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 "cryptlib.h"
62#include <openssl/hmac.h>
63
64void 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			EVP_DigestInit_ex(&ctx->md_ctx,md, impl);
86			EVP_DigestUpdate(&ctx->md_ctx,key,len);
87			EVP_DigestFinal_ex(&(ctx->md_ctx),ctx->key,
88				&ctx->key_length);
89			}
90		else
91			{
92			OPENSSL_assert(len>=0 && len<=(int)sizeof(ctx->key));
93			memcpy(ctx->key,key,len);
94			ctx->key_length=len;
95			}
96		if(ctx->key_length != HMAC_MAX_MD_CBLOCK)
97			memset(&ctx->key[ctx->key_length], 0,
98				HMAC_MAX_MD_CBLOCK - ctx->key_length);
99		}
100
101	if (reset)
102		{
103		for (i=0; i<HMAC_MAX_MD_CBLOCK; i++)
104			pad[i]=0x36^ctx->key[i];
105		EVP_DigestInit_ex(&ctx->i_ctx,md, impl);
106		EVP_DigestUpdate(&ctx->i_ctx,pad,EVP_MD_block_size(md));
107
108		for (i=0; i<HMAC_MAX_MD_CBLOCK; i++)
109			pad[i]=0x5c^ctx->key[i];
110		EVP_DigestInit_ex(&ctx->o_ctx,md, impl);
111		EVP_DigestUpdate(&ctx->o_ctx,pad,EVP_MD_block_size(md));
112		}
113	EVP_MD_CTX_copy_ex(&ctx->md_ctx,&ctx->i_ctx);
114	}
115
116void HMAC_Init(HMAC_CTX *ctx, const void *key, int len,
117	       const EVP_MD *md)
118	{
119	if(key && md)
120	    HMAC_CTX_init(ctx);
121	HMAC_Init_ex(ctx,key,len,md, NULL);
122	}
123
124void HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len)
125	{
126	EVP_DigestUpdate(&ctx->md_ctx,data,len);
127	}
128
129void HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
130	{
131	int j;
132	unsigned int i;
133	unsigned char buf[EVP_MAX_MD_SIZE];
134
135	j=EVP_MD_block_size(ctx->md);
136
137	EVP_DigestFinal_ex(&ctx->md_ctx,buf,&i);
138	EVP_MD_CTX_copy_ex(&ctx->md_ctx,&ctx->o_ctx);
139	EVP_DigestUpdate(&ctx->md_ctx,buf,i);
140	EVP_DigestFinal_ex(&ctx->md_ctx,md,len);
141	}
142
143void HMAC_CTX_init(HMAC_CTX *ctx)
144	{
145	EVP_MD_CTX_init(&ctx->i_ctx);
146	EVP_MD_CTX_init(&ctx->o_ctx);
147	EVP_MD_CTX_init(&ctx->md_ctx);
148	}
149
150void HMAC_CTX_cleanup(HMAC_CTX *ctx)
151	{
152	EVP_MD_CTX_cleanup(&ctx->i_ctx);
153	EVP_MD_CTX_cleanup(&ctx->o_ctx);
154	EVP_MD_CTX_cleanup(&ctx->md_ctx);
155	memset(ctx,0,sizeof *ctx);
156	}
157
158unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
159		    const unsigned char *d, size_t n, unsigned char *md,
160		    unsigned int *md_len)
161	{
162	HMAC_CTX c;
163	static unsigned char m[EVP_MAX_MD_SIZE];
164
165	if (md == NULL) md=m;
166	HMAC_CTX_init(&c);
167	HMAC_Init(&c,key,key_len,evp_md);
168	HMAC_Update(&c,d,n);
169	HMAC_Final(&c,md,md_len);
170	HMAC_CTX_cleanup(&c);
171	return(md);
172	}
173
174