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/rsa_key_factory.h> |
| 18 | |
Shawn Willden | 0f906ec | 2015-06-20 09:16:30 -0600 | [diff] [blame] | 19 | #include <new> |
| 20 | |
Shawn Willden | 398c158 | 2015-05-28 00:04:06 -0600 | [diff] [blame] | 21 | #include <keymaster/keymaster_context.h> |
| 22 | |
| 23 | #include "openssl_err.h" |
| 24 | #include "openssl_utils.h" |
| 25 | #include "rsa_key.h" |
| 26 | #include "rsa_operation.h" |
| 27 | |
Shawn Willden | 398c158 | 2015-05-28 00:04:06 -0600 | [diff] [blame] | 28 | namespace keymaster { |
| 29 | |
Shawn Willden | d530305 | 2015-06-22 05:25:59 -0600 | [diff] [blame] | 30 | const int kMaximumRsaKeySize = 16 * 1024; // 16kbits should be enough for anyone. |
| 31 | |
Shawn Willden | 398c158 | 2015-05-28 00:04:06 -0600 | [diff] [blame] | 32 | static RsaSigningOperationFactory sign_factory; |
| 33 | static RsaVerificationOperationFactory verify_factory; |
| 34 | static RsaEncryptionOperationFactory encrypt_factory; |
| 35 | static RsaDecryptionOperationFactory decrypt_factory; |
| 36 | |
| 37 | OperationFactory* RsaKeyFactory::GetOperationFactory(keymaster_purpose_t purpose) const { |
| 38 | switch (purpose) { |
| 39 | case KM_PURPOSE_SIGN: |
| 40 | return &sign_factory; |
| 41 | case KM_PURPOSE_VERIFY: |
| 42 | return &verify_factory; |
| 43 | case KM_PURPOSE_ENCRYPT: |
| 44 | return &encrypt_factory; |
| 45 | case KM_PURPOSE_DECRYPT: |
| 46 | return &decrypt_factory; |
| 47 | default: |
| 48 | return nullptr; |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | keymaster_error_t RsaKeyFactory::GenerateKey(const AuthorizationSet& key_description, |
| 53 | KeymasterKeyBlob* key_blob, |
| 54 | AuthorizationSet* hw_enforced, |
| 55 | AuthorizationSet* sw_enforced) const { |
| 56 | if (!key_blob || !hw_enforced || !sw_enforced) |
| 57 | return KM_ERROR_OUTPUT_PARAMETER_NULL; |
| 58 | |
| 59 | AuthorizationSet authorizations(key_description); |
| 60 | |
| 61 | uint64_t public_exponent; |
| 62 | if (!authorizations.GetTagValue(TAG_RSA_PUBLIC_EXPONENT, &public_exponent)) { |
| 63 | LOG_E("%s", "No public exponent specified for RSA key generation"); |
| 64 | return KM_ERROR_INVALID_ARGUMENT; |
| 65 | } |
| 66 | |
| 67 | uint32_t key_size; |
| 68 | if (!authorizations.GetTagValue(TAG_KEY_SIZE, &key_size)) { |
Shawn Willden | d530305 | 2015-06-22 05:25:59 -0600 | [diff] [blame] | 69 | LOG_E("No key size specified for RSA key generation", 0); |
| 70 | return KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| 71 | } |
| 72 | if (key_size % 8 != 0 || key_size > kMaximumRsaKeySize) { |
| 73 | LOG_E("Invalid key size of %u bits specified for RSA key generation", key_size); |
Shawn Willden | 398c158 | 2015-05-28 00:04:06 -0600 | [diff] [blame] | 74 | return KM_ERROR_UNSUPPORTED_KEY_SIZE; |
| 75 | } |
| 76 | |
| 77 | UniquePtr<BIGNUM, BIGNUM_Delete> exponent(BN_new()); |
| 78 | UniquePtr<RSA, RsaKey::RSA_Delete> rsa_key(RSA_new()); |
| 79 | UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey(EVP_PKEY_new()); |
| 80 | if (exponent.get() == NULL || rsa_key.get() == NULL || pkey.get() == NULL) |
| 81 | return KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| 82 | |
| 83 | if (!BN_set_word(exponent.get(), public_exponent) || |
| 84 | !RSA_generate_key_ex(rsa_key.get(), key_size, exponent.get(), NULL /* callback */)) |
| 85 | return TranslateLastOpenSslError(); |
| 86 | |
| 87 | if (EVP_PKEY_set1_RSA(pkey.get(), rsa_key.get()) != 1) |
| 88 | return TranslateLastOpenSslError(); |
| 89 | |
| 90 | KeymasterKeyBlob key_material; |
| 91 | keymaster_error_t error = EvpKeyToKeyMaterial(pkey.get(), &key_material); |
| 92 | if (error != KM_ERROR_OK) |
| 93 | return error; |
| 94 | |
| 95 | return context_->CreateKeyBlob(authorizations, KM_ORIGIN_GENERATED, key_material, key_blob, |
| 96 | hw_enforced, sw_enforced); |
| 97 | } |
| 98 | |
| 99 | keymaster_error_t RsaKeyFactory::ImportKey(const AuthorizationSet& key_description, |
| 100 | keymaster_key_format_t input_key_material_format, |
| 101 | const KeymasterKeyBlob& input_key_material, |
| 102 | KeymasterKeyBlob* output_key_blob, |
| 103 | AuthorizationSet* hw_enforced, |
| 104 | AuthorizationSet* sw_enforced) const { |
| 105 | if (!output_key_blob || !hw_enforced || !sw_enforced) |
| 106 | return KM_ERROR_OUTPUT_PARAMETER_NULL; |
| 107 | |
| 108 | AuthorizationSet authorizations; |
| 109 | uint64_t public_exponent; |
| 110 | uint32_t key_size; |
| 111 | keymaster_error_t error = |
| 112 | UpdateImportKeyDescription(key_description, input_key_material_format, input_key_material, |
| 113 | &authorizations, &public_exponent, &key_size); |
| 114 | if (error != KM_ERROR_OK) |
| 115 | return error; |
| 116 | return context_->CreateKeyBlob(authorizations, KM_ORIGIN_IMPORTED, input_key_material, |
| 117 | output_key_blob, hw_enforced, sw_enforced); |
| 118 | } |
| 119 | |
| 120 | keymaster_error_t RsaKeyFactory::UpdateImportKeyDescription(const AuthorizationSet& key_description, |
| 121 | keymaster_key_format_t key_format, |
| 122 | const KeymasterKeyBlob& key_material, |
| 123 | AuthorizationSet* updated_description, |
| 124 | uint64_t* public_exponent, |
| 125 | uint32_t* key_size) const { |
| 126 | if (!updated_description || !public_exponent || !key_size) |
| 127 | return KM_ERROR_OUTPUT_PARAMETER_NULL; |
| 128 | |
| 129 | UniquePtr<EVP_PKEY, EVP_PKEY_Delete> pkey; |
| 130 | keymaster_error_t error = |
| 131 | KeyMaterialToEvpKey(key_format, key_material, keymaster_key_type(), &pkey); |
| 132 | if (error != KM_ERROR_OK) |
| 133 | return error; |
| 134 | |
| 135 | UniquePtr<RSA, RsaKey::RSA_Delete> rsa_key(EVP_PKEY_get1_RSA(pkey.get())); |
| 136 | if (!rsa_key.get()) |
| 137 | return TranslateLastOpenSslError(); |
| 138 | |
| 139 | updated_description->Reinitialize(key_description); |
| 140 | |
| 141 | *public_exponent = BN_get_word(rsa_key->e); |
| 142 | if (*public_exponent == 0xffffffffL) |
| 143 | return KM_ERROR_INVALID_KEY_BLOB; |
| 144 | if (!updated_description->GetTagValue(TAG_RSA_PUBLIC_EXPONENT, public_exponent)) |
| 145 | updated_description->push_back(TAG_RSA_PUBLIC_EXPONENT, *public_exponent); |
Shawn Willden | d530305 | 2015-06-22 05:25:59 -0600 | [diff] [blame] | 146 | if (*public_exponent != BN_get_word(rsa_key->e)) { |
| 147 | LOG_E("Imported public exponent (%u) does not match specified public exponent (%u)", |
| 148 | *public_exponent, BN_get_word(rsa_key->e)); |
Shawn Willden | 398c158 | 2015-05-28 00:04:06 -0600 | [diff] [blame] | 149 | return KM_ERROR_IMPORT_PARAMETER_MISMATCH; |
Shawn Willden | d530305 | 2015-06-22 05:25:59 -0600 | [diff] [blame] | 150 | } |
Shawn Willden | 398c158 | 2015-05-28 00:04:06 -0600 | [diff] [blame] | 151 | |
| 152 | *key_size = RSA_size(rsa_key.get()) * 8; |
| 153 | if (!updated_description->GetTagValue(TAG_KEY_SIZE, key_size)) |
| 154 | updated_description->push_back(TAG_KEY_SIZE, *key_size); |
Shawn Willden | d530305 | 2015-06-22 05:25:59 -0600 | [diff] [blame] | 155 | if (RSA_size(rsa_key.get()) * 8 != *key_size) { |
| 156 | LOG_E("Imported key size (%u bits) does not match specified key size (%u bits)", |
| 157 | RSA_size(rsa_key.get()) * 8, *key_size); |
Shawn Willden | 398c158 | 2015-05-28 00:04:06 -0600 | [diff] [blame] | 158 | return KM_ERROR_IMPORT_PARAMETER_MISMATCH; |
Shawn Willden | d530305 | 2015-06-22 05:25:59 -0600 | [diff] [blame] | 159 | } |
Shawn Willden | 398c158 | 2015-05-28 00:04:06 -0600 | [diff] [blame] | 160 | |
| 161 | keymaster_algorithm_t algorithm = KM_ALGORITHM_RSA; |
| 162 | if (!updated_description->GetTagValue(TAG_ALGORITHM, &algorithm)) |
| 163 | updated_description->push_back(TAG_ALGORITHM, KM_ALGORITHM_RSA); |
| 164 | if (algorithm != KM_ALGORITHM_RSA) |
| 165 | return KM_ERROR_IMPORT_PARAMETER_MISMATCH; |
| 166 | |
| 167 | return KM_ERROR_OK; |
| 168 | } |
| 169 | |
| 170 | keymaster_error_t RsaKeyFactory::CreateEmptyKey(const AuthorizationSet& hw_enforced, |
| 171 | const AuthorizationSet& sw_enforced, |
| 172 | UniquePtr<AsymmetricKey>* key) const { |
| 173 | keymaster_error_t error; |
Shawn Willden | 0f906ec | 2015-06-20 09:16:30 -0600 | [diff] [blame] | 174 | key->reset(new (std::nothrow) RsaKey(hw_enforced, sw_enforced, &error)); |
Shawn Willden | 398c158 | 2015-05-28 00:04:06 -0600 | [diff] [blame] | 175 | if (!key->get()) |
| 176 | error = KM_ERROR_MEMORY_ALLOCATION_FAILED; |
| 177 | return error; |
| 178 | } |
| 179 | |
| 180 | } // namespace keymaster |