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031e5cce | 1 | /* crypto/cmac/cmac.c */ |
d3819813 | 2 | /* |
031e5cce SM |
3 | * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL |
4 | * project. | |
5 | */ | |
6 | /* ==================================================================== | |
7 | * Copyright (c) 2010 The OpenSSL Project. All rights reserved. | |
8 | * | |
9 | * Redistribution and use in source and binary forms, with or without | |
10 | * modification, are permitted provided that the following conditions | |
11 | * are met: | |
12 | * | |
13 | * 1. Redistributions of source code must retain the above copyright | |
14 | * notice, this list of conditions and the following disclaimer. | |
15 | * | |
16 | * 2. Redistributions in binary form must reproduce the above copyright | |
17 | * notice, this list of conditions and the following disclaimer in | |
18 | * the documentation and/or other materials provided with the | |
19 | * distribution. | |
20 | * | |
21 | * 3. All advertising materials mentioning features or use of this | |
22 | * software must display the following acknowledgment: | |
23 | * "This product includes software developed by the OpenSSL Project | |
24 | * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" | |
25 | * | |
26 | * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to | |
27 | * endorse or promote products derived from this software without | |
28 | * prior written permission. For written permission, please contact | |
29 | * licensing@OpenSSL.org. | |
d3819813 | 30 | * |
031e5cce SM |
31 | * 5. Products derived from this software may not be called "OpenSSL" |
32 | * nor may "OpenSSL" appear in their names without prior written | |
33 | * permission of the OpenSSL Project. | |
34 | * | |
35 | * 6. Redistributions of any form whatsoever must retain the following | |
36 | * acknowledgment: | |
37 | * "This product includes software developed by the OpenSSL Project | |
38 | * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" | |
39 | * | |
40 | * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY | |
41 | * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
42 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | |
43 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR | |
44 | * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
45 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
46 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |
47 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
48 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
49 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
50 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED | |
51 | * OF THE POSSIBILITY OF SUCH DAMAGE. | |
52 | * ==================================================================== | |
d3819813 MTL |
53 | */ |
54 | ||
55 | #include <stdio.h> | |
56 | #include <stdlib.h> | |
57 | #include <string.h> | |
031e5cce | 58 | #include "cryptlib.h" |
d3819813 MTL |
59 | #include <openssl/cmac.h> |
60 | ||
031e5cce SM |
61 | #ifdef OPENSSL_FIPS |
62 | # include <openssl/fips.h> | |
63 | #endif | |
64 | ||
d3819813 MTL |
65 | struct CMAC_CTX_st { |
66 | /* Cipher context to use */ | |
031e5cce | 67 | EVP_CIPHER_CTX cctx; |
d3819813 MTL |
68 | /* Keys k1 and k2 */ |
69 | unsigned char k1[EVP_MAX_BLOCK_LENGTH]; | |
70 | unsigned char k2[EVP_MAX_BLOCK_LENGTH]; | |
71 | /* Temporary block */ | |
72 | unsigned char tbl[EVP_MAX_BLOCK_LENGTH]; | |
73 | /* Last (possibly partial) block */ | |
74 | unsigned char last_block[EVP_MAX_BLOCK_LENGTH]; | |
75 | /* Number of bytes in last block: -1 means context not initialised */ | |
76 | int nlast_block; | |
77 | }; | |
78 | ||
79 | /* Make temporary keys K1 and K2 */ | |
80 | ||
031e5cce | 81 | static void make_kn(unsigned char *k1, unsigned char *l, int bl) |
d3819813 MTL |
82 | { |
83 | int i; | |
84 | /* Shift block to left, including carry */ | |
031e5cce SM |
85 | for (i = 0; i < bl; i++) { |
86 | k1[i] = l[i] << 1; | |
87 | if (i < bl - 1 && l[i + 1] & 0x80) | |
88 | k1[i] |= 1; | |
89 | } | |
d3819813 | 90 | /* If MSB set fixup with R */ |
031e5cce SM |
91 | if (l[0] & 0x80) |
92 | k1[bl - 1] ^= bl == 16 ? 0x87 : 0x1b; | |
d3819813 MTL |
93 | } |
94 | ||
95 | CMAC_CTX *CMAC_CTX_new(void) | |
96 | { | |
97 | CMAC_CTX *ctx; | |
031e5cce SM |
98 | ctx = OPENSSL_malloc(sizeof(CMAC_CTX)); |
99 | if (!ctx) | |
7bf7a6d0 | 100 | return NULL; |
031e5cce | 101 | EVP_CIPHER_CTX_init(&ctx->cctx); |
d3819813 MTL |
102 | ctx->nlast_block = -1; |
103 | return ctx; | |
104 | } | |
105 | ||
106 | void CMAC_CTX_cleanup(CMAC_CTX *ctx) | |
107 | { | |
031e5cce SM |
108 | #ifdef OPENSSL_FIPS |
109 | if (FIPS_mode() && !ctx->cctx.engine) { | |
110 | FIPS_cmac_ctx_cleanup(ctx); | |
111 | return; | |
112 | } | |
113 | #endif | |
114 | EVP_CIPHER_CTX_cleanup(&ctx->cctx); | |
d3819813 MTL |
115 | OPENSSL_cleanse(ctx->tbl, EVP_MAX_BLOCK_LENGTH); |
116 | OPENSSL_cleanse(ctx->k1, EVP_MAX_BLOCK_LENGTH); | |
117 | OPENSSL_cleanse(ctx->k2, EVP_MAX_BLOCK_LENGTH); | |
118 | OPENSSL_cleanse(ctx->last_block, EVP_MAX_BLOCK_LENGTH); | |
119 | ctx->nlast_block = -1; | |
120 | } | |
121 | ||
122 | EVP_CIPHER_CTX *CMAC_CTX_get0_cipher_ctx(CMAC_CTX *ctx) | |
123 | { | |
031e5cce | 124 | return &ctx->cctx; |
d3819813 MTL |
125 | } |
126 | ||
127 | void CMAC_CTX_free(CMAC_CTX *ctx) | |
128 | { | |
129 | if (!ctx) | |
130 | return; | |
131 | CMAC_CTX_cleanup(ctx); | |
132 | OPENSSL_free(ctx); | |
133 | } | |
134 | ||
135 | int CMAC_CTX_copy(CMAC_CTX *out, const CMAC_CTX *in) | |
136 | { | |
137 | int bl; | |
138 | if (in->nlast_block == -1) | |
139 | return 0; | |
031e5cce | 140 | if (!EVP_CIPHER_CTX_copy(&out->cctx, &in->cctx)) |
d3819813 | 141 | return 0; |
031e5cce | 142 | bl = EVP_CIPHER_CTX_block_size(&in->cctx); |
d3819813 MTL |
143 | memcpy(out->k1, in->k1, bl); |
144 | memcpy(out->k2, in->k2, bl); | |
145 | memcpy(out->tbl, in->tbl, bl); | |
146 | memcpy(out->last_block, in->last_block, bl); | |
147 | out->nlast_block = in->nlast_block; | |
148 | return 1; | |
149 | } | |
150 | ||
151 | int CMAC_Init(CMAC_CTX *ctx, const void *key, size_t keylen, | |
152 | const EVP_CIPHER *cipher, ENGINE *impl) | |
153 | { | |
031e5cce SM |
154 | static unsigned char zero_iv[EVP_MAX_BLOCK_LENGTH]; |
155 | #ifdef OPENSSL_FIPS | |
156 | if (FIPS_mode()) { | |
157 | /* If we have an ENGINE need to allow non FIPS */ | |
158 | if ((impl || ctx->cctx.engine) | |
159 | && !(ctx->cctx.flags & EVP_CIPH_FLAG_NON_FIPS_ALLOW)) { | |
160 | EVPerr(EVP_F_CMAC_INIT, EVP_R_DISABLED_FOR_FIPS); | |
161 | return 0; | |
162 | } | |
163 | ||
164 | /* Switch to FIPS cipher implementation if possible */ | |
165 | if (cipher != NULL) { | |
166 | const EVP_CIPHER *fcipher; | |
167 | fcipher = FIPS_get_cipherbynid(EVP_CIPHER_nid(cipher)); | |
168 | if (fcipher != NULL) | |
169 | cipher = fcipher; | |
170 | } | |
171 | /* | |
172 | * Other algorithm blocking will be done in FIPS_cmac_init, via | |
173 | * FIPS_cipherinit(). | |
174 | */ | |
175 | if (!impl && !ctx->cctx.engine) | |
176 | return FIPS_cmac_init(ctx, key, keylen, cipher, NULL); | |
177 | } | |
178 | #endif | |
d3819813 MTL |
179 | /* All zeros means restart */ |
180 | if (!key && !cipher && !impl && keylen == 0) { | |
181 | /* Not initialised */ | |
182 | if (ctx->nlast_block == -1) | |
183 | return 0; | |
031e5cce | 184 | if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv)) |
d3819813 | 185 | return 0; |
031e5cce | 186 | memset(ctx->tbl, 0, EVP_CIPHER_CTX_block_size(&ctx->cctx)); |
d3819813 MTL |
187 | ctx->nlast_block = 0; |
188 | return 1; | |
189 | } | |
031e5cce SM |
190 | /* Initialiase context */ |
191 | if (cipher && !EVP_EncryptInit_ex(&ctx->cctx, cipher, impl, NULL, NULL)) | |
d3819813 MTL |
192 | return 0; |
193 | /* Non-NULL key means initialisation complete */ | |
194 | if (key) { | |
195 | int bl; | |
031e5cce | 196 | if (!EVP_CIPHER_CTX_cipher(&ctx->cctx)) |
d3819813 | 197 | return 0; |
031e5cce | 198 | if (!EVP_CIPHER_CTX_set_key_length(&ctx->cctx, keylen)) |
d3819813 | 199 | return 0; |
031e5cce | 200 | if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, key, zero_iv)) |
d3819813 | 201 | return 0; |
031e5cce SM |
202 | bl = EVP_CIPHER_CTX_block_size(&ctx->cctx); |
203 | if (!EVP_Cipher(&ctx->cctx, ctx->tbl, zero_iv, bl)) | |
d3819813 MTL |
204 | return 0; |
205 | make_kn(ctx->k1, ctx->tbl, bl); | |
206 | make_kn(ctx->k2, ctx->k1, bl); | |
207 | OPENSSL_cleanse(ctx->tbl, bl); | |
208 | /* Reset context again ready for first data block */ | |
031e5cce | 209 | if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv)) |
d3819813 MTL |
210 | return 0; |
211 | /* Zero tbl so resume works */ | |
212 | memset(ctx->tbl, 0, bl); | |
213 | ctx->nlast_block = 0; | |
214 | } | |
215 | return 1; | |
216 | } | |
217 | ||
218 | int CMAC_Update(CMAC_CTX *ctx, const void *in, size_t dlen) | |
219 | { | |
220 | const unsigned char *data = in; | |
221 | size_t bl; | |
031e5cce SM |
222 | #ifdef OPENSSL_FIPS |
223 | if (FIPS_mode() && !ctx->cctx.engine) | |
224 | return FIPS_cmac_update(ctx, in, dlen); | |
225 | #endif | |
d3819813 MTL |
226 | if (ctx->nlast_block == -1) |
227 | return 0; | |
228 | if (dlen == 0) | |
229 | return 1; | |
031e5cce | 230 | bl = EVP_CIPHER_CTX_block_size(&ctx->cctx); |
d3819813 MTL |
231 | /* Copy into partial block if we need to */ |
232 | if (ctx->nlast_block > 0) { | |
233 | size_t nleft; | |
234 | nleft = bl - ctx->nlast_block; | |
235 | if (dlen < nleft) | |
236 | nleft = dlen; | |
237 | memcpy(ctx->last_block + ctx->nlast_block, data, nleft); | |
238 | dlen -= nleft; | |
239 | ctx->nlast_block += nleft; | |
240 | /* If no more to process return */ | |
241 | if (dlen == 0) | |
242 | return 1; | |
243 | data += nleft; | |
244 | /* Else not final block so encrypt it */ | |
031e5cce | 245 | if (!EVP_Cipher(&ctx->cctx, ctx->tbl, ctx->last_block, bl)) |
d3819813 MTL |
246 | return 0; |
247 | } | |
248 | /* Encrypt all but one of the complete blocks left */ | |
249 | while (dlen > bl) { | |
031e5cce | 250 | if (!EVP_Cipher(&ctx->cctx, ctx->tbl, data, bl)) |
d3819813 MTL |
251 | return 0; |
252 | dlen -= bl; | |
253 | data += bl; | |
254 | } | |
255 | /* Copy any data left to last block buffer */ | |
256 | memcpy(ctx->last_block, data, dlen); | |
257 | ctx->nlast_block = dlen; | |
258 | return 1; | |
259 | ||
260 | } | |
261 | ||
262 | int CMAC_Final(CMAC_CTX *ctx, unsigned char *out, size_t *poutlen) | |
263 | { | |
264 | int i, bl, lb; | |
031e5cce SM |
265 | #ifdef OPENSSL_FIPS |
266 | if (FIPS_mode() && !ctx->cctx.engine) | |
267 | return FIPS_cmac_final(ctx, out, poutlen); | |
268 | #endif | |
d3819813 MTL |
269 | if (ctx->nlast_block == -1) |
270 | return 0; | |
031e5cce | 271 | bl = EVP_CIPHER_CTX_block_size(&ctx->cctx); |
d3819813 MTL |
272 | *poutlen = (size_t)bl; |
273 | if (!out) | |
274 | return 1; | |
275 | lb = ctx->nlast_block; | |
276 | /* Is last block complete? */ | |
277 | if (lb == bl) { | |
278 | for (i = 0; i < bl; i++) | |
279 | out[i] = ctx->last_block[i] ^ ctx->k1[i]; | |
280 | } else { | |
281 | ctx->last_block[lb] = 0x80; | |
282 | if (bl - lb > 1) | |
283 | memset(ctx->last_block + lb + 1, 0, bl - lb - 1); | |
284 | for (i = 0; i < bl; i++) | |
285 | out[i] = ctx->last_block[i] ^ ctx->k2[i]; | |
286 | } | |
031e5cce | 287 | if (!EVP_Cipher(&ctx->cctx, out, out, bl)) { |
d3819813 MTL |
288 | OPENSSL_cleanse(out, bl); |
289 | return 0; | |
290 | } | |
291 | return 1; | |
292 | } | |
293 | ||
294 | int CMAC_resume(CMAC_CTX *ctx) | |
295 | { | |
296 | if (ctx->nlast_block == -1) | |
297 | return 0; | |
298 | /* | |
031e5cce | 299 | * The buffer "tbl" containes the last fully encrypted block which is the |
d3819813 | 300 | * last IV (or all zeroes if no last encrypted block). The last block has |
031e5cce | 301 | * not been modified since CMAC_final(). So reinitliasing using the last |
d3819813 MTL |
302 | * decrypted block will allow CMAC to continue after calling |
303 | * CMAC_Final(). | |
304 | */ | |
031e5cce | 305 | return EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, ctx->tbl); |
d3819813 | 306 | } |