259 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			259 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C++
		
	
	
	
| /*
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| **
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| ** Copyright 2017, The Android Open Source Project
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| **
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| ** Licensed under the Apache License, Version 2.0 (the "License");
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| ** you may not use this file except in compliance with the License.
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| ** You may obtain a copy of the License at
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| **
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| **     http://www.apache.org/licenses/LICENSE-2.0
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| **
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| ** Unless required by applicable law or agreed to in writing, software
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| ** distributed under the License is distributed on an "AS IS" BASIS,
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| ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| ** See the License for the specific language governing permissions and
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| ** limitations under the License.
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| */
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| 
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| #include <keymaster/contexts/keymaster1_passthrough_context.h>
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| 
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| #include <keymaster/contexts/soft_attestation_cert.h>
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| #include <keymaster/key_blob_utils/integrity_assured_key_blob.h>
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| #include <keymaster/key_blob_utils/ocb_utils.h>
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| #include <keymaster/key_blob_utils/software_keyblobs.h>
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| #include <keymaster/km_openssl/aes_key.h>
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| #include <keymaster/km_openssl/attestation_utils.h>
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| #include <keymaster/km_openssl/hmac_key.h>
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| #include <keymaster/km_version.h>
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| #include <keymaster/legacy_support/ec_keymaster1_key.h>
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| #include <keymaster/legacy_support/keymaster1_engine.h>
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| #include <keymaster/legacy_support/keymaster1_legacy_support.h>
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| #include <keymaster/legacy_support/keymaster_passthrough_engine.h>
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| #include <keymaster/legacy_support/keymaster_passthrough_key.h>
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| #include <keymaster/legacy_support/rsa_keymaster1_key.h>
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| 
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| namespace keymaster {
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| 
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| Keymaster1PassthroughContext::Keymaster1PassthroughContext(KmVersion version,
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|                                                            keymaster1_device_t* dev)
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|     : SoftAttestationContext(version), device_(dev),
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|       pt_engine_(KeymasterPassthroughEngine::createInstance(dev)),
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|       km1_engine_(new (std::nothrow) Keymaster1Engine(dev)) {}
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| 
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| keymaster_error_t Keymaster1PassthroughContext::SetSystemVersion(uint32_t os_version,
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|                                                                  uint32_t os_patchlevel) {
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|     os_version_ = os_version;
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|     os_patchlevel_ = os_patchlevel;
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|     return KM_ERROR_OK;
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| }
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| 
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| void Keymaster1PassthroughContext::GetSystemVersion(uint32_t* os_version,
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|                                                     uint32_t* os_patchlevel) const {
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|     if (os_version) *os_version = os_version_;
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|     if (os_patchlevel) *os_patchlevel = os_patchlevel_;
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| }
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| 
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| KeyFactory* Keymaster1PassthroughContext::GetKeyFactory(keymaster_algorithm_t algorithm) const {
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|     auto& result = factories_[algorithm];
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|     if (!result) {
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|         switch (algorithm) {
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|         case KM_ALGORITHM_RSA:
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|             result.reset(new (std::nothrow) Keymaster1ArbitrationFactory<RsaKeymaster1KeyFactory>(
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|                 pt_engine_.get(), KM_ALGORITHM_RSA, device_, *this /* blob_maker */,
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|                 *this /* context */, km1_engine_.get()));
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|             break;
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|         case KM_ALGORITHM_EC:
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|             result.reset(new (std::nothrow) Keymaster1ArbitrationFactory<EcdsaKeymaster1KeyFactory>(
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|                 pt_engine_.get(), KM_ALGORITHM_EC, device_, *this /* blob_maker */,
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|                 *this /* context */, km1_engine_.get()));
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|             break;
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|         case KM_ALGORITHM_AES:
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|             result.reset(new (std::nothrow) Keymaster1ArbitrationFactory<AesKeyFactory>(
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|                 pt_engine_.get(), KM_ALGORITHM_AES, device_, *this /* blob_maker */,
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|                 *this /* random_source */));
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|             break;
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|         case KM_ALGORITHM_HMAC:
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|             result.reset(new (std::nothrow) Keymaster1ArbitrationFactory<HmacKeyFactory>(
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|                 pt_engine_.get(), KM_ALGORITHM_HMAC, device_, *this /* blob_maker */,
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|                 *this /* random_source */));
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|             break;
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|         case KM_ALGORITHM_TRIPLE_DES:
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|             // Not supported by KM1.
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|             return nullptr;
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|         }
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|     }
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|     return result.get();
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| }
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| OperationFactory*
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| Keymaster1PassthroughContext::GetOperationFactory(keymaster_algorithm_t algorithm,
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|                                                   keymaster_purpose_t purpose) const {
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|     auto keyfactory = GetKeyFactory(algorithm);
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|     return keyfactory->GetOperationFactory(purpose);
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| }
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| keymaster_algorithm_t*
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| Keymaster1PassthroughContext::GetSupportedAlgorithms(size_t* algorithms_count) const {
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|     if (algorithms_count) *algorithms_count = 0;
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|     return nullptr;
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| }
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| 
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| keymaster_error_t
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| Keymaster1PassthroughContext::UpgradeKeyBlob(const KeymasterKeyBlob& key_to_upgrade,
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|                                              const AuthorizationSet& upgrade_params,
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|                                              KeymasterKeyBlob* upgraded_key) const {
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| 
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|     UniquePtr<Key> key;
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|     keymaster_error_t error = ParseKeyBlob(key_to_upgrade, upgrade_params, &key);
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|     if (error != KM_ERROR_OK) return error;
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| 
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|     if (key->hw_enforced().Contains(TAG_PURPOSE) &&
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|         !key->hw_enforced().Contains(TAG_OS_PATCHLEVEL)) {
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|         return KM_ERROR_INVALID_ARGUMENT;
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|     }
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| 
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|     return UpgradeSoftKeyBlob(key, os_version_, os_patchlevel_, upgrade_params, upgraded_key);
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| }
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| 
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| static keymaster_error_t
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| parseKeymaster1HwBlob(const keymaster1_device_t* device, const KeymasterKeyBlob& blob,
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|                       const AuthorizationSet& additional_params, KeymasterKeyBlob* key_material,
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|                       AuthorizationSet* hw_enforced, AuthorizationSet* sw_enforced) {
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|     keymaster_blob_t client_id = {nullptr, 0};
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|     keymaster_blob_t app_data = {nullptr, 0};
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|     keymaster_blob_t* client_id_ptr = nullptr;
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|     keymaster_blob_t* app_data_ptr = nullptr;
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|     if (additional_params.GetTagValue(TAG_APPLICATION_ID, &client_id)) client_id_ptr = &client_id;
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|     if (additional_params.GetTagValue(TAG_APPLICATION_DATA, &app_data)) app_data_ptr = &app_data;
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| 
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|     // Get key characteristics, which incidentally verifies that the HW recognizes the key.
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|     keymaster_key_characteristics_t* characteristics;
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|     keymaster_error_t error = device->get_key_characteristics(device, &blob, client_id_ptr,
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|                                                               app_data_ptr, &characteristics);
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|     if (error != KM_ERROR_OK) return error;
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| 
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|     UniquePtr<keymaster_key_characteristics_t, Characteristics_Delete> characteristics_deleter(
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|         characteristics);
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| 
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|     hw_enforced->Reinitialize(characteristics->hw_enforced);
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|     sw_enforced->Reinitialize(characteristics->sw_enforced);
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|     *key_material = blob;
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|     return KM_ERROR_OK;
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| }
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| 
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| keymaster_error_t
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| Keymaster1PassthroughContext::ParseKeyBlob(const KeymasterKeyBlob& blob,
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|                                            const AuthorizationSet& additional_params,
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|                                            UniquePtr<Key>* key) const {
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|     AuthorizationSet hw_enforced;
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|     AuthorizationSet sw_enforced;
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|     KeymasterKeyBlob key_material;
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| 
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|     AuthorizationSet hidden;
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|     keymaster_error_t error =
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|         BuildHiddenAuthorizations(additional_params, &hidden, softwareRootOfTrust);
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|     if (error != KM_ERROR_OK) return error;
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| 
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|     // Assume it's an integrity-assured blob (new software-only blob).
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|     error =
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|         DeserializeIntegrityAssuredBlob(blob, hidden, &key_material, &hw_enforced, &sw_enforced);
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|     if (error != KM_ERROR_INVALID_KEY_BLOB && error != KM_ERROR_OK) return error;
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| 
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|     if (error == KM_ERROR_INVALID_KEY_BLOB) {
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|         error = parseKeymaster1HwBlob(km1_engine_->device(), blob, additional_params, &key_material,
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|                                       &hw_enforced, &sw_enforced);
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|         if (error != KM_ERROR_OK) return error;
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|     }
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| 
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|     // GetKeyFactory
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|     keymaster_algorithm_t algorithm;
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|     if (!hw_enforced.GetTagValue(TAG_ALGORITHM, &algorithm) &&
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|         !sw_enforced.GetTagValue(TAG_ALGORITHM, &algorithm)) {
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|         return KM_ERROR_INVALID_ARGUMENT;
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|     }
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|     auto factory = GetKeyFactory(algorithm);
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| 
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|     return factory->LoadKey(move(key_material), additional_params, move(hw_enforced),
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|                             move(sw_enforced), key);
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| }
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| 
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| keymaster_error_t Keymaster1PassthroughContext::DeleteKey(const KeymasterKeyBlob& blob) const {
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|     // HACK. Due to a bug with Qualcomm's Keymaster implementation, which causes the device to
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|     // reboot if we pass it a key blob it doesn't understand, we need to check for software
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|     // keys.  If it looks like a software key there's nothing to do so we just return.
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|     // Can be removed once b/33385206 is fixed
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|     KeymasterKeyBlob key_material;
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|     AuthorizationSet hw_enforced, sw_enforced;
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|     keymaster_error_t error = DeserializeIntegrityAssuredBlob_NoHmacCheck(
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|         blob, &key_material, &hw_enforced, &sw_enforced);
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|     if (error == KM_ERROR_OK) {
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|         return KM_ERROR_OK;
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|     }
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| 
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|     error = km1_engine_->DeleteKey(blob);
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|     if (error == KM_ERROR_INVALID_KEY_BLOB) {
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|         // Some implementations diagnose invalid keys.
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|         // However, all care we about is that the key blob, as supplied, is not usable after the
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|         // call.
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|         return KM_ERROR_OK;
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|     }
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|     return error;
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| }
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| 
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| keymaster_error_t Keymaster1PassthroughContext::DeleteAllKeys() const {
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|     return km1_engine_->DeleteAllKeys();
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| }
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| 
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| keymaster_error_t Keymaster1PassthroughContext::AddRngEntropy(const uint8_t* buf,
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|                                                               size_t length) const {
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|     return device_->add_rng_entropy(device_, buf, length);
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| }
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| 
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| KeymasterEnforcement* Keymaster1PassthroughContext::enforcement_policy() {
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|     return nullptr;
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| }
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| 
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| keymaster_error_t Keymaster1PassthroughContext::CreateKeyBlob(
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|     const AuthorizationSet& key_description, const keymaster_key_origin_t origin,
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|     const KeymasterKeyBlob& key_material, KeymasterKeyBlob* blob, AuthorizationSet* hw_enforced,
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|     AuthorizationSet* sw_enforced) const {
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|     keymaster_error_t error =
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|         SetKeyBlobAuthorizations(key_description, origin, os_version_, os_patchlevel_, hw_enforced,
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|                                  sw_enforced, GetKmVersion());
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|     if (error != KM_ERROR_OK) return error;
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| 
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|     AuthorizationSet hidden;
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|     error = BuildHiddenAuthorizations(key_description, &hidden, softwareRootOfTrust);
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|     if (error != KM_ERROR_OK) return error;
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| 
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|     return SerializeIntegrityAssuredBlob(key_material, hidden, *hw_enforced, *sw_enforced, blob);
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| }
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| 
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| CertificateChain Keymaster1PassthroughContext::GenerateAttestation(
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|     const Key& key, const AuthorizationSet& attest_params, UniquePtr<Key> /* attest_key */,
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|     const KeymasterBlob& /* issuer_subject */, keymaster_error_t* error) const {
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|     keymaster_algorithm_t key_algorithm;
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|     if (!key.authorizations().GetTagValue(TAG_ALGORITHM, &key_algorithm)) {
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|         *error = KM_ERROR_UNKNOWN_ERROR;
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|         return {};
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|     }
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| 
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|     if ((key_algorithm != KM_ALGORITHM_RSA && key_algorithm != KM_ALGORITHM_EC)) {
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|         *error = KM_ERROR_INCOMPATIBLE_ALGORITHM;
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|         return {};
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|     }
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| 
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|     // We have established that the given key has the correct algorithm, and because this is the
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|     // SoftKeymasterContext we can assume that the Key is an AsymmetricKey. So we can downcast.
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|     const AsymmetricKey& asymmetric_key = static_cast<const AsymmetricKey&>(key);
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| 
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|     return generate_attestation(asymmetric_key, attest_params, {} /* attest_key */,
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|                                 *this /* AttestationContext */, error);
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| }
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| 
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| keymaster_error_t Keymaster1PassthroughContext::UnwrapKey(
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|     const KeymasterKeyBlob&, const KeymasterKeyBlob&, const AuthorizationSet&,
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|     const KeymasterKeyBlob&, AuthorizationSet*, keymaster_key_format_t*, KeymasterKeyBlob*) const {
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|     return KM_ERROR_UNIMPLEMENTED;
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| }
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| 
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| }  // namespace keymaster
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