| /* |
| * 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 "WritableIdentityCredential" |
| |
| #include "WritableIdentityCredential.h" |
| #include "IdentityCredentialStore.h" |
| |
| #include <android/hardware/identity/support/IdentityCredentialSupport.h> |
| |
| #include <android-base/logging.h> |
| |
| #include <cppbor/cppbor.h> |
| #include <cppbor/cppbor_parse.h> |
| |
| #include <utility> |
| |
| #include "IdentityCredentialStore.h" |
| #include "Util.h" |
| #include "WritableIdentityCredential.h" |
| |
| namespace aidl::android::hardware::identity { |
| |
| using ::std::optional; |
| using namespace ::android::hardware::identity; |
| |
| bool WritableIdentityCredential::initialize() { |
| optional<vector<uint8_t>> random = support::getRandom(16); |
| if (!random) { |
| LOG(ERROR) << "Error creating storageKey"; |
| return false; |
| } |
| storageKey_ = random.value(); |
| |
| return true; |
| } |
| |
| // This function generates the attestation certificate using the passed in |
| // |attestationApplicationId| and |attestationChallenge|. It will generate an |
| // attestation certificate with current time and expires one year from now. The |
| // certificate shall contain all values as specified in hal. |
| ndk::ScopedAStatus WritableIdentityCredential::getAttestationCertificate( |
| const vector<uint8_t>& attestationApplicationId, // |
| const vector<uint8_t>& attestationChallenge, // |
| vector<Certificate>* outCertificateChain) { |
| if (!credentialPrivKey_.empty() || !credentialPubKey_.empty() || !certificateChain_.empty()) { |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_FAILED, |
| "Error attestation certificate previously generated")); |
| } |
| |
| vector<uint8_t> challenge(attestationChallenge.begin(), attestationChallenge.end()); |
| vector<uint8_t> appId(attestationApplicationId.begin(), attestationApplicationId.end()); |
| |
| optional<std::pair<vector<uint8_t>, vector<vector<uint8_t>>>> keyAttestationPair = |
| support::createEcKeyPairAndAttestation(challenge, appId); |
| if (!keyAttestationPair) { |
| LOG(ERROR) << "Error creating credentialKey and attestation"; |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_FAILED, |
| "Error creating credentialKey and attestation")); |
| } |
| |
| vector<uint8_t> keyPair = keyAttestationPair.value().first; |
| certificateChain_ = keyAttestationPair.value().second; |
| |
| optional<vector<uint8_t>> pubKey = support::ecKeyPairGetPublicKey(keyPair); |
| if (!pubKey) { |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_FAILED, |
| "Error getting public part of credentialKey")); |
| } |
| credentialPubKey_ = pubKey.value(); |
| |
| optional<vector<uint8_t>> privKey = support::ecKeyPairGetPrivateKey(keyPair); |
| if (!privKey) { |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_FAILED, |
| "Error getting private part of credentialKey")); |
| } |
| credentialPrivKey_ = privKey.value(); |
| |
| // convert from vector<vector<uint8_t>>> to vector<Certificate>* |
| *outCertificateChain = vector<Certificate>(); |
| for (const vector<uint8_t>& cert : certificateChain_) { |
| Certificate c = Certificate(); |
| c.encodedCertificate = cert; |
| outCertificateChain->push_back(std::move(c)); |
| } |
| return ndk::ScopedAStatus::ok(); |
| } |
| |
| ndk::ScopedAStatus WritableIdentityCredential::startPersonalization( |
| int32_t accessControlProfileCount, const vector<int32_t>& entryCounts) { |
| numAccessControlProfileRemaining_ = accessControlProfileCount; |
| remainingEntryCounts_ = entryCounts; |
| entryNameSpace_ = ""; |
| |
| signedDataAccessControlProfiles_ = cppbor::Array(); |
| signedDataNamespaces_ = cppbor::Map(); |
| signedDataCurrentNamespace_ = cppbor::Array(); |
| |
| return ndk::ScopedAStatus::ok(); |
| } |
| |
| 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) { |
| 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) { |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_INVALID_DATA, |
| "userAuthenticationRequired is false but timeout is non-zero")); |
| } |
| |
| profile.id = id; |
| profile.readerCertificate = readerCertificate; |
| profile.userAuthenticationRequired = userAuthenticationRequired; |
| profile.timeoutMillis = timeoutMillis; |
| profile.secureUserId = secureUserId; |
| optional<vector<uint8_t>> mac = secureAccessControlProfileCalcMac(profile, storageKey_); |
| if (!mac) { |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_FAILED, "Error calculating MAC for profile")); |
| } |
| profile.mac = mac.value(); |
| |
| cppbor::Map profileMap; |
| profileMap.add("id", profile.id); |
| if (profile.readerCertificate.encodedCertificate.size() > 0) { |
| profileMap.add("readerCertificate", |
| cppbor::Bstr(profile.readerCertificate.encodedCertificate)); |
| } |
| if (profile.userAuthenticationRequired) { |
| profileMap.add("userAuthenticationRequired", profile.userAuthenticationRequired); |
| profileMap.add("timeoutMillis", profile.timeoutMillis); |
| } |
| signedDataAccessControlProfiles_.add(std::move(profileMap)); |
| |
| numAccessControlProfileRemaining_--; |
| |
| *outSecureAccessControlProfile = profile; |
| return ndk::ScopedAStatus::ok(); |
| } |
| |
| 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"; |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_INVALID_DATA, |
| "numAccessControlProfileRemaining_ is not zero")); |
| } |
| |
| if (remainingEntryCounts_.size() == 0) { |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_INVALID_DATA, "No more namespaces to add to")); |
| } |
| |
| // Handle initial beginEntry() call. |
| if (entryNameSpace_ == "") { |
| entryNameSpace_ = nameSpace; |
| } |
| |
| // If the namespace changed... |
| if (nameSpace != entryNameSpace_) { |
| // Then check that all entries in the previous namespace have been added.. |
| if (remainingEntryCounts_[0] != 0) { |
| 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()); |
| |
| if (signedDataCurrentNamespace_.size() > 0) { |
| signedDataNamespaces_.add(entryNameSpace_, std::move(signedDataCurrentNamespace_)); |
| signedDataCurrentNamespace_ = cppbor::Array(); |
| } |
| } else { |
| // Same namespace... |
| if (remainingEntryCounts_[0] == 0) { |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_INVALID_DATA, |
| "Same namespace but no entries remain to be added")); |
| } |
| remainingEntryCounts_[0] -= 1; |
| } |
| |
| entryAdditionalData_ = entryCreateAdditionalData(nameSpace, name, accessControlProfileIds); |
| |
| entryRemainingBytes_ = entrySize; |
| entryNameSpace_ = nameSpace; |
| entryName_ = name; |
| entryAccessControlProfileIds_ = accessControlProfileIds; |
| entryBytes_.resize(0); |
| // LOG(INFO) << "name=" << name << " entrySize=" << entrySize; |
| return ndk::ScopedAStatus::ok(); |
| } |
| |
| ndk::ScopedAStatus WritableIdentityCredential::addEntryValue(const vector<uint8_t>& content, |
| vector<uint8_t>* outEncryptedContent) { |
| size_t contentSize = content.size(); |
| |
| if (contentSize > IdentityCredentialStore::kGcmChunkSize) { |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_INVALID_DATA, |
| "Passed in chunk of is bigger than kGcmChunkSize")); |
| } |
| if (contentSize > entryRemainingBytes_) { |
| 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) { |
| 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) { |
| 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) { |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_FAILED, "Error encrypting content")); |
| } |
| |
| if (entryRemainingBytes_ == 0) { |
| // TODO: ideally do do this without parsing the data (but still validate data is valid |
| // CBOR). |
| auto [item, _, message] = cppbor::parse(entryBytes_); |
| if (item == nullptr) { |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_INVALID_DATA, "Data is not valid CBOR")); |
| } |
| cppbor::Map entryMap; |
| entryMap.add("name", entryName_); |
| entryMap.add("value", std::move(item)); |
| cppbor::Array profileIdArray; |
| for (auto id : entryAccessControlProfileIds_) { |
| profileIdArray.add(id); |
| } |
| entryMap.add("accessControlProfiles", std::move(profileIdArray)); |
| signedDataCurrentNamespace_.add(std::move(entryMap)); |
| } |
| |
| *outEncryptedContent = 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; |
| } |
| |
| ndk::ScopedAStatus WritableIdentityCredential::finishAddingEntries( |
| vector<uint8_t>* outCredentialData, vector<uint8_t>* outProofOfProvisioningSignature) { |
| if (signedDataCurrentNamespace_.size() > 0) { |
| signedDataNamespaces_.add(entryNameSpace_, std::move(signedDataCurrentNamespace_)); |
| } |
| cppbor::Array popArray; |
| popArray.add("ProofOfProvisioning") |
| .add(docType_) |
| .add(std::move(signedDataAccessControlProfiles_)) |
| .add(std::move(signedDataNamespaces_)) |
| .add(testCredential_); |
| vector<uint8_t> encodedCbor = popArray.encode(); |
| |
| optional<vector<uint8_t>> signature = support::coseSignEcDsa(credentialPrivKey_, |
| encodedCbor, // payload |
| {}, // additionalData |
| {}); // certificateChain |
| if (!signature) { |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_FAILED, "Error signing data")); |
| } |
| |
| vector<uint8_t> credentialKeys; |
| if (!generateCredentialKeys(storageKey_, credentialPrivKey_, credentialKeys)) { |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_FAILED, "Error generating CredentialKeys")); |
| } |
| |
| vector<uint8_t> credentialData; |
| if (!generateCredentialData( |
| testCredential_ ? support::getTestHardwareBoundKey() : getHardwareBoundKey(), |
| docType_, testCredential_, credentialKeys, credentialData)) { |
| return ndk::ScopedAStatus(AStatus_fromServiceSpecificErrorWithMessage( |
| IIdentityCredentialStore::STATUS_FAILED, "Error generating CredentialData")); |
| } |
| |
| *outCredentialData = credentialData; |
| *outProofOfProvisioningSignature = signature.value(); |
| return ndk::ScopedAStatus::ok(); |
| } |
| |
| } // namespace aidl::android::hardware::identity |