Shawn Willden | 95e1382 | 2014-12-15 16:12:16 -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 "symmetric_key.h" |
| 18 | |
| 19 | #include <assert.h> |
| 20 | |
| 21 | #include <openssl/err.h> |
| 22 | #include <openssl/rand.h> |
| 23 | |
Shawn Willden | 0629810 | 2015-05-25 23:12:48 -0600 | [diff] [blame] | 24 | #include <keymaster/android_keymaster_utils.h> |
Shawn Willden | 567a4a0 | 2014-12-31 12:14:46 -0700 | [diff] [blame] | 25 | #include <keymaster/logger.h> |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 26 | #include <keymaster/keymaster_context.h> |
Shawn Willden | 567a4a0 | 2014-12-31 12:14:46 -0700 | [diff] [blame] | 27 | |
Shawn Willden | 95e1382 | 2014-12-15 16:12:16 -0700 | [diff] [blame] | 28 | #include "aes_key.h" |
Shawn Willden | 0d560bf | 2014-12-15 17:44:02 -0700 | [diff] [blame] | 29 | #include "hmac_key.h" |
Shawn Willden | 567a4a0 | 2014-12-31 12:14:46 -0700 | [diff] [blame] | 30 | #include "openssl_err.h" |
Shawn Willden | 95e1382 | 2014-12-15 16:12:16 -0700 | [diff] [blame] | 31 | |
| 32 | namespace keymaster { |
| 33 | |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 34 | keymaster_error_t SymmetricKeyFactory::GenerateKey(const AuthorizationSet& key_description, |
| 35 | KeymasterKeyBlob* key_blob, |
| 36 | AuthorizationSet* hw_enforced, |
Shawn Willden | 0629810 | 2015-05-25 23:12:48 -0600 | [diff] [blame] | 37 | AuthorizationSet* sw_enforced) const { |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 38 | if (!key_blob || !hw_enforced || !sw_enforced) |
| 39 | return KM_ERROR_OUTPUT_PARAMETER_NULL; |
Shawn Willden | 7dad93b | 2015-02-05 10:20:47 -0700 | [diff] [blame] | 40 | |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 41 | uint32_t key_size_bits; |
| 42 | if (!key_description.GetTagValue(TAG_KEY_SIZE, &key_size_bits) || |
| 43 | !key_size_supported(key_size_bits)) |
| 44 | return KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| 45 | |
Shawn Willden | 33ab038 | 2015-07-08 08:47:25 -0600 | [diff] [blame] | 46 | keymaster_error_t error = validate_algorithm_specific_new_key_params(key_description); |
| 47 | if (error != KM_ERROR_OK) |
| 48 | return error; |
| 49 | |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 50 | size_t key_data_size = key_size_bits / 8; |
| 51 | KeymasterKeyBlob key_material(key_data_size); |
| 52 | if (!key_material.key_material) |
| 53 | return KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| 54 | |
Shawn Willden | 33ab038 | 2015-07-08 08:47:25 -0600 | [diff] [blame] | 55 | error = context_->GenerateRandom(key_material.writable_data(), key_data_size); |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 56 | if (error != KM_ERROR_OK) { |
| 57 | LOG_E("Error generating %d bit symmetric key", key_size_bits); |
| 58 | return error; |
Shawn Willden | 7dad93b | 2015-02-05 10:20:47 -0700 | [diff] [blame] | 59 | } |
| 60 | |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 61 | return context_->CreateKeyBlob(key_description, KM_ORIGIN_GENERATED, key_material, key_blob, |
| 62 | hw_enforced, sw_enforced); |
Shawn Willden | 7dad93b | 2015-02-05 10:20:47 -0700 | [diff] [blame] | 63 | } |
| 64 | |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 65 | keymaster_error_t SymmetricKeyFactory::ImportKey(const AuthorizationSet& key_description, |
| 66 | keymaster_key_format_t input_key_material_format, |
| 67 | const KeymasterKeyBlob& input_key_material, |
| 68 | KeymasterKeyBlob* output_key_blob, |
| 69 | AuthorizationSet* hw_enforced, |
Shawn Willden | 0629810 | 2015-05-25 23:12:48 -0600 | [diff] [blame] | 70 | AuthorizationSet* sw_enforced) const { |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 71 | if (!output_key_blob || !hw_enforced || !sw_enforced) |
| 72 | return KM_ERROR_OUTPUT_PARAMETER_NULL; |
Shawn Willden | 7dad93b | 2015-02-05 10:20:47 -0700 | [diff] [blame] | 73 | |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 74 | AuthorizationSet authorizations(key_description); |
| 75 | |
| 76 | uint32_t key_size_bits; |
| 77 | if (!authorizations.GetTagValue(TAG_KEY_SIZE, &key_size_bits)) { |
| 78 | // Default key size if not specified. |
| 79 | key_size_bits = input_key_material.key_material_size * 8; |
| 80 | authorizations.push_back(TAG_KEY_SIZE, key_size_bits); |
Shawn Willden | 7dad93b | 2015-02-05 10:20:47 -0700 | [diff] [blame] | 81 | } |
| 82 | |
Shawn Willden | 33ab038 | 2015-07-08 08:47:25 -0600 | [diff] [blame] | 83 | keymaster_error_t error = validate_algorithm_specific_new_key_params(key_description); |
| 84 | if (error != KM_ERROR_OK) |
| 85 | return error; |
| 86 | |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 87 | if (!key_size_supported(key_size_bits)) |
| 88 | return KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| 89 | |
| 90 | if (input_key_material_format != KM_KEY_FORMAT_RAW) |
| 91 | return KM_ERROR_UNSUPPORTED_KEY_FORMAT; |
| 92 | |
| 93 | if (key_size_bits != input_key_material.key_material_size * 8) { |
| 94 | LOG_E("Expected %d-bit key data but got %d bits", key_size_bits, |
| 95 | input_key_material.key_material_size * 8); |
| 96 | return KM_ERROR_INVALID_KEY_BLOB; |
Shawn Willden | 7dad93b | 2015-02-05 10:20:47 -0700 | [diff] [blame] | 97 | } |
| 98 | |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 99 | return context_->CreateKeyBlob(authorizations, KM_ORIGIN_IMPORTED, input_key_material, |
| 100 | output_key_blob, hw_enforced, sw_enforced); |
Shawn Willden | 7dad93b | 2015-02-05 10:20:47 -0700 | [diff] [blame] | 101 | } |
| 102 | |
| 103 | static const keymaster_key_format_t supported_import_formats[] = {KM_KEY_FORMAT_RAW}; |
Shawn Willden | 0629810 | 2015-05-25 23:12:48 -0600 | [diff] [blame] | 104 | const keymaster_key_format_t* |
| 105 | SymmetricKeyFactory::SupportedImportFormats(size_t* format_count) const { |
Shawn Willden | 7dad93b | 2015-02-05 10:20:47 -0700 | [diff] [blame] | 106 | *format_count = array_length(supported_import_formats); |
| 107 | return supported_import_formats; |
| 108 | } |
| 109 | |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 110 | SymmetricKey::SymmetricKey(const KeymasterKeyBlob& key_material, |
| 111 | const AuthorizationSet& hw_enforced, const AuthorizationSet& sw_enforced, |
| 112 | keymaster_error_t* error) |
| 113 | : Key(hw_enforced, sw_enforced, error) { |
Shawn Willden | 13fbe3e | 2015-05-23 03:36:30 +0000 | [diff] [blame] | 114 | if (*error != KM_ERROR_OK) |
Shawn Willden | 13fbe3e | 2015-05-23 03:36:30 +0000 | [diff] [blame] | 115 | return; |
Shawn Willden | 13fbe3e | 2015-05-23 03:36:30 +0000 | [diff] [blame] | 116 | |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 117 | uint8_t* tmp = dup_buffer(key_material.key_material, key_material.key_material_size); |
| 118 | if (tmp) { |
| 119 | key_data_.reset(tmp); |
| 120 | key_data_size_ = key_material.key_material_size; |
Shawn Willden | 13fbe3e | 2015-05-23 03:36:30 +0000 | [diff] [blame] | 121 | *error = KM_ERROR_OK; |
Shawn Willden | 0cb6942 | 2015-05-26 08:31:37 -0600 | [diff] [blame] | 122 | } else { |
| 123 | *error = KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| 124 | } |
Shawn Willden | 95e1382 | 2014-12-15 16:12:16 -0700 | [diff] [blame] | 125 | } |
| 126 | |
| 127 | SymmetricKey::~SymmetricKey() { |
Shawn Willden | 7dad93b | 2015-02-05 10:20:47 -0700 | [diff] [blame] | 128 | memset_s(key_data_.get(), 0, key_data_size_); |
Shawn Willden | 95e1382 | 2014-12-15 16:12:16 -0700 | [diff] [blame] | 129 | } |
| 130 | |
Shawn Willden | 95e1382 | 2014-12-15 16:12:16 -0700 | [diff] [blame] | 131 | keymaster_error_t SymmetricKey::key_material(UniquePtr<uint8_t[]>* key_material, |
| 132 | size_t* size) const { |
| 133 | *size = key_data_size_; |
Shawn Willden | 0f906ec | 2015-06-20 09:16:30 -0600 | [diff] [blame] | 134 | key_material->reset(new (std::nothrow) uint8_t[*size]); |
Shawn Willden | 95e1382 | 2014-12-15 16:12:16 -0700 | [diff] [blame] | 135 | if (!key_material->get()) |
| 136 | return KM_ERROR_MEMORY_ALLOCATION_FAILED; |
Shawn Willden | 7dad93b | 2015-02-05 10:20:47 -0700 | [diff] [blame] | 137 | memcpy(key_material->get(), key_data_.get(), *size); |
| 138 | return KM_ERROR_OK; |
| 139 | } |
| 140 | |
Shawn Willden | 95e1382 | 2014-12-15 16:12:16 -0700 | [diff] [blame] | 141 | } // namespace keymaster |