1/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
2 * Use of this source code is governed by a BSD-style license that can be
3 * found in the LICENSE file.
4 *
5 * Utility functions for message digest functions.
6 */
7
8#include "sysincludes.h"
9
10#include "cryptolib.h"
11#include "utility.h"
12#include "vboot_api.h"
13
14void DigestInit(DigestContext* ctx, int sig_algorithm) {
15  ctx->algorithm = hash_type_map[sig_algorithm];
16  switch(ctx->algorithm) {
17#ifndef CHROMEOS_EC
18    case SHA1_DIGEST_ALGORITHM:
19      ctx->sha1_ctx = (SHA1_CTX*) VbExMalloc(sizeof(SHA1_CTX));
20      SHA1_init(ctx->sha1_ctx);
21      break;
22#endif
23    case SHA256_DIGEST_ALGORITHM:
24      ctx->sha256_ctx = (VB_SHA256_CTX*) VbExMalloc(sizeof(VB_SHA256_CTX));
25      SHA256_init(ctx->sha256_ctx);
26      break;
27#ifndef CHROMEOS_EC
28    case SHA512_DIGEST_ALGORITHM:
29      ctx->sha512_ctx = (VB_SHA512_CTX*) VbExMalloc(sizeof(VB_SHA512_CTX));
30      SHA512_init(ctx->sha512_ctx);
31      break;
32#endif
33  };
34}
35
36void DigestUpdate(DigestContext* ctx, const uint8_t* data, uint32_t len) {
37  switch(ctx->algorithm) {
38#ifndef CHROMEOS_EC
39    case SHA1_DIGEST_ALGORITHM:
40      SHA1_update(ctx->sha1_ctx, data, len);
41      break;
42#endif
43    case SHA256_DIGEST_ALGORITHM:
44      SHA256_update(ctx->sha256_ctx, data, len);
45      break;
46#ifndef CHROMEOS_EC
47    case SHA512_DIGEST_ALGORITHM:
48      SHA512_update(ctx->sha512_ctx, data, len);
49      break;
50#endif
51  };
52}
53
54uint8_t* DigestFinal(DigestContext* ctx) {
55  uint8_t* digest = NULL;
56  switch(ctx->algorithm) {
57#ifndef CHROMEOS_EC
58    case SHA1_DIGEST_ALGORITHM:
59      digest = (uint8_t*) VbExMalloc(SHA1_DIGEST_SIZE);
60      Memcpy(digest, SHA1_final(ctx->sha1_ctx), SHA1_DIGEST_SIZE);
61      VbExFree(ctx->sha1_ctx);
62      break;
63#endif
64    case SHA256_DIGEST_ALGORITHM:
65      digest = (uint8_t*) VbExMalloc(SHA256_DIGEST_SIZE);
66      Memcpy(digest, SHA256_final(ctx->sha256_ctx), SHA256_DIGEST_SIZE);
67      VbExFree(ctx->sha256_ctx);
68      break;
69#ifndef CHROMEOS_EC
70    case SHA512_DIGEST_ALGORITHM:
71      digest = (uint8_t*) VbExMalloc(SHA512_DIGEST_SIZE);
72      Memcpy(digest, SHA512_final(ctx->sha512_ctx), SHA512_DIGEST_SIZE);
73      VbExFree(ctx->sha512_ctx);
74      break;
75#endif
76  };
77  return digest;
78}
79
80uint8_t* DigestBuf(const uint8_t* buf, uint64_t len, int sig_algorithm) {
81  /* Allocate enough space for the largest digest */
82  uint8_t* digest = (uint8_t*) VbExMalloc(SHA512_DIGEST_SIZE);
83  /* Define an array mapping [sig_algorithm] to function pointers to the
84   * SHA{1|256|512} functions.
85   */
86  typedef uint8_t* (*Hash_ptr) (const uint8_t*, uint64_t, uint8_t*);
87  Hash_ptr hash[] = {
88#ifdef CHROMEOS_EC
89    0,  /* RSA 1024 */
90    0,
91    0,
92    0,  /* RSA 2048 */
93    0,
94    0,
95    0,  /* RSA 4096 */
96    internal_SHA256,
97    0,
98    0,  /* RSA 8192 */
99    0,
100    0,
101#else
102    internal_SHA1,  /* RSA 1024 */
103    internal_SHA256,
104    internal_SHA512,
105    internal_SHA1,  /* RSA 2048 */
106    internal_SHA256,
107    internal_SHA512,
108    internal_SHA1,  /* RSA 4096 */
109    internal_SHA256,
110    internal_SHA512,
111    internal_SHA1,  /* RSA 8192 */
112    internal_SHA256,
113    internal_SHA512,
114#endif
115  };
116  /* Call the appropriate hash function. */
117  return hash[sig_algorithm](buf, len, digest);
118}
119