hidl_vec<uint8_t>& publicKey, setReaderEphemeralPublicKey_cb _hidl_cb) {
-    readerPublicKey_ = publicKey;
-    _hidl_cb(support::resultOK());
-    return Void();
-}
-
-ResultCode IdentityCredential::initialize() {
+int IdentityCredential::initialize() {
     auto [item, _, message] = cppbor::parse(credentialData_);
     if (item == nullptr) {
         LOG(ERROR) << "CredentialData is not valid CBOR: " << message;
-        return ResultCode::INVALID_DATA;
+        return IIdentityCredentialStore::STATUS_INVALID_DATA;
     }
 
     const cppbor::Array* arrayItem = item->asArray();
     if (arrayItem == nullptr || arrayItem->size() != 3) {
         LOG(ERROR) << "CredentialData is not an array with three elements";
-        return ResultCode::INVALID_DATA;
+        return IIdentityCredentialStore::STATUS_INVALID_DATA;
     }
 
     const cppbor::Tstr* docTypeItem = (*arrayItem)[0]->asTstr();
@@ -103,7 +57,7 @@ ResultCode IdentityCredential::initialize() {
     if (docTypeItem == nullptr || testCredentialItem == nullptr ||
         encryptedCredentialKeysItem == nullptr) {
         LOG(ERROR) << "CredentialData unexpected item types";
-        return ResultCode::INVALID_DATA;
+        return IIdentityCredentialStore::STATUS_INVALID_DATA;
     }
 
     docType_ = docTypeItem->value();
@@ -113,7 +67,7 @@ ResultCode IdentityCredential::initialize() {
     if (testCredential_) {
         hardwareBoundKey = support::getTestHardwareBoundKey();
     } else {
-        hardwareBoundKey = support::getHardwareBoundKey();
+        hardwareBoundKey = getHardwareBoundKey();
     }
 
     const vector<uint8_t>& encryptedCredentialKeys = encryptedCredentialKeysItem->value();
@@ -122,39 +76,83 @@ ResultCode IdentityCredential::initialize() {
             support::decryptAes128Gcm(hardwareBoundKey, encryptedCredentialKeys, docTypeVec);
     if (!decryptedCredentialKeys) {
         LOG(ERROR) << "Error decrypting CredentialKeys";
-        return ResultCode::INVALID_DATA;
+        return IIdentityCredentialStore::STATUS_INVALID_DATA;
     }
 
     auto [dckItem, dckPos, dckMessage] = cppbor::parse(decryptedCredentialKeys.value());
     if (dckItem == nullptr) {
         LOG(ERROR) << "Decrypted CredentialKeys is not valid CBOR: " << dckMessage;
-        return ResultCode::INVALID_DATA;
+        return IIdentityCredentialStore::STATUS_INVALID_DATA;
     }
     const cppbor::Array* dckArrayItem = dckItem->asArray();
     if (dckArrayItem == nullptr || dckArrayItem->size() != 2) {
         LOG(ERROR) << "Decrypted CredentialKeys is not an array with two elements";
-        return ResultCode::INVALID_DATA;
+        return IIdentityCredentialStore::STATUS_INVALID_DATA;
     }
     const cppbor::Bstr* storageKeyItem = (*dckArrayItem)[0]->asBstr();
     const cppbor::Bstr* credentialPrivKeyItem = (*dckArrayItem)[1]->asBstr();
     if (storageKeyItem == nullptr || credentialPrivKeyItem == nullptr) {
         LOG(ERROR) << "CredentialKeys unexpected item types";
-        return ResultCode::INVALID_DATA;
+        return IIdentityCredentialStore::STATUS_INVALID_DATA;
     }
     storageKey_ = storageKeyItem->value();
     credentialPrivKey_ = credentialPrivKeyItem->value();
 
-    return ResultCode::OK;
+    return IIdentityCredentialStore::STATUS_OK;
 }
 
-Return<void> IdentityCredential::createAuthChallenge(createAuthChallenge_cb _hidl_cb) {
+ndk::ScopedAStatus IdentityCredential::deleteCredential(
+        vector<int8_t>* outProofOfDeletionSignature) {
+    cppbor::Array array = {"ProofOfDeletion", docType_, testCredential_};
+    vector<uint8_t> proofOfDeletion = array.encode();
+
+    optional<vector<uint8_t>> signature = support::coseSignEcDsa(credentialPrivKey_,
+                                                                 proofOfDeletion,  // payload
+                                                                 {},               // additionalData
+                                                                 {});  // certificateChain
+    if (!signature) {
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED, "Error signing data"));
+    }
+
+    *outProofOfDeletionSignature = byteStringToSigned(signature.value());
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus IdentityCredential::createEphemeralKeyPair(vector<int8_t>* outKeyPair) {
+    optional<vector<uint8_t>> kp = support::createEcKeyPair();
+    if (!kp) {
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED, "Error creating ephemeral key pair"));
+    }
+
+    // Stash public key of this key-pair for later check in startRetrieval().
+    optional<vector<uint8_t>> publicKey = support::ecKeyPairGetPublicKey(kp.value());
+    if (!publicKey) {
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED,
+                "Error getting public part of ephemeral key pair"));
+    }
+    ephemeralPublicKey_ = publicKey.value();
+
+    *outKeyPair = byteStringToSigned(kp.value());
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus IdentityCredential::setReaderEphemeralPublicKey(
+        const vector<int8_t>& publicKey) {
+    readerPublicKey_ = byteStringToUnsigned(publicKey);
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus IdentityCredential::createAuthChallenge(int64_t* outChallenge) {
     uint64_t challenge = 0;
     while (challenge == 0) {
         optional<vector<uint8_t>> bytes = support::getRandom(8);
         if (!bytes) {
-            _hidl_cb(support::result(ResultCode::FAILED, "Error getting random data for challenge"),
-                     0);
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_FAILED,
+                    "Error getting random data for challenge"));
         }
 
         challenge = 0;
@@ -163,17 +161,16 @@ Return<void> IdentityCredential::createAuthChallenge(createAuthChallenge_cb _hid
         }
     }
 
-    authChallenge_ = challenge;
-    _hidl_cb(support::resultOK(), challenge);
-    return Void();
+    *outChallenge = challenge;
+    return ndk::ScopedAStatus::ok();
 }
 
 // TODO: this could be a lot faster if we did all the splitting and pubkey extraction
 // ahead of time.
 bool checkReaderAuthentication(const SecureAccessControlProfile& profile,
                                const vector<uint8_t>& readerCertificateChain) {
-    optional<vector<uint8_t>> acpPubKey =
-            support::certificateChainGetTopMostKey(profile.readerCertificate);
+    optional<vector<uint8_t>> acpPubKey = support::certificateChainGetTopMostKey(
+            byteStringToUnsigned(profile.readerCertificate.encodedCertificate));
     if (!acpPubKey) {
         LOG(ERROR) << "Error extracting public key from readerCertificate in profile";
         return false;
@@ -202,7 +199,9 @@ bool checkReaderAuthentication(const SecureAccessControlProfile& profile,
 Timestamp clockGetTime() {
     struct timespec time;
     clock_gettime(CLOCK_MONOTONIC, &time);
-    return time.tv_sec * 1000 + time.tv_nsec / 1000000;
+    Timestamp ts;
+    ts.milliSeconds = time.tv_sec * 1000 + time.tv_nsec / 1000000;
+    return ts;
 }
 
 bool checkUserAuthentication(const SecureAccessControlProfile& profile,
@@ -219,7 +218,7 @@ bool checkUserAuthentication(const SecureAccessControlProfile& profile,
             return false;
         }
 
-        if (authToken.challenge != authChallenge) {
+        if (authToken.challenge != int64_t(authChallenge)) {
             LOG(ERROR) << "Challenge in authToken doesn't match the challenge we created";
             return false;
         }
@@ -239,42 +238,44 @@ bool checkUserAuthentication(const SecureAccessControlProfile& profile,
     // implementation should never be used on a real device.
     //
     Timestamp now = clockGetTime();
-    if (authToken.timestamp > now) {
-        LOG(ERROR) << "Timestamp in authToken (" << authToken.timestamp
-                   << ") is in the future (now: " << now << ")";
+    if (authToken.timestamp.milliSeconds > now.milliSeconds) {
+        LOG(ERROR) << "Timestamp in authToken (" << authToken.timestamp.milliSeconds
+                   << ") is in the future (now: " << now.milliSeconds << ")";
         return false;
     }
-    if (now > authToken.timestamp + profile.timeoutMillis) {
-        LOG(ERROR) << "Deadline for authToken (" << authToken.timestamp << " + "
+    if (now.milliSeconds > authToken.timestamp.milliSeconds + profile.timeoutMillis) {
+        LOG(ERROR) << "Deadline for authToken (" << authToken.timestamp.milliSeconds << " + "
                    << profile.timeoutMillis << " = "
-                   << (authToken.timestamp + profile.timeoutMillis)
-                   << ") is in the past (now: " << now << ")";
+                   << (authToken.timestamp.milliSeconds + profile.timeoutMillis)
+                   << ") is in the past (now: " << now.milliSeconds << ")";
         return false;
     }
-
     return true;
 }
 
-Return<void> IdentityCredential::startRetrieval(
-        const hidl_vec<SecureAccessControlProfile>& accessControlProfiles,
-        const HardwareAuthToken& authToken, const hidl_vec<uint8_t>& itemsRequest,
-        const hidl_vec<uint8_t>& sessionTranscript, const hidl_vec<uint8_t>& readerSignature,
-        const hidl_vec<uint16_t>& requestCounts, startRetrieval_cb _hidl_cb) {
+ndk::ScopedAStatus IdentityCredential::startRetrieval(
+        const vector<SecureAccessControlProfile>& accessControlProfiles,
+        const HardwareAuthToken& authToken, const vector<int8_t>& itemsRequestS,
+        const vector<int8_t>& sessionTranscriptS, const vector<int8_t>& readerSignatureS,
+        const vector<int32_t>& requestCounts) {
+    auto sessionTranscript = byteStringToUnsigned(sessionTranscriptS);
+    auto itemsRequest = byteStringToUnsigned(itemsRequestS);
+    auto readerSignature = byteStringToUnsigned(readerSignatureS);
+
     if (sessionTranscript.size() > 0) {
         auto [item, _, message] = cppbor::parse(sessionTranscript);
         if (item == nullptr) {
-            _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                     "SessionTranscript contains invalid CBOR"));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_DATA,
+                    "SessionTranscript contains invalid CBOR"));
         }
         sessionTranscriptItem_ = std::move(item);
     }
     if (numStartRetrievalCalls_ > 0) {
-        if (sessionTranscript_ != vector<uint8_t>(sessionTranscript)) {
-            _hidl_cb(support::result(
-                    ResultCode::SESSION_TRANSCRIPT_MISMATCH,
+        if (sessionTranscript_ != sessionTranscript) {
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_SESSION_TRANSCRIPT_MISMATCH,
                     "Passed-in SessionTranscript doesn't match previously used SessionTranscript"));
-            return Void();
         }
     }
     sessionTranscript_ = sessionTranscript;
@@ -285,23 +286,23 @@ Return<void> IdentityCredential::startRetrieval(
     if (readerSignature.size() > 0) {
         readerCertificateChain = support::coseSignGetX5Chain(readerSignature);
         if (!readerCertificateChain) {
-            _hidl_cb(support::result(ResultCode::READER_SIGNATURE_CHECK_FAILED,
-                                     "Unable to get reader certificate chain from COSE_Sign1"));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_READER_SIGNATURE_CHECK_FAILED,
+                    "Unable to get reader certificate chain from COSE_Sign1"));
         }
 
         if (!support::certificateChainValidate(readerCertificateChain.value())) {
-            _hidl_cb(support::result(ResultCode::READER_SIGNATURE_CHECK_FAILED,
-                                     "Error validating reader certificate chain"));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_READER_SIGNATURE_CHECK_FAILED,
+                    "Error validating reader certificate chain"));
         }
 
         optional<vector<uint8_t>> readerPublicKey =
                 support::certificateChainGetTopMostKey(readerCertificateChain.value());
         if (!readerPublicKey) {
-            _hidl_cb(support::result(ResultCode::READER_SIGNATURE_CHECK_FAILED,
-                                     "Unable to get public key from reader certificate chain"));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_READER_SIGNATURE_CHECK_FAILED,
+                    "Unable to get public key from reader certificate chain"));
         }
 
         const vector<uint8_t>& itemsRequestBytes = itemsRequest;
@@ -313,9 +314,9 @@ Return<void> IdentityCredential::startRetrieval(
         if (!support::coseCheckEcDsaSignature(readerSignature,
                                               dataThatWasSigned,  // detached content
                                               readerPublicKey.value())) {
-            _hidl_cb(support::result(ResultCode::READER_SIGNATURE_CHECK_FAILED,
-                                     "readerSignature check failed"));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_READER_SIGNATURE_CHECK_FAILED,
+                    "readerSignature check failed"));
         }
     }
 
@@ -334,39 +335,39 @@ Return<void> IdentityCredential::startRetrieval(
     if (sessionTranscript.size() > 0) {
         const cppbor::Array* array = sessionTranscriptItem_->asArray();
         if (array == nullptr || array->size() != 2) {
-            _hidl_cb(support::result(ResultCode::EPHEMERAL_PUBLIC_KEY_NOT_FOUND,
-                                     "SessionTranscript is not an array with two items"));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_EPHEMERAL_PUBLIC_KEY_NOT_FOUND,
+                    "SessionTranscript is not an array with two items"));
         }
         const cppbor::Semantic* taggedEncodedDE = (*array)[0]->asSemantic();
         if (taggedEncodedDE == nullptr || taggedEncodedDE->value() != 24) {
-            _hidl_cb(support::result(ResultCode::EPHEMERAL_PUBLIC_KEY_NOT_FOUND,
-                                     "First item in SessionTranscript array is not a "
-                                     "semantic with value 24"));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_EPHEMERAL_PUBLIC_KEY_NOT_FOUND,
+                    "First item in SessionTranscript array is not a "
+                    "semantic with value 24"));
         }
         const cppbor::Bstr* encodedDE = (taggedEncodedDE->child())->asBstr();
         if (encodedDE == nullptr) {
-            _hidl_cb(support::result(ResultCode::EPHEMERAL_PUBLIC_KEY_NOT_FOUND,
-                                     "Child of semantic in first item in SessionTranscript "
-                                     "array is not a bstr"));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_EPHEMERAL_PUBLIC_KEY_NOT_FOUND,
+                    "Child of semantic in first item in SessionTranscript "
+                    "array is not a bstr"));
         }
         const vector<uint8_t>& bytesDE = encodedDE->value();
 
         auto [getXYSuccess, ePubX, ePubY] = support::ecPublicKeyGetXandY(ephemeralPublicKey_);
         if (!getXYSuccess) {
-            _hidl_cb(support::result(ResultCode::EPHEMERAL_PUBLIC_KEY_NOT_FOUND,
-                                     "Error extracting X and Y from ePub"));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_EPHEMERAL_PUBLIC_KEY_NOT_FOUND,
+                    "Error extracting X and Y from ePub"));
         }
         if (sessionTranscript.size() > 0 &&
             !(memmem(bytesDE.data(), bytesDE.size(), ePubX.data(), ePubX.size()) != nullptr &&
               memmem(bytesDE.data(), bytesDE.size(), ePubY.data(), ePubY.size()) != nullptr)) {
-            _hidl_cb(support::result(ResultCode::EPHEMERAL_PUBLIC_KEY_NOT_FOUND,
-                                     "Did not find ephemeral public key's X and Y coordinates in "
-                                     "SessionTranscript (make sure leading zeroes are not used)"));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_EPHEMERAL_PUBLIC_KEY_NOT_FOUND,
+                    "Did not find ephemeral public key's X and Y coordinates in "
+                    "SessionTranscript (make sure leading zeroes are not used)"));
         }
     }
 
@@ -378,17 +379,17 @@ Return<void> IdentityCredential::startRetrieval(
         // 1. The content must be a CBOR-encoded structure.
         auto [item, _, message] = cppbor::parse(itemsRequest);
         if (item == nullptr) {
-            _hidl_cb(support::result(ResultCode::INVALID_ITEMS_REQUEST_MESSAGE,
-                                     "Error decoding CBOR in itemsRequest: %s", message.c_str()));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_ITEMS_REQUEST_MESSAGE,
+                    "Error decoding CBOR in itemsRequest"));
         }
 
         // 2. The CBOR structure must be a map.
         const cppbor::Map* map = item->asMap();
         if (map == nullptr) {
-            _hidl_cb(support::result(ResultCode::INVALID_ITEMS_REQUEST_MESSAGE,
-                                     "itemsRequest is not a CBOR map"));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_ITEMS_REQUEST_MESSAGE,
+                    "itemsRequest is not a CBOR map"));
         }
 
         // 3. The map must contain a key "nameSpaces" whose value contains a map, as described in
@@ -435,9 +436,9 @@ Return<void> IdentityCredential::startRetrieval(
             }
         }
         if (nsMap == nullptr) {
-            _hidl_cb(support::result(ResultCode::INVALID_ITEMS_REQUEST_MESSAGE,
-                                     "No nameSpaces map in top-most map"));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_ITEMS_REQUEST_MESSAGE,
+                    "No nameSpaces map in top-most map"));
         }
 
         for (size_t n = 0; n < nsMap->size(); n++) {
@@ -445,9 +446,9 @@ Return<void> IdentityCredential::startRetrieval(
             const cppbor::Tstr* nsKey = nsKeyItem->asTstr();
             const cppbor::Map* nsInnerMap = nsValueItem->asMap();
             if (nsKey == nullptr || nsInnerMap == nullptr) {
-                _hidl_cb(support::result(ResultCode::INVALID_ITEMS_REQUEST_MESSAGE,
-                                         "Type mismatch in nameSpaces map"));
-                return Void();
+                return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                        IIdentityCredentialStore::STATUS_INVALID_ITEMS_REQUEST_MESSAGE,
+                        "Type mismatch in nameSpaces map"));
             }
             string requestedNamespace = nsKey->value();
             vector<string> requestedKeys;
@@ -458,9 +459,9 @@ Return<void> IdentityCredential::startRetrieval(
                 const cppbor::Bool* intentToRetainItem =
                         (simple != nullptr) ? simple->asBool() : nullptr;
                 if (nameItem == nullptr || intentToRetainItem == nullptr) {
-                    _hidl_cb(support::result(ResultCode::INVALID_ITEMS_REQUEST_MESSAGE,
-                                             "Type mismatch in value in nameSpaces map"));
-                    return Void();
+                    return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                            IIdentityCredentialStore::STATUS_INVALID_ITEMS_REQUEST_MESSAGE,
+                            "Type mismatch in value in nameSpaces map"));
                 }
                 requestedKeys.push_back(nameItem->value());
             }
@@ -471,20 +472,20 @@ Return<void> IdentityCredential::startRetrieval(
     // Finally, validate all the access control profiles in the requestData.
     bool haveAuthToken = (authToken.mac.size() > 0);
     for (const auto& profile : accessControlProfiles) {
-        if (!support::secureAccessControlProfileCheckMac(profile, storageKey_)) {
-            _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                     "Error checking MAC for profile with id %d", int(profile.id)));
-            return Void();
+        if (!secureAccessControlProfileCheckMac(profile, storageKey_)) {
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_DATA,
+                    "Error checking MAC for profile"));
         }
-        ResultCode accessControlCheck = ResultCode::OK;
+        int accessControlCheck = IIdentityCredentialStore::STATUS_OK;
         if (profile.userAuthenticationRequired) {
             if (!haveAuthToken || !checkUserAuthentication(profile, authToken, authChallenge_)) {
-                accessControlCheck = ResultCode::USER_AUTHENTICATION_FAILED;
+                accessControlCheck = IIdentityCredentialStore::STATUS_USER_AUTHENTICATION_FAILED;
             }
-        } else if (profile.readerCertificate.size() > 0) {
+        } else if (profile.readerCertificate.encodedCertificate.size() > 0) {
             if (!readerCertificateChain ||
                 !checkReaderAuthentication(profile, readerCertificateChain.value())) {
-                accessControlCheck = ResultCode::READER_AUTHENTICATION_FAILED;
+                accessControlCheck = IIdentityCredentialStore::STATUS_READER_AUTHENTICATION_FAILED;
             }
         }
         profileIdToAccessCheckResult_[profile.id] = accessControlCheck;
@@ -499,26 +500,25 @@ Return<void> IdentityCredential::startRetrieval(
     itemsRequest_ = itemsRequest;
 
     numStartRetrievalCalls_ += 1;
-    _hidl_cb(support::resultOK());
-    return Void();
+    return ndk::ScopedAStatus::ok();
 }
 
-Return<void> IdentityCredential::startRetrieveEntryValue(
-        const hidl_string& nameSpace, const hidl_string& name, uint32_t entrySize,
-        const hidl_vec<uint16_t>& accessControlProfileIds, startRetrieveEntryValue_cb _hidl_cb) {
+ndk::ScopedAStatus IdentityCredential::startRetrieveEntryValue(
+        const string& nameSpace, const string& name, int32_t entrySize,
+        const vector<int32_t>& accessControlProfileIds) {
     if (name.empty()) {
-        _hidl_cb(support::result(ResultCode::INVALID_DATA, "Name cannot be empty"));
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_INVALID_DATA, "Name cannot be empty"));
     }
     if (nameSpace.empty()) {
-        _hidl_cb(support::result(ResultCode::INVALID_DATA, "Name space cannot be empty"));
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_INVALID_DATA, "Name space cannot be empty"));
     }
 
     if (requestCountsRemaining_.size() == 0) {
-        _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                 "No more name spaces left to go through"));
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_INVALID_DATA,
+                "No more name spaces left to go through"));
     }
 
     if (currentNameSpace_ == "") {
@@ -529,19 +529,18 @@ Return<void> IdentityCredential::startRetrieveEntryValue(
     if (nameSpace == currentNameSpace_) {
         // Same namespace.
         if (requestCountsRemaining_[0] == 0) {
-            _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                     "No more entries to be retrieved in current name space"));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_DATA,
+                    "No more entries to be retrieved in current name space"));
         }
         requestCountsRemaining_[0] -= 1;
     } else {
         // New namespace.
         if (requestCountsRemaining_[0] != 0) {
-            _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                     "Moved to new name space but %d entries need to be retrieved "
-                                     "in current name space",
-                                     int(requestCountsRemaining_[0])));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_DATA,
+                    "Moved to new name space but one or more entries need to be retrieved "
+                    "in current name space"));
         }
         if (currentNameSpaceDeviceNameSpacesMap_.size() > 0) {
             deviceNameSpacesMap_.add(currentNameSpace_,
@@ -558,18 +557,15 @@ Return<void> IdentityCredential::startRetrieveEntryValue(
     if (itemsRequest_.size() > 0) {
         const auto& it = requestedNameSpacesAndNames_.find(nameSpace);
         if (it == requestedNameSpacesAndNames_.end()) {
-            _hidl_cb(support::result(ResultCode::NOT_IN_REQUEST_MESSAGE,
-                                     "Name space '%s' was not requested in startRetrieval",
-                                     nameSpace.c_str()));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_NOT_IN_REQUEST_MESSAGE,
+                    "Name space was not requested in startRetrieval"));
         }
         const auto& dataItemNames = it->second;
         if (std::find(dataItemNames.begin(), dataItemNames.end(), name) == dataItemNames.end()) {
-            _hidl_cb(support::result(
-                    ResultCode::NOT_IN_REQUEST_MESSAGE,
-                    "Data item name '%s' in name space '%s' was not requested in startRetrieval",
-                    name.c_str(), nameSpace.c_str()));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_NOT_IN_REQUEST_MESSAGE,
+                    "Data item name in name space was not requested in startRetrieval"));
         }
     }
 
@@ -579,44 +575,44 @@ Return<void> IdentityCredential::startRetrieveEntryValue(
     //
     // If an item is configured without any profiles, access is denied.
     //
-    ResultCode accessControl = ResultCode::NO_ACCESS_CONTROL_PROFILES;
+    int accessControl = IIdentityCredentialStore::STATUS_NO_ACCESS_CONTROL_PROFILES;
     for (auto id : accessControlProfileIds) {
         auto search = profileIdToAccessCheckResult_.find(id);
         if (search == profileIdToAccessCheckResult_.end()) {
-            _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                     "Requested entry with unvalidated profile id %d", (int(id))));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_DATA,
+                    "Requested entry with unvalidated profile id"));
         }
-        ResultCode accessControlForProfile = search->second;
-        if (accessControlForProfile == ResultCode::OK) {
-            accessControl = ResultCode::OK;
+        int accessControlForProfile = search->second;
+        if (accessControlForProfile == IIdentityCredentialStore::STATUS_OK) {
+            accessControl = IIdentityCredentialStore::STATUS_OK;
             break;
         }
         accessControl = accessControlForProfile;
     }
-    if (accessControl != ResultCode::OK) {
-        _hidl_cb(support::result(accessControl, "Access control check failed"));
-        return Void();
+    if (accessControl != IIdentityCredentialStore::STATUS_OK) {
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                int(accessControl), "Access control check failed"));
     }
 
-    entryAdditionalData_ =
-            support::entryCreateAdditionalData(nameSpace, name, accessControlProfileIds);
+    entryAdditionalData_ = entryCreateAdditionalData(nameSpace, name, accessControlProfileIds);
 
     currentName_ = name;
     entryRemainingBytes_ = entrySize;
     entryValue_.resize(0);
 
-    _hidl_cb(support::resultOK());
-    return Void();
+    return ndk::ScopedAStatus::ok();
 }
 
-Return<void> IdentityCredential::retrieveEntryValue(const hidl_vec<uint8_t>& encryptedContent,
-                                                    retrieveEntryValue_cb _hidl_cb) {
+ndk::ScopedAStatus IdentityCredential::retrieveEntryValue(const vector<int8_t>& encryptedContentS,
+                                                          vector<int8_t>* outContent) {
+    auto encryptedContent = byteStringToUnsigned(encryptedContentS);
+
     optional<vector<uint8_t>> content =
             support::decryptAes128Gcm(storageKey_, encryptedContent, entryAdditionalData_);
     if (!content) {
-        _hidl_cb(support::result(ResultCode::INVALID_DATA, "Error decrypting data"), {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_INVALID_DATA, "Error decrypting data"));
     }
 
     size_t chunkSize = content.value().size();
@@ -624,23 +620,17 @@ Return<void> IdentityCredential::retrieveEntryValue(const hidl_vec<uint8_t>& enc
     if (chunkSize > entryRemainingBytes_) {
         LOG(ERROR) << "Retrieved chunk of size " << chunkSize
                    << " is bigger than remaining space of size " << entryRemainingBytes_;
-        _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                 "Retrieved chunk of size %zd is bigger than remaining space "
-                                 "of size %zd",
-                                 chunkSize, entryRemainingBytes_),
-                 {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_INVALID_DATA,
+                "Retrieved chunk is bigger than remaining space"));
     }
 
     entryRemainingBytes_ -= chunkSize;
     if (entryRemainingBytes_ > 0) {
         if (chunkSize != IdentityCredentialStore::kGcmChunkSize) {
-            _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                     "Retrieved non-final chunk of size %zd but expected "
-                                     "kGcmChunkSize which is %zd",
-                                     chunkSize, IdentityCredentialStore::kGcmChunkSize),
-                     {});
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_DATA,
+                    "Retrieved non-final chunk of size which isn't kGcmChunkSize"));
         }
     }
 
@@ -649,18 +639,22 @@ Return<void> IdentityCredential::retrieveEntryValue(const hidl_vec<uint8_t>& enc
     if (entryRemainingBytes_ == 0) {
         auto [entryValueItem, _, message] = cppbor::parse(entryValue_);
         if (entryValueItem == nullptr) {
-            _hidl_cb(support::result(ResultCode::INVALID_DATA, "Retrieved data invalid CBOR"), {});
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_DATA,
+                    "Retrieved data which is invalid CBOR"));
         }
         currentNameSpaceDeviceNameSpacesMap_.add(currentName_, std::move(entryValueItem));
     }
 
-    _hidl_cb(support::resultOK(), content.value());
-    return Void();
+    *outContent = byteStringToSigned(content.value());
+    return ndk::ScopedAStatus::ok();
 }
 
-Return<void> IdentityCredential::finishRetrieval(const hidl_vec<uint8_t>& signingKeyBlob,
-                                                 finishRetrieval_cb _hidl_cb) {
+ndk::ScopedAStatus IdentityCredential::finishRetrieval(const vector<int8_t>& signingKeyBlobS,
+                                                       vector<int8_t>* outMac,
+                                                       vector<int8_t>* outDeviceNameSpaces) {
+    auto signingKeyBlob = byteStringToUnsigned(signingKeyBlobS);
+
     if (currentNameSpaceDeviceNameSpacesMap_.size() > 0) {
         deviceNameSpacesMap_.add(currentNameSpace_,
                                  std::move(currentNameSpaceDeviceNameSpacesMap_));
@@ -682,40 +676,42 @@ Return<void> IdentityCredential::finishRetrieval(const hidl_vec<uint8_t>& signin
         optional<vector<uint8_t>> signingKey =
                 support::decryptAes128Gcm(storageKey_, signingKeyBlob, docTypeAsBlob);
         if (!signingKey) {
-            _hidl_cb(support::result(ResultCode::INVALID_DATA, "Error decrypting signingKeyBlob"),
-                     {}, {});
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_DATA,
+                    "Error decrypting signingKeyBlob"));
         }
 
         optional<vector<uint8_t>> sharedSecret =
                 support::ecdh(readerPublicKey_, signingKey.value());
         if (!sharedSecret) {
-            _hidl_cb(support::result(ResultCode::FAILED, "Error doing ECDH"), {}, {});
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_FAILED, "Error doing ECDH"));
         }
 
         vector<uint8_t> salt = {0x00};
         vector<uint8_t> info = {};
         optional<vector<uint8_t>> derivedKey = support::hkdf(sharedSecret.value(), salt, info, 32);
         if (!derivedKey) {
-            _hidl_cb(support::result(ResultCode::FAILED, "Error deriving key from shared secret"),
-                     {}, {});
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_FAILED,
+                    "Error deriving key from shared secret"));
         }
 
         mac = support::coseMac0(derivedKey.value(), {},        // payload
                                 encodedDeviceAuthentication);  // additionalData
         if (!mac) {
-            _hidl_cb(support::result(ResultCode::FAILED, "Error MACing data"), {}, {});
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_FAILED, "Error MACing data"));
         }
     }
 
-    _hidl_cb(support::resultOK(), mac.value_or(vector<uint8_t>({})), encodedDeviceNameSpaces);
-    return Void();
+    *outMac = byteStringToSigned(mac.value_or(vector<uint8_t>({})));
+    *outDeviceNameSpaces = byteStringToSigned(encodedDeviceNameSpaces);
+    return ndk::ScopedAStatus::ok();
 }
 
-Return<void> IdentityCredential::generateSigningKeyPair(generateSigningKeyPair_cb _hidl_cb) {
+ndk::ScopedAStatus IdentityCredential::generateSigningKeyPair(
+        vector<int8_t>* outSigningKeyBlob, Certificate* outSigningKeyCertificate) {
     string serialDecimal = "0";  // TODO: set serial to something unique
     string issuer = "Android Open Source Project";
     string subject = "Android IdentityCredential Reference Implementation";
@@ -724,50 +720,49 @@ Return<void> IdentityCredential::generateSigningKeyPair(generateSigningKeyPair_c
 
     optional<vector<uint8_t>> signingKeyPKCS8 = support::createEcKeyPair();
     if (!signingKeyPKCS8) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error creating signingKey"), {}, {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED, "Error creating signingKey"));
     }
 
     optional<vector<uint8_t>> signingPublicKey =
             support::ecKeyPairGetPublicKey(signingKeyPKCS8.value());
     if (!signingPublicKey) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error getting public part of signingKey"), {},
-                 {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED,
+                "Error getting public part of signingKey"));
     }
 
     optional<vector<uint8_t>> signingKey = support::ecKeyPairGetPrivateKey(signingKeyPKCS8.value());
     if (!signingKey) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error getting private part of signingKey"),
-                 {}, {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED,
+                "Error getting private part of signingKey"));
     }
 
     optional<vector<uint8_t>> certificate = support::ecPublicKeyGenerateCertificate(
             signingPublicKey.value(), credentialPrivKey_, serialDecimal, issuer, subject,
             validityNotBefore, validityNotAfter);
     if (!certificate) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error creating signingKey"), {}, {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED, "Error creating signingKey"));
     }
 
     optional<vector<uint8_t>> nonce = support::getRandom(12);
     if (!nonce) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error getting random"), {}, {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED, "Error getting random"));
     }
     vector<uint8_t> docTypeAsBlob(docType_.begin(), docType_.end());
     optional<vector<uint8_t>> encryptedSigningKey = support::encryptAes128Gcm(
             storageKey_, nonce.value(), signingKey.value(), docTypeAsBlob);
     if (!encryptedSigningKey) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error encrypting signingKey"), {}, {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED, "Error encrypting signingKey"));
     }
-    _hidl_cb(support::resultOK(), encryptedSigningKey.value(), certificate.value());
-    return Void();
+    *outSigningKeyBlob = byteStringToSigned(encryptedSigningKey.value());
+    *outSigningKeyCertificate = Certificate();
+    outSigningKeyCertificate->encodedCertificate = byteStringToSigned(certificate.value());
+    return ndk::ScopedAStatus::ok();
 }
 
-}  // namespace implementation
-}  // namespace identity
-}  // namespace hardware
-}  // namespace android
+}  // namespace aidl::android::hardware::identity
diff --git a/identity/aidl/default/IdentityCredential.h b/identity/aidl/default/IdentityCredential.h
new file mode 100644
index 0000000000..49ed0d45b8
--- /dev/null
+++ b/identity/aidl/default/IdentityCredential.h
@@ -0,0 +1,109 @@
+/*
+ * Copyright 2019, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_IDENTITY_IDENTITYCREDENTIAL_H
+#define ANDROID_HARDWARE_IDENTITY_IDENTITYCREDENTIAL_H
+
+#include <aidl/android/hardware/identity/BnIdentityCredential.h>
+#include <aidl/android/hardware/keymaster/HardwareAuthToken.h>
+#include <android/hardware/identity/support/IdentityCredentialSupport.h>
+
+#include <map>
+#include <set>
+#include <string>
+#include <vector>
+
+#include <cppbor/cppbor.h>
+
+namespace aidl::android::hardware::identity {
+
+using ::aidl::android::hardware::keymaster::HardwareAuthToken;
+using ::std::map;
+using ::std::string;
+using ::std::vector;
+
+using MapStringToVectorOfStrings = map<string, vector<string>>;
+
+class IdentityCredential : public BnIdentityCredential {
+  public:
+    IdentityCredential(const vector<uint8_t>& credentialData)
+        : credentialData_(credentialData), numStartRetrievalCalls_(0), authChallenge_(0) {}
+
+    // Parses and decrypts credentialData_, return a status code from
+    // IIdentityCredentialStore. Must be called right after construction.
+    int initialize();
+
+    // Methods from IIdentityCredential follow.
+    ndk::ScopedAStatus deleteCredential(vector<int8_t>* outProofOfDeletionSignature) override;
+    ndk::ScopedAStatus createEphemeralKeyPair(vector<int8_t>* outKeyPair) override;
+    ndk::ScopedAStatus setReaderEphemeralPublicKey(const vector<int8_t>& publicKey) override;
+    ndk::ScopedAStatus createAuthChallenge(int64_t* outChallenge) override;
+    ndk::ScopedAStatus startRetrieval(
+            const vector<SecureAccessControlProfile>& accessControlProfiles,
+            const HardwareAuthToken& authToken, const vector<int8_t>& itemsRequest,
+            const vector<int8_t>& sessionTranscript, const vector<int8_t>& readerSignature,
+            const vector<int32_t>& requestCounts) override;
+    ndk::ScopedAStatus startRetrieveEntryValue(
+            const string& nameSpace, const string& name, int32_t entrySize,
+            const vector<int32_t>& accessControlProfileIds) override;
+    ndk::ScopedAStatus retrieveEntryValue(const vector<int8_t>& encryptedContent,
+                                          vector<int8_t>* outContent) override;
+    ndk::ScopedAStatus finishRetrieval(const vector<int8_t>& signingKeyBlob, vector<int8_t>* outMac,
+                                       vector<int8_t>* outDeviceNameSpaces) override;
+    ndk::ScopedAStatus generateSigningKeyPair(vector<int8_t>* outSigningKeyBlob,
+                                              Certificate* outSigningKeyCertificate) override;
+
+  private:
+    // Set by constructor
+    vector<uint8_t> credentialData_;
+    int numStartRetrievalCalls_;
+
+    // Set by initialize()
+    string docType_;
+    bool testCredential_;
+    vector<uint8_t> storageKey_;
+    vector<uint8_t> credentialPrivKey_;
+
+    // Set by createEphemeralKeyPair()
+    vector<uint8_t> ephemeralPublicKey_;
+
+    // Set by setReaderEphemeralPublicKey()
+    vector<uint8_t> readerPublicKey_;
+
+    // Set by createAuthChallenge()
+    uint64_t authChallenge_;
+
+    // Set at startRetrieval() time.
+    map<int32_t, int> profileIdToAccessCheckResult_;
+    vector<uint8_t> sessionTranscript_;
+    std::unique_ptr<cppbor::Item> sessionTranscriptItem_;
+    vector<uint8_t> itemsRequest_;
+    vector<int32_t> requestCountsRemaining_;
+    MapStringToVectorOfStrings requestedNameSpacesAndNames_;
+    cppbor::Map deviceNameSpacesMap_;
+    cppbor::Map currentNameSpaceDeviceNameSpacesMap_;
+
+    // Set at startRetrieveEntryValue() time.
+    string currentNameSpace_;
+    string currentName_;
+    size_t entryRemainingBytes_;
+    vector<uint8_t> entryValue_;
+    vector<uint8_t> entryAdditionalData_;
+};
+
+}  // namespace aidl::android::hardware::identity
+
+#endif  // ANDROID_HARDWARE_IDENTITY_IDENTITYCREDENTIAL_H
diff --git a/identity/aidl/default/IdentityCredentialStore.cpp b/identity/aidl/default/IdentityCredentialStore.cpp
new file mode 100644
index 0000000000..1efb4b4937
--- /dev/null
+++ b/identity/aidl/default/IdentityCredentialStore.cpp
@@ -0,0 +1,74 @@
+/*
+ * Copyright 2019, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "IdentityCredentialStore"
+
+#include <android-base/logging.h>
+
+#include "IdentityCredential.h"
+#include "IdentityCredentialStore.h"
+#include "WritableIdentityCredential.h"
+
+namespace aidl::android::hardware::identity {
+
+ndk::ScopedAStatus IdentityCredentialStore::getHardwareInformation(
+        HardwareInformation* hardwareInformation) {
+    HardwareInformation hw;
+    hw.credentialStoreName = "Identity Credential Reference Implementation";
+    hw.credentialStoreAuthorName = "Google";
+    hw.dataChunkSize = kGcmChunkSize;
+    hw.isDirectAccess = false;
+    hw.supportedDocTypes = {};
+    *hardwareInformation = hw;
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus IdentityCredentialStore::createCredential(
+        const string& docType, bool testCredential,
+        shared_ptr<IWritableIdentityCredential>* outWritableCredential) {
+    shared_ptr<WritableIdentityCredential> wc =
+            ndk::SharedRefBase::make<WritableIdentityCredential>(docType, testCredential);
+    if (!wc->initialize()) {
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED,
+                "Error initializing WritableIdentityCredential"));
+    }
+    *outWritableCredential = wc;
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus IdentityCredentialStore::getCredential(
+        CipherSuite cipherSuite, const vector<int8_t>& credentialData,
+        shared_ptr<IIdentityCredential>* outCredential) {
+    // We only support CIPHERSUITE_ECDHE_HKDF_ECDSA_WITH_AES_256_GCM_SHA256 right now.
+    if (cipherSuite != CipherSuite::CIPHERSUITE_ECDHE_HKDF_ECDSA_WITH_AES_256_GCM_SHA256) {
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_CIPHER_SUITE_NOT_SUPPORTED,
+                "Unsupported cipher suite"));
+    }
+
+    vector<uint8_t> data = vector<uint8_t>(credentialData.begin(), credentialData.end());
+    shared_ptr<IdentityCredential> credential = ndk::SharedRefBase::make<IdentityCredential>(data);
+    auto ret = credential->initialize();
+    if (ret != IIdentityCredentialStore::STATUS_OK) {
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                int(ret), "Error initializing IdentityCredential"));
+    }
+    *outCredential = credential;
+    return ndk::ScopedAStatus::ok();
+}
+
+}  // namespace aidl::android::hardware::identity
diff --git a/identity/aidl/default/IdentityCredentialStore.h b/identity/aidl/default/IdentityCredentialStore.h
new file mode 100644
index 0000000000..a2051130b0
--- /dev/null
+++ b/identity/aidl/default/IdentityCredentialStore.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2019, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_IDENTITY_IDENTITYCREDENTIALSTORE_H
+#define ANDROID_HARDWARE_IDENTITY_IDENTITYCREDENTIALSTORE_H
+
+#include <aidl/android/hardware/identity/BnIdentityCredentialStore.h>
+
+namespace aidl::android::hardware::identity {
+
+using ::std::shared_ptr;
+using ::std::string;
+using ::std::vector;
+
+class IdentityCredentialStore : public BnIdentityCredentialStore {
+  public:
+    IdentityCredentialStore() {}
+
+    // The GCM chunk size used by this implementation is 64 KiB.
+    static constexpr size_t kGcmChunkSize = 64 * 1024;
+
+    // Methods from IIdentityCredentialStore follow.
+    ndk::ScopedAStatus getHardwareInformation(HardwareInformation* hardwareInformation) override;
+
+    ndk::ScopedAStatus createCredential(
+            const string& docType, bool testCredential,
+            shared_ptr<IWritableIdentityCredential>* outWritableCredential) override;
+
+    ndk::ScopedAStatus getCredential(CipherSuite cipherSuite, const vector<int8_t>& credentialData,
+                                     shared_ptr<IIdentityCredential>* outCredential) override;
+};
+
+}  // namespace aidl::android::hardware::identity
+
+#endif  // ANDROID_HARDWARE_IDENTITY_IDENTITYCREDENTIALSTORE_H
diff --git a/identity/aidl/default/Util.cpp b/identity/aidl/default/Util.cpp
new file mode 100644
index 0000000000..a0f86bedcd
--- /dev/null
+++ b/identity/aidl/default/Util.cpp
@@ -0,0 +1,117 @@
+/*
+ * Copyright 2019, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "Util"
+
+#include "Util.h"
+
+#include <android/hardware/identity/support/IdentityCredentialSupport.h>
+
+#include <string.h>
+
+#include <android-base/logging.h>
+
+#include <cppbor.h>
+#include <cppbor_parse.h>
+
+namespace aidl::android::hardware::identity {
+
+using namespace ::android::hardware::identity;
+
+// This is not a very random HBK but that's OK because this is the SW
+// implementation where it can't be kept secret.
+vector<uint8_t> hardwareBoundKey = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
+
+const vector<uint8_t>& getHardwareBoundKey() {
+    return hardwareBoundKey;
+}
+
+vector<uint8_t> byteStringToUnsigned(const vector<int8_t>& value) {
+    return vector<uint8_t>(value.begin(), value.end());
+}
+
+vector<int8_t> byteStringToSigned(const vector<uint8_t>& value) {
+    return vector<int8_t>(value.begin(), value.end());
+}
+
+vector<uint8_t> secureAccessControlProfileEncodeCbor(const SecureAccessControlProfile& profile) {
+    cppbor::Map map;
+    map.add("id", profile.id);
+
+    if (profile.readerCertificate.encodedCertificate.size() > 0) {
+        map.add("readerCertificate",
+                cppbor::Bstr(byteStringToUnsigned(profile.readerCertificate.encodedCertificate)));
+    }
+
+    if (profile.userAuthenticationRequired) {
+        map.add("userAuthenticationRequired", profile.userAuthenticationRequired);
+        map.add("timeoutMillis", profile.timeoutMillis);
+        map.add("secureUserId", profile.secureUserId);
+    }
+
+    return map.encode();
+}
+
+optional<vector<uint8_t>> secureAccessControlProfileCalcMac(
+        const SecureAccessControlProfile& profile, const vector<uint8_t>& storageKey) {
+    vector<uint8_t> cborData = secureAccessControlProfileEncodeCbor(profile);
+
+    optional<vector<uint8_t>> nonce = support::getRandom(12);
+    if (!nonce) {
+        return {};
+    }
+    optional<vector<uint8_t>> macO =
+            support::encryptAes128Gcm(storageKey, nonce.value(), {}, cborData);
+    if (!macO) {
+        return {};
+    }
+    return macO.value();
+}
+
+bool secureAccessControlProfileCheckMac(const SecureAccessControlProfile& profile,
+                                        const vector<uint8_t>& storageKey) {
+    vector<uint8_t> cborData = secureAccessControlProfileEncodeCbor(profile);
+
+    if (profile.mac.size() < support::kAesGcmIvSize) {
+        return false;
+    }
+    vector<uint8_t> nonce =
+            vector<uint8_t>(profile.mac.begin(), profile.mac.begin() + support::kAesGcmIvSize);
+    optional<vector<uint8_t>> mac = support::encryptAes128Gcm(storageKey, nonce, {}, cborData);
+    if (!mac) {
+        return false;
+    }
+    if (mac.value() != byteStringToUnsigned(profile.mac)) {
+        return false;
+    }
+    return true;
+}
+
+vector<uint8_t> entryCreateAdditionalData(const string& nameSpace, const string& name,
+                                          const vector<int32_t> accessControlProfileIds) {
+    cppbor::Map map;
+    map.add("Namespace", nameSpace);
+    map.add("Name", name);
+
+    cppbor::Array acpIds;
+    for (auto id : accessControlProfileIds) {
+        acpIds.add(id);
+    }
+    map.add("AccessControlProfileIds", std::move(acpIds));
+    return map.encode();
+}
+
+}  // namespace aidl::android::hardware::identity
diff --git a/identity/aidl/default/Util.h b/identity/aidl/default/Util.h
new file mode 100644
index 0000000000..ee41ad1aac
--- /dev/null
+++ b/identity/aidl/default/Util.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2019, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_IDENTITY_UTIL_H
+#define ANDROID_HARDWARE_IDENTITY_UTIL_H
+
+#include <aidl/android/hardware/identity/BnIdentityCredential.h>
+#include <android/hardware/identity/support/IdentityCredentialSupport.h>
+
+#include <map>
+#include <optional>
+#include <set>
+#include <string>
+#include <vector>
+
+#include <cppbor/cppbor.h>
+
+namespace aidl::android::hardware::identity {
+
+using ::std::optional;
+using ::std::string;
+using ::std::vector;
+
+// Returns the hardware-bound AES-128 key.
+const vector<uint8_t>& getHardwareBoundKey();
+
+// Calculates the MAC for |profile| using |storageKey|.
+optional<vector<uint8_t>> secureAccessControlProfileCalcMac(
+        const SecureAccessControlProfile& profile, const vector<uint8_t>& storageKey);
+
+// Checks authenticity of the MAC in |profile| using |storageKey|.
+bool secureAccessControlProfileCheckMac(const SecureAccessControlProfile& profile,
+                                        const vector<uint8_t>& storageKey);
+
+// Creates the AdditionalData CBOR used in the addEntryValue() HIDL method.
+vector<uint8_t> entryCreateAdditionalData(const string& nameSpace, const string& name,
+                                          const vector<int32_t> accessControlProfileIds);
+
+vector<uint8_t> byteStringToUnsigned(const vector<int8_t>& value);
+
+vector<int8_t> byteStringToSigned(const vector<uint8_t>& value);
+
+}  // namespace aidl::android::hardware::identity
+
+#endif  // ANDROID_HARDWARE_IDENTITY_UTIL_H
diff --git a/identity/1.0/default/WritableIdentityCredential.cpp b/identity/aidl/default/WritableIdentityCredential.cpp
index 4c39f85eb3..ba2062d7c0 100644
--- a/identity/1.0/default/WritableIdentityCredential.cpp
+++ b/identity/aidl/default/WritableIdentityCredential.cpp
@@ -16,9 +16,6 @@
 
 #define LOG_TAG "WritableIdentityCredential"
 
-#include "WritableIdentityCredential.h"
-#include "IdentityCredentialStore.h"
-
 #include <android/hardware/identity/support/IdentityCredentialSupport.h>
 
 #include <android-base/logging.h>
@@ -26,56 +23,14 @@
 #include <cppbor/cppbor.h>
 #include <cppbor/cppbor_parse.h>
 
-namespace android {
-namespace hardware {
-namespace identity {
-namespace implementation {
-
-using ::std::optional;
-
-// Writes CBOR-encoded structure to |credentialKeys| containing |storageKey| and
-// |credentialPrivKey|.
-static bool generateCredentialKeys(const vector<uint8_t>& storageKey,
-                                   const vector<uint8_t>& credentialPrivKey,
-                                   vector<uint8_t>& credentialKeys) {
-    if (storageKey.size() != 16) {
-        LOG(ERROR) << "Size of storageKey is not 16";
-        return false;
-    }
+#include "IdentityCredentialStore.h"
+#include "Util.h"
+#include "WritableIdentityCredential.h"
 
-    cppbor::Array array;
-    array.add(cppbor::Bstr(storageKey));
-    array.add(cppbor::Bstr(credentialPrivKey));
-    credentialKeys = array.encode();
-    return true;
-}
+namespace aidl::android::hardware::identity {
 
-// Writes CBOR-encoded structure to |credentialData| containing |docType|,
-// |testCredential| and |credentialKeys|. The latter element will be stored in
-// encrypted form, using |hardwareBoundKey| as the encryption key.
-bool generateCredentialData(const vector<uint8_t>& hardwareBoundKey, const string& docType,
-                            bool testCredential, const vector<uint8_t>& credentialKeys,
-                            vector<uint8_t>& credentialData) {
-    optional<vector<uint8_t>> nonce = support::getRandom(12);
-    if (!nonce) {
-        LOG(ERROR) << "Error getting random";
-        return false;
-    }
-    vector<uint8_t> docTypeAsVec(docType.begin(), docType.end());
-    optional<vector<uint8_t>> credentialBlob = support::encryptAes128Gcm(
-            hardwareBoundKey, nonce.value(), credentialKeys, docTypeAsVec);
-    if (!credentialBlob) {
-        LOG(ERROR) << "Error encrypting CredentialKeys blob";
-        return false;
-    }
-
-    cppbor::Array array;
-    array.add(docType);
-    array.add(testCredential);
-    array.add(cppbor::Bstr(credentialBlob.value()));
-    credentialData = array.encode();
-    return true;
-}
+using ::std::optional;
+using namespace ::android::hardware::identity;
 
 bool WritableIdentityCredential::initialize() {
     optional<vector<uint8_t>> keyPair = support::createEcKeyPair();
@@ -112,34 +67,32 @@ bool WritableIdentityCredential::initialize() {
 //       ensure the returned certificate chain satisfy the requirements listed in
 //       the docs for IWritableIdentityCredential::getAttestationCertificate()
 //
-Return<void> WritableIdentityCredential::getAttestationCertificate(
-        const hidl_vec<uint8_t>& /* attestationApplicationId */,
-        const hidl_vec<uint8_t>& /* attestationChallenge */,
-        getAttestationCertificate_cb _hidl_cb) {
+ndk::ScopedAStatus WritableIdentityCredential::getAttestationCertificate(
+        const vector<int8_t>& /*attestationApplicationId*/,
+        const vector<int8_t>& /*attestationChallenge*/, vector<Certificate>* outCertificateChain) {
     // For now, we dynamically generate an attestion key on each and every
     // request and use that to sign CredentialKey. In a real implementation this
     // would look very differently.
     optional<vector<uint8_t>> attestationKeyPair = support::createEcKeyPair();
     if (!attestationKeyPair) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error creating attestationKey"), {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED, "Error creating attestationKey"));
     }
 
     optional<vector<uint8_t>> attestationPubKey =
             support::ecKeyPairGetPublicKey(attestationKeyPair.value());
     if (!attestationPubKey) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error getting public part of attestationKey"),
-                 {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED,
+                "Error getting public part of attestationKey"));
     }
 
     optional<vector<uint8_t>> attestationPrivKey =
             support::ecKeyPairGetPrivateKey(attestationKeyPair.value());
     if (!attestationPrivKey) {
-        _hidl_cb(
-                support::result(ResultCode::FAILED, "Error getting private part of attestationKey"),
-                {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED,
+                "Error getting private part of attestationKey"));
     }
 
     string serialDecimal;
@@ -158,10 +111,9 @@ Return<void> WritableIdentityCredential::getAttestationCertificate(
             credentialPubKey_, attestationPrivKey.value(), serialDecimal, issuer, subject,
             validityNotBefore, validityNotAfter);
     if (!credentialPubKeyCertificate) {
-        _hidl_cb(support::result(ResultCode::FAILED,
-                                 "Error creating certificate for credentialPubKey"),
-                 {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED,
+                "Error creating certificate for credentialPubKey"));
     }
 
     // This is followed by a certificate for |attestationPubKey| self-signed by
@@ -173,10 +125,9 @@ Return<void> WritableIdentityCredential::getAttestationCertificate(
             attestationPubKey.value(), attestationPrivKey.value(), serialDecimal, issuer, subject,
             validityNotBefore, validityNotAfter);
     if (!attestationKeyCertificate) {
-        _hidl_cb(support::result(ResultCode::FAILED,
-                                 "Error creating certificate for attestationPubKey"),
-                 {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED,
+                "Error creating certificate for attestationPubKey"));
     }
 
     // Concatenate the certificates to form the chain.
@@ -189,19 +140,20 @@ Return<void> WritableIdentityCredential::getAttestationCertificate(
     optional<vector<vector<uint8_t>>> splitCertChain =
             support::certificateChainSplit(certificateChain);
     if (!splitCertChain) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error splitting certificate chain"), {});
-        return Void();
-    }
-    hidl_vec<hidl_vec<uint8_t>> ret;
-    ret.resize(splitCertChain.value().size());
-    std::copy(splitCertChain.value().begin(), splitCertChain.value().end(), ret.begin());
-    _hidl_cb(support::resultOK(), ret);
-    return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED, "Error splitting certificate chain"));
+    }
+    *outCertificateChain = vector<Certificate>();
+    for (const vector<uint8_t>& cert : splitCertChain.value()) {
+        Certificate c = Certificate();
+        c.encodedCertificate = byteStringToSigned(cert);
+        outCertificateChain->push_back(std::move(c));
+    }
+    return ndk::ScopedAStatus::ok();
 }
 
-Return<void> WritableIdentityCredential::startPersonalization(uint16_t accessControlProfileCount,
-                                                              const hidl_vec<uint16_t>& entryCounts,
-                                                              startPersonalization_cb _hidl_cb) {
+ndk::ScopedAStatus WritableIdentityCredential::startPersonalization(
+        int32_t accessControlProfileCount, const vector<int32_t>& entryCounts) {
     numAccessControlProfileRemaining_ = accessControlProfileCount;
     remainingEntryCounts_ = entryCounts;
     entryNameSpace_ = "";
@@ -210,29 +162,27 @@ Return<void> WritableIdentityCredential::startPersonalization(uint16_t accessCon
     signedDataNamespaces_ = cppbor::Map();
     signedDataCurrentNamespace_ = cppbor::Array();
 
-    _hidl_cb(support::resultOK());
-    return Void();
+    return ndk::ScopedAStatus::ok();
 }
 
-Return<void> WritableIdentityCredential::addAccessControlProfile(
-        uint16_t id, const hidl_vec<uint8_t>& readerCertificate, bool userAuthenticationRequired,
-        uint64_t timeoutMillis, uint64_t secureUserId, addAccessControlProfile_cb _hidl_cb) {
+ndk::ScopedAStatus WritableIdentityCredential::addAccessControlProfile(
+        int32_t id, const Certificate& readerCertificate, bool userAuthenticationRequired,
+        int64_t timeoutMillis, int64_t secureUserId,
+        SecureAccessControlProfile* outSecureAccessControlProfile) {
     SecureAccessControlProfile profile;
 
     if (numAccessControlProfileRemaining_ == 0) {
-        _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                 "numAccessControlProfileRemaining_ is 0 and expected non-zero"),
-                 profile);
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_INVALID_DATA,
+                "numAccessControlProfileRemaining_ is 0 and expected non-zero"));
     }
 
     // Spec requires if |userAuthenticationRequired| is false, then |timeoutMillis| must also
     // be zero.
     if (!userAuthenticationRequired && timeoutMillis != 0) {
-        _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                 "userAuthenticationRequired is false but timeout is non-zero"),
-                 profile);
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_INVALID_DATA,
+                "userAuthenticationRequired is false but timeout is non-zero"));
     }
 
     profile.id = id;
@@ -240,18 +190,19 @@ Return<void> WritableIdentityCredential::addAccessControlProfile(
     profile.userAuthenticationRequired = userAuthenticationRequired;
     profile.timeoutMillis = timeoutMillis;
     profile.secureUserId = secureUserId;
-    optional<vector<uint8_t>> mac =
-            support::secureAccessControlProfileCalcMac(profile, storageKey_);
+    optional<vector<uint8_t>> mac = secureAccessControlProfileCalcMac(profile, storageKey_);
     if (!mac) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error calculating MAC for profile"), profile);
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED, "Error calculating MAC for profile"));
     }
-    profile.mac = mac.value();
+    profile.mac = byteStringToSigned(mac.value());
 
     cppbor::Map profileMap;
     profileMap.add("id", profile.id);
-    if (profile.readerCertificate.size() > 0) {
-        profileMap.add("readerCertificate", cppbor::Bstr(profile.readerCertificate));
+    if (profile.readerCertificate.encodedCertificate.size() > 0) {
+        profileMap.add(
+                "readerCertificate",
+                cppbor::Bstr(byteStringToUnsigned(profile.readerCertificate.encodedCertificate)));
     }
     if (profile.userAuthenticationRequired) {
         profileMap.add("userAuthenticationRequired", profile.userAuthenticationRequired);
@@ -261,25 +212,24 @@ Return<void> WritableIdentityCredential::addAccessControlProfile(
 
     numAccessControlProfileRemaining_--;
 
-    _hidl_cb(support::resultOK(), profile);
-    return Void();
+    *outSecureAccessControlProfile = profile;
+    return ndk::ScopedAStatus::ok();
 }
 
-Return<void> WritableIdentityCredential::beginAddEntry(
-        const hidl_vec<uint16_t>& accessControlProfileIds, const hidl_string& nameSpace,
-        const hidl_string& name, uint32_t entrySize, beginAddEntry_cb _hidl_cb) {
+ndk::ScopedAStatus WritableIdentityCredential::beginAddEntry(
+        const vector<int32_t>& accessControlProfileIds, const string& nameSpace, const string& name,
+        int32_t entrySize) {
     if (numAccessControlProfileRemaining_ != 0) {
         LOG(ERROR) << "numAccessControlProfileRemaining_ is " << numAccessControlProfileRemaining_
                    << " and expected zero";
-        _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                 "numAccessControlProfileRemaining_ is %zd and expected zero",
-                                 numAccessControlProfileRemaining_));
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_INVALID_DATA,
+                "numAccessControlProfileRemaining_ is not zero"));
     }
 
     if (remainingEntryCounts_.size() == 0) {
-        _hidl_cb(support::result(ResultCode::INVALID_DATA, "No more namespaces to add to"));
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_INVALID_DATA, "No more namespaces to add to"));
     }
 
     // Handle initial beginEntry() call.
@@ -291,10 +241,9 @@ Return<void> WritableIdentityCredential::beginAddEntry(
     if (nameSpace != entryNameSpace_) {
         // Then check that all entries in the previous namespace have been added..
         if (remainingEntryCounts_[0] != 0) {
-            _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                     "New namespace but %d entries remain to be added",
-                                     int(remainingEntryCounts_[0])));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_DATA,
+                    "New namespace but a non-zero number of entries remain to be added"));
         }
         remainingEntryCounts_.erase(remainingEntryCounts_.begin());
 
@@ -305,15 +254,14 @@ Return<void> WritableIdentityCredential::beginAddEntry(
     } else {
         // Same namespace...
         if (remainingEntryCounts_[0] == 0) {
-            _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                     "Same namespace but no entries remain to be added"));
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_DATA,
+                    "Same namespace but no entries remain to be added"));
         }
         remainingEntryCounts_[0] -= 1;
     }
 
-    entryAdditionalData_ =
-            support::entryCreateAdditionalData(nameSpace, name, accessControlProfileIds);
+    entryAdditionalData_ = entryCreateAdditionalData(nameSpace, name, accessControlProfileIds);
 
     entryRemainingBytes_ = entrySize;
     entryNameSpace_ = nameSpace;
@@ -321,55 +269,45 @@ Return<void> WritableIdentityCredential::beginAddEntry(
     entryAccessControlProfileIds_ = accessControlProfileIds;
     entryBytes_.resize(0);
     // LOG(INFO) << "name=" << name << " entrySize=" << entrySize;
-
-    _hidl_cb(support::resultOK());
-    return Void();
+    return ndk::ScopedAStatus::ok();
 }
 
-Return<void> WritableIdentityCredential::addEntryValue(const hidl_vec<uint8_t>& content,
-                                                       addEntryValue_cb _hidl_cb) {
+ndk::ScopedAStatus WritableIdentityCredential::addEntryValue(const vector<int8_t>& contentS,
+                                                             vector<int8_t>* outEncryptedContent) {
+    auto content = byteStringToUnsigned(contentS);
     size_t contentSize = content.size();
 
     if (contentSize > IdentityCredentialStore::kGcmChunkSize) {
-        _hidl_cb(support::result(
-                         ResultCode::INVALID_DATA,
-                         "Passed in chunk of size %zd is bigger than kGcmChunkSize which is %zd",
-                         contentSize, IdentityCredentialStore::kGcmChunkSize),
-                 {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_INVALID_DATA,
+                "Passed in chunk of is bigger than kGcmChunkSize"));
     }
     if (contentSize > entryRemainingBytes_) {
-        _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                 "Passed in chunk of size %zd is bigger than remaining space "
-                                 "of size %zd",
-                                 contentSize, entryRemainingBytes_),
-                 {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_INVALID_DATA,
+                "Passed in chunk is bigger than remaining space"));
     }
 
     entryBytes_.insert(entryBytes_.end(), content.begin(), content.end());
     entryRemainingBytes_ -= contentSize;
     if (entryRemainingBytes_ > 0) {
         if (contentSize != IdentityCredentialStore::kGcmChunkSize) {
-            _hidl_cb(support::result(ResultCode::INVALID_DATA,
-                                     "Retrieved non-final chunk of size %zd but expected "
-                                     "kGcmChunkSize which is %zd",
-                                     contentSize, IdentityCredentialStore::kGcmChunkSize),
-                     {});
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_DATA,
+                    "Retrieved non-final chunk which isn't kGcmChunkSize"));
         }
     }
 
     optional<vector<uint8_t>> nonce = support::getRandom(12);
     if (!nonce) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error getting nonce"), {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED, "Error getting nonce"));
     }
     optional<vector<uint8_t>> encryptedContent =
             support::encryptAes128Gcm(storageKey_, nonce.value(), content, entryAdditionalData_);
     if (!encryptedContent) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error encrypting content"), {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED, "Error encrypting content"));
     }
 
     if (entryRemainingBytes_ == 0) {
@@ -377,8 +315,8 @@ Return<void> WritableIdentityCredential::addEntryValue(const hidl_vec<uint8_t>&
         // CBOR).
         auto [item, _, message] = cppbor::parse(entryBytes_);
         if (item == nullptr) {
-            _hidl_cb(support::result(ResultCode::INVALID_DATA, "Data is not valid CBOR"), {});
-            return Void();
+            return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                    IIdentityCredentialStore::STATUS_INVALID_DATA, "Data is not valid CBOR"));
         }
         cppbor::Map entryMap;
         entryMap.add("name", entryName_);
@@ -391,11 +329,56 @@ Return<void> WritableIdentityCredential::addEntryValue(const hidl_vec<uint8_t>&
         signedDataCurrentNamespace_.add(std::move(entryMap));
     }
 
-    _hidl_cb(support::resultOK(), encryptedContent.value());
-    return Void();
+    *outEncryptedContent = byteStringToSigned(encryptedContent.value());
+    return ndk::ScopedAStatus::ok();
+}
+
+// Writes CBOR-encoded structure to |credentialKeys| containing |storageKey| and
+// |credentialPrivKey|.
+static bool generateCredentialKeys(const vector<uint8_t>& storageKey,
+                                   const vector<uint8_t>& credentialPrivKey,
+                                   vector<uint8_t>& credentialKeys) {
+    if (storageKey.size() != 16) {
+        LOG(ERROR) << "Size of storageKey is not 16";
+        return false;
+    }
+
+    cppbor::Array array;
+    array.add(cppbor::Bstr(storageKey));
+    array.add(cppbor::Bstr(credentialPrivKey));
+    credentialKeys = array.encode();
+    return true;
+}
+
+// Writes CBOR-encoded structure to |credentialData| containing |docType|,
+// |testCredential| and |credentialKeys|. The latter element will be stored in
+// encrypted form, using |hardwareBoundKey| as the encryption key.
+bool generateCredentialData(const vector<uint8_t>& hardwareBoundKey, const string& docType,
+                            bool testCredential, const vector<uint8_t>& credentialKeys,
+                            vector<uint8_t>& credentialData) {
+    optional<vector<uint8_t>> nonce = support::getRandom(12);
+    if (!nonce) {
+        LOG(ERROR) << "Error getting random";
+        return false;
+    }
+    vector<uint8_t> docTypeAsVec(docType.begin(), docType.end());
+    optional<vector<uint8_t>> credentialBlob = support::encryptAes128Gcm(
+            hardwareBoundKey, nonce.value(), credentialKeys, docTypeAsVec);
+    if (!credentialBlob) {
+        LOG(ERROR) << "Error encrypting CredentialKeys blob";
+        return false;
+    }
+
+    cppbor::Array array;
+    array.add(docType);
+    array.add(testCredential);
+    array.add(cppbor::Bstr(credentialBlob.value()));
+    credentialData = array.encode();
+    return true;
 }
 
-Return<void> WritableIdentityCredential::finishAddingEntries(finishAddingEntries_cb _hidl_cb) {
+ndk::ScopedAStatus WritableIdentityCredential::finishAddingEntries(
+        vector<int8_t>* outCredentialData, vector<int8_t>* outProofOfProvisioningSignature) {
     if (signedDataCurrentNamespace_.size() > 0) {
         signedDataNamespaces_.add(entryNameSpace_, std::move(signedDataCurrentNamespace_));
     }
@@ -412,29 +395,27 @@ Return<void> WritableIdentityCredential::finishAddingEntries(finishAddingEntries
                                                                  {},           // additionalData
                                                                  {});          // certificateChain
     if (!signature) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error signing data"), {}, {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED, "Error signing data"));
     }
 
     vector<uint8_t> credentialKeys;
     if (!generateCredentialKeys(storageKey_, credentialPrivKey_, credentialKeys)) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error generating CredentialKeys"), {}, {});
-        return Void();
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED, "Error generating CredentialKeys"));
     }
 
     vector<uint8_t> credentialData;
-    if (!generateCredentialData(testCredential_ ? support::getTestHardwareBoundKey()
-                                                : support::getHardwareBoundKey(),
-                                docType_, testCredential_, credentialKeys, credentialData)) {
-        _hidl_cb(support::result(ResultCode::FAILED, "Error generating CredentialData"), {}, {});
-        return Void();
+    if (!generateCredentialData(
+                testCredential_ ? support::getTestHardwareBoundKey() : getHardwareBoundKey(),
+                docType_, testCredential_, credentialKeys, credentialData)) {
+        return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage(
+                IIdentityCredentialStore::STATUS_FAILED, "Error generating CredentialData"));
     }
 
-    _hidl_cb(support::resultOK(), credentialData, signature.value());
-    return Void();
+    *outCredentialData = byteStringToSigned(credentialData);
+    *outProofOfProvisioningSignature = byteStringToSigned(signature.value());
+    return ndk::ScopedAStatus::ok();
 }
 
-}  // namespace implementation
-}  // namespace identity
-}  // namespace hardware
-}  // namespace android
+}  // namespace aidl::android::hardware::identity
diff --git a/identity/aidl/default/WritableIdentityCredential.h b/identity/aidl/default/WritableIdentityCredential.h
new file mode 100644
index 0000000000..b380f897a1
--- /dev/null
+++ b/identity/aidl/default/WritableIdentityCredential.h
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2019, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_IDENTITY_WRITABLEIDENTITYCREDENTIAL_H
+#define ANDROID_HARDWARE_IDENTITY_WRITABLEIDENTITYCREDENTIAL_H
+
+#include <aidl/android/hardware/identity/BnWritableIdentityCredential.h>
+#include <android/hardware/identity/support/IdentityCredentialSupport.h>
+
+#include <cppbor.h>
+
+namespace aidl::android::hardware::identity {
+
+using ::std::string;
+using ::std::vector;
+
+class WritableIdentityCredential : public BnWritableIdentityCredential {
+  public:
+    WritableIdentityCredential(const string& docType, bool testCredential)
+        : docType_(docType), testCredential_(testCredential) {}
+
+    // Creates the Credential Key. Returns false on failure. Must be called
+    // right after construction.
+    bool initialize();
+
+    // Methods from IWritableIdentityCredential follow.
+    ndk::ScopedAStatus getAttestationCertificate(const vector<int8_t>& attestationApplicationId,
+                                                 const vector<int8_t>& attestationChallenge,
+                                                 vector<Certificate>* outCertificateChain) override;
+
+    ndk::ScopedAStatus startPersonalization(int32_t accessControlProfileCount,
+                                            const vector<int32_t>& entryCounts) override;
+
+    ndk::ScopedAStatus addAccessControlProfile(
+            int32_t id, const Certificate& readerCertificate, bool userAuthenticationRequired,
+            int64_t timeoutMillis, int64_t secureUserId,
+            SecureAccessControlProfile* outSecureAccessControlProfile) override;
+
+    ndk::ScopedAStatus beginAddEntry(const vector<int32_t>& accessControlProfileIds,
+                                     const string& nameSpace, const string& name,
+                                     int32_t entrySize) override;
+
+    ndk::ScopedAStatus addEntryValue(const vector<int8_t>& content,
+                                     vector<int8_t>* outEncryptedContent) override;
+
+    ndk::ScopedAStatus finishAddingEntries(
+            vector<int8_t>* outCredentialData,
+            vector<int8_t>* outProofOfProvisioningSignature) override;
+
+    // private:
+    string docType_;
+    bool testCredential_;
+
+    // These are set in initialize().
+    vector<uint8_t> storageKey_;
+    vector<uint8_t> credentialPrivKey_;
+    vector<uint8_t> credentialPubKey_;
+
+    // These fields are initialized during startPersonalization()
+    size_t numAccessControlProfileRemaining_;
+    vector<int32_t> remainingEntryCounts_;
+    cppbor::Array signedDataAccessControlProfiles_;
+    cppbor::Map signedDataNamespaces_;
+    cppbor::Array signedDataCurrentNamespace_;
+
+    // These fields are initialized during beginAddEntry()
+    size_t entryRemainingBytes_;
+    vector<uint8_t> entryAdditionalData_;
+    string entryNameSpace_;
+    string entryName_;
+    vector<int32_t> entryAccessControlProfileIds_;
+    vector<uint8_t> entryBytes_;
+};
+
+}  // namespace aidl::android::hardware::identity
+
+#endif  // ANDROID_HARDWARE_IDENTITY_WRITABLEIDENTITYCREDENTIAL_H
diff --git a/identity/aidl/default/identity-default.rc b/identity/aidl/default/identity-default.rc
new file mode 100644
index 0000000000..d3b62c1042
--- /dev/null
+++ b/identity/aidl/default/identity-default.rc
@@ -0,0 +1,3 @@
+service vendor.identity-default /vendor/bin/hw/android.hardware.identity-service.example
+    class hal
+    user nobody
diff --git a/identity/aidl/default/identity-default.xml b/identity/aidl/default/identity-default.xml
new file mode 100644
index 0000000000..a47d354ce5
--- /dev/null
+++ b/identity/aidl/default/identity-default.xml
@@ -0,0 +1,9 @@
+<manifest version="1.0" type="device">
+    <hal format="aidl">
+        <name>android.hardware.identity</name>
+        <interface>
+            <name>IIdentityCredentialStore</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
+</manifest>
diff --git a/identity/aidl/default/service.cpp b/identity/aidl/default/service.cpp
new file mode 100644
index 0000000000..f05c615001
--- /dev/null
+++ b/identity/aidl/default/service.cpp
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2019, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "android.hardware.identity-service"
+
+#include <android-base/logging.h>
+#include <android/binder_manager.h>
+#include <android/binder_process.h>
+
+#include "IdentityCredentialStore.h"
+
+using aidl::android::hardware::identity::IdentityCredentialStore;
+
+int main() {
+    ABinderProcess_setThreadPoolMaxThreadCount(0);
+    std::shared_ptr<IdentityCredentialStore> store =
+            ndk::SharedRefBase::make<IdentityCredentialStore>();
+
+    const std::string instance = std::string() + IdentityCredentialStore::descriptor + "/default";
+    LOG(INFO) << "instance: " << instance;
+    binder_status_t status = AServiceManager_addService(store->asBinder().get(), instance.c_str());
+    CHECK(status == STATUS_OK);
+
+    ABinderProcess_joinThreadPool();
+    return EXIT_FAILURE;  // should not reach
+}
diff --git a/identity/aidl/vts/Android.bp b/identity/aidl/vts/Android.bp
new file mode 100644
index 0000000000..21ff440075
--- /dev/null
+++ b/identity/aidl/vts/Android.bp
@@ -0,0 +1,21 @@
+cc_test {
+    name: "VtsHalIdentityTargetTest",
+    defaults: [
+        "VtsHalTargetTestDefaults",
+        "use_libaidlvintf_gtest_helper_static",
+    ],
+    srcs: ["VtsHalIdentityTargetTest.cpp"],
+    shared_libs: [
+        "libbinder",
+        "libcppbor",
+        "android.hardware.identity-support-lib",
+    ],
+    static_libs: [
+        "android.hardware.identity-cpp",
+        "android.hardware.keymaster-cpp",
+    ],
+    test_suites: [
+        "general-tests",
+        "vts-core",
+    ],
+}
diff --git a/identity/1.0/vts/functional/VtsHalIdentityCredentialTargetTest.cpp b/identity/aidl/vts/VtsHalIdentityTargetTest.cpp
index 88b06df046..5abe5a2f66 100644
--- a/identity/1.0/vts/functional/VtsHalIdentityCredentialTargetTest.cpp
+++ b/identity/aidl/vts/VtsHalIdentityTargetTest.cpp
@@ -13,62 +13,56 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+#define LOG_TAG "VtsHalIdentityTargetTest"
 
-#define LOG_TAG "IdentityCredentialHidlHalTest"
-
-#include <map>
-
+#include <aidl/Gtest.h>
+#include <aidl/Vintf.h>
 #include <android-base/logging.h>
-#include <android/hardware/identity/1.0/IIdentityCredentialStore.h>
-#include <android/hardware/identity/1.0/types.h>
+#include <android/hardware/identity/IIdentityCredentialStore.h>
 #include <android/hardware/identity/support/IdentityCredentialSupport.h>
-
+#include <binder/IServiceManager.h>
+#include <binder/ProcessState.h>
 #include <cppbor.h>
 #include <cppbor_parse.h>
 #include <gtest/gtest.h>
-#include <hidl/GtestPrinter.h>
-#include <hidl/ServiceManagement.h>
+#include <future>
+#include <map>
+
+namespace android::hardware::identity {
 
 using std::map;
 using std::optional;
 using std::string;
 using std::vector;
 
-namespace android {
-namespace hardware {
-namespace identity {
-namespace test {
+using ::android::sp;
+using ::android::String16;
+using ::android::binder::Status;
 
-using ::android::hardware::identity::V1_0::IIdentityCredential;
-using ::android::hardware::identity::V1_0::IIdentityCredentialStore;
-using ::android::hardware::identity::V1_0::IWritableIdentityCredential;
-using ::android::hardware::identity::V1_0::Result;
-using ::android::hardware::identity::V1_0::ResultCode;
-using ::android::hardware::identity::V1_0::SecureAccessControlProfile;
-using ::android::hardware::keymaster::V4_0::HardwareAuthToken;
+using ::android::hardware::keymaster::HardwareAuthToken;
 
 // ---------------------------------------------------------------------------
 // Test Data.
 // ---------------------------------------------------------------------------
 
 struct TestEntryData {
-    TestEntryData(string nameSpace, string name, vector<uint16_t> profileIds)
+    TestEntryData(string nameSpace, string name, vector<int32_t> profileIds)
         : nameSpace(nameSpace), name(name), profileIds(profileIds) {}
 
-    TestEntryData(string nameSpace, string name, const string& value, vector<uint16_t> profileIds)
+    TestEntryData(string nameSpace, string name, const string& value, vector<int32_t> profileIds)
         : TestEntryData(nameSpace, name, profileIds) {
         valueCbor = cppbor::Tstr(((const char*)value.data())).encode();
     }
     TestEntryData(string nameSpace, string name, const vector<uint8_t>& value,
-                  vector<uint16_t> profileIds)
+                  vector<int32_t> profileIds)
         : TestEntryData(nameSpace, name, profileIds) {
         valueCbor = cppbor::Bstr(value).encode();
     }
-    TestEntryData(string nameSpace, string name, bool value, vector<uint16_t> profileIds)
+    TestEntryData(string nameSpace, string name, bool value, vector<int32_t> profileIds)
         : TestEntryData(nameSpace, name, profileIds) {
         valueCbor = cppbor::Bool(value).encode();
     }
-    TestEntryData(string nameSpace, string name, int64_t value, vector<uint16_t> profileIds)
+    TestEntryData(string nameSpace, string name, int64_t value, vector<int32_t> profileIds)
         : TestEntryData(nameSpace, name, profileIds) {
         if (value >= 0) {
             valueCbor = cppbor::Uint(value).encode();
@@ -80,63 +74,38 @@ struct TestEntryData {
     string nameSpace;
     string name;
     vector<uint8_t> valueCbor;
-    vector<uint16_t> profileIds;
+    vector<int32_t> profileIds;
 };
 
 struct TestProfile {
     uint16_t id;
-    hidl_vec<uint8_t> readerCertificate;
+    vector<uint8_t> readerCertificate;
     bool userAuthenticationRequired;
     uint64_t timeoutMillis;
 };
 
-/************************************
- *   TEST DATA FOR AUTHENTICATION
- ************************************/
-// Test authentication token for user authentication
+// ----------------------------------------------------------------
 
-class IdentityCredentialStoreHidlTest : public ::testing::TestWithParam<std::string> {
+class IdentityAidl : public testing::TestWithParam<std::string> {
   public:
     virtual void SetUp() override {
-        string serviceName = GetParam();
-        ASSERT_FALSE(serviceName.empty());
-        credentialStore_ = IIdentityCredentialStore::getService(serviceName);
+        credentialStore_ = android::waitForDeclaredService<IIdentityCredentialStore>(
+                String16(GetParam().c_str()));
         ASSERT_NE(credentialStore_, nullptr);
-
-        credentialStore_->getHardwareInformation(
-                [&](const Result& result, const hidl_string& credentialStoreName,
-                    const hidl_string& credentialStoreAuthorName, uint32_t chunkSize,
-                    bool /* isDirectAccess */,
-                    const hidl_vec<hidl_string> /* supportedDocTypes */) {
-                    EXPECT_EQ("", result.message);
-                    ASSERT_EQ(ResultCode::OK, result.code);
-                    ASSERT_GT(credentialStoreName.size(), 0u);
-                    ASSERT_GT(credentialStoreAuthorName.size(), 0u);
-                    ASSERT_GE(chunkSize, 256u);  // Chunk sizes < APDU buffer won't be supported
-                    dataChunkSize_ = chunkSize;
-                });
     }
-    virtual void TearDown() override {}
-
-    uint32_t dataChunkSize_ = 0;
 
     sp<IIdentityCredentialStore> credentialStore_;
 };
 
-TEST_P(IdentityCredentialStoreHidlTest, HardwareConfiguration) {
-    credentialStore_->getHardwareInformation(
-            [&](const Result& result, const hidl_string& credentialStoreName,
-                const hidl_string& credentialStoreAuthorName, uint32_t chunkSize,
-                bool /* isDirectAccess */, const hidl_vec<hidl_string> /* supportedDocTypes */) {
-                EXPECT_EQ("", result.message);
-                ASSERT_EQ(ResultCode::OK, result.code);
-                ASSERT_GT(credentialStoreName.size(), 0u);
-                ASSERT_GT(credentialStoreAuthorName.size(), 0u);
-                ASSERT_GE(chunkSize, 256u);  // Chunk sizes < APDU buffer won't be supported
-            });
+TEST_P(IdentityAidl, hardwareInformation) {
+    HardwareInformation info;
+    ASSERT_TRUE(credentialStore_->getHardwareInformation(&info).isOk());
+    ASSERT_GT(info.credentialStoreName.size(), 0);
+    ASSERT_GT(info.credentialStoreAuthorName.size(), 0);
+    ASSERT_GE(info.dataChunkSize, 256);
 }
 
-TEST_P(IdentityCredentialStoreHidlTest, createAndRetrieveCredential) {
+TEST_P(IdentityAidl, createAndRetrieveCredential) {
     // First, generate a key-pair for the reader since its public key will be
     // part of the request data.
     optional<vector<uint8_t>> readerKeyPKCS8 = support::createEcKeyPair();
@@ -168,75 +137,59 @@ TEST_P(IdentityCredentialStoreHidlTest, createAndRetrieveCredential) {
                                               // Profile 1 (no authentication)
                                               {1, {}, false, 0}};
 
-    HardwareAuthToken authToken = {};
+    HardwareAuthToken authToken;
 
     // Here's the actual test data:
     const vector<TestEntryData> testEntries = {
-            {"PersonalData", "Last name", string("Turing"), vector<uint16_t>{0, 1}},
-            {"PersonalData", "Birth date", string("19120623"), vector<uint16_t>{0, 1}},
-            {"PersonalData", "First name", string("Alan"), vector<uint16_t>{0, 1}},
+            {"PersonalData", "Last name", string("Turing"), vector<int32_t>{0, 1}},
+            {"PersonalData", "Birth date", string("19120623"), vector<int32_t>{0, 1}},
+            {"PersonalData", "First name", string("Alan"), vector<int32_t>{0, 1}},
             {"PersonalData", "Home address", string("Maida Vale, London, England"),
-             vector<uint16_t>{0}},
-            {"Image", "Portrait image", portraitImage, vector<uint16_t>{0, 1}},
+             vector<int32_t>{0}},
+            {"Image", "Portrait image", portraitImage, vector<int32_t>{0, 1}},
     };
-    const vector<uint16_t> testEntriesEntryCounts = {static_cast<uint16_t>(testEntries.size() - 1),
-                                                     1u};
+    const vector<int32_t> testEntriesEntryCounts = {static_cast<int32_t>(testEntries.size() - 1),
+                                                    1u};
+    HardwareInformation hwInfo;
+    ASSERT_TRUE(credentialStore_->getHardwareInformation(&hwInfo).isOk());
 
     string cborPretty;
     sp<IWritableIdentityCredential> writableCredential;
-
-    hidl_vec<uint8_t> empty{0};
-
     string docType = "org.iso.18013-5.2019.mdl";
     bool testCredential = true;
-    Result result;
-    credentialStore_->createCredential(
-            docType, testCredential,
-            [&](const Result& _result, const sp<IWritableIdentityCredential>& _writableCredential) {
-                result = _result;
-                writableCredential = _writableCredential;
-            });
-    EXPECT_EQ("", result.message);
-    ASSERT_EQ(ResultCode::OK, result.code);
+    ASSERT_TRUE(credentialStore_->createCredential(docType, testCredential, &writableCredential)
+                        .isOk());
     ASSERT_NE(writableCredential, nullptr);
 
     string challenge = "attestationChallenge";
     // TODO: set it to something random and check it's in the cert chain
     vector<uint8_t> attestationApplicationId = {};
     vector<uint8_t> attestationChallenge(challenge.begin(), challenge.end());
-    vector<uint8_t> attestationCertificate;
-    writableCredential->getAttestationCertificate(
-            attestationApplicationId, attestationChallenge,
-            [&](const Result& _result, const hidl_vec<hidl_vec<uint8_t>>& _splitCertChain) {
-                result = _result;
-                vector<vector<uint8_t>> splitCerts;
-                std::copy(_splitCertChain.begin(), _splitCertChain.end(),
-                          std::back_inserter(splitCerts));
-                attestationCertificate = support::certificateChainJoin(splitCerts);
-            });
-    EXPECT_EQ("", result.message);
-    ASSERT_EQ(ResultCode::OK, result.code);
-
-    writableCredential->startPersonalization(testProfiles.size(), testEntriesEntryCounts,
-                                             [&](const Result& _result) { result = _result; });
-    EXPECT_EQ("", result.message);
-    ASSERT_EQ(ResultCode::OK, result.code);
+    vector<Certificate> attestationCertificates;
+    ASSERT_TRUE(writableCredential
+                        ->getAttestationCertificate(attestationApplicationId, attestationChallenge,
+                                                    &attestationCertificates)
+                        .isOk());
+    ASSERT_GE(attestationCertificates.size(), 2);
+
+    ASSERT_TRUE(
+            writableCredential->startPersonalization(testProfiles.size(), testEntriesEntryCounts)
+                    .isOk());
 
     vector<SecureAccessControlProfile> returnedSecureProfiles;
     for (const auto& testProfile : testProfiles) {
         SecureAccessControlProfile profile;
-        writableCredential->addAccessControlProfile(
-                testProfile.id, testProfile.readerCertificate,
-                testProfile.userAuthenticationRequired, testProfile.timeoutMillis,
-                0,  // secureUserId
-                [&](const Result& _result, const SecureAccessControlProfile& _profile) {
-                    result = _result;
-                    profile = _profile;
-                });
-        EXPECT_EQ("", result.message);
-        ASSERT_EQ(ResultCode::OK, result.code);
+        Certificate cert;
+        cert.encodedCertificate = testProfile.readerCertificate;
+        ASSERT_TRUE(writableCredential
+                            ->addAccessControlProfile(testProfile.id, cert,
+                                                      testProfile.userAuthenticationRequired,
+                                                      testProfile.timeoutMillis,
+                                                      0,  // secureUserId
+                                                      &profile)
+                            .isOk());
         ASSERT_EQ(testProfile.id, profile.id);
-        ASSERT_EQ(testProfile.readerCertificate, profile.readerCertificate);
+        ASSERT_EQ(testProfile.readerCertificate, profile.readerCertificate.encodedCertificate);
         ASSERT_EQ(testProfile.userAuthenticationRequired, profile.userAuthenticationRequired);
         ASSERT_EQ(testProfile.timeoutMillis, profile.timeoutMillis);
         ASSERT_EQ(support::kAesGcmTagSize + support::kAesGcmIvSize, profile.mac.size());
@@ -248,38 +201,28 @@ TEST_P(IdentityCredentialStoreHidlTest, createAndRetrieveCredential) {
     map<const TestEntryData*, vector<vector<uint8_t>>> encryptedBlobs;
 
     for (const auto& entry : testEntries) {
-        vector<vector<uint8_t>> chunks = support::chunkVector(entry.valueCbor, dataChunkSize_);
+        vector<vector<uint8_t>> chunks =
+                support::chunkVector(entry.valueCbor, hwInfo.dataChunkSize);
 
-        writableCredential->beginAddEntry(entry.profileIds, entry.nameSpace, entry.name,
-                                          entry.valueCbor.size(),
-                                          [&](const Result& _result) { result = _result; });
-        EXPECT_EQ("", result.message);
-        ASSERT_EQ(ResultCode::OK, result.code);
+        ASSERT_TRUE(writableCredential
+                            ->beginAddEntry(entry.profileIds, entry.nameSpace, entry.name,
+                                            entry.valueCbor.size())
+                            .isOk());
 
         vector<vector<uint8_t>> encryptedChunks;
         for (const auto& chunk : chunks) {
-            writableCredential->addEntryValue(
-                    chunk, [&](const Result& result, hidl_vec<uint8_t> encryptedContent) {
-                        EXPECT_EQ("", result.message);
-                        ASSERT_EQ(ResultCode::OK, result.code);
-                        ASSERT_GT(encryptedContent.size(), 0u);
-                        encryptedChunks.push_back(encryptedContent);
-                    });
+            vector<uint8_t> encryptedChunk;
+            ASSERT_TRUE(writableCredential->addEntryValue(chunk, &encryptedChunk).isOk());
+            encryptedChunks.push_back(encryptedChunk);
         }
         encryptedBlobs[&entry] = encryptedChunks;
     }
 
     vector<uint8_t> credentialData;
     vector<uint8_t> proofOfProvisioningSignature;
-    writableCredential->finishAddingEntries(
-            [&](const Result& _result, const hidl_vec<uint8_t>& _credentialData,
-                const hidl_vec<uint8_t>& _proofOfProvisioningSignature) {
-                result = _result;
-                credentialData = _credentialData;
-                proofOfProvisioningSignature = _proofOfProvisioningSignature;
-            });
-    EXPECT_EQ("", result.message);
-    ASSERT_EQ(ResultCode::OK, result.code);
+    ASSERT_TRUE(
+            writableCredential->finishAddingEntries(&credentialData, &proofOfProvisioningSignature)
+                    .isOk());
 
     optional<vector<uint8_t>> proofOfProvisioning =
             support::coseSignGetPayload(proofOfProvisioningSignature);
@@ -334,7 +277,7 @@ TEST_P(IdentityCredentialStoreHidlTest, createAndRetrieveCredential) {
             cborPretty);
 
     optional<vector<uint8_t>> credentialPubKey =
-            support::certificateChainGetTopMostKey(attestationCertificate);
+            support::certificateChainGetTopMostKey(attestationCertificates[0].encodedCertificate);
     ASSERT_TRUE(credentialPubKey);
     EXPECT_TRUE(support::coseCheckEcDsaSignature(proofOfProvisioningSignature,
                                                  {},  // Additional data
@@ -344,32 +287,21 @@ TEST_P(IdentityCredentialStoreHidlTest, createAndRetrieveCredential) {
     // Now that the credential has been provisioned, read it back and check the
     // correct data is returned.
     sp<IIdentityCredential> credential;
-    credentialStore_->getCredential(
-            credentialData, [&](const Result& _result, const sp<IIdentityCredential>& _credential) {
-                result = _result;
-                credential = _credential;
-            });
-    EXPECT_EQ("", result.message);
-    ASSERT_EQ(ResultCode::OK, result.code);
+    ASSERT_TRUE(credentialStore_
+                        ->getCredential(
+                                CipherSuite::CIPHERSUITE_ECDHE_HKDF_ECDSA_WITH_AES_256_GCM_SHA256,
+                                credentialData, &credential)
+                        .isOk());
     ASSERT_NE(credential, nullptr);
 
     optional<vector<uint8_t>> readerEphemeralKeyPair = support::createEcKeyPair();
     ASSERT_TRUE(readerEphemeralKeyPair);
     optional<vector<uint8_t>> readerEphemeralPublicKey =
             support::ecKeyPairGetPublicKey(readerEphemeralKeyPair.value());
-    credential->setReaderEphemeralPublicKey(readerEphemeralPublicKey.value(),
-                                            [&](const Result& _result) { result = _result; });
-    EXPECT_EQ("", result.message);
-    ASSERT_EQ(ResultCode::OK, result.code);
+    ASSERT_TRUE(credential->setReaderEphemeralPublicKey(readerEphemeralPublicKey.value()).isOk());
 
     vector<uint8_t> ephemeralKeyPair;
-    credential->createEphemeralKeyPair(
-            [&](const Result& _result, const hidl_vec<uint8_t>& _ephemeralKeyPair) {
-                result = _result;
-                ephemeralKeyPair = _ephemeralKeyPair;
-            });
-    EXPECT_EQ("", result.message);
-    ASSERT_EQ(ResultCode::OK, result.code);
+    ASSERT_TRUE(credential->createEphemeralKeyPair(&ephemeralKeyPair).isOk());
     optional<vector<uint8_t>> ephemeralPublicKey = support::ecKeyPairGetPublicKey(ephemeralKeyPair);
 
     // Calculate requestData field and sign it with the reader key.
@@ -420,19 +352,17 @@ TEST_P(IdentityCredentialStoreHidlTest, createAndRetrieveCredential) {
                                    readerCertificate.value());
     ASSERT_TRUE(readerSignature);
 
-    credential->startRetrieval(returnedSecureProfiles, authToken, itemsRequestBytes,
-                               sessionTranscriptBytes, readerSignature.value(),
-                               testEntriesEntryCounts,
-                               [&](const Result& _result) { result = _result; });
-    EXPECT_EQ("", result.message);
-    ASSERT_EQ(ResultCode::OK, result.code);
+    ASSERT_TRUE(credential
+                        ->startRetrieval(returnedSecureProfiles, authToken, itemsRequestBytes,
+                                         sessionTranscriptBytes, readerSignature.value(),
+                                         testEntriesEntryCounts)
+                        .isOk());
 
     for (const auto& entry : testEntries) {
-        credential->startRetrieveEntryValue(entry.nameSpace, entry.name, entry.valueCbor.size(),
-                                            entry.profileIds,
-                                            [&](const Result& _result) { result = _result; });
-        EXPECT_EQ("", result.message);
-        ASSERT_EQ(ResultCode::OK, result.code);
+        ASSERT_TRUE(credential
+                            ->startRetrieveEntryValue(entry.nameSpace, entry.name,
+                                                      entry.valueCbor.size(), entry.profileIds)
+                            .isOk());
 
         auto it = encryptedBlobs.find(&entry);
         ASSERT_NE(it, encryptedBlobs.end());
@@ -441,13 +371,7 @@ TEST_P(IdentityCredentialStoreHidlTest, createAndRetrieveCredential) {
         vector<uint8_t> content;
         for (const auto& encryptedChunk : encryptedChunks) {
             vector<uint8_t> chunk;
-            credential->retrieveEntryValue(
-                    encryptedChunk, [&](const Result& _result, const hidl_vec<uint8_t>& _chunk) {
-                        result = _result;
-                        chunk = _chunk;
-                    });
-            EXPECT_EQ("", result.message);
-            ASSERT_EQ(ResultCode::OK, result.code);
+            ASSERT_TRUE(credential->retrieveEntryValue(encryptedChunk, &chunk).isOk());
             content.insert(content.end(), chunk.begin(), chunk.end());
         }
         EXPECT_EQ(content, entry.valueCbor);
@@ -455,28 +379,12 @@ TEST_P(IdentityCredentialStoreHidlTest, createAndRetrieveCredential) {
 
     // Generate the key that will be used to sign AuthenticatedData.
     vector<uint8_t> signingKeyBlob;
-    vector<uint8_t> signingKeyCertificate;
-    credential->generateSigningKeyPair([&](const Result& _result,
-                                           const hidl_vec<uint8_t> _signingKeyBlob,
-                                           const hidl_vec<uint8_t> _signingKeyCertificate) {
-        result = _result;
-        signingKeyBlob = _signingKeyBlob;
-        signingKeyCertificate = _signingKeyCertificate;
-    });
-    EXPECT_EQ("", result.message);
-    ASSERT_EQ(ResultCode::OK, result.code);
+    Certificate signingKeyCertificate;
+    ASSERT_TRUE(credential->generateSigningKeyPair(&signingKeyBlob, &signingKeyCertificate).isOk());
 
     vector<uint8_t> mac;
     vector<uint8_t> deviceNameSpacesBytes;
-    credential->finishRetrieval(signingKeyBlob,
-                                [&](const Result& _result, const hidl_vec<uint8_t> _mac,
-                                    const hidl_vec<uint8_t> _deviceNameSpacesBytes) {
-                                    result = _result;
-                                    mac = _mac;
-                                    deviceNameSpacesBytes = _deviceNameSpacesBytes;
-                                });
-    EXPECT_EQ("", result.message);
-    ASSERT_EQ(ResultCode::OK, result.code);
+    ASSERT_TRUE(credential->finishRetrieval(signingKeyBlob, &mac, &deviceNameSpacesBytes).isOk());
     cborPretty = support::cborPrettyPrint(deviceNameSpacesBytes, 32, {});
     ASSERT_EQ(
             "{\n"
@@ -501,7 +409,7 @@ TEST_P(IdentityCredentialStoreHidlTest, createAndRetrieveCredential) {
     deviceAuthentication.add(cppbor::Semantic(24, deviceNameSpacesBytes));
     vector<uint8_t> encodedDeviceAuthentication = deviceAuthentication.encode();
     optional<vector<uint8_t>> signingPublicKey =
-            support::certificateChainGetTopMostKey(signingKeyCertificate);
+            support::certificateChainGetTopMostKey(signingKeyCertificate.encodedCertificate);
     EXPECT_TRUE(signingPublicKey);
 
     // Derive the key used for MACing.
@@ -521,12 +429,18 @@ TEST_P(IdentityCredentialStoreHidlTest, createAndRetrieveCredential) {
     EXPECT_EQ(mac, calculatedMac);
 }
 
-INSTANTIATE_TEST_SUITE_P(PerInstance, IdentityCredentialStoreHidlTest,
-                         testing::ValuesIn(android::hardware::getAllHalInstanceNames(
-                                 IIdentityCredentialStore::descriptor)),
-                         android::hardware::PrintInstanceNameToString);
+INSTANTIATE_TEST_SUITE_P(
+        Identity, IdentityAidl,
+        testing::ValuesIn(android::getAidlHalInstanceNames(IIdentityCredentialStore::descriptor)),
+        android::PrintInstanceNameToString);
+// INSTANTIATE_TEST_SUITE_P(Identity, IdentityAidl,
+// testing::Values("android.hardware.identity.IIdentityCredentialStore/default"));
+
+}  // namespace android::hardware::identity
 
-}  // namespace test
-}  // namespace identity
-}  // namespace hardware
-}  // namespace android
+int main(int argc, char** argv) {
+    ::testing::InitGoogleTest(&argc, argv);
+    ::android::ProcessState::self()->setThreadPoolMaxThreadCount(1);
+    ::android::ProcessState::self()->startThreadPool();
+    return RUN_ALL_TESTS();
+}
diff --git a/identity/support/Android.bp b/identity/support/Android.bp
index 38dc10b485..7b4546b20f 100644
--- a/identity/support/Android.bp
+++ b/identity/support/Android.bp
@@ -23,7 +23,6 @@ cc_library {
         "include",
     ],
     shared_libs: [
-        "android.hardware.identity@1.0",
         "libcrypto",
         "libbase",
         "libhidlbase",
@@ -41,7 +40,6 @@ cc_test {
     ],
     shared_libs: [
         "android.hardware.identity-support-lib",
-        "android.hardware.identity@1.0",
         "libcrypto",
         "libbase",
         "libhidlbase",
diff --git a/identity/support/include/android/hardware/identity/support/IdentityCredentialSupport.h b/identity/support/include/android/hardware/identity/support/IdentityCredentialSupport.h
index 485571a775..4533ad946c 100644
--- a/identity/support/include/android/hardware/identity/support/IdentityCredentialSupport.h
+++ b/identity/support/include/android/hardware/identity/support/IdentityCredentialSupport.h
@@ -18,12 +18,11 @@
 #define IDENTITY_SUPPORT_INCLUDE_IDENTITY_CREDENTIAL_UTILS_H_
 
 #include <cstdint>
+#include <optional>
 #include <string>
 #include <tuple>
 #include <vector>
 
-#include <android/hardware/identity/1.0/types.h>
-
 namespace android {
 namespace hardware {
 namespace identity {
@@ -34,10 +33,6 @@ using ::std::string;
 using ::std::tuple;
 using ::std::vector;
 
-using ::android::hardware::identity::V1_0::Result;
-using ::android::hardware::identity::V1_0::ResultCode;
-using ::android::hardware::identity::V1_0::SecureAccessControlProfile;
-
 // ---------------------------------------------------------------------------
 // Miscellaneous utilities.
 // ---------------------------------------------------------------------------
@@ -258,21 +253,11 @@ optional<vector<uint8_t>> coseMac0(const vector<uint8_t>& key, const vector<uint
                                    const vector<uint8_t>& detachedContent);
 
 // ---------------------------------------------------------------------------
-// Platform abstraction.
-// ---------------------------------------------------------------------------
-
-// Returns the hardware-bound AES-128 key.
-const vector<uint8_t>& getHardwareBoundKey();
-
-// ---------------------------------------------------------------------------
 // Utility functions specific to IdentityCredential.
 // ---------------------------------------------------------------------------
 
-// Returns a reference to a Result with code OK and empty message.
-const Result& resultOK();
-
-// Returns a new Result with the given code and message.
-Result result(ResultCode code, const char* format, ...) __attribute__((format(printf, 2, 3)));
+// Returns the testing AES-128 key where all bits are set to 0.
+const vector<uint8_t>& getTestHardwareBoundKey();
 
 // Splits the given bytestring into chunks. If the given vector is smaller or equal to
 // |maxChunkSize| a vector with |content| as the only element is returned. Otherwise
@@ -280,21 +265,6 @@ Result result(ResultCode code, const char* format, ...) __attribute__((format(pr
 // may be smaller than |maxChunkSize|.
 vector<vector<uint8_t>> chunkVector(const vector<uint8_t>& content, size_t maxChunkSize);
 
-// Calculates the MAC for |profile| using |storageKey|.
-optional<vector<uint8_t>> secureAccessControlProfileCalcMac(
-        const SecureAccessControlProfile& profile, const vector<uint8_t>& storageKey);
-
-// Checks authenticity of the MAC in |profile| using |storageKey|.
-bool secureAccessControlProfileCheckMac(const SecureAccessControlProfile& profile,
-                                        const vector<uint8_t>& storageKey);
-
-// Returns the testing AES-128 key where all bits are set to 0.
-const vector<uint8_t>& getTestHardwareBoundKey();
-
-// Creates the AdditionalData CBOR used in the addEntryValue() HIDL method.
-vector<uint8_t> entryCreateAdditionalData(const string& nameSpace, const string& name,
-                                          const vector<uint16_t> accessControlProfileIds);
-
 }  // namespace support
 }  // namespace identity
 }  // namespace hardware
diff --git a/identity/support/src/IdentityCredentialSupport.cpp b/identity/support/src/IdentityCredentialSupport.cpp
index 7d93a4b737..e2828bf2bd 100644
--- a/identity/support/src/IdentityCredentialSupport.cpp
+++ b/identity/support/src/IdentityCredentialSupport.cpp
@@ -1682,36 +1682,9 @@ optional<vector<uint8_t>> coseMac0(const vector<uint8_t>& key, const vector<uint
 }
 
 // ---------------------------------------------------------------------------
-// Platform abstraction.
-// ---------------------------------------------------------------------------
-
-// This is not a very random HBK but that's OK because this is the SW
-// implementation where it can't be kept secret.
-vector<uint8_t> hardwareBoundKey = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
-
-const vector<uint8_t>& getHardwareBoundKey() {
-    return hardwareBoundKey;
-}
-
-// ---------------------------------------------------------------------------
 // Utility functions specific to IdentityCredential.
 // ---------------------------------------------------------------------------
 
-Result okResult{ResultCode::OK, ""};
-
-const Result& resultOK() {
-    return okResult;
-}
-
-Result result(ResultCode code, const char* format, ...) {
-    va_list ap;
-    va_start(ap, format);
-    string str;
-    android::base::StringAppendV(&str, format, ap);
-    va_end(ap);
-    return Result{code, str};
-}
-
 vector<vector<uint8_t>> chunkVector(const vector<uint8_t>& content, size_t maxChunkSize) {
     vector<vector<uint8_t>> ret;
 
@@ -1738,56 +1711,6 @@ vector<vector<uint8_t>> chunkVector(const vector<uint8_t>& content, size_t maxCh
     return ret;
 }
 
-vector<uint8_t> secureAccessControlProfileEncodeCbor(const SecureAccessControlProfile& profile) {
-    cppbor::Map map;
-    map.add("id", profile.id);
-
-    if (profile.readerCertificate.size() > 0) {
-        map.add("readerCertificate", cppbor::Bstr(profile.readerCertificate));
-    }
-
-    if (profile.userAuthenticationRequired) {
-        map.add("userAuthenticationRequired", profile.userAuthenticationRequired);
-        map.add("timeoutMillis", profile.timeoutMillis);
-        map.add("secureUserId", profile.secureUserId);
-    }
-
-    return map.encode();
-}
-
-optional<vector<uint8_t>> secureAccessControlProfileCalcMac(
-        const SecureAccessControlProfile& profile, const vector<uint8_t>& storageKey) {
-    vector<uint8_t> cborData = secureAccessControlProfileEncodeCbor(profile);
-
-    optional<vector<uint8_t>> nonce = getRandom(12);
-    if (!nonce) {
-        return {};
-    }
-    optional<vector<uint8_t>> macO = encryptAes128Gcm(storageKey, nonce.value(), {}, cborData);
-    if (!macO) {
-        return {};
-    }
-    return macO.value();
-}
-
-bool secureAccessControlProfileCheckMac(const SecureAccessControlProfile& profile,
-                                        const vector<uint8_t>& storageKey) {
-    vector<uint8_t> cborData = secureAccessControlProfileEncodeCbor(profile);
-
-    if (profile.mac.size() < kAesGcmIvSize) {
-        return false;
-    }
-    vector<uint8_t> nonce =
-            vector<uint8_t>(profile.mac.begin(), profile.mac.begin() + kAesGcmIvSize);
-    optional<vector<uint8_t>> mac = encryptAes128Gcm(storageKey, nonce, {}, cborData);
-    if (!mac) {
-        return false;
-    }
-    if (mac.value() != vector<uint8_t>(profile.mac)) {
-        return false;
-    }
-    return true;
-}
 
 vector<uint8_t> testHardwareBoundKey = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
 
@@ -1795,20 +1718,6 @@ const vector<uint8_t>& getTestHardwareBoundKey() {
     return testHardwareBoundKey;
 }
 
-vector<uint8_t> entryCreateAdditionalData(const string& nameSpace, const string& name,
-                                          const vector<uint16_t> accessControlProfileIds) {
-    cppbor::Map map;
-    map.add("Namespace", nameSpace);
-    map.add("Name", name);
-
-    cppbor::Array acpIds;
-    for (auto id : accessControlProfileIds) {
-        acpIds.add(id);
-    }
-    map.add("AccessControlProfileIds", std::move(acpIds));
-    return map.encode();
-}
-
 }  // namespace support
 }  // namespace identity
 }  // namespace hardware