| /* |
| * Copyright 2014 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 "ecdsa_key.h" |
| #include "ecdsa_operation.h" |
| #include "openssl_utils.h" |
| #include "unencrypted_key_blob.h" |
| |
| namespace keymaster { |
| |
| const uint32_t ECDSA_DEFAULT_KEY_SIZE = 224; |
| |
| /* static */ |
| EcdsaKey* EcdsaKey::GenerateKey(const AuthorizationSet& key_description, const Logger& logger, |
| keymaster_error_t* error) { |
| if (!error) |
| return NULL; |
| |
| AuthorizationSet authorizations(key_description); |
| |
| uint32_t key_size = ECDSA_DEFAULT_KEY_SIZE; |
| if (!authorizations.GetTagValue(TAG_KEY_SIZE, &key_size)) |
| authorizations.push_back(Authorization(TAG_KEY_SIZE, key_size)); |
| |
| UniquePtr<EC_KEY, ECDSA_Delete> ecdsa_key(EC_KEY_new()); |
| UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey(EVP_PKEY_new()); |
| if (ecdsa_key.get() == NULL || pkey.get() == NULL) { |
| *error = KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| return NULL; |
| } |
| |
| UniquePtr<EC_GROUP, EC_GROUP_Delete> group(choose_group(key_size)); |
| if (group.get() == NULL) { |
| // Technically, could also have been a memory allocation problem. |
| *error = KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| return NULL; |
| } |
| |
| EC_GROUP_set_point_conversion_form(group.get(), POINT_CONVERSION_UNCOMPRESSED); |
| #if !defined(OPENSSL_IS_BORINGSSL) |
| EC_GROUP_set_asn1_flag(group.get(), OPENSSL_EC_NAMED_CURVE); |
| #endif |
| |
| if (EC_KEY_set_group(ecdsa_key.get(), group.get()) != 1 || |
| EC_KEY_generate_key(ecdsa_key.get()) != 1 || EC_KEY_check_key(ecdsa_key.get()) < 0) { |
| *error = KM_ERROR_UNKNOWN_ERROR; |
| return NULL; |
| } |
| |
| EcdsaKey* new_key = new EcdsaKey(ecdsa_key.release(), authorizations, logger); |
| *error = new_key ? KM_ERROR_OK : KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| return new_key; |
| } |
| |
| /* static */ |
| EcdsaKey* EcdsaKey::ImportKey(const AuthorizationSet& key_description, EVP_PKEY* pkey, |
| const Logger& logger, keymaster_error_t* error) { |
| if (!error) |
| return NULL; |
| *error = KM_ERROR_UNKNOWN_ERROR; |
| |
| UniquePtr<EC_KEY, ECDSA_Delete> ecdsa_key(EVP_PKEY_get1_EC_KEY(pkey)); |
| if (!ecdsa_key.get()) |
| return NULL; |
| |
| AuthorizationSet authorizations(key_description); |
| |
| size_t extracted_key_size_bits; |
| *error = get_group_size(*EC_KEY_get0_group(ecdsa_key.get()), &extracted_key_size_bits); |
| if (*error != KM_ERROR_OK) |
| return NULL; |
| |
| uint32_t key_size_bits; |
| if (authorizations.GetTagValue(TAG_KEY_SIZE, &key_size_bits)) { |
| // key_size_bits specified, make sure it matches the key. |
| if (key_size_bits != extracted_key_size_bits) { |
| *error = KM_ERROR_IMPORT_PARAMETER_MISMATCH; |
| return NULL; |
| } |
| } else { |
| // key_size_bits not specified, add it. |
| authorizations.push_back(TAG_KEY_SIZE, extracted_key_size_bits); |
| } |
| |
| keymaster_algorithm_t algorithm; |
| if (authorizations.GetTagValue(TAG_ALGORITHM, &algorithm)) { |
| if (algorithm != KM_ALGORITHM_ECDSA) { |
| *error = KM_ERROR_IMPORT_PARAMETER_MISMATCH; |
| return NULL; |
| } |
| } else { |
| authorizations.push_back(TAG_ALGORITHM, KM_ALGORITHM_ECDSA); |
| } |
| |
| // Don't bother with the other parameters. If the necessary padding, digest, purpose, etc. are |
| // missing, the error will be diagnosed when the key is used (when auth checking is |
| // implemented). |
| *error = KM_ERROR_OK; |
| return new EcdsaKey(ecdsa_key.release(), authorizations, logger); |
| } |
| |
| /* static */ |
| EC_GROUP* EcdsaKey::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 EcdsaKey::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; |
| } |
| |
| EcdsaKey::EcdsaKey(const UnencryptedKeyBlob& blob, const Logger& logger, keymaster_error_t* error) |
| : AsymmetricKey(blob, logger) { |
| if (error) |
| *error = LoadKey(blob); |
| } |
| |
| Operation* EcdsaKey::CreateOperation(keymaster_purpose_t purpose, keymaster_error_t* error) { |
| keymaster_digest_t digest = KM_DIGEST_NONE; |
| if (!authorizations().GetTagValue(TAG_DIGEST, &digest) || digest != KM_DIGEST_NONE) { |
| *error = KM_ERROR_UNSUPPORTED_DIGEST; |
| return NULL; |
| } |
| |
| Operation* op; |
| switch (purpose) { |
| case KM_PURPOSE_SIGN: |
| op = new EcdsaSignOperation(purpose, logger_, digest, ecdsa_key_.release()); |
| break; |
| case KM_PURPOSE_VERIFY: |
| op = new EcdsaVerifyOperation(purpose, logger_, digest, ecdsa_key_.release()); |
| break; |
| default: |
| *error = KM_ERROR_UNIMPLEMENTED; |
| return NULL; |
| } |
| *error = op ? KM_ERROR_OK : KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| return op; |
| } |
| |
| bool EcdsaKey::EvpToInternal(const EVP_PKEY* pkey) { |
| ecdsa_key_.reset(EVP_PKEY_get1_EC_KEY(const_cast<EVP_PKEY*>(pkey))); |
| return ecdsa_key_.get() != NULL; |
| } |
| |
| bool EcdsaKey::InternalToEvp(EVP_PKEY* pkey) const { |
| return EVP_PKEY_set1_EC_KEY(pkey, ecdsa_key_.get()) == 1; |
| } |
| |
| } // namespace keymaster |