Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 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 "hmac_operation.h" |
| 18 | |
| 19 | #include <openssl/evp.h> |
| 20 | #include <openssl/hmac.h> |
| 21 | |
Shawn Willden | 567a4a0 | 2014-12-31 12:14:46 -0700 | [diff] [blame] | 22 | #include "openssl_err.h" |
Shawn Willden | 63ac043 | 2014-12-29 14:07:08 -0700 | [diff] [blame] | 23 | #include "symmetric_key.h" |
| 24 | |
Shawn Willden | d79791b | 2015-05-09 12:48:36 +0000 | [diff] [blame] | 25 | #if defined(OPENSSL_IS_BORINGSSL) |
Adam Langley | c332655 | 2015-04-28 13:20:52 -0700 | [diff] [blame] | 26 | #include <openssl/mem.h> |
Shawn Willden | d79791b | 2015-05-09 12:48:36 +0000 | [diff] [blame] | 27 | typedef size_t openssl_size_t; |
| 28 | #else |
| 29 | typedef int openssl_size_t; |
| 30 | #endif |
| 31 | |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 32 | namespace keymaster { |
| 33 | |
Shawn Willden | 3ed6d06 | 2015-04-15 13:39:38 -0600 | [diff] [blame] | 34 | Operation* HmacOperationFactory::CreateOperation(const Key& key, |
Shawn Willden | 09f2527 | 2015-04-15 13:49:49 -0600 | [diff] [blame] | 35 | const AuthorizationSet& begin_params, |
Shawn Willden | 3ed6d06 | 2015-04-15 13:39:38 -0600 | [diff] [blame] | 36 | keymaster_error_t* error) { |
Shawn Willden | 09f2527 | 2015-04-15 13:49:49 -0600 | [diff] [blame] | 37 | uint32_t tag_length = 0; |
| 38 | begin_params.GetTagValue(TAG_MAC_LENGTH, &tag_length); |
Shawn Willden | 0c60f6f | 2015-04-27 23:40:10 -0600 | [diff] [blame] | 39 | if (tag_length % 8 != 0) { |
| 40 | LOG_E("MAC length %d nod a multiple of 8 bits", tag_length); |
| 41 | *error = KM_ERROR_UNSUPPORTED_MAC_LENGTH; |
| 42 | return nullptr; |
| 43 | } |
Shawn Willden | 63ac043 | 2014-12-29 14:07:08 -0700 | [diff] [blame] | 44 | |
Shawn Willden | 226746b | 2015-05-08 11:36:56 -0600 | [diff] [blame] | 45 | keymaster_digest_t digest; |
| 46 | if (!begin_params.GetTagValue(TAG_DIGEST, &digest)) { |
| 47 | LOG_E("%d digests specified in begin params", begin_params.GetTagCount(TAG_DIGEST)); |
| 48 | *error = KM_ERROR_UNSUPPORTED_DIGEST; |
| 49 | return nullptr; |
| 50 | } else if (!key.authorizations().Contains(TAG_DIGEST, digest)) { |
| 51 | LOG_E("Digest %d was specified, but not authorized by key", digest); |
| 52 | *error = KM_ERROR_INCOMPATIBLE_DIGEST; |
| 53 | return nullptr; |
| 54 | } |
Shawn Willden | 63ac043 | 2014-12-29 14:07:08 -0700 | [diff] [blame] | 55 | |
| 56 | const SymmetricKey* symmetric_key = static_cast<const SymmetricKey*>(&key); |
Shawn Willden | 0c60f6f | 2015-04-27 23:40:10 -0600 | [diff] [blame] | 57 | UniquePtr<HmacOperation> op(new HmacOperation(purpose(), symmetric_key->key_data(), |
| 58 | symmetric_key->key_data_size(), digest, |
| 59 | tag_length / 8)); |
Shawn Willden | 09f2527 | 2015-04-15 13:49:49 -0600 | [diff] [blame] | 60 | if (!op.get()) |
Shawn Willden | 63ac043 | 2014-12-29 14:07:08 -0700 | [diff] [blame] | 61 | *error = KM_ERROR_MEMORY_ALLOCATION_FAILED; |
Shawn Willden | 09f2527 | 2015-04-15 13:49:49 -0600 | [diff] [blame] | 62 | else |
| 63 | *error = op->error(); |
| 64 | |
| 65 | if (*error != KM_ERROR_OK) |
| 66 | return nullptr; |
| 67 | |
| 68 | return op.release(); |
Shawn Willden | 63ac043 | 2014-12-29 14:07:08 -0700 | [diff] [blame] | 69 | } |
| 70 | |
| 71 | static keymaster_digest_t supported_digests[] = {KM_DIGEST_SHA1, KM_DIGEST_SHA_2_224, |
| 72 | KM_DIGEST_SHA_2_256, KM_DIGEST_SHA_2_384, |
| 73 | KM_DIGEST_SHA_2_512}; |
| 74 | const keymaster_digest_t* HmacOperationFactory::SupportedDigests(size_t* digest_count) const { |
| 75 | *digest_count = array_length(supported_digests); |
| 76 | return supported_digests; |
| 77 | } |
| 78 | |
Shawn Willden | 567a4a0 | 2014-12-31 12:14:46 -0700 | [diff] [blame] | 79 | HmacOperation::HmacOperation(keymaster_purpose_t purpose, const uint8_t* key_data, |
| 80 | size_t key_data_size, keymaster_digest_t digest, size_t tag_length) |
| 81 | : Operation(purpose), error_(KM_ERROR_OK), tag_length_(tag_length) { |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 82 | // Initialize CTX first, so dtor won't crash even if we error out later. |
| 83 | HMAC_CTX_init(&ctx_); |
| 84 | |
Shawn Willden | 09f2527 | 2015-04-15 13:49:49 -0600 | [diff] [blame] | 85 | const EVP_MD* md = nullptr; |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 86 | switch (digest) { |
Shawn Willden | 09f2527 | 2015-04-15 13:49:49 -0600 | [diff] [blame] | 87 | case KM_DIGEST_NONE: |
| 88 | case KM_DIGEST_MD5: |
| 89 | error_ = KM_ERROR_UNSUPPORTED_DIGEST; |
| 90 | break; |
Shawn Willden | 51d5e0e | 2014-12-18 10:44:03 -0700 | [diff] [blame] | 91 | case KM_DIGEST_SHA1: |
| 92 | md = EVP_sha1(); |
| 93 | break; |
Shawn Willden | 62c2286 | 2014-12-17 08:36:20 -0700 | [diff] [blame] | 94 | case KM_DIGEST_SHA_2_224: |
| 95 | md = EVP_sha224(); |
| 96 | break; |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 97 | case KM_DIGEST_SHA_2_256: |
| 98 | md = EVP_sha256(); |
| 99 | break; |
Shawn Willden | 62c2286 | 2014-12-17 08:36:20 -0700 | [diff] [blame] | 100 | case KM_DIGEST_SHA_2_384: |
| 101 | md = EVP_sha384(); |
| 102 | break; |
| 103 | case KM_DIGEST_SHA_2_512: |
| 104 | md = EVP_sha512(); |
| 105 | break; |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 106 | } |
| 107 | |
Shawn Willden | 09f2527 | 2015-04-15 13:49:49 -0600 | [diff] [blame] | 108 | if (md == nullptr) { |
| 109 | error_ = KM_ERROR_UNSUPPORTED_DIGEST; |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 110 | return; |
| 111 | } |
| 112 | |
| 113 | HMAC_Init_ex(&ctx_, key_data, key_data_size, md, NULL /* engine */); |
| 114 | } |
| 115 | |
| 116 | HmacOperation::~HmacOperation() { |
| 117 | HMAC_CTX_cleanup(&ctx_); |
| 118 | } |
| 119 | |
Shawn Willden | 111edb3 | 2015-02-05 22:44:24 -0700 | [diff] [blame] | 120 | keymaster_error_t HmacOperation::Begin(const AuthorizationSet& /* input_params */, |
| 121 | AuthorizationSet* /* output_params */) { |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 122 | return error_; |
| 123 | } |
| 124 | |
Shawn Willden | 6bfbff0 | 2015-02-06 19:48:24 -0700 | [diff] [blame] | 125 | keymaster_error_t HmacOperation::Update(const AuthorizationSet& /* additional_params */, |
Shawn Willden | ded8e7d | 2015-06-01 15:29:12 -0600 | [diff] [blame] | 126 | const Buffer& input, AuthorizationSet* /* output_params */, |
| 127 | Buffer* /* output */, size_t* input_consumed) { |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 128 | if (!HMAC_Update(&ctx_, input.peek_read(), input.available_read())) |
Shawn Willden | 567a4a0 | 2014-12-31 12:14:46 -0700 | [diff] [blame] | 129 | return TranslateLastOpenSslError(); |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 130 | *input_consumed = input.available_read(); |
| 131 | return KM_ERROR_OK; |
| 132 | } |
| 133 | |
| 134 | keymaster_error_t HmacOperation::Abort() { |
| 135 | return KM_ERROR_OK; |
| 136 | } |
| 137 | |
Shawn Willden | 6bfbff0 | 2015-02-06 19:48:24 -0700 | [diff] [blame] | 138 | keymaster_error_t HmacOperation::Finish(const AuthorizationSet& /* additional_params */, |
Shawn Willden | ded8e7d | 2015-06-01 15:29:12 -0600 | [diff] [blame] | 139 | const Buffer& signature, |
| 140 | AuthorizationSet* /* output_params */, Buffer* output) { |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 141 | uint8_t digest[EVP_MAX_MD_SIZE]; |
| 142 | unsigned int digest_len; |
| 143 | if (!HMAC_Final(&ctx_, digest, &digest_len)) |
Shawn Willden | 567a4a0 | 2014-12-31 12:14:46 -0700 | [diff] [blame] | 144 | return TranslateLastOpenSslError(); |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 145 | |
| 146 | switch (purpose()) { |
| 147 | case KM_PURPOSE_SIGN: |
Shawn Willden | 09f2527 | 2015-04-15 13:49:49 -0600 | [diff] [blame] | 148 | if (tag_length_ > digest_len) |
| 149 | return KM_ERROR_UNSUPPORTED_MAC_LENGTH; |
| 150 | if (!output->reserve(tag_length_) || !output->write(digest, tag_length_)) |
| 151 | return KM_ERROR_MEMORY_ALLOCATION_FAILED; |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 152 | return KM_ERROR_OK; |
| 153 | case KM_PURPOSE_VERIFY: |
Shawn Willden | 09f2527 | 2015-04-15 13:49:49 -0600 | [diff] [blame] | 154 | if (signature.available_read() > digest_len) |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 155 | return KM_ERROR_INVALID_INPUT_LENGTH; |
Shawn Willden | 09f2527 | 2015-04-15 13:49:49 -0600 | [diff] [blame] | 156 | if (CRYPTO_memcmp(signature.peek_read(), digest, signature.available_read()) != 0) |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 157 | return KM_ERROR_VERIFICATION_FAILED; |
| 158 | return KM_ERROR_OK; |
| 159 | default: |
| 160 | return KM_ERROR_UNSUPPORTED_PURPOSE; |
| 161 | } |
| 162 | } |
| 163 | |
| 164 | } // namespace keymaster |