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 <new>
18
19 #include <keymaster/android_keymaster_utils.h>
20
21 namespace keymaster {
22
23 // Keymaster never manages enormous buffers, so anything particularly large is bad data or the
24 // result of a bug. We arbitrarily set a 16 MiB limit.
25 const size_t kMaxDupBufferSize = 16 * 1024 * 1024;
26
dup_buffer(const void * buf,size_t size)27 uint8_t* dup_buffer(const void* buf, size_t size) {
28 if (size >= kMaxDupBufferSize) return nullptr;
29 uint8_t* retval = new (std::nothrow) uint8_t[size];
30 if (retval) memcpy(retval, buf, size);
31 return retval;
32 }
33
memcmp_s(const void * p1,const void * p2,size_t length)34 int memcmp_s(const void* p1, const void* p2, size_t length) {
35 const uint8_t* s1 = static_cast<const uint8_t*>(p1);
36 const uint8_t* s2 = static_cast<const uint8_t*>(p2);
37 uint8_t result = 0;
38 for (; length > 0; length--)
39 result |= *s1++ ^ *s2++;
40 return result == 0 ? 0 : 1;
41 }
42
EllipticKeySizeToCurve(uint32_t key_size_bits,keymaster_ec_curve_t * curve)43 keymaster_error_t EllipticKeySizeToCurve(uint32_t key_size_bits, keymaster_ec_curve_t* curve) {
44 switch (key_size_bits) {
45 default:
46 return KM_ERROR_UNSUPPORTED_KEY_SIZE;
47
48 case 224:
49 *curve = KM_EC_CURVE_P_224;
50 break;
51
52 case 256:
53 // 256 bits could be P-256 or Curve25519
54 return KM_ERROR_UNSUPPORTED_KEY_SIZE;
55
56 case 384:
57 *curve = KM_EC_CURVE_P_384;
58 break;
59
60 case 521:
61 *curve = KM_EC_CURVE_P_521;
62 break;
63 }
64
65 return KM_ERROR_OK;
66 }
67
EcKeySizeToCurve(uint32_t key_size_bits,keymaster_ec_curve_t * curve)68 keymaster_error_t EcKeySizeToCurve(uint32_t key_size_bits, keymaster_ec_curve_t* curve) {
69 switch (key_size_bits) {
70 default:
71 return KM_ERROR_UNSUPPORTED_KEY_SIZE;
72
73 case 224:
74 *curve = KM_EC_CURVE_P_224;
75 break;
76
77 case 256:
78 *curve = KM_EC_CURVE_P_256;
79 break;
80
81 case 384:
82 *curve = KM_EC_CURVE_P_384;
83 break;
84
85 case 521:
86 *curve = KM_EC_CURVE_P_521;
87 break;
88 }
89
90 return KM_ERROR_OK;
91 }
92
EcCurveToKeySize(keymaster_ec_curve_t curve,uint32_t * key_size_bits)93 keymaster_error_t EcCurveToKeySize(keymaster_ec_curve_t curve, uint32_t* key_size_bits) {
94 switch (curve) {
95 default:
96 return KM_ERROR_UNSUPPORTED_EC_CURVE;
97
98 case KM_EC_CURVE_P_224:
99 *key_size_bits = 224;
100 break;
101
102 case KM_EC_CURVE_P_256:
103 *key_size_bits = 256;
104 break;
105
106 case KM_EC_CURVE_P_384:
107 *key_size_bits = 384;
108 break;
109
110 case KM_EC_CURVE_P_521:
111 *key_size_bits = 521;
112 break;
113
114 case KM_EC_CURVE_CURVE_25519:
115 *key_size_bits = 256;
116 break;
117 }
118
119 return KM_ERROR_OK;
120 }
121
122 } // namespace keymaster
123