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 <keymaster/android_keymaster_utils.h>
18
19 #include <keymaster/new>
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)
29 return nullptr;
30 uint8_t* retval = new (std::nothrow) uint8_t[size];
31 if (retval)
32 memcpy(retval, buf, size);
33 return retval;
34 }
35
memcmp_s(const void * p1,const void * p2,size_t length)36 int memcmp_s(const void* p1, const void* p2, size_t length) {
37 const uint8_t* s1 = static_cast<const uint8_t*>(p1);
38 const uint8_t* s2 = static_cast<const uint8_t*>(p2);
39 uint8_t result = 0;
40 while (length-- > 0)
41 result |= *s1++ ^ *s2++;
42 return result == 0 ? 0 : 1;
43 }
44
EcKeySizeToCurve(uint32_t key_size_bits,keymaster_ec_curve_t * curve)45 keymaster_error_t EcKeySizeToCurve(uint32_t key_size_bits, keymaster_ec_curve_t* curve) {
46 switch (key_size_bits) {
47 default:
48 return KM_ERROR_UNSUPPORTED_KEY_SIZE;
49
50 case 224:
51 *curve = KM_EC_CURVE_P_224;
52 break;
53
54 case 256:
55 *curve = KM_EC_CURVE_P_256;
56 break;
57
58 case 384:
59 *curve = KM_EC_CURVE_P_384;
60 break;
61
62 case 521:
63 *curve = KM_EC_CURVE_P_521;
64 break;
65 }
66
67 return KM_ERROR_OK;
68 }
69
EcCurveToKeySize(keymaster_ec_curve_t curve,uint32_t * key_size_bits)70 keymaster_error_t EcCurveToKeySize(keymaster_ec_curve_t curve, uint32_t* key_size_bits) {
71 switch (curve) {
72 default:
73 return KM_ERROR_UNSUPPORTED_EC_CURVE;
74
75 case KM_EC_CURVE_P_224:
76 *key_size_bits = 224;
77 break;
78
79 case KM_EC_CURVE_P_256:
80 *key_size_bits = 256;
81 break;
82
83 case KM_EC_CURVE_P_384:
84 *key_size_bits = 384;
85 break;
86
87 case KM_EC_CURVE_P_521:
88 *key_size_bits = 521;
89 break;
90 }
91
92 return KM_ERROR_OK;
93 }
94
95 } // namespace keymaster
96