Fix wrongly initialized test key.

According to spec the test key has 32 bytes set to TextKeyBits::BYTE.
The VTS test and default implmementation only set the first 16 bytes and
left the remaining 16 bytes zero.

This bug fixes both, the VTS test and the default implementation.

Also some long overdue changes to how the auth token key is handled
by the generic operation.

Bug: 78456249
Test: VtsHalConfirmationUIV1_0TargetTest
Change-Id: I509f2c2a99704ee00625e6f6169479771a3bc17a

5 files changed, 36 insertions, 32 deletions

diff --git a/confirmationui/1.0/default/PlatformSpecifics.cpp b/confirmationui/1.0/default/PlatformSpecifics.cpp
index dd039e22b..03d616547 100644
--- a/confirmationui/1.0/default/PlatformSpecifics.cpp
+++ b/confirmationui/1.0/default/PlatformSpecifics.cpp
@@ -36,11 +36,11 @@ MonotonicClockTimeStamper::TimeStamp MonotonicClockTimeStamper::now() {
     }
 }
 
-support::NullOr<support::array<uint8_t, 32>> HMacImplementation::hmac256(
-    const uint8_t key[32], std::initializer_list<support::ByteBufferProxy> buffers) {
+support::NullOr<support::hmac_t> HMacImplementation::hmac256(
+    const support::auth_token_key_t& key, std::initializer_list<support::ByteBufferProxy> buffers) {
     HMAC_CTX hmacCtx;
     HMAC_CTX_init(&hmacCtx);
-    if (!HMAC_Init_ex(&hmacCtx, key, 32, EVP_sha256(), nullptr)) {
+    if (!HMAC_Init_ex(&hmacCtx, key.data(), key.size(), EVP_sha256(), nullptr)) {
         return {};
     }
     for (auto& buffer : buffers) {
@@ -48,7 +48,7 @@ support::NullOr<support::array<uint8_t, 32>> HMacImplementation::hmac256(
             return {};
         }
     }
-    support::array<uint8_t, 32> result;
+    support::hmac_t result;
     if (!HMAC_Final(&hmacCtx, result.data(), nullptr)) {
         return {};
     }
diff --git a/confirmationui/1.0/default/PlatformSpecifics.h b/confirmationui/1.0/default/PlatformSpecifics.h
index 488da6d1b..29f299c7d 100644
--- a/confirmationui/1.0/default/PlatformSpecifics.h
+++ b/confirmationui/1.0/default/PlatformSpecifics.h
@@ -48,8 +48,9 @@ struct MonotonicClockTimeStamper {
 
 class HMacImplementation {
    public:
-    static support::NullOr<support::array<uint8_t, 32>> hmac256(
-        const uint8_t key[32], std::initializer_list<support::ByteBufferProxy> buffers);
+    static support::NullOr<support::hmac_t> hmac256(
+        const support::auth_token_key_t& key,
+        std::initializer_list<support::ByteBufferProxy> buffers);
 };
 
 class MyOperation : public generic::Operation<sp<IConfirmationResultCallback>,
diff --git a/confirmationui/1.0/vts/functional/VtsHalConfirmationUIV1_0TargetTest.cpp b/confirmationui/1.0/vts/functional/VtsHalConfirmationUIV1_0TargetTest.cpp
index 463bb40a1..278d1f444 100644
--- a/confirmationui/1.0/vts/functional/VtsHalConfirmationUIV1_0TargetTest.cpp
+++ b/confirmationui/1.0/vts/functional/VtsHalConfirmationUIV1_0TargetTest.cpp
@@ -46,13 +46,16 @@ namespace V1_0 {
 
 namespace test {
 namespace {
+const support::auth_token_key_t testKey(static_cast<uint8_t>(TestKeyBits::BYTE));
+
 class HMacImplementation {
    public:
-    static support::NullOr<support::array<uint8_t, 32>> hmac256(
-        const uint8_t key[32], std::initializer_list<support::ByteBufferProxy> buffers) {
+    static support::NullOr<support::hmac_t> hmac256(
+        const support::auth_token_key_t& key,
+        std::initializer_list<support::ByteBufferProxy> buffers) {
         HMAC_CTX hmacCtx;
         HMAC_CTX_init(&hmacCtx);
-        if (!HMAC_Init_ex(&hmacCtx, key, 32, EVP_sha256(), nullptr)) {
+        if (!HMAC_Init_ex(&hmacCtx, key.data(), key.size(), EVP_sha256(), nullptr)) {
             return {};
         }
         for (auto& buffer : buffers) {
@@ -60,7 +63,7 @@ class HMacImplementation {
                 return {};
             }
         }
-        support::array<uint8_t, 32> result;
+        support::hmac_t result;
         if (!HMAC_Final(&hmacCtx, result.data(), nullptr)) {
             return {};
         }
@@ -70,23 +73,15 @@ class HMacImplementation {
 
 using HMacer = support::HMac<HMacImplementation>;
 
-constexpr uint8_t testKeyByte = static_cast<uint8_t>(TestKeyBits::BYTE);
-
 template <typename... Data>
 hidl_vec<uint8_t> testHMAC(const Data&... data) {
-    constexpr uint8_t testKey[32] = {testKeyByte, testKeyByte, testKeyByte, testKeyByte,
-                                     testKeyByte, testKeyByte, testKeyByte, testKeyByte,
-                                     testKeyByte, testKeyByte, testKeyByte, testKeyByte,
-                                     testKeyByte, testKeyByte, testKeyByte, testKeyByte};
-    constexpr uint8_t hmac_size_bytes = sizeof testKey;
-
     auto hmac = HMacer::hmac256(testKey, data...);
     if (!hmac.isOk()) {
         EXPECT_TRUE(false) << "Failed to compute test hmac.  This is a self-test error.";
         return {};
     }
-    hidl_vec<uint8_t> result(hmac_size_bytes);
-    copy(hmac.value().data(), hmac.value().data() + hmac_size_bytes, result.data());
+    hidl_vec<uint8_t> result(hmac.value().size());
+    copy(hmac.value().data(), hmac.value().data() + hmac.value().size(), result.data());
     return result;
 }
 
diff --git a/confirmationui/support/include/android/hardware/confirmationui/1.0/generic/GenericOperation.h b/confirmationui/support/include/android/hardware/confirmationui/1.0/generic/GenericOperation.h
index b48094299..b1c322ce5 100644
--- a/confirmationui/support/include/android/hardware/confirmationui/1.0/generic/GenericOperation.h
+++ b/confirmationui/support/include/android/hardware/confirmationui/1.0/generic/GenericOperation.h
@@ -99,7 +99,8 @@ class Operation {
 
     void setPending() { error_ = ResponseCode::OK; }
 
-    void setHmacKey(const uint8_t (&key)[32]) { hmacKey_ = {key}; }
+    void setHmacKey(const auth_token_key_t& key) { hmacKey_ = key; }
+    NullOr<auth_token_key_t> hmacKey() const { return hmacKey_; }
 
     void abort() {
         if (isPending()) {
@@ -112,7 +113,7 @@ class Operation {
         if (isPending()) error_ = ResponseCode::Canceled;
     }
 
-    void finalize(const uint8_t key[32]) {
+    void finalize(const auth_token_key_t& key) {
         if (error_ == ResponseCode::Ignored) return;
         resultCB_->result(error_, getMessage(), userConfirm(key));
         error_ = ResponseCode::Ignored;
@@ -127,11 +128,7 @@ class Operation {
     }
 
     ResponseCode deliverSecureInputEvent(const HardwareAuthToken& secureInputToken) {
-        constexpr uint8_t testKeyByte = static_cast<uint8_t>(TestKeyBits::BYTE);
-        constexpr uint8_t testKey[32] = {testKeyByte, testKeyByte, testKeyByte, testKeyByte,
-                                         testKeyByte, testKeyByte, testKeyByte, testKeyByte,
-                                         testKeyByte, testKeyByte, testKeyByte, testKeyByte,
-                                         testKeyByte, testKeyByte, testKeyByte, testKeyByte};
+        const auth_token_key_t testKey(static_cast<uint8_t>(TestKeyBits::BYTE));
 
         auto hmac = HMacer::hmac256(testKey, "\0", bytes_cast(secureInputToken.challenge),
                                     bytes_cast(secureInputToken.userId),
@@ -171,7 +168,7 @@ class Operation {
         result.setToExternal(formattedMessageBuffer_, formattedMessageLength_);
         return result;
     }
-    hidl_vec<uint8_t> userConfirm(const uint8_t key[32]) {
+    hidl_vec<uint8_t> userConfirm(const auth_token_key_t& key) {
         if (error_ != ResponseCode::OK) return {};
         confirmationTokenScratchpad_ = HMacer::hmac256(key, "confirmation token", getMessage());
         if (!confirmationTokenScratchpad_.isOk()) {
@@ -188,10 +185,10 @@ class Operation {
     uint8_t formattedMessageBuffer_[uint32_t(MessageSize::MAX)];
     char promptStringBuffer_[uint32_t(MessageSize::MAX)];
     size_t formattedMessageLength_ = 0;
-    NullOr<array<uint8_t, 32>> confirmationTokenScratchpad_;
+    NullOr<hmac_t> confirmationTokenScratchpad_;
     Callback resultCB_;
     typename TimeStamper::TimeStamp startTime_;
-    NullOr<array<uint8_t, 32>> hmacKey_;
+    NullOr<auth_token_key_t> hmacKey_;
 };
 
 }  // namespace
diff --git a/confirmationui/support/include/android/hardware/confirmationui/support/confirmationui_utils.h b/confirmationui/support/include/android/hardware/confirmationui/support/confirmationui_utils.h
index d55143362..3f7810a7e 100644
--- a/confirmationui/support/include/android/hardware/confirmationui/support/confirmationui_utils.h
+++ b/confirmationui/support/include/android/hardware/confirmationui/support/confirmationui_utils.h
@@ -81,17 +81,23 @@ class array {
    public:
     array() : data_{} {}
     array(const T (&data)[elements]) { std::copy(data, data + elements, data_); }
+    explicit array(const T& v) { fill(v); }
 
     T* data() { return data_; }
     const T* data() const { return data_; }
     constexpr size_t size() const { return elements; }
-    operator const array_type&() const { return data_; }
 
     T* begin() { return data_; }
     T* end() { return data_ + elements; }
     const T* begin() const { return data_; }
     const T* end() const { return data_ + elements; }
 
+    void fill(const T& v) {
+        for (size_t i = 0; i < elements; ++i) {
+            data_[i] = v;
+        }
+    }
+
    private:
     array_type data_;
 };
@@ -157,6 +163,11 @@ class ByteBufferProxy {
     size_t size_;
 };
 
+constexpr uint8_t auth_token_key_size = 32;
+constexpr uint8_t hmac_size_bytes = support::auth_token_key_size;
+using auth_token_key_t = array<uint8_t, auth_token_key_size>;
+using hmac_t = auth_token_key_t;
+
 /**
  * Implementer are expected to provide an implementation with the following prototype:
  *  static NullOr<array<uint8_t, 32>> hmac256(const uint8_t key[32],
@@ -166,7 +177,7 @@ template <typename Impl>
 class HMac {
    public:
     template <typename... Data>
-    static NullOr<array<uint8_t, 32>> hmac256(const uint8_t key[32], const Data&... data) {
+    static NullOr<hmac_t> hmac256(const auth_token_key_t& key, const Data&... data) {
         return Impl::hmac256(key, {data...});
     }
 };