Shawn Willden | 398c158 | 2015-05-28 00:04:06 -0600 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2015 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/ec_key_factory.h> |
| 18 | |
Shawn Willden | efbd7e4 | 2015-06-01 07:07:33 -0600 | [diff] [blame] | 19 | #include <openssl/evp.h> |
| 20 | |
Shawn Willden | 398c158 | 2015-05-28 00:04:06 -0600 | [diff] [blame] | 21 | #include <keymaster/keymaster_context.h> |
| 22 | |
| 23 | #include "ec_key.h" |
| 24 | #include "ecdsa_operation.h" |
| 25 | #include "openssl_err.h" |
| 26 | |
| 27 | namespace keymaster { |
| 28 | |
| 29 | static EcdsaSignOperationFactory sign_factory; |
| 30 | static EcdsaVerifyOperationFactory verify_factory; |
| 31 | |
| 32 | OperationFactory* EcKeyFactory::GetOperationFactory(keymaster_purpose_t purpose) const { |
| 33 | switch (purpose) { |
| 34 | case KM_PURPOSE_SIGN: |
| 35 | return &sign_factory; |
| 36 | case KM_PURPOSE_VERIFY: |
| 37 | return &verify_factory; |
| 38 | default: |
| 39 | return nullptr; |
| 40 | } |
| 41 | } |
| 42 | |
| 43 | keymaster_error_t EcKeyFactory::GenerateKey(const AuthorizationSet& key_description, |
| 44 | KeymasterKeyBlob* key_blob, |
| 45 | AuthorizationSet* hw_enforced, |
| 46 | AuthorizationSet* sw_enforced) const { |
| 47 | if (!key_blob || !hw_enforced || !sw_enforced) |
| 48 | return KM_ERROR_OUTPUT_PARAMETER_NULL; |
| 49 | |
| 50 | AuthorizationSet authorizations(key_description); |
| 51 | |
| 52 | uint32_t key_size; |
| 53 | if (!authorizations.GetTagValue(TAG_KEY_SIZE, &key_size)) { |
| 54 | LOG_E("%s", "No key size specified for EC key generation"); |
| 55 | return KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| 56 | } |
| 57 | |
| 58 | UniquePtr<EC_KEY, EC_Delete> ec_key(EC_KEY_new()); |
| 59 | UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey(EVP_PKEY_new()); |
| 60 | if (ec_key.get() == NULL || pkey.get() == NULL) |
| 61 | return KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| 62 | |
| 63 | UniquePtr<EC_GROUP, EC_GROUP_Delete> group(choose_group(key_size)); |
| 64 | if (group.get() == NULL) { |
| 65 | LOG_E("Unable to get EC group for key of size %d", key_size); |
| 66 | return KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| 67 | } |
| 68 | |
| 69 | #if !defined(OPENSSL_IS_BORINGSSL) |
| 70 | EC_GROUP_set_point_conversion_form(group.get(), POINT_CONVERSION_UNCOMPRESSED); |
| 71 | EC_GROUP_set_asn1_flag(group.get(), OPENSSL_EC_NAMED_CURVE); |
| 72 | #endif |
| 73 | |
| 74 | if (EC_KEY_set_group(ec_key.get(), group.get()) != 1 || |
| 75 | EC_KEY_generate_key(ec_key.get()) != 1 || EC_KEY_check_key(ec_key.get()) < 0) { |
| 76 | return TranslateLastOpenSslError(); |
| 77 | } |
| 78 | |
| 79 | if (EVP_PKEY_set1_EC_KEY(pkey.get(), ec_key.get()) != 1) |
| 80 | return TranslateLastOpenSslError(); |
| 81 | |
| 82 | KeymasterKeyBlob key_material; |
| 83 | keymaster_error_t error = EvpKeyToKeyMaterial(pkey.get(), &key_material); |
| 84 | if (error != KM_ERROR_OK) |
| 85 | return error; |
| 86 | |
| 87 | return context_->CreateKeyBlob(authorizations, KM_ORIGIN_GENERATED, key_material, key_blob, |
| 88 | hw_enforced, sw_enforced); |
| 89 | } |
| 90 | |
| 91 | keymaster_error_t EcKeyFactory::ImportKey(const AuthorizationSet& key_description, |
| 92 | keymaster_key_format_t input_key_material_format, |
| 93 | const KeymasterKeyBlob& input_key_material, |
| 94 | KeymasterKeyBlob* output_key_blob, |
| 95 | AuthorizationSet* hw_enforced, |
| 96 | AuthorizationSet* sw_enforced) const { |
| 97 | if (!output_key_blob || !hw_enforced || !sw_enforced) |
| 98 | return KM_ERROR_OUTPUT_PARAMETER_NULL; |
| 99 | |
| 100 | AuthorizationSet authorizations; |
| 101 | uint32_t key_size; |
| 102 | keymaster_error_t error = UpdateImportKeyDescription( |
| 103 | key_description, input_key_material_format, input_key_material, &authorizations, &key_size); |
| 104 | if (error != KM_ERROR_OK) |
| 105 | return error; |
| 106 | |
| 107 | return context_->CreateKeyBlob(authorizations, KM_ORIGIN_IMPORTED, input_key_material, |
| 108 | output_key_blob, hw_enforced, sw_enforced); |
| 109 | } |
| 110 | |
| 111 | keymaster_error_t EcKeyFactory::UpdateImportKeyDescription(const AuthorizationSet& key_description, |
| 112 | keymaster_key_format_t key_format, |
| 113 | const KeymasterKeyBlob& key_material, |
| 114 | AuthorizationSet* updated_description, |
| 115 | uint32_t* key_size_bits) const { |
| 116 | if (!updated_description || !key_size_bits) |
| 117 | return KM_ERROR_OUTPUT_PARAMETER_NULL; |
| 118 | |
| 119 | UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey; |
| 120 | keymaster_error_t error = |
| 121 | KeyMaterialToEvpKey(key_format, key_material, keymaster_key_type(), &pkey); |
| 122 | if (error != KM_ERROR_OK) |
| 123 | return error; |
| 124 | |
| 125 | UniquePtr<EC_KEY, EC_Delete> ec_key(EVP_PKEY_get1_EC_KEY(pkey.get())); |
| 126 | if (!ec_key.get()) |
| 127 | return TranslateLastOpenSslError(); |
| 128 | |
| 129 | updated_description->Reinitialize(key_description); |
| 130 | |
| 131 | size_t extracted_key_size_bits; |
| 132 | error = get_group_size(*EC_KEY_get0_group(ec_key.get()), &extracted_key_size_bits); |
| 133 | if (error != KM_ERROR_OK) |
| 134 | return error; |
| 135 | |
| 136 | *key_size_bits = extracted_key_size_bits; |
| 137 | if (!updated_description->GetTagValue(TAG_KEY_SIZE, key_size_bits)) |
| 138 | updated_description->push_back(TAG_KEY_SIZE, extracted_key_size_bits); |
| 139 | if (*key_size_bits != extracted_key_size_bits) |
| 140 | return KM_ERROR_IMPORT_PARAMETER_MISMATCH; |
| 141 | |
| 142 | keymaster_algorithm_t algorithm = KM_ALGORITHM_EC; |
| 143 | if (!updated_description->GetTagValue(TAG_ALGORITHM, &algorithm)) |
| 144 | updated_description->push_back(TAG_ALGORITHM, KM_ALGORITHM_EC); |
| 145 | if (algorithm != KM_ALGORITHM_EC) |
| 146 | return KM_ERROR_IMPORT_PARAMETER_MISMATCH; |
| 147 | |
| 148 | return KM_ERROR_OK; |
| 149 | } |
| 150 | |
| 151 | /* static */ |
| 152 | EC_GROUP* EcKeyFactory::choose_group(size_t key_size_bits) { |
| 153 | switch (key_size_bits) { |
| 154 | case 224: |
| 155 | return EC_GROUP_new_by_curve_name(NID_secp224r1); |
| 156 | break; |
| 157 | case 256: |
| 158 | return EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1); |
| 159 | break; |
| 160 | case 384: |
| 161 | return EC_GROUP_new_by_curve_name(NID_secp384r1); |
| 162 | break; |
| 163 | case 521: |
| 164 | return EC_GROUP_new_by_curve_name(NID_secp521r1); |
| 165 | break; |
| 166 | default: |
| 167 | return NULL; |
| 168 | break; |
| 169 | } |
| 170 | } |
| 171 | /* static */ |
| 172 | keymaster_error_t EcKeyFactory::get_group_size(const EC_GROUP& group, size_t* key_size_bits) { |
| 173 | switch (EC_GROUP_get_curve_name(&group)) { |
| 174 | case NID_secp224r1: |
| 175 | *key_size_bits = 224; |
| 176 | break; |
| 177 | case NID_X9_62_prime256v1: |
| 178 | *key_size_bits = 256; |
| 179 | break; |
| 180 | case NID_secp384r1: |
| 181 | *key_size_bits = 384; |
| 182 | break; |
| 183 | case NID_secp521r1: |
| 184 | *key_size_bits = 521; |
| 185 | break; |
| 186 | default: |
| 187 | return KM_ERROR_UNSUPPORTED_EC_FIELD; |
| 188 | } |
| 189 | return KM_ERROR_OK; |
| 190 | } |
| 191 | |
| 192 | keymaster_error_t EcKeyFactory::CreateEmptyKey(const AuthorizationSet& hw_enforced, |
| 193 | const AuthorizationSet& sw_enforced, |
| 194 | UniquePtr<AsymmetricKey>* key) const { |
| 195 | keymaster_error_t error; |
Shawn Willden | 0f906ec | 2015-06-20 09:16:30 -0600 | [diff] [blame] | 196 | key->reset(new (std::nothrow) EcKey(hw_enforced, sw_enforced, &error)); |
Shawn Willden | 398c158 | 2015-05-28 00:04:06 -0600 | [diff] [blame] | 197 | if (!key->get()) |
| 198 | error = KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| 199 | return error; |
| 200 | } |
| 201 | |
| 202 | } // namespace keymaster |