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/*
* 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.
*/
#define LOG_TAG "android.hardware.security.keymint-impl"
#include <android-base/logging.h>
#include "AndroidKeyMintDevice.h"
#include <aidl/android/hardware/security/keymint/ErrorCode.h>
#include <keymaster/android_keymaster.h>
#include <keymaster/contexts/pure_soft_keymaster_context.h>
#include <keymaster/keymaster_configuration.h>
#include "AndroidKeyMintOperation.h"
#include "KeyMintUtils.h"
namespace aidl::android::hardware::security::keymint {
using namespace keymaster; // NOLINT(google-build-using-namespace)
using km_utils::authToken2AidlVec;
using km_utils::kmBlob2vector;
using km_utils::kmError2ScopedAStatus;
using km_utils::kmParam2Aidl;
using km_utils::KmParamSet;
using km_utils::kmParamSet2Aidl;
using km_utils::legacy_enum_conversion;
using secureclock::TimeStampToken;
namespace {
vector<KeyCharacteristics> convertKeyCharacteristics(SecurityLevel keyMintSecurityLevel,
const AuthorizationSet& requestParams,
const AuthorizationSet& sw_enforced,
const AuthorizationSet& hw_enforced,
bool include_keystore_enforced = true) {
KeyCharacteristics keyMintEnforced{keyMintSecurityLevel, {}};
if (keyMintSecurityLevel != SecurityLevel::SOFTWARE) {
// We're pretending to be TRUSTED_ENVIRONMENT or STRONGBOX.
keyMintEnforced.authorizations = kmParamSet2Aidl(hw_enforced);
if (include_keystore_enforced) {
// Put all the software authorizations in the keystore list.
KeyCharacteristics keystoreEnforced{SecurityLevel::KEYSTORE,
kmParamSet2Aidl(sw_enforced)};
return {std::move(keyMintEnforced), std::move(keystoreEnforced)};
} else {
return {std::move(keyMintEnforced)};
}
}
KeyCharacteristics keystoreEnforced{SecurityLevel::KEYSTORE, {}};
CHECK(hw_enforced.empty()) << "Hardware-enforced list is non-empty for pure SW KeyMint";
// This is a pure software implementation, so all tags are in sw_enforced.
// We need to walk through the SW-enforced list and figure out which tags to
// return in the software list and which in the keystore list.
for (auto& entry : sw_enforced) {
switch (entry.tag) {
/* Invalid and unused */
case KM_TAG_ECIES_SINGLE_HASH_MODE:
case KM_TAG_INVALID:
case KM_TAG_KDF:
case KM_TAG_ROLLBACK_RESISTANCE:
CHECK(false) << "We shouldn't see tag " << entry.tag;
break;
/* Unimplemented */
case KM_TAG_ALLOW_WHILE_ON_BODY:
case KM_TAG_BOOTLOADER_ONLY:
case KM_TAG_ROLLBACK_RESISTANT:
case KM_TAG_STORAGE_KEY:
break;
/* Keystore-enforced if not locally generated. */
case KM_TAG_CREATION_DATETIME:
// A KeyMaster implementation is required to add this tag to generated/imported keys.
// A KeyMint implementation is not required to create this tag, only to echo it back if
// it was included in the key generation/import request.
if (requestParams.Contains(KM_TAG_CREATION_DATETIME)) {
keystoreEnforced.authorizations.push_back(kmParam2Aidl(entry));
}
break;
/* Disallowed in KeyCharacteristics */
case KM_TAG_APPLICATION_DATA:
case KM_TAG_ATTESTATION_APPLICATION_ID:
break;
/* Not key characteristics */
case KM_TAG_ASSOCIATED_DATA:
case KM_TAG_ATTESTATION_CHALLENGE:
case KM_TAG_ATTESTATION_ID_BRAND:
case KM_TAG_ATTESTATION_ID_DEVICE:
case KM_TAG_ATTESTATION_ID_IMEI:
case KM_TAG_ATTESTATION_ID_MANUFACTURER:
case KM_TAG_ATTESTATION_ID_MEID:
case KM_TAG_ATTESTATION_ID_MODEL:
case KM_TAG_ATTESTATION_ID_PRODUCT:
case KM_TAG_ATTESTATION_ID_SERIAL:
case KM_TAG_AUTH_TOKEN:
case KM_TAG_CERTIFICATE_SERIAL:
case KM_TAG_CERTIFICATE_SUBJECT:
case KM_TAG_CERTIFICATE_NOT_AFTER:
case KM_TAG_CERTIFICATE_NOT_BEFORE:
case KM_TAG_CONFIRMATION_TOKEN:
case KM_TAG_DEVICE_UNIQUE_ATTESTATION:
case KM_TAG_IDENTITY_CREDENTIAL_KEY:
case KM_TAG_MAC_LENGTH:
case KM_TAG_NONCE:
case KM_TAG_RESET_SINCE_ID_ROTATION:
case KM_TAG_ROOT_OF_TRUST:
case KM_TAG_UNIQUE_ID:
break;
/* KeyMint-enforced */
case KM_TAG_ALGORITHM:
case KM_TAG_APPLICATION_ID:
case KM_TAG_AUTH_TIMEOUT:
case KM_TAG_BLOB_USAGE_REQUIREMENTS:
case KM_TAG_BLOCK_MODE:
case KM_TAG_BOOT_PATCHLEVEL:
case KM_TAG_CALLER_NONCE:
case KM_TAG_DIGEST:
case KM_TAG_EARLY_BOOT_ONLY:
case KM_TAG_EC_CURVE:
case KM_TAG_EXPORTABLE:
case KM_TAG_INCLUDE_UNIQUE_ID:
case KM_TAG_KEY_SIZE:
case KM_TAG_MAX_USES_PER_BOOT:
case KM_TAG_MIN_MAC_LENGTH:
case KM_TAG_MIN_SECONDS_BETWEEN_OPS:
case KM_TAG_NO_AUTH_REQUIRED:
case KM_TAG_ORIGIN:
case KM_TAG_OS_PATCHLEVEL:
case KM_TAG_OS_VERSION:
case KM_TAG_PADDING:
case KM_TAG_PURPOSE:
case KM_TAG_RSA_OAEP_MGF_DIGEST:
case KM_TAG_RSA_PUBLIC_EXPONENT:
case KM_TAG_TRUSTED_CONFIRMATION_REQUIRED:
case KM_TAG_TRUSTED_USER_PRESENCE_REQUIRED:
case KM_TAG_UNLOCKED_DEVICE_REQUIRED:
case KM_TAG_USER_AUTH_TYPE:
case KM_TAG_USER_SECURE_ID:
case KM_TAG_VENDOR_PATCHLEVEL:
keyMintEnforced.authorizations.push_back(kmParam2Aidl(entry));
break;
/* Keystore-enforced */
case KM_TAG_ACTIVE_DATETIME:
case KM_TAG_ALL_APPLICATIONS:
case KM_TAG_ALL_USERS:
case KM_TAG_MAX_BOOT_LEVEL:
case KM_TAG_ORIGINATION_EXPIRE_DATETIME:
case KM_TAG_USAGE_EXPIRE_DATETIME:
case KM_TAG_USER_ID:
case KM_TAG_USAGE_COUNT_LIMIT:
keystoreEnforced.authorizations.push_back(kmParam2Aidl(entry));
break;
}
}
vector<KeyCharacteristics> retval;
retval.reserve(2);
if (!keyMintEnforced.authorizations.empty()) retval.push_back(std::move(keyMintEnforced));
if (include_keystore_enforced && !keystoreEnforced.authorizations.empty()) {
retval.push_back(std::move(keystoreEnforced));
}
return retval;
}
Certificate convertCertificate(const keymaster_blob_t& cert) {
return {std::vector<uint8_t>(cert.data, cert.data + cert.data_length)};
}
vector<Certificate> convertCertificateChain(const CertificateChain& chain) {
vector<Certificate> retval;
retval.reserve(chain.entry_count);
std::transform(chain.begin(), chain.end(), std::back_inserter(retval), convertCertificate);
return retval;
}
void addClientAndAppData(const std::vector<uint8_t>& appId, const std::vector<uint8_t>& appData,
::keymaster::AuthorizationSet* params) {
params->Clear();
if (appId.size()) {
params->push_back(::keymaster::TAG_APPLICATION_ID, appId.data(), appId.size());
}
if (appData.size()) {
params->push_back(::keymaster::TAG_APPLICATION_DATA, appData.data(), appData.size());
}
}
} // namespace
constexpr size_t kOperationTableSize = 16;
AndroidKeyMintDevice::AndroidKeyMintDevice(SecurityLevel securityLevel)
: impl_(new ::keymaster::AndroidKeymaster(
[&]() -> auto {
auto context = new PureSoftKeymasterContext(
KmVersion::KEYMINT_1, static_cast<keymaster_security_level_t>(securityLevel));
context->SetSystemVersion(::keymaster::GetOsVersion(),
::keymaster::GetOsPatchlevel());
return context;
}(),
kOperationTableSize)),
securityLevel_(securityLevel) {}
AndroidKeyMintDevice::~AndroidKeyMintDevice() {}
ScopedAStatus AndroidKeyMintDevice::getHardwareInfo(KeyMintHardwareInfo* info) {
info->versionNumber = 1;
info->securityLevel = securityLevel_;
info->keyMintName = "FakeKeyMintDevice";
info->keyMintAuthorName = "Google";
info->timestampTokenRequired = false;
return ScopedAStatus::ok();
}
ScopedAStatus AndroidKeyMintDevice::addRngEntropy(const vector<uint8_t>& data) {
if (data.size() == 0) {
return ScopedAStatus::ok();
}
AddEntropyRequest request(impl_->message_version());
request.random_data.Reinitialize(data.data(), data.size());
AddEntropyResponse response(impl_->message_version());
impl_->AddRngEntropy(request, &response);
return kmError2ScopedAStatus(response.error);
}
ScopedAStatus AndroidKeyMintDevice::generateKey(const vector<KeyParameter>& keyParams,
const optional<AttestationKey>& attestationKey,
KeyCreationResult* creationResult) {
GenerateKeyRequest request(impl_->message_version());
request.key_description.Reinitialize(KmParamSet(keyParams));
if (attestationKey) {
request.attestation_signing_key_blob =
KeymasterKeyBlob(attestationKey->keyBlob.data(), attestationKey->keyBlob.size());
request.attest_key_params.Reinitialize(KmParamSet(attestationKey->attestKeyParams));
request.issuer_subject = KeymasterBlob(attestationKey->issuerSubjectName.data(),
attestationKey->issuerSubjectName.size());
}
GenerateKeyResponse response(impl_->message_version());
impl_->GenerateKey(request, &response);
if (response.error != KM_ERROR_OK) {
// Note a key difference between this current aidl and previous hal, is
// that hal returns void where as aidl returns the error status. If
// aidl returns error, then aidl will not return any change you may make
// to the out parameters. This is quite different from hal where all
// output variable can be modified due to hal returning void.
//
// So the caller need to be aware not to expect aidl functions to clear
// the output variables for you in case of error. If you left some
// wrong data set in the out parameters, they will stay there.
return kmError2ScopedAStatus(response.error);
}
creationResult->keyBlob = kmBlob2vector(response.key_blob);
creationResult->keyCharacteristics = convertKeyCharacteristics(
securityLevel_, request.key_description, response.unenforced, response.enforced);
creationResult->certificateChain = convertCertificateChain(response.certificate_chain);
return ScopedAStatus::ok();
}
ScopedAStatus AndroidKeyMintDevice::importKey(const vector<KeyParameter>& keyParams,
KeyFormat keyFormat, const vector<uint8_t>& keyData,
const optional<AttestationKey>& attestationKey,
KeyCreationResult* creationResult) {
ImportKeyRequest request(impl_->message_version());
request.key_description.Reinitialize(KmParamSet(keyParams));
request.key_format = legacy_enum_conversion(keyFormat);
request.key_data = KeymasterKeyBlob(keyData.data(), keyData.size());
if (attestationKey) {
request.attestation_signing_key_blob =
KeymasterKeyBlob(attestationKey->keyBlob.data(), attestationKey->keyBlob.size());
request.attest_key_params.Reinitialize(KmParamSet(attestationKey->attestKeyParams));
request.issuer_subject = KeymasterBlob(attestationKey->issuerSubjectName.data(),
attestationKey->issuerSubjectName.size());
}
ImportKeyResponse response(impl_->message_version());
impl_->ImportKey(request, &response);
if (response.error != KM_ERROR_OK) {
return kmError2ScopedAStatus(response.error);
}
creationResult->keyBlob = kmBlob2vector(response.key_blob);
creationResult->keyCharacteristics = convertKeyCharacteristics(
securityLevel_, request.key_description, response.unenforced, response.enforced);
creationResult->certificateChain = convertCertificateChain(response.certificate_chain);
return ScopedAStatus::ok();
}
ScopedAStatus
AndroidKeyMintDevice::importWrappedKey(const vector<uint8_t>& wrappedKeyData, //
const vector<uint8_t>& wrappingKeyBlob, //
const vector<uint8_t>& maskingKey, //
const vector<KeyParameter>& unwrappingParams, //
int64_t passwordSid, int64_t biometricSid, //
KeyCreationResult* creationResult) {
ImportWrappedKeyRequest request(impl_->message_version());
request.SetWrappedMaterial(wrappedKeyData.data(), wrappedKeyData.size());
request.SetWrappingMaterial(wrappingKeyBlob.data(), wrappingKeyBlob.size());
request.SetMaskingKeyMaterial(maskingKey.data(), maskingKey.size());
request.additional_params.Reinitialize(KmParamSet(unwrappingParams));
request.password_sid = static_cast<uint64_t>(passwordSid);
request.biometric_sid = static_cast<uint64_t>(biometricSid);
ImportWrappedKeyResponse response(impl_->message_version());
impl_->ImportWrappedKey(request, &response);
if (response.error != KM_ERROR_OK) {
return kmError2ScopedAStatus(response.error);
}
creationResult->keyBlob = kmBlob2vector(response.key_blob);
creationResult->keyCharacteristics = convertKeyCharacteristics(
securityLevel_, request.additional_params, response.unenforced, response.enforced);
creationResult->certificateChain = convertCertificateChain(response.certificate_chain);
return ScopedAStatus::ok();
}
ScopedAStatus AndroidKeyMintDevice::upgradeKey(const vector<uint8_t>& keyBlobToUpgrade,
const vector<KeyParameter>& upgradeParams,
vector<uint8_t>* keyBlob) {
UpgradeKeyRequest request(impl_->message_version());
request.SetKeyMaterial(keyBlobToUpgrade.data(), keyBlobToUpgrade.size());
request.upgrade_params.Reinitialize(KmParamSet(upgradeParams));
UpgradeKeyResponse response(impl_->message_version());
impl_->UpgradeKey(request, &response);
if (response.error != KM_ERROR_OK) {
return kmError2ScopedAStatus(response.error);
}
*keyBlob = kmBlob2vector(response.upgraded_key);
return ScopedAStatus::ok();
}
ScopedAStatus AndroidKeyMintDevice::deleteKey(const vector<uint8_t>& keyBlob) {
DeleteKeyRequest request(impl_->message_version());
request.SetKeyMaterial(keyBlob.data(), keyBlob.size());
DeleteKeyResponse response(impl_->message_version());
impl_->DeleteKey(request, &response);
return kmError2ScopedAStatus(response.error);
}
ScopedAStatus AndroidKeyMintDevice::deleteAllKeys() {
// There's nothing to be done to delete software key blobs.
DeleteAllKeysRequest request(impl_->message_version());
DeleteAllKeysResponse response(impl_->message_version());
impl_->DeleteAllKeys(request, &response);
return kmError2ScopedAStatus(response.error);
}
ScopedAStatus AndroidKeyMintDevice::destroyAttestationIds() {
return kmError2ScopedAStatus(KM_ERROR_UNIMPLEMENTED);
}
ScopedAStatus AndroidKeyMintDevice::begin(KeyPurpose purpose, const vector<uint8_t>& keyBlob,
const vector<KeyParameter>& params,
const optional<HardwareAuthToken>& authToken,
BeginResult* result) {
BeginOperationRequest request(impl_->message_version());
request.purpose = legacy_enum_conversion(purpose);
request.SetKeyMaterial(keyBlob.data(), keyBlob.size());
request.additional_params.Reinitialize(KmParamSet(params));
vector<uint8_t> vector_token = authToken2AidlVec(authToken);
request.additional_params.push_back(
TAG_AUTH_TOKEN, reinterpret_cast<uint8_t*>(vector_token.data()), vector_token.size());
BeginOperationResponse response(impl_->message_version());
impl_->BeginOperation(request, &response);
if (response.error != KM_ERROR_OK) {
return kmError2ScopedAStatus(response.error);
}
result->params = kmParamSet2Aidl(response.output_params);
result->challenge = response.op_handle;
result->operation =
ndk::SharedRefBase::make<AndroidKeyMintOperation>(impl_, response.op_handle);
return ScopedAStatus::ok();
}
ScopedAStatus AndroidKeyMintDevice::deviceLocked(
bool passwordOnly, const std::optional<secureclock::TimeStampToken>& timestampToken) {
DeviceLockedRequest request(impl_->message_version());
request.passwordOnly = passwordOnly;
if (timestampToken.has_value()) {
request.token.challenge = timestampToken->challenge;
request.token.mac = {timestampToken->mac.data(), timestampToken->mac.size()};
request.token.timestamp = timestampToken->timestamp.milliSeconds;
}
DeviceLockedResponse response = impl_->DeviceLocked(request);
return kmError2ScopedAStatus(response.error);
}
ScopedAStatus AndroidKeyMintDevice::earlyBootEnded() {
EarlyBootEndedResponse response = impl_->EarlyBootEnded();
return kmError2ScopedAStatus(response.error);
}
ScopedAStatus
AndroidKeyMintDevice::convertStorageKeyToEphemeral(const std::vector<uint8_t>& /* storageKeyBlob */,
std::vector<uint8_t>* /* ephemeralKeyBlob */) {
return kmError2ScopedAStatus(KM_ERROR_UNIMPLEMENTED);
}
ScopedAStatus AndroidKeyMintDevice::getKeyCharacteristics(
const std::vector<uint8_t>& keyBlob, const std::vector<uint8_t>& appId,
const std::vector<uint8_t>& appData, std::vector<KeyCharacteristics>* keyCharacteristics) {
GetKeyCharacteristicsRequest request(impl_->message_version());
request.SetKeyMaterial(keyBlob.data(), keyBlob.size());
addClientAndAppData(appId, appData, &request.additional_params);
GetKeyCharacteristicsResponse response(impl_->message_version());
impl_->GetKeyCharacteristics(request, &response);
if (response.error != KM_ERROR_OK) {
return kmError2ScopedAStatus(response.error);
}
AuthorizationSet emptySet;
*keyCharacteristics =
convertKeyCharacteristics(securityLevel_, emptySet, response.unenforced, response.enforced,
/* include_keystore_enforced = */ false);
return ScopedAStatus::ok();
}
IKeyMintDevice* CreateKeyMintDevice(SecurityLevel securityLevel) {
return ::new AndroidKeyMintDevice(securityLevel);
}
} // namespace aidl::android::hardware::security::keymint