]> git.ipfire.org Git - thirdparty/openssl.git/blame - crypto/cmac/cmac.c
bn_nist.c: harmonize buf in BN_nist_mod_256 with other mod functions.
[thirdparty/openssl.git] / crypto / cmac / cmac.c
CommitLineData
8c968e03
DSH
1/* crypto/cmac/cmac.c */
2/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3 * project.
4 */
5/* ====================================================================
6 * Copyright (c) 2010 The OpenSSL Project. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * 3. All advertising materials mentioning features or use of this
21 * software must display the following acknowledgment:
22 * "This product includes software developed by the OpenSSL Project
23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24 *
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 * endorse or promote products derived from this software without
27 * prior written permission. For written permission, please contact
28 * licensing@OpenSSL.org.
29 *
30 * 5. Products derived from this software may not be called "OpenSSL"
31 * nor may "OpenSSL" appear in their names without prior written
32 * permission of the OpenSSL Project.
33 *
34 * 6. Redistributions of any form whatsoever must retain the following
35 * acknowledgment:
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38 *
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
52 */
53
399aa6b5
RL
54#define OPENSSL_FIPSAPI
55
8c968e03
DSH
56#include <stdio.h>
57#include <stdlib.h>
58#include <string.h>
59#include "cryptlib.h"
60#include <openssl/cmac.h>
61
62struct CMAC_CTX_st
63 {
64 /* Cipher context to use */
65 EVP_CIPHER_CTX cctx;
66 /* Keys k1 and k2 */
67 unsigned char k1[EVP_MAX_BLOCK_LENGTH];
68 unsigned char k2[EVP_MAX_BLOCK_LENGTH];
69 /* Temporary block */
70 unsigned char tbl[EVP_MAX_BLOCK_LENGTH];
71 /* Last (possibly partial) block */
72 unsigned char last_block[EVP_MAX_BLOCK_LENGTH];
73 /* Number of bytes in last block: -1 means context not initialised */
74 int nlast_block;
75 };
76
77
78/* Make temporary keys K1 and K2 */
79
80static void make_kn(unsigned char *k1, unsigned char *l, int bl)
81 {
82 int i;
83 /* Shift block to left, including carry */
84 for (i = 0; i < bl; i++)
85 {
86 k1[i] = l[i] << 1;
87 if (i < bl - 1 && l[i + 1] & 0x80)
88 k1[i] |= 1;
89 }
90 /* If MSB set fixup with R */
91 if (l[0] & 0x80)
92 k1[bl - 1] ^= bl == 16 ? 0x87 : 0x1b;
93 }
94
95CMAC_CTX *CMAC_CTX_new(void)
96 {
97 CMAC_CTX *ctx;
98 ctx = OPENSSL_malloc(sizeof(CMAC_CTX));
99 if (!ctx)
100 return NULL;
101 EVP_CIPHER_CTX_init(&ctx->cctx);
102 ctx->nlast_block = -1;
103 return ctx;
104 }
105
106void CMAC_CTX_cleanup(CMAC_CTX *ctx)
107 {
108 EVP_CIPHER_CTX_cleanup(&ctx->cctx);
109 OPENSSL_cleanse(ctx->tbl, EVP_MAX_BLOCK_LENGTH);
110 OPENSSL_cleanse(ctx->k1, EVP_MAX_BLOCK_LENGTH);
111 OPENSSL_cleanse(ctx->k2, EVP_MAX_BLOCK_LENGTH);
112 OPENSSL_cleanse(ctx->last_block, EVP_MAX_BLOCK_LENGTH);
113 ctx->nlast_block = -1;
114 }
115
116EVP_CIPHER_CTX *CMAC_CTX_get0_cipher_ctx(CMAC_CTX *ctx)
117 {
118 return &ctx->cctx;
119 }
120
121void CMAC_CTX_free(CMAC_CTX *ctx)
122 {
123 CMAC_CTX_cleanup(ctx);
124 OPENSSL_free(ctx);
125 }
126
c8ef656d
DSH
127int CMAC_CTX_copy(CMAC_CTX *out, const CMAC_CTX *in)
128 {
129 int bl;
130 if (in->nlast_block == -1)
131 return 0;
132 if (!EVP_CIPHER_CTX_copy(&out->cctx, &in->cctx))
133 return 0;
399aa6b5 134 bl = M_EVP_CIPHER_CTX_block_size(&in->cctx);
c8ef656d
DSH
135 memcpy(out->k1, in->k1, bl);
136 memcpy(out->k2, in->k2, bl);
137 memcpy(out->tbl, in->tbl, bl);
138 memcpy(out->last_block, in->last_block, bl);
139 out->nlast_block = in->nlast_block;
140 return 1;
141 }
142
8c968e03
DSH
143int CMAC_Init(CMAC_CTX *ctx, const void *key, size_t keylen,
144 const EVP_CIPHER *cipher, ENGINE *impl)
145 {
146 static unsigned char zero_iv[EVP_MAX_BLOCK_LENGTH];
147 /* All zeros means restart */
148 if (!key && !cipher && !impl && keylen == 0)
149 {
150 /* Not initialised */
c8ef656d 151 if (ctx->nlast_block == -1)
8c968e03 152 return 0;
399aa6b5 153 if (!M_EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv))
8c968e03 154 return 0;
c8ef656d 155 return 1;
8c968e03
DSH
156 }
157 /* Initialiase context */
399aa6b5 158 if (cipher && !M_EVP_EncryptInit_ex(&ctx->cctx, cipher, impl, NULL, NULL))
8c968e03
DSH
159 return 0;
160 /* Non-NULL key means initialisation complete */
161 if (key)
162 {
163 int bl;
399aa6b5 164 if (!M_EVP_CIPHER_CTX_cipher(&ctx->cctx))
8c968e03
DSH
165 return 0;
166 if (!EVP_CIPHER_CTX_set_key_length(&ctx->cctx, keylen))
167 return 0;
399aa6b5 168 if (!M_EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, key, zero_iv))
8c968e03 169 return 0;
399aa6b5 170 bl = M_EVP_CIPHER_CTX_block_size(&ctx->cctx);
8c968e03
DSH
171 if (!EVP_Cipher(&ctx->cctx, ctx->tbl, zero_iv, bl))
172 return 0;
173 make_kn(ctx->k1, ctx->tbl, bl);
174 make_kn(ctx->k2, ctx->k1, bl);
175 OPENSSL_cleanse(ctx->tbl, bl);
176 /* Reset context again ready for first data block */
399aa6b5 177 if (!M_EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv))
8c968e03 178 return 0;
c8ef656d
DSH
179 /* Zero tbl so resume works */
180 memset(ctx->tbl, 0, bl);
8c968e03
DSH
181 ctx->nlast_block = 0;
182 }
183 return 1;
184 }
185
186int CMAC_Update(CMAC_CTX *ctx, const void *in, size_t dlen)
187 {
188 const unsigned char *data = in;
189 size_t bl;
190 if (ctx->nlast_block == -1)
191 return 0;
192 if (dlen == 0)
193 return 1;
399aa6b5 194 bl = M_EVP_CIPHER_CTX_block_size(&ctx->cctx);
8c968e03
DSH
195 /* Copy into partial block if we need to */
196 if (ctx->nlast_block > 0)
197 {
198 size_t nleft;
199 nleft = bl - ctx->nlast_block;
200 if (dlen < nleft)
201 nleft = dlen;
202 memcpy(ctx->last_block + ctx->nlast_block, data, nleft);
203 dlen -= nleft;
204 ctx->nlast_block += nleft;
205 /* If no more to process return */
206 if (dlen == 0)
207 return 1;
208 data += nleft;
209 /* Else not final block so encrypt it */
210 if (!EVP_Cipher(&ctx->cctx, ctx->tbl, ctx->last_block,bl))
211 return 0;
212 }
213 /* Encrypt all but one of the complete blocks left */
214 while(dlen > bl)
215 {
216 if (!EVP_Cipher(&ctx->cctx, ctx->tbl, data, bl))
217 return 0;
218 dlen -= bl;
219 data += bl;
220 }
221 /* Copy any data left to last block buffer */
222 memcpy(ctx->last_block, data, dlen);
223 ctx->nlast_block = dlen;
224 return 1;
225
226 }
227
c8ef656d 228int CMAC_Final(CMAC_CTX *ctx, unsigned char *out, size_t *poutlen)
8c968e03
DSH
229 {
230 int i, bl, lb;
231 if (ctx->nlast_block == -1)
232 return 0;
399aa6b5 233 bl = M_EVP_CIPHER_CTX_block_size(&ctx->cctx);
c8ef656d
DSH
234 *poutlen = (size_t)bl;
235 if (!out)
236 return 1;
8c968e03
DSH
237 lb = ctx->nlast_block;
238 /* Is last block complete? */
239 if (lb == bl)
240 {
241 for (i = 0; i < bl; i++)
c8ef656d 242 out[i] = ctx->last_block[i] ^ ctx->k1[i];
8c968e03
DSH
243 }
244 else
245 {
246 ctx->last_block[lb] = 0x80;
247 if (bl - lb > 1)
248 memset(ctx->last_block + lb + 1, 0, bl - lb - 1);
249 for (i = 0; i < bl; i++)
c8ef656d 250 out[i] = ctx->last_block[i] ^ ctx->k2[i];
8c968e03 251 }
c8ef656d
DSH
252 if (!EVP_Cipher(&ctx->cctx, out, out, bl))
253 {
254 OPENSSL_cleanse(out, bl);
255 return 0;
256 }
257 return 1;
258 }
259
260int CMAC_resume(CMAC_CTX *ctx)
261 {
262 if (ctx->nlast_block == -1)
8c968e03 263 return 0;
c8ef656d
DSH
264 /* The buffer "tbl" containes the last fully encrypted block
265 * which is the last IV (or all zeroes if no last encrypted block).
266 * The last block has not been modified since CMAC_final().
267 * So reinitliasing using the last decrypted block will allow
268 * CMAC to continue after calling CMAC_Final().
269 */
399aa6b5 270 return M_EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, ctx->tbl);
8c968e03 271 }