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 
DigestInit(DigestContext * ctx,int sig_algorithm)14 void 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 
DigestUpdate(DigestContext * ctx,const uint8_t * data,uint32_t len)36 void 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 
DigestFinal(DigestContext * ctx)54 uint8_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 
DigestBuf(const uint8_t * buf,uint64_t len,int sig_algorithm)80 uint8_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