1 /* 2 * Copyright 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <keymaster/km_openssl/ecdsa_operation.h> 18 19 #include <openssl/ecdsa.h> 20 21 #include <keymaster/km_openssl/ec_key.h> 22 #include <keymaster/km_openssl/openssl_err.h> 23 #include <keymaster/km_openssl/openssl_utils.h> 24 25 namespace keymaster { 26 27 static const keymaster_digest_t supported_digests[] = {KM_DIGEST_NONE, KM_DIGEST_SHA1, 28 KM_DIGEST_SHA_2_224, KM_DIGEST_SHA_2_256, 29 KM_DIGEST_SHA_2_384, KM_DIGEST_SHA_2_512}; 30 31 OperationPtr EcdsaOperationFactory::CreateOperation(Key&& key, const AuthorizationSet& begin_params, 32 keymaster_error_t* error) { 33 const EcKey& ecdsa_key = static_cast<EcKey&>(key); 34 35 UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey(EVP_PKEY_new()); 36 if (!ecdsa_key.InternalToEvp(pkey.get())) { 37 *error = KM_ERROR_UNKNOWN_ERROR; 38 return nullptr; 39 } 40 41 keymaster_digest_t digest; 42 if (!GetAndValidateDigest(begin_params, ecdsa_key, &digest, error)) return nullptr; 43 44 *error = KM_ERROR_OK; 45 auto op = OperationPtr(InstantiateOperation(key.hw_enforced_move(), key.sw_enforced_move(), 46 digest, pkey.release())); 47 if (!op) *error = KM_ERROR_MEMORY_ALLOCATION_FAILED; 48 return op; 49 } 50 51 const keymaster_digest_t* EcdsaOperationFactory::SupportedDigests(size_t* digest_count) const { 52 *digest_count = array_length(supported_digests); 53 return supported_digests; 54 } 55 56 EcdsaOperation::~EcdsaOperation() { 57 if (ecdsa_key_ != NULL) 58 EVP_PKEY_free(ecdsa_key_); 59 EVP_MD_CTX_cleanup(&digest_ctx_); 60 } 61 62 keymaster_error_t EcdsaOperation::InitDigest() { 63 switch (digest_) { 64 case KM_DIGEST_NONE: 65 return KM_ERROR_OK; 66 case KM_DIGEST_MD5: 67 return KM_ERROR_UNSUPPORTED_DIGEST; 68 case KM_DIGEST_SHA1: 69 digest_algorithm_ = EVP_sha1(); 70 return KM_ERROR_OK; 71 case KM_DIGEST_SHA_2_224: 72 digest_algorithm_ = EVP_sha224(); 73 return KM_ERROR_OK; 74 case KM_DIGEST_SHA_2_256: 75 digest_algorithm_ = EVP_sha256(); 76 return KM_ERROR_OK; 77 case KM_DIGEST_SHA_2_384: 78 digest_algorithm_ = EVP_sha384(); 79 return KM_ERROR_OK; 80 case KM_DIGEST_SHA_2_512: 81 digest_algorithm_ = EVP_sha512(); 82 return KM_ERROR_OK; 83 default: 84 return KM_ERROR_UNSUPPORTED_DIGEST; 85 } 86 } 87 88 inline size_t min(size_t a, size_t b) { 89 return (a < b) ? a : b; 90 } 91 92 keymaster_error_t EcdsaOperation::StoreData(const Buffer& input, size_t* input_consumed) { 93 if (!data_.reserve((EVP_PKEY_bits(ecdsa_key_) + 7) / 8)) 94 return KM_ERROR_MEMORY_ALLOCATION_FAILED; 95 96 if (!data_.write(input.peek_read(), min(data_.available_write(), input.available_read()))) 97 return KM_ERROR_UNKNOWN_ERROR; 98 99 *input_consumed = input.available_read(); 100 return KM_ERROR_OK; 101 } 102 103 keymaster_error_t EcdsaSignOperation::Begin(const AuthorizationSet& /* input_params */, 104 AuthorizationSet* /* output_params */) { 105 auto rc = GenerateRandom(reinterpret_cast<uint8_t*>(&operation_handle_), 106 (size_t)sizeof(operation_handle_)); 107 if (rc != KM_ERROR_OK) return rc; 108 109 keymaster_error_t error = InitDigest(); 110 if (error != KM_ERROR_OK) 111 return error; 112 113 if (digest_ == KM_DIGEST_NONE) 114 return KM_ERROR_OK; 115 116 EVP_PKEY_CTX* pkey_ctx; 117 if (EVP_DigestSignInit(&digest_ctx_, &pkey_ctx, digest_algorithm_, nullptr /* engine */, 118 ecdsa_key_) != 1) 119 return TranslateLastOpenSslError(); 120 return KM_ERROR_OK; 121 } 122 123 keymaster_error_t EcdsaSignOperation::Update(const AuthorizationSet& /* additional_params */, 124 const Buffer& input, 125 AuthorizationSet* /* output_params */, 126 Buffer* /* output */, size_t* input_consumed) { 127 if (digest_ == KM_DIGEST_NONE) 128 return StoreData(input, input_consumed); 129 130 if (EVP_DigestSignUpdate(&digest_ctx_, input.peek_read(), input.available_read()) != 1) 131 return TranslateLastOpenSslError(); 132 *input_consumed = input.available_read(); 133 return KM_ERROR_OK; 134 } 135 136 keymaster_error_t EcdsaSignOperation::Finish(const AuthorizationSet& additional_params, 137 const Buffer& input, const Buffer& /* signature */, 138 AuthorizationSet* /* output_params */, 139 Buffer* output) { 140 if (!output) 141 return KM_ERROR_OUTPUT_PARAMETER_NULL; 142 143 keymaster_error_t error = UpdateForFinish(additional_params, input); 144 if (error != KM_ERROR_OK) 145 return error; 146 147 size_t siglen; 148 if (digest_ == KM_DIGEST_NONE) { 149 UniquePtr<EC_KEY, EC_KEY_Delete> ecdsa(EVP_PKEY_get1_EC_KEY(ecdsa_key_)); 150 if (!ecdsa.get()) 151 return TranslateLastOpenSslError(); 152 153 output->Reinitialize(ECDSA_size(ecdsa.get())); 154 unsigned int siglen_tmp; 155 if (!ECDSA_sign(0 /* type -- ignored */, data_.peek_read(), data_.available_read(), 156 output->peek_write(), &siglen_tmp, ecdsa.get())) 157 return TranslateLastOpenSslError(); 158 siglen = siglen_tmp; 159 } else { 160 if (EVP_DigestSignFinal(&digest_ctx_, nullptr /* signature */, &siglen) != 1) 161 return TranslateLastOpenSslError(); 162 if (!output->Reinitialize(siglen)) 163 return KM_ERROR_MEMORY_ALLOCATION_FAILED; 164 if (EVP_DigestSignFinal(&digest_ctx_, output->peek_write(), &siglen) <= 0) 165 return TranslateLastOpenSslError(); 166 } 167 if (!output->advance_write(siglen)) 168 return KM_ERROR_UNKNOWN_ERROR; 169 return KM_ERROR_OK; 170 } 171 172 keymaster_error_t EcdsaVerifyOperation::Begin(const AuthorizationSet& /* input_params */, 173 AuthorizationSet* /* output_params */) { 174 auto rc = GenerateRandom(reinterpret_cast<uint8_t*>(&operation_handle_), 175 (size_t)sizeof(operation_handle_)); 176 if (rc != KM_ERROR_OK) return rc; 177 178 keymaster_error_t error = InitDigest(); 179 if (error != KM_ERROR_OK) 180 return error; 181 182 if (digest_ == KM_DIGEST_NONE) 183 return KM_ERROR_OK; 184 185 EVP_PKEY_CTX* pkey_ctx; 186 if (EVP_DigestVerifyInit(&digest_ctx_, &pkey_ctx, digest_algorithm_, nullptr /* engine */, 187 ecdsa_key_) != 1) 188 return TranslateLastOpenSslError(); 189 return KM_ERROR_OK; 190 } 191 192 keymaster_error_t EcdsaVerifyOperation::Update(const AuthorizationSet& /* additional_params */, 193 const Buffer& input, 194 AuthorizationSet* /* output_params */, 195 Buffer* /* output */, size_t* input_consumed) { 196 if (digest_ == KM_DIGEST_NONE) 197 return StoreData(input, input_consumed); 198 199 if (EVP_DigestVerifyUpdate(&digest_ctx_, input.peek_read(), input.available_read()) != 1) 200 return TranslateLastOpenSslError(); 201 *input_consumed = input.available_read(); 202 return KM_ERROR_OK; 203 } 204 205 keymaster_error_t EcdsaVerifyOperation::Finish(const AuthorizationSet& additional_params, 206 const Buffer& input, const Buffer& signature, 207 AuthorizationSet* /* output_params */, 208 Buffer* /* output */) { 209 keymaster_error_t error = UpdateForFinish(additional_params, input); 210 if (error != KM_ERROR_OK) 211 return error; 212 213 if (digest_ == KM_DIGEST_NONE) { 214 UniquePtr<EC_KEY, EC_KEY_Delete> ecdsa(EVP_PKEY_get1_EC_KEY(ecdsa_key_)); 215 if (!ecdsa.get()) 216 return TranslateLastOpenSslError(); 217 218 int result = 219 ECDSA_verify(0 /* type -- ignored */, data_.peek_read(), data_.available_read(), 220 signature.peek_read(), signature.available_read(), ecdsa.get()); 221 if (result < 0) 222 return TranslateLastOpenSslError(); 223 else if (result == 0) 224 return KM_ERROR_VERIFICATION_FAILED; 225 } else if (!EVP_DigestVerifyFinal(&digest_ctx_, signature.peek_read(), 226 signature.available_read())) 227 return KM_ERROR_VERIFICATION_FAILED; 228 229 return KM_ERROR_OK; 230 } 231 232 } // namespace keymaster 233
