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 "openssl_utils.h"
18
19 #include <keymaster/android_keymaster_utils.h>
20
21 #include "openssl_err.h"
22
23 namespace keymaster {
24
convert_to_evp(keymaster_algorithm_t algorithm)25 static int convert_to_evp(keymaster_algorithm_t algorithm) {
26 switch (algorithm) {
27 case KM_ALGORITHM_RSA:
28 return EVP_PKEY_RSA;
29 case KM_ALGORITHM_EC:
30 return EVP_PKEY_EC;
31 default:
32 return -1;
33 };
34 }
35
convert_pkcs8_blob_to_evp(const uint8_t * key_data,size_t key_length,keymaster_algorithm_t expected_algorithm,UniquePtr<EVP_PKEY,EVP_PKEY_Delete> * pkey)36 keymaster_error_t convert_pkcs8_blob_to_evp(const uint8_t* key_data, size_t key_length,
37 keymaster_algorithm_t expected_algorithm,
38 UniquePtr<EVP_PKEY, EVP_PKEY_Delete>* pkey) {
39 if (key_data == NULL || key_length <= 0)
40 return KM_ERROR_INVALID_KEY_BLOB;
41
42 UniquePtr<PKCS8_PRIV_KEY_INFO, PKCS8_PRIV_KEY_INFO_Delete> pkcs8(
43 d2i_PKCS8_PRIV_KEY_INFO(NULL, &key_data, key_length));
44 if (pkcs8.get() == NULL)
45 return TranslateLastOpenSslError(true /* log_message */);
46
47 pkey->reset(EVP_PKCS82PKEY(pkcs8.get()));
48 if (!pkey->get())
49 return TranslateLastOpenSslError(true /* log_message */);
50
51 if (EVP_PKEY_type((*pkey)->type) != convert_to_evp(expected_algorithm)) {
52 LOG_E("EVP key algorithm was %d, not the expected %d", EVP_PKEY_type((*pkey)->type),
53 convert_to_evp(expected_algorithm));
54 return KM_ERROR_INVALID_KEY_BLOB;
55 }
56
57 return KM_ERROR_OK;
58 }
59
KeyMaterialToEvpKey(keymaster_key_format_t key_format,const KeymasterKeyBlob & key_material,keymaster_algorithm_t expected_algorithm,UniquePtr<EVP_PKEY,EVP_PKEY_Delete> * pkey)60 keymaster_error_t KeyMaterialToEvpKey(keymaster_key_format_t key_format,
61 const KeymasterKeyBlob& key_material,
62 keymaster_algorithm_t expected_algorithm,
63 UniquePtr<EVP_PKEY, EVP_PKEY_Delete>* pkey) {
64 if (key_format != KM_KEY_FORMAT_PKCS8)
65 return KM_ERROR_UNSUPPORTED_KEY_FORMAT;
66
67 return convert_pkcs8_blob_to_evp(key_material.key_material, key_material.key_material_size,
68 expected_algorithm, pkey);
69 }
70
EvpKeyToKeyMaterial(const EVP_PKEY * pkey,KeymasterKeyBlob * key_blob)71 keymaster_error_t EvpKeyToKeyMaterial(const EVP_PKEY* pkey, KeymasterKeyBlob* key_blob) {
72 int key_data_size = i2d_PrivateKey(pkey, NULL /* key_data*/);
73 if (key_data_size <= 0)
74 return TranslateLastOpenSslError();
75
76 if (!key_blob->Reset(key_data_size))
77 return KM_ERROR_MEMORY_ALLOCATION_FAILED;
78
79 uint8_t* tmp = key_blob->writable_data();
80 i2d_PrivateKey(pkey, &tmp);
81
82 return KM_ERROR_OK;
83 }
84
85 } // namespace keymaster
86