1/* crypto/hmac/hmac.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@cryptsoft.com)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58#include <stdio.h>
59#include <stdlib.h>
60#include <string.h>
61#include <openssl/local/cryptlib.h>
62#include <openssl/hmac.h>
63
64int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,
65		  const EVP_MD *md, ENGINE *impl)
66	{
67	int i,j,reset=0;
68	unsigned char pad[HMAC_MAX_MD_CBLOCK];
69
70	if (md != NULL)
71		{
72		reset=1;
73		ctx->md=md;
74		}
75	else
76		md=ctx->md;
77
78	if (key != NULL)
79		{
80		reset=1;
81		j=EVP_MD_block_size(md);
82		OPENSSL_assert(j <= (int)sizeof(ctx->key));
83		if (j < len)
84			{
85			if (!EVP_DigestInit_ex(&ctx->md_ctx,md, impl))
86				goto err;
87			if (!EVP_DigestUpdate(&ctx->md_ctx,key,len))
88				goto err;
89			if (!EVP_DigestFinal_ex(&(ctx->md_ctx),ctx->key,
90				&ctx->key_length))
91				goto err;
92			}
93		else
94			{
95			OPENSSL_assert(len>=0 && len<=(int)sizeof(ctx->key));
96			memcpy(ctx->key,key,len);
97			ctx->key_length=len;
98			}
99		if(ctx->key_length != HMAC_MAX_MD_CBLOCK)
100			memset(&ctx->key[ctx->key_length], 0,
101				HMAC_MAX_MD_CBLOCK - ctx->key_length);
102		}
103
104	if (reset)
105		{
106		for (i=0; i<HMAC_MAX_MD_CBLOCK; i++)
107			pad[i]=0x36^ctx->key[i];
108		if (!EVP_DigestInit_ex(&ctx->i_ctx,md, impl))
109			goto err;
110		if (!EVP_DigestUpdate(&ctx->i_ctx,pad,EVP_MD_block_size(md)))
111			goto err;
112
113		for (i=0; i<HMAC_MAX_MD_CBLOCK; i++)
114			pad[i]=0x5c^ctx->key[i];
115		if (!EVP_DigestInit_ex(&ctx->o_ctx,md, impl))
116			goto err;
117		if (!EVP_DigestUpdate(&ctx->o_ctx,pad,EVP_MD_block_size(md)))
118			goto err;
119		}
120	if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx,&ctx->i_ctx))
121			goto err;
122	return 1;
123	err:
124	return 0;
125	}
126
127int HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md)
128	{
129	if(key && md)
130	    HMAC_CTX_init(ctx);
131	return HMAC_Init_ex(ctx,key,len,md, NULL);
132	}
133
134int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len)
135	{
136	return EVP_DigestUpdate(&ctx->md_ctx,data,len);
137	}
138
139int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
140	{
141	unsigned int i;
142	unsigned char buf[EVP_MAX_MD_SIZE];
143
144	if (!EVP_DigestFinal_ex(&ctx->md_ctx,buf,&i))
145		goto err;
146	if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx,&ctx->o_ctx))
147		goto err;
148	if (!EVP_DigestUpdate(&ctx->md_ctx,buf,i))
149		goto err;
150	if (!EVP_DigestFinal_ex(&ctx->md_ctx,md,len))
151		goto err;
152	return 1;
153	err:
154	return 0;
155	}
156
157void HMAC_CTX_init(HMAC_CTX *ctx)
158	{
159	EVP_MD_CTX_init(&ctx->i_ctx);
160	EVP_MD_CTX_init(&ctx->o_ctx);
161	EVP_MD_CTX_init(&ctx->md_ctx);
162	}
163
164int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx)
165	{
166	if (!EVP_MD_CTX_copy(&dctx->i_ctx, &sctx->i_ctx))
167		goto err;
168	if (!EVP_MD_CTX_copy(&dctx->o_ctx, &sctx->o_ctx))
169		goto err;
170	if (!EVP_MD_CTX_copy(&dctx->md_ctx, &sctx->md_ctx))
171		goto err;
172	memcpy(dctx->key, sctx->key, HMAC_MAX_MD_CBLOCK);
173	dctx->key_length = sctx->key_length;
174	dctx->md = sctx->md;
175	return 1;
176	err:
177	return 0;
178	}
179
180void HMAC_CTX_cleanup(HMAC_CTX *ctx)
181	{
182	EVP_MD_CTX_cleanup(&ctx->i_ctx);
183	EVP_MD_CTX_cleanup(&ctx->o_ctx);
184	EVP_MD_CTX_cleanup(&ctx->md_ctx);
185	memset(ctx,0,sizeof *ctx);
186	}
187
188unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
189		    const unsigned char *d, size_t n, unsigned char *md,
190		    unsigned int *md_len)
191	{
192	HMAC_CTX c;
193	static unsigned char m[EVP_MAX_MD_SIZE];
194
195	if (md == NULL) md=m;
196	HMAC_CTX_init(&c);
197	if (!HMAC_Init(&c,key,key_len,evp_md))
198		goto err;
199	if (!HMAC_Update(&c,d,n))
200		goto err;
201	if (!HMAC_Final(&c,md,md_len))
202		goto err;
203	HMAC_CTX_cleanup(&c);
204	return md;
205	err:
206	return NULL;
207	}
208
209void HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags)
210	{
211	EVP_MD_CTX_set_flags(&ctx->i_ctx, flags);
212	EVP_MD_CTX_set_flags(&ctx->o_ctx, flags);
213	EVP_MD_CTX_set_flags(&ctx->md_ctx, flags);
214	}
215