| /* |
| * 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 "openssl_utils.h" |
| #include "rsa_key.h" |
| #include "rsa_operation.h" |
| #include "unencrypted_key_blob.h" |
| |
| namespace keymaster { |
| |
| const uint32_t RSA_DEFAULT_KEY_SIZE = 2048; |
| const uint64_t RSA_DEFAULT_EXPONENT = 65537; |
| |
| /* static */ |
| RsaKey* RsaKey::GenerateKey(const AuthorizationSet& key_description, const Logger& logger, |
| keymaster_error_t* error) { |
| if (!error) |
| return NULL; |
| |
| AuthorizationSet authorizations(key_description); |
| |
| uint64_t public_exponent = RSA_DEFAULT_EXPONENT; |
| if (!authorizations.GetTagValue(TAG_RSA_PUBLIC_EXPONENT, &public_exponent)) |
| authorizations.push_back(Authorization(TAG_RSA_PUBLIC_EXPONENT, public_exponent)); |
| |
| uint32_t key_size = RSA_DEFAULT_KEY_SIZE; |
| if (!authorizations.GetTagValue(TAG_KEY_SIZE, &key_size)) |
| authorizations.push_back(Authorization(TAG_KEY_SIZE, key_size)); |
| |
| UniquePtr<BIGNUM, BIGNUM_Delete> exponent(BN_new()); |
| UniquePtr<RSA, RSA_Delete> rsa_key(RSA_new()); |
| UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey(EVP_PKEY_new()); |
| if (rsa_key.get() == NULL || pkey.get() == NULL) { |
| *error = KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| return NULL; |
| } |
| |
| if (!BN_set_word(exponent.get(), public_exponent) || |
| !RSA_generate_key_ex(rsa_key.get(), key_size, exponent.get(), NULL /* callback */)) { |
| *error = KM_ERROR_UNKNOWN_ERROR; |
| return NULL; |
| } |
| |
| RsaKey* new_key = new RsaKey(rsa_key.release(), authorizations, logger); |
| *error = new_key ? KM_ERROR_OK : KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| return new_key; |
| } |
| |
| /* static */ |
| RsaKey* RsaKey::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<RSA, RSA_Delete> rsa_key(EVP_PKEY_get1_RSA(pkey)); |
| if (!rsa_key.get()) |
| return NULL; |
| |
| AuthorizationSet authorizations(key_description); |
| |
| uint64_t public_exponent; |
| if (authorizations.GetTagValue(TAG_RSA_PUBLIC_EXPONENT, &public_exponent)) { |
| // public_exponent specified, make sure it matches the key |
| UniquePtr<BIGNUM, BIGNUM_Delete> public_exponent_bn(BN_new()); |
| if (!BN_set_word(public_exponent_bn.get(), public_exponent)) |
| return NULL; |
| if (BN_cmp(public_exponent_bn.get(), rsa_key->e) != 0) { |
| *error = KM_ERROR_IMPORT_PARAMETER_MISMATCH; |
| return NULL; |
| } |
| } else { |
| // public_exponent not specified, use the one from the key. |
| public_exponent = BN_get_word(rsa_key->e); |
| if (public_exponent == 0xffffffffL) { |
| *error = KM_ERROR_IMPORT_PARAMETER_MISMATCH; |
| return NULL; |
| } |
| authorizations.push_back(TAG_RSA_PUBLIC_EXPONENT, public_exponent); |
| } |
| |
| uint32_t key_size; |
| if (authorizations.GetTagValue(TAG_KEY_SIZE, &key_size)) { |
| // key_size specified, make sure it matches the key. |
| if (RSA_size(rsa_key.get()) != (int)key_size) { |
| *error = KM_ERROR_IMPORT_PARAMETER_MISMATCH; |
| return NULL; |
| } |
| } else { |
| key_size = RSA_size(rsa_key.get()) * 8; |
| authorizations.push_back(TAG_KEY_SIZE, key_size); |
| } |
| |
| keymaster_algorithm_t algorithm; |
| if (authorizations.GetTagValue(TAG_ALGORITHM, &algorithm)) { |
| if (algorithm != KM_ALGORITHM_RSA) { |
| *error = KM_ERROR_IMPORT_PARAMETER_MISMATCH; |
| return NULL; |
| } |
| } else { |
| authorizations.push_back(TAG_ALGORITHM, KM_ALGORITHM_RSA); |
| } |
| |
| // 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 RsaKey(rsa_key.release(), authorizations, logger); |
| } |
| |
| RsaKey::RsaKey(const UnencryptedKeyBlob& blob, const Logger& logger, keymaster_error_t* error) |
| : AsymmetricKey(blob, logger) { |
| if (error) |
| *error = LoadKey(blob); |
| } |
| |
| Operation* RsaKey::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; |
| } |
| keymaster_padding_t padding = KM_PAD_NONE; |
| if (!authorizations().GetTagValue(TAG_PADDING, &padding) || padding != KM_PAD_NONE) { |
| *error = KM_ERROR_UNSUPPORTED_PADDING_MODE; |
| return NULL; |
| } |
| |
| Operation* op; |
| switch (purpose) { |
| case KM_PURPOSE_SIGN: |
| op = new RsaSignOperation(purpose, logger_, digest, padding, rsa_key_.release()); |
| break; |
| case KM_PURPOSE_VERIFY: |
| op = new RsaVerifyOperation(purpose, logger_, digest, padding, rsa_key_.release()); |
| break; |
| default: |
| *error = KM_ERROR_UNIMPLEMENTED; |
| return NULL; |
| } |
| *error = op ? KM_ERROR_OK : KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| return op; |
| } |
| |
| bool RsaKey::EvpToInternal(const EVP_PKEY* pkey) { |
| rsa_key_.reset(EVP_PKEY_get1_RSA(const_cast<EVP_PKEY*>(pkey))); |
| return rsa_key_.get() != NULL; |
| } |
| |
| bool RsaKey::InternalToEvp(EVP_PKEY* pkey) const { |
| return EVP_PKEY_set1_RSA(pkey, rsa_key_.get()) == 1; |
| } |
| |
| } // namespace keymaster |