| /* |
| * Copyright 2015 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. |
| */ |
| |
| #include <keymaster/ec_key_factory.h> |
| |
| #include <openssl/evp.h> |
| |
| #include <keymaster/keymaster_context.h> |
| |
| #include "ec_key.h" |
| #include "ecdsa_operation.h" |
| #include "openssl_err.h" |
| |
| namespace keymaster { |
| |
| static EcdsaSignOperationFactory sign_factory; |
| static EcdsaVerifyOperationFactory verify_factory; |
| |
| OperationFactory* EcKeyFactory::GetOperationFactory(keymaster_purpose_t purpose) const { |
| switch (purpose) { |
| case KM_PURPOSE_SIGN: |
| return &sign_factory; |
| case KM_PURPOSE_VERIFY: |
| return &verify_factory; |
| default: |
| return nullptr; |
| } |
| } |
| |
| keymaster_error_t EcKeyFactory::GenerateKey(const AuthorizationSet& key_description, |
| KeymasterKeyBlob* key_blob, |
| AuthorizationSet* hw_enforced, |
| AuthorizationSet* sw_enforced) const { |
| if (!key_blob || !hw_enforced || !sw_enforced) |
| return KM_ERROR_OUTPUT_PARAMETER_NULL; |
| |
| AuthorizationSet authorizations(key_description); |
| |
| uint32_t key_size; |
| if (!authorizations.GetTagValue(TAG_KEY_SIZE, &key_size)) { |
| LOG_E("%s", "No key size specified for EC key generation"); |
| return KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| } |
| |
| UniquePtr<EC_KEY, EC_Delete> ec_key(EC_KEY_new()); |
| UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey(EVP_PKEY_new()); |
| if (ec_key.get() == NULL || pkey.get() == NULL) |
| return KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| |
| UniquePtr<EC_GROUP, EC_GROUP_Delete> group(choose_group(key_size)); |
| if (group.get() == NULL) { |
| LOG_E("Unable to get EC group for key of size %d", key_size); |
| return KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| } |
| |
| #if !defined(OPENSSL_IS_BORINGSSL) |
| EC_GROUP_set_point_conversion_form(group.get(), POINT_CONVERSION_UNCOMPRESSED); |
| EC_GROUP_set_asn1_flag(group.get(), OPENSSL_EC_NAMED_CURVE); |
| #endif |
| |
| if (EC_KEY_set_group(ec_key.get(), group.get()) != 1 || |
| EC_KEY_generate_key(ec_key.get()) != 1 || EC_KEY_check_key(ec_key.get()) < 0) { |
| return TranslateLastOpenSslError(); |
| } |
| |
| if (EVP_PKEY_set1_EC_KEY(pkey.get(), ec_key.get()) != 1) |
| return TranslateLastOpenSslError(); |
| |
| KeymasterKeyBlob key_material; |
| keymaster_error_t error = EvpKeyToKeyMaterial(pkey.get(), &key_material); |
| if (error != KM_ERROR_OK) |
| return error; |
| |
| return context_->CreateKeyBlob(authorizations, KM_ORIGIN_GENERATED, key_material, key_blob, |
| hw_enforced, sw_enforced); |
| } |
| |
| keymaster_error_t EcKeyFactory::ImportKey(const AuthorizationSet& key_description, |
| keymaster_key_format_t input_key_material_format, |
| const KeymasterKeyBlob& input_key_material, |
| KeymasterKeyBlob* output_key_blob, |
| AuthorizationSet* hw_enforced, |
| AuthorizationSet* sw_enforced) const { |
| if (!output_key_blob || !hw_enforced || !sw_enforced) |
| return KM_ERROR_OUTPUT_PARAMETER_NULL; |
| |
| AuthorizationSet authorizations; |
| uint32_t key_size; |
| keymaster_error_t error = UpdateImportKeyDescription( |
| key_description, input_key_material_format, input_key_material, &authorizations, &key_size); |
| if (error != KM_ERROR_OK) |
| return error; |
| |
| return context_->CreateKeyBlob(authorizations, KM_ORIGIN_IMPORTED, input_key_material, |
| output_key_blob, hw_enforced, sw_enforced); |
| } |
| |
| keymaster_error_t EcKeyFactory::UpdateImportKeyDescription(const AuthorizationSet& key_description, |
| keymaster_key_format_t key_format, |
| const KeymasterKeyBlob& key_material, |
| AuthorizationSet* updated_description, |
| uint32_t* key_size_bits) const { |
| if (!updated_description || !key_size_bits) |
| return KM_ERROR_OUTPUT_PARAMETER_NULL; |
| |
| UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey; |
| keymaster_error_t error = |
| KeyMaterialToEvpKey(key_format, key_material, keymaster_key_type(), &pkey); |
| if (error != KM_ERROR_OK) |
| return error; |
| |
| UniquePtr<EC_KEY, EC_Delete> ec_key(EVP_PKEY_get1_EC_KEY(pkey.get())); |
| if (!ec_key.get()) |
| return TranslateLastOpenSslError(); |
| |
| updated_description->Reinitialize(key_description); |
| |
| size_t extracted_key_size_bits; |
| error = get_group_size(*EC_KEY_get0_group(ec_key.get()), &extracted_key_size_bits); |
| if (error != KM_ERROR_OK) |
| return error; |
| |
| *key_size_bits = extracted_key_size_bits; |
| if (!updated_description->GetTagValue(TAG_KEY_SIZE, key_size_bits)) |
| updated_description->push_back(TAG_KEY_SIZE, extracted_key_size_bits); |
| if (*key_size_bits != extracted_key_size_bits) |
| return KM_ERROR_IMPORT_PARAMETER_MISMATCH; |
| |
| keymaster_algorithm_t algorithm = KM_ALGORITHM_EC; |
| if (!updated_description->GetTagValue(TAG_ALGORITHM, &algorithm)) |
| updated_description->push_back(TAG_ALGORITHM, KM_ALGORITHM_EC); |
| if (algorithm != KM_ALGORITHM_EC) |
| return KM_ERROR_IMPORT_PARAMETER_MISMATCH; |
| |
| return KM_ERROR_OK; |
| } |
| |
| /* static */ |
| EC_GROUP* EcKeyFactory::choose_group(size_t key_size_bits) { |
| switch (key_size_bits) { |
| case 224: |
| return EC_GROUP_new_by_curve_name(NID_secp224r1); |
| break; |
| case 256: |
| return EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1); |
| break; |
| case 384: |
| return EC_GROUP_new_by_curve_name(NID_secp384r1); |
| break; |
| case 521: |
| return EC_GROUP_new_by_curve_name(NID_secp521r1); |
| break; |
| default: |
| return NULL; |
| break; |
| } |
| } |
| /* static */ |
| keymaster_error_t EcKeyFactory::get_group_size(const EC_GROUP& group, size_t* key_size_bits) { |
| switch (EC_GROUP_get_curve_name(&group)) { |
| case NID_secp224r1: |
| *key_size_bits = 224; |
| break; |
| case NID_X9_62_prime256v1: |
| *key_size_bits = 256; |
| break; |
| case NID_secp384r1: |
| *key_size_bits = 384; |
| break; |
| case NID_secp521r1: |
| *key_size_bits = 521; |
| break; |
| default: |
| return KM_ERROR_UNSUPPORTED_EC_FIELD; |
| } |
| return KM_ERROR_OK; |
| } |
| |
| keymaster_error_t EcKeyFactory::CreateEmptyKey(const AuthorizationSet& hw_enforced, |
| const AuthorizationSet& sw_enforced, |
| UniquePtr<AsymmetricKey>* key) const { |
| keymaster_error_t error; |
| key->reset(new EcKey(hw_enforced, sw_enforced, &error)); |
| if (!key->get()) |
| error = KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| return error; |
| } |
| |
| } // namespace keymaster |
