1 /*
2 * Copyright (C) 2004-2007, 2009 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 2000, 2001 Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 /* $Id: hmacmd5.c,v 1.16 2009/02/06 23:47:42 tbox Exp $ */
19
20 /*! \file
21 * This code implements the HMAC-MD5 keyed hash algorithm
22 * described in RFC2104.
23 */
24
25 #include "config.h"
26
27 #include <isc/assertions.h>
28 #include <isc/hmacmd5.h>
29 #include <isc/md5.h>
30 #include <isc/platform.h>
31 #include <isc/string.h>
32 #include <isc/types.h>
33 #include <isc/util.h>
34
35 #ifdef ISC_PLATFORM_OPENSSLHASH
36
37 void
isc_hmacmd5_init(isc_hmacmd5_t * ctx,const unsigned char * key,unsigned int len)38 isc_hmacmd5_init(isc_hmacmd5_t *ctx, const unsigned char *key,
39 unsigned int len)
40 {
41 HMAC_Init(ctx, (const void *) key, (int) len, EVP_md5());
42 }
43
44 void
isc_hmacmd5_invalidate(isc_hmacmd5_t * ctx)45 isc_hmacmd5_invalidate(isc_hmacmd5_t *ctx) {
46 HMAC_CTX_cleanup(ctx);
47 }
48
49 void
isc_hmacmd5_update(isc_hmacmd5_t * ctx,const unsigned char * buf,unsigned int len)50 isc_hmacmd5_update(isc_hmacmd5_t *ctx, const unsigned char *buf,
51 unsigned int len)
52 {
53 HMAC_Update(ctx, buf, (int) len);
54 }
55
56 void
isc_hmacmd5_sign(isc_hmacmd5_t * ctx,unsigned char * digest)57 isc_hmacmd5_sign(isc_hmacmd5_t *ctx, unsigned char *digest) {
58 HMAC_Final(ctx, digest, NULL);
59 HMAC_CTX_cleanup(ctx);
60 }
61
62 #else
63
64 #define PADLEN 64
65 #define IPAD 0x36
66 #define OPAD 0x5C
67
68 /*!
69 * Start HMAC-MD5 process. Initialize an md5 context and digest the key.
70 */
71 void
isc_hmacmd5_init(isc_hmacmd5_t * ctx,const unsigned char * key,unsigned int len)72 isc_hmacmd5_init(isc_hmacmd5_t *ctx, const unsigned char *key,
73 unsigned int len)
74 {
75 unsigned char ipad[PADLEN];
76 int i;
77
78 memset(ctx->key, 0, sizeof(ctx->key));
79 if (len > sizeof(ctx->key)) {
80 isc_md5_t md5ctx;
81 isc_md5_init(&md5ctx);
82 isc_md5_update(&md5ctx, key, len);
83 isc_md5_final(&md5ctx, ctx->key);
84 } else
85 memcpy(ctx->key, key, len);
86
87 isc_md5_init(&ctx->md5ctx);
88 memset(ipad, IPAD, sizeof(ipad));
89 for (i = 0; i < PADLEN; i++)
90 ipad[i] ^= ctx->key[i];
91 isc_md5_update(&ctx->md5ctx, ipad, sizeof(ipad));
92 }
93
94 void
isc_hmacmd5_invalidate(isc_hmacmd5_t * ctx)95 isc_hmacmd5_invalidate(isc_hmacmd5_t *ctx) {
96 isc_md5_invalidate(&ctx->md5ctx);
97 memset(ctx->key, 0, sizeof(ctx->key));
98 }
99
100 /*!
101 * Update context to reflect the concatenation of another buffer full
102 * of bytes.
103 */
104 void
isc_hmacmd5_update(isc_hmacmd5_t * ctx,const unsigned char * buf,unsigned int len)105 isc_hmacmd5_update(isc_hmacmd5_t *ctx, const unsigned char *buf,
106 unsigned int len)
107 {
108 isc_md5_update(&ctx->md5ctx, buf, len);
109 }
110
111 /*!
112 * Compute signature - finalize MD5 operation and reapply MD5.
113 */
114 void
isc_hmacmd5_sign(isc_hmacmd5_t * ctx,unsigned char * digest)115 isc_hmacmd5_sign(isc_hmacmd5_t *ctx, unsigned char *digest) {
116 unsigned char opad[PADLEN];
117 int i;
118
119 isc_md5_final(&ctx->md5ctx, digest);
120
121 memset(opad, OPAD, sizeof(opad));
122 for (i = 0; i < PADLEN; i++)
123 opad[i] ^= ctx->key[i];
124
125 isc_md5_init(&ctx->md5ctx);
126 isc_md5_update(&ctx->md5ctx, opad, sizeof(opad));
127 isc_md5_update(&ctx->md5ctx, digest, ISC_MD5_DIGESTLENGTH);
128 isc_md5_final(&ctx->md5ctx, digest);
129 isc_hmacmd5_invalidate(ctx);
130 }
131 #endif /* !ISC_PLATFORM_OPENSSLHASH */
132
133 /*!
134 * Verify signature - finalize MD5 operation and reapply MD5, then
135 * compare to the supplied digest.
136 */
137 isc_boolean_t
isc_hmacmd5_verify(isc_hmacmd5_t * ctx,unsigned char * digest)138 isc_hmacmd5_verify(isc_hmacmd5_t *ctx, unsigned char *digest) {
139 return (isc_hmacmd5_verify2(ctx, digest, ISC_MD5_DIGESTLENGTH));
140 }
141
142 isc_boolean_t
isc_hmacmd5_verify2(isc_hmacmd5_t * ctx,unsigned char * digest,size_t len)143 isc_hmacmd5_verify2(isc_hmacmd5_t *ctx, unsigned char *digest, size_t len) {
144 unsigned char newdigest[ISC_MD5_DIGESTLENGTH];
145
146 REQUIRE(len <= ISC_MD5_DIGESTLENGTH);
147 isc_hmacmd5_sign(ctx, newdigest);
148 return (ISC_TF(memcmp(digest, newdigest, len) == 0));
149 }
150