diff options
Diffstat (limited to 'asymmetric_key.cpp')
| -rw-r--r-- | asymmetric_key.cpp | 186 |
1 files changed, 1 insertions, 185 deletions
diff --git a/asymmetric_key.cpp b/asymmetric_key.cpp index e0af5a5..2ead3c5 100644 --- a/asymmetric_key.cpp +++ b/asymmetric_key.cpp @@ -18,11 +18,8 @@ #include <new> -#include <openssl/asn1.h> -#include <openssl/stack.h> #include <openssl/x509.h> -#include "attestation_record.h" #include "openssl_err.h" #include "openssl_utils.h" @@ -37,7 +34,7 @@ keymaster_error_t AsymmetricKey::formatted_key_material(keymaster_key_format_t f if (material == NULL || size == NULL) return KM_ERROR_OUTPUT_PARAMETER_NULL; - EVP_PKEY_Ptr pkey(EVP_PKEY_new()); + UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey(EVP_PKEY_new()); if (!InternalToEvp(pkey.get())) return TranslateLastOpenSslError(); @@ -59,185 +56,4 @@ keymaster_error_t AsymmetricKey::formatted_key_material(keymaster_key_format_t f return KM_ERROR_OK; } -static keymaster_error_t build_attestation_extension(const AuthorizationSet& tee_enforced, - const AuthorizationSet& sw_enforced, - X509_EXTENSION_Ptr* extension) { - ASN1_OBJECT_Ptr oid( - OBJ_txt2obj(kAttestionRecordOid, 1 /* accept numerical dotted string form only */)); - if (!oid.get()) - return TranslateLastOpenSslError(); - - UniquePtr<uint8_t[]> attest_bytes; - size_t attest_bytes_len; - keymaster_error_t error = - build_attestation_record(sw_enforced, tee_enforced, &attest_bytes, &attest_bytes_len); - if (error != KM_ERROR_OK) - return error; - - ASN1_OCTET_STRING_Ptr attest_str(ASN1_OCTET_STRING_new()); - if (!attest_str.get() || - !ASN1_OCTET_STRING_set(attest_str.get(), attest_bytes.get(), attest_bytes_len)) - return TranslateLastOpenSslError(); - - extension->reset( - X509_EXTENSION_create_by_OBJ(nullptr, oid.get(), 0 /* not critical */, attest_str.get())); - if (!extension->get()) - return TranslateLastOpenSslError(); - - return KM_ERROR_OK; -} - -static bool add_public_key(EVP_PKEY* key, X509* certificate, keymaster_error_t* error) { - if (!X509_set_pubkey(certificate, key)) { - *error = TranslateLastOpenSslError(); - return false; - } - return true; -} - -static bool add_attestation_extension(const AuthorizationSet& tee_enforced, - const AuthorizationSet& sw_enforced, X509* certificate, - keymaster_error_t* error) { - X509_EXTENSION_Ptr attest_extension; - *error = build_attestation_extension(tee_enforced, sw_enforced, &attest_extension); - if (*error != KM_ERROR_OK) - return false; - - if (!X509_add_ext(certificate, attest_extension.get() /* Don't release; copied */, - -1 /* insert at end */)) { - *error = TranslateLastOpenSslError(); - return false; - } - - return true; -} - -static keymaster_error_t get_certificate_blob(X509* certificate, keymaster_blob_t* blob) { - int len = i2d_X509(certificate, nullptr); - if (len < 0) - return TranslateLastOpenSslError(); - - uint8_t* data = new uint8_t[len]; - if (!data) - return KM_ERROR_MEMORY_ALLOCATION_FAILED; - - uint8_t* p = data; - i2d_X509(certificate, &p); - - blob->data_length = len; - blob->data = data; - - return KM_ERROR_OK; -} - -static bool allocate_cert_chain(size_t entry_count, keymaster_cert_chain_t* chain, - keymaster_error_t* error) { - if (chain->entries) { - for (size_t i = 0; i < chain->entry_count; ++i) - delete[] chain->entries[i].data; - delete[] chain->entries; - } - - chain->entry_count = entry_count; - chain->entries = new keymaster_blob_t[entry_count]; - if (!chain->entries) { - *error = KM_ERROR_MEMORY_ALLOCATION_FAILED; - return false; - } - return true; -} - -// Copies the intermediate and root certificates into chain, leaving the first slot for the leaf -// certificate. -static bool copy_attestation_chain(const KeymasterContext& context, - keymaster_algorithm_t sign_algorithm, - keymaster_cert_chain_t* chain, keymaster_error_t* error) { - - UniquePtr<keymaster_cert_chain_t, CertificateChainDelete> attest_key_chain( - context.AttestationChain(sign_algorithm, error)); - if (!attest_key_chain.get()) - return false; - - if (!allocate_cert_chain(attest_key_chain->entry_count + 1, chain, error)) - return false; - - chain->entries[0] = {}; // Leave empty for the leaf certificate. - for (size_t i = 0; i < attest_key_chain->entry_count; ++i) { - chain->entries[i + 1] = attest_key_chain->entries[i]; - attest_key_chain->entries[i].data = nullptr; - } - - return true; -} - -keymaster_error_t AsymmetricKey::GenerateAttestation(const KeymasterContext& context, - const AuthorizationSet& attest_params, - const AuthorizationSet& tee_enforced, - const AuthorizationSet& sw_enforced, - keymaster_cert_chain_t* cert_chain) const { - - keymaster_algorithm_t sign_algorithm; - if (!attest_params.GetTagValue(TAG_ALGORITHM, &sign_algorithm) || - (sign_algorithm != KM_ALGORITHM_RSA && sign_algorithm != KM_ALGORITHM_EC)) - return KM_ERROR_INCOMPATIBLE_ALGORITHM; - - EVP_PKEY_Ptr pkey(EVP_PKEY_new()); - if (!InternalToEvp(pkey.get())) - return TranslateLastOpenSslError(); - - X509_Ptr certificate(X509_new()); - if (!certificate.get()) - return TranslateLastOpenSslError(); - - if (!X509_set_version(certificate.get(), 2 /* version 3, but zero-based */)) - return TranslateLastOpenSslError(); - - ASN1_INTEGER_Ptr serialNumber(ASN1_INTEGER_new()); - if (!serialNumber.get() || - !ASN1_INTEGER_set( - serialNumber.get(), - 10000 /* TODO(swillden): Figure out what should go in serial number; probably a random - * value */) || - !X509_set_serialNumber(certificate.get(), serialNumber.get() /* Don't release; copied */)) - return TranslateLastOpenSslError(); - - // TODO(swillden): Find useful values (if possible) for issuerName and subjectName. - X509_NAME_Ptr issuerName(X509_NAME_new()); - if (!issuerName.get() || - !X509_set_subject_name(certificate.get(), issuerName.get() /* Don't release; copied */)) - return TranslateLastOpenSslError(); - - X509_NAME_Ptr subjectName(X509_NAME_new()); - if (!subjectName.get() || - !X509_set_subject_name(certificate.get(), subjectName.get() /* Don't release; copied */)) - return TranslateLastOpenSslError(); - - // TODO(swillden): Use key activity and expiration dates for notBefore and notAfter. - ASN1_TIME_Ptr notBefore(ASN1_TIME_new()); - if (!notBefore.get() || !ASN1_TIME_set(notBefore.get(), 0) || - !X509_set_notBefore(certificate.get(), notBefore.get() /* Don't release; copied */)) - return TranslateLastOpenSslError(); - - ASN1_TIME_Ptr notAfter(ASN1_TIME_new()); - if (!notAfter.get() || !ASN1_TIME_set(notAfter.get(), 10000) || - !X509_set_notAfter(certificate.get(), notAfter.get() /* Don't release; copied */)) - return TranslateLastOpenSslError(); - - keymaster_error_t error = KM_ERROR_OK; - EVP_PKEY_Ptr sign_key(context.AttestationKey(sign_algorithm, &error)); - - if (!sign_key.get() || // - !add_public_key(pkey.get(), certificate.get(), &error) || - !add_attestation_extension(tee_enforced, sw_enforced, certificate.get(), &error)) - return error; - - if (!X509_sign(certificate.get(), sign_key.get(), EVP_sha256())) - return TranslateLastOpenSslError(); - - if (!copy_attestation_chain(context, sign_algorithm, cert_chain, &error)) - return error; - - return get_certificate_blob(certificate.get(), &cert_chain->entries[0]); -} - } // namespace keymaster |