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 
64 #ifdef OPENSSL_FIPS
65 #include <openssl/fips.h>
66 #endif
67 
68 int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,
69 		  const EVP_MD *md, ENGINE *impl)
70 	{
71 	int i,j,reset=0;
72 	unsigned char pad[HMAC_MAX_MD_CBLOCK];
73 
74 #ifdef OPENSSL_FIPS
75 	if (FIPS_mode())
76 		{
77 		/* If we have an ENGINE need to allow non FIPS */
78 		if ((impl || ctx->i_ctx.engine)
79 			&&  !(ctx->i_ctx.flags & EVP_CIPH_FLAG_NON_FIPS_ALLOW))
80 			{
81 			EVPerr(EVP_F_HMAC_INIT_EX, EVP_R_DISABLED_FOR_FIPS);
82 			return 0;
83 			}
84 		/* Other algorithm blocking will be done in FIPS_cmac_init,
85 		 * via FIPS_hmac_init_ex().
86 		 */
87 		if (!impl && !ctx->i_ctx.engine)
88 			return FIPS_hmac_init_ex(ctx, key, len, md, NULL);
89 		}
90 #endif
91 
92 	if (md != NULL)
93 		{
94 		reset=1;
95 		ctx->md=md;
96 		}
97 	else
98 		md=ctx->md;
99 
100 	if (key != NULL)
101 		{
102 		reset=1;
103 		j=EVP_MD_block_size(md);
104 		OPENSSL_assert(j <= (int)sizeof(ctx->key));
105 		if (j < len)
106 			{
107 			if (!EVP_DigestInit_ex(&ctx->md_ctx,md, impl))
108 				goto err;
109 			if (!EVP_DigestUpdate(&ctx->md_ctx,key,len))
110 				goto err;
111 			if (!EVP_DigestFinal_ex(&(ctx->md_ctx),ctx->key,
112 				&ctx->key_length))
113 				goto err;
114 			}
115 		else
116 			{
117 			OPENSSL_assert(len>=0 && len<=(int)sizeof(ctx->key));
118 			memcpy(ctx->key,key,len);
119 			ctx->key_length=len;
120 			}
121 		if(ctx->key_length != HMAC_MAX_MD_CBLOCK)
122 			memset(&ctx->key[ctx->key_length], 0,
123 				HMAC_MAX_MD_CBLOCK - ctx->key_length);
124 		}
125 
126 	if (reset)
127 		{
128 		for (i=0; i<HMAC_MAX_MD_CBLOCK; i++)
129 			pad[i]=0x36^ctx->key[i];
130 		if (!EVP_DigestInit_ex(&ctx->i_ctx,md, impl))
131 			goto err;
132 		if (!EVP_DigestUpdate(&ctx->i_ctx,pad,EVP_MD_block_size(md)))
133 			goto err;
134 
135 		for (i=0; i<HMAC_MAX_MD_CBLOCK; i++)
136 			pad[i]=0x5c^ctx->key[i];
137 		if (!EVP_DigestInit_ex(&ctx->o_ctx,md, impl))
138 			goto err;
139 		if (!EVP_DigestUpdate(&ctx->o_ctx,pad,EVP_MD_block_size(md)))
140 			goto err;
141 		}
142 	if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx,&ctx->i_ctx))
143 			goto err;
144 	return 1;
145 	err:
146 	return 0;
147 	}
148 
149 int HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md)
150 	{
151 	if(key && md)
152 	    HMAC_CTX_init(ctx);
153 	return HMAC_Init_ex(ctx,key,len,md, NULL);
154 	}
155 
156 int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len)
157 	{
158 #ifdef OPENSSL_FIPS
159 	if (FIPS_mode() && !ctx->i_ctx.engine)
160 		return FIPS_hmac_update(ctx, data, len);
161 #endif
162 	return EVP_DigestUpdate(&ctx->md_ctx,data,len);
163 	}
164 
165 int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
166 	{
167 	unsigned int i;
168 	unsigned char buf[EVP_MAX_MD_SIZE];
169 #ifdef OPENSSL_FIPS
170 	if (FIPS_mode() && !ctx->i_ctx.engine)
171 		return FIPS_hmac_final(ctx, md, len);
172 #endif
173 
174 	if (!EVP_DigestFinal_ex(&ctx->md_ctx,buf,&i))
175 		goto err;
176 	if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx,&ctx->o_ctx))
177 		goto err;
178 	if (!EVP_DigestUpdate(&ctx->md_ctx,buf,i))
179 		goto err;
180 	if (!EVP_DigestFinal_ex(&ctx->md_ctx,md,len))
181 		goto err;
182 	return 1;
183 	err:
184 	return 0;
185 	}
186 
187 void HMAC_CTX_init(HMAC_CTX *ctx)
188 	{
189 	EVP_MD_CTX_init(&ctx->i_ctx);
190 	EVP_MD_CTX_init(&ctx->o_ctx);
191 	EVP_MD_CTX_init(&ctx->md_ctx);
192 	}
193 
194 int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx)
195 	{
196 	if (!EVP_MD_CTX_copy(&dctx->i_ctx, &sctx->i_ctx))
197 		goto err;
198 	if (!EVP_MD_CTX_copy(&dctx->o_ctx, &sctx->o_ctx))
199 		goto err;
200 	if (!EVP_MD_CTX_copy(&dctx->md_ctx, &sctx->md_ctx))
201 		goto err;
202 	memcpy(dctx->key, sctx->key, HMAC_MAX_MD_CBLOCK);
203 	dctx->key_length = sctx->key_length;
204 	dctx->md = sctx->md;
205 	return 1;
206 	err:
207 	return 0;
208 	}
209 
210 void HMAC_CTX_cleanup(HMAC_CTX *ctx)
211 	{
212 #ifdef OPENSSL_FIPS
213 	if (FIPS_mode() && !ctx->i_ctx.engine)
214 		{
215 		FIPS_hmac_ctx_cleanup(ctx);
216 		return;
217 		}
218 #endif
219 	EVP_MD_CTX_cleanup(&ctx->i_ctx);
220 	EVP_MD_CTX_cleanup(&ctx->o_ctx);
221 	EVP_MD_CTX_cleanup(&ctx->md_ctx);
222 	memset(ctx,0,sizeof *ctx);
223 	}
224 
225 unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
226 		    const unsigned char *d, size_t n, unsigned char *md,
227 		    unsigned int *md_len)
228 	{
229 	HMAC_CTX c;
230 	static unsigned char m[EVP_MAX_MD_SIZE];
231 
232 	if (md == NULL) md=m;
233 	HMAC_CTX_init(&c);
234 	if (!HMAC_Init(&c,key,key_len,evp_md))
235 		goto err;
236 	if (!HMAC_Update(&c,d,n))
237 		goto err;
238 	if (!HMAC_Final(&c,md,md_len))
239 		goto err;
240 	HMAC_CTX_cleanup(&c);
241 	return md;
242 	err:
243 	return NULL;
244 	}
245 
246 void HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags)
247 	{
248 	EVP_MD_CTX_set_flags(&ctx->i_ctx, flags);
249 	EVP_MD_CTX_set_flags(&ctx->o_ctx, flags);
250 	EVP_MD_CTX_set_flags(&ctx->md_ctx, flags);
251 	}
252