1 /*
2  * Copyright (C) 2016 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 #ifndef NVRAM_CORE_CRYPTO_H_
18 #define NVRAM_CORE_CRYPTO_H_
19 
20 extern "C" {
21 #include <stddef.h>
22 #include <stdint.h>
23 }  // extern "C"
24 
25 namespace nvram {
26 namespace crypto {
27 
28 // Size of a SHA-256 digest in bytes.
29 constexpr size_t kSHA256DigestSize = 32;
30 
31 // Computes the SHA-256 digest of the |data_size| input bytes stored at |data|.
32 // The digest is written to |digest|, which is a buffer of size |digest_size|.
33 // Note that |digest_size| doesn't have to match SHA-256's output size of 32
34 // bytes. If it doesn't the digest is truncated or zero-padded as necessary.
35 //
36 // Returns true if the digest was computed successfully, false otherwise.
37 void SHA256(const uint8_t* data,
38             size_t data_size,
39             uint8_t* digest,
40             size_t digest_size);
41 
42 }  // namespace crypto
43 }  // namespace nvram
44 
45 #endif  // NVRAM_CORE_CRYPTO_H_
46