1 /*
2 * sha1.c
3 *
4 * an implementation of the Secure Hash Algorithm v.1 (SHA-1),
5 * specified in FIPS 180-1
6 *
7 * David A. McGrew
8 * Cisco Systems, Inc.
9 */
10
11 /*
12 *
13 * Copyright (c) 2001-2017, Cisco Systems, Inc.
14 * All rights reserved.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 *
20 * Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 *
23 * Redistributions in binary form must reproduce the above
24 * copyright notice, this list of conditions and the following
25 * disclaimer in the documentation and/or other materials provided
26 * with the distribution.
27 *
28 * Neither the name of the Cisco Systems, Inc. nor the names of its
29 * contributors may be used to endorse or promote products derived
30 * from this software without specific prior written permission.
31 *
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
35 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
36 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
37 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
38 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
39 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
41 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
42 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
43 * OF THE POSSIBILITY OF SUCH DAMAGE.
44 *
45 */
46
47 #ifdef HAVE_CONFIG_H
48 #include <config.h>
49 #endif
50
51 #include "sha1.h"
52
53 srtp_debug_module_t srtp_mod_sha1 = {
54 0, /* debugging is off by default */
55 "sha-1" /* printable module name */
56 };
57
58 /* SN == Rotate left N bits */
59 #define S1(X) ((X << 1) | (X >> 31))
60 #define S5(X) ((X << 5) | (X >> 27))
61 #define S30(X) ((X << 30) | (X >> 2))
62
63 #define f0(B, C, D) ((B & C) | (~B & D))
64 #define f1(B, C, D) (B ^ C ^ D)
65 #define f2(B, C, D) ((B & C) | (B & D) | (C & D))
66 #define f3(B, C, D) (B ^ C ^ D)
67
68 /*
69 * nota bene: the variable K0 appears in the curses library, so we
70 * give longer names to these variables to avoid spurious warnings
71 * on systems that uses curses
72 */
73
74 uint32_t SHA_K0 = 0x5A827999; /* Kt for 0 <= t <= 19 */
75 uint32_t SHA_K1 = 0x6ED9EBA1; /* Kt for 20 <= t <= 39 */
76 uint32_t SHA_K2 = 0x8F1BBCDC; /* Kt for 40 <= t <= 59 */
77 uint32_t SHA_K3 = 0xCA62C1D6; /* Kt for 60 <= t <= 79 */
78
79 /*
80 * srtp_sha1_core(M, H) computes the core compression function, where M is
81 * the next part of the message (in network byte order) and H is the
82 * intermediate state { H0, H1, ...} (in host byte order)
83 *
84 * this function does not do any of the padding required in the
85 * complete SHA1 function
86 *
87 * this function is used in the SEAL 3.0 key setup routines
88 * (crypto/cipher/seal.c)
89 */
90
srtp_sha1_core(const uint32_t M[16],uint32_t hash_value[5])91 void srtp_sha1_core(const uint32_t M[16], uint32_t hash_value[5])
92 {
93 uint32_t H0;
94 uint32_t H1;
95 uint32_t H2;
96 uint32_t H3;
97 uint32_t H4;
98 uint32_t W[80];
99 uint32_t A, B, C, D, E, TEMP;
100 int t;
101
102 /* copy hash_value into H0, H1, H2, H3, H4 */
103 H0 = hash_value[0];
104 H1 = hash_value[1];
105 H2 = hash_value[2];
106 H3 = hash_value[3];
107 H4 = hash_value[4];
108
109 /* copy/xor message into array */
110
111 W[0] = be32_to_cpu(M[0]);
112 W[1] = be32_to_cpu(M[1]);
113 W[2] = be32_to_cpu(M[2]);
114 W[3] = be32_to_cpu(M[3]);
115 W[4] = be32_to_cpu(M[4]);
116 W[5] = be32_to_cpu(M[5]);
117 W[6] = be32_to_cpu(M[6]);
118 W[7] = be32_to_cpu(M[7]);
119 W[8] = be32_to_cpu(M[8]);
120 W[9] = be32_to_cpu(M[9]);
121 W[10] = be32_to_cpu(M[10]);
122 W[11] = be32_to_cpu(M[11]);
123 W[12] = be32_to_cpu(M[12]);
124 W[13] = be32_to_cpu(M[13]);
125 W[14] = be32_to_cpu(M[14]);
126 W[15] = be32_to_cpu(M[15]);
127 TEMP = W[13] ^ W[8] ^ W[2] ^ W[0];
128 W[16] = S1(TEMP);
129 TEMP = W[14] ^ W[9] ^ W[3] ^ W[1];
130 W[17] = S1(TEMP);
131 TEMP = W[15] ^ W[10] ^ W[4] ^ W[2];
132 W[18] = S1(TEMP);
133 TEMP = W[16] ^ W[11] ^ W[5] ^ W[3];
134 W[19] = S1(TEMP);
135 TEMP = W[17] ^ W[12] ^ W[6] ^ W[4];
136 W[20] = S1(TEMP);
137 TEMP = W[18] ^ W[13] ^ W[7] ^ W[5];
138 W[21] = S1(TEMP);
139 TEMP = W[19] ^ W[14] ^ W[8] ^ W[6];
140 W[22] = S1(TEMP);
141 TEMP = W[20] ^ W[15] ^ W[9] ^ W[7];
142 W[23] = S1(TEMP);
143 TEMP = W[21] ^ W[16] ^ W[10] ^ W[8];
144 W[24] = S1(TEMP);
145 TEMP = W[22] ^ W[17] ^ W[11] ^ W[9];
146 W[25] = S1(TEMP);
147 TEMP = W[23] ^ W[18] ^ W[12] ^ W[10];
148 W[26] = S1(TEMP);
149 TEMP = W[24] ^ W[19] ^ W[13] ^ W[11];
150 W[27] = S1(TEMP);
151 TEMP = W[25] ^ W[20] ^ W[14] ^ W[12];
152 W[28] = S1(TEMP);
153 TEMP = W[26] ^ W[21] ^ W[15] ^ W[13];
154 W[29] = S1(TEMP);
155 TEMP = W[27] ^ W[22] ^ W[16] ^ W[14];
156 W[30] = S1(TEMP);
157 TEMP = W[28] ^ W[23] ^ W[17] ^ W[15];
158 W[31] = S1(TEMP);
159
160 /* process the remainder of the array */
161 for (t = 32; t < 80; t++) {
162 TEMP = W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16];
163 W[t] = S1(TEMP);
164 }
165
166 A = H0;
167 B = H1;
168 C = H2;
169 D = H3;
170 E = H4;
171
172 for (t = 0; t < 20; t++) {
173 TEMP = S5(A) + f0(B, C, D) + E + W[t] + SHA_K0;
174 E = D;
175 D = C;
176 C = S30(B);
177 B = A;
178 A = TEMP;
179 }
180 for (; t < 40; t++) {
181 TEMP = S5(A) + f1(B, C, D) + E + W[t] + SHA_K1;
182 E = D;
183 D = C;
184 C = S30(B);
185 B = A;
186 A = TEMP;
187 }
188 for (; t < 60; t++) {
189 TEMP = S5(A) + f2(B, C, D) + E + W[t] + SHA_K2;
190 E = D;
191 D = C;
192 C = S30(B);
193 B = A;
194 A = TEMP;
195 }
196 for (; t < 80; t++) {
197 TEMP = S5(A) + f3(B, C, D) + E + W[t] + SHA_K3;
198 E = D;
199 D = C;
200 C = S30(B);
201 B = A;
202 A = TEMP;
203 }
204
205 hash_value[0] = H0 + A;
206 hash_value[1] = H1 + B;
207 hash_value[2] = H2 + C;
208 hash_value[3] = H3 + D;
209 hash_value[4] = H4 + E;
210
211 return;
212 }
213
srtp_sha1_init(srtp_sha1_ctx_t * ctx)214 void srtp_sha1_init(srtp_sha1_ctx_t *ctx)
215 {
216 /* initialize state vector */
217 ctx->H[0] = 0x67452301;
218 ctx->H[1] = 0xefcdab89;
219 ctx->H[2] = 0x98badcfe;
220 ctx->H[3] = 0x10325476;
221 ctx->H[4] = 0xc3d2e1f0;
222
223 /* indicate that message buffer is empty */
224 ctx->octets_in_buffer = 0;
225
226 /* reset message bit-count to zero */
227 ctx->num_bits_in_msg = 0;
228 }
229
srtp_sha1_update(srtp_sha1_ctx_t * ctx,const uint8_t * msg,int octets_in_msg)230 void srtp_sha1_update(srtp_sha1_ctx_t *ctx,
231 const uint8_t *msg,
232 int octets_in_msg)
233 {
234 int i;
235 uint8_t *buf = (uint8_t *)ctx->M;
236
237 /* update message bit-count */
238 ctx->num_bits_in_msg += octets_in_msg * 8;
239
240 /* loop over 16-word blocks of M */
241 while (octets_in_msg > 0) {
242 if (octets_in_msg + ctx->octets_in_buffer >= 64) {
243 /*
244 * copy words of M into msg buffer until that buffer is full,
245 * converting them into host byte order as needed
246 */
247 octets_in_msg -= (64 - ctx->octets_in_buffer);
248 for (i = ctx->octets_in_buffer; i < 64; i++) {
249 buf[i] = *msg++;
250 }
251 ctx->octets_in_buffer = 0;
252
253 /* process a whole block */
254
255 debug_print0(srtp_mod_sha1, "(update) running srtp_sha1_core()");
256
257 srtp_sha1_core(ctx->M, ctx->H);
258
259 } else {
260 debug_print0(srtp_mod_sha1,
261 "(update) not running srtp_sha1_core()");
262
263 for (i = ctx->octets_in_buffer;
264 i < (ctx->octets_in_buffer + octets_in_msg); i++) {
265 buf[i] = *msg++;
266 }
267 ctx->octets_in_buffer += octets_in_msg;
268 octets_in_msg = 0;
269 }
270 }
271 }
272
273 /*
274 * srtp_sha1_final(ctx, output) computes the result for ctx and copies it
275 * into the twenty octets located at *output
276 */
277
srtp_sha1_final(srtp_sha1_ctx_t * ctx,uint32_t output[5])278 void srtp_sha1_final(srtp_sha1_ctx_t *ctx, uint32_t output[5])
279 {
280 uint32_t A, B, C, D, E, TEMP;
281 uint32_t W[80];
282 int i, t;
283
284 /*
285 * process the remaining octets_in_buffer, padding and terminating as
286 * necessary
287 */
288 {
289 int tail = ctx->octets_in_buffer % 4;
290
291 /* copy/xor message into array */
292 for (i = 0; i < (ctx->octets_in_buffer + 3) / 4; i++) {
293 W[i] = be32_to_cpu(ctx->M[i]);
294 }
295
296 /* set the high bit of the octet immediately following the message */
297 switch (tail) {
298 case (3):
299 W[i - 1] = (be32_to_cpu(ctx->M[i - 1]) & 0xffffff00) | 0x80;
300 W[i] = 0x0;
301 break;
302 case (2):
303 W[i - 1] = (be32_to_cpu(ctx->M[i - 1]) & 0xffff0000) | 0x8000;
304 W[i] = 0x0;
305 break;
306 case (1):
307 W[i - 1] = (be32_to_cpu(ctx->M[i - 1]) & 0xff000000) | 0x800000;
308 W[i] = 0x0;
309 break;
310 case (0):
311 W[i] = 0x80000000;
312 break;
313 }
314
315 /* zeroize remaining words */
316 for (i++; i < 15; i++) {
317 W[i] = 0x0;
318 }
319
320 /*
321 * if there is room at the end of the word array, then set the
322 * last word to the bit-length of the message; otherwise, set that
323 * word to zero and then we need to do one more run of the
324 * compression algo.
325 */
326 if (ctx->octets_in_buffer < 56) {
327 W[15] = ctx->num_bits_in_msg;
328 } else if (ctx->octets_in_buffer < 60) {
329 W[15] = 0x0;
330 }
331
332 /* process the word array */
333 for (t = 16; t < 80; t++) {
334 TEMP = W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16];
335 W[t] = S1(TEMP);
336 }
337
338 A = ctx->H[0];
339 B = ctx->H[1];
340 C = ctx->H[2];
341 D = ctx->H[3];
342 E = ctx->H[4];
343
344 for (t = 0; t < 20; t++) {
345 TEMP = S5(A) + f0(B, C, D) + E + W[t] + SHA_K0;
346 E = D;
347 D = C;
348 C = S30(B);
349 B = A;
350 A = TEMP;
351 }
352 for (; t < 40; t++) {
353 TEMP = S5(A) + f1(B, C, D) + E + W[t] + SHA_K1;
354 E = D;
355 D = C;
356 C = S30(B);
357 B = A;
358 A = TEMP;
359 }
360 for (; t < 60; t++) {
361 TEMP = S5(A) + f2(B, C, D) + E + W[t] + SHA_K2;
362 E = D;
363 D = C;
364 C = S30(B);
365 B = A;
366 A = TEMP;
367 }
368 for (; t < 80; t++) {
369 TEMP = S5(A) + f3(B, C, D) + E + W[t] + SHA_K3;
370 E = D;
371 D = C;
372 C = S30(B);
373 B = A;
374 A = TEMP;
375 }
376
377 ctx->H[0] += A;
378 ctx->H[1] += B;
379 ctx->H[2] += C;
380 ctx->H[3] += D;
381 ctx->H[4] += E;
382 }
383
384 debug_print0(srtp_mod_sha1, "(final) running srtp_sha1_core()");
385
386 if (ctx->octets_in_buffer >= 56) {
387 debug_print0(srtp_mod_sha1, "(final) running srtp_sha1_core() again");
388
389 /* we need to do one final run of the compression algo */
390
391 /*
392 * set initial part of word array to zeros, and set the
393 * final part to the number of bits in the message
394 */
395 for (i = 0; i < 15; i++) {
396 W[i] = 0x0;
397 }
398 W[15] = ctx->num_bits_in_msg;
399
400 /* process the word array */
401 for (t = 16; t < 80; t++) {
402 TEMP = W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16];
403 W[t] = S1(TEMP);
404 }
405
406 A = ctx->H[0];
407 B = ctx->H[1];
408 C = ctx->H[2];
409 D = ctx->H[3];
410 E = ctx->H[4];
411
412 for (t = 0; t < 20; t++) {
413 TEMP = S5(A) + f0(B, C, D) + E + W[t] + SHA_K0;
414 E = D;
415 D = C;
416 C = S30(B);
417 B = A;
418 A = TEMP;
419 }
420 for (; t < 40; t++) {
421 TEMP = S5(A) + f1(B, C, D) + E + W[t] + SHA_K1;
422 E = D;
423 D = C;
424 C = S30(B);
425 B = A;
426 A = TEMP;
427 }
428 for (; t < 60; t++) {
429 TEMP = S5(A) + f2(B, C, D) + E + W[t] + SHA_K2;
430 E = D;
431 D = C;
432 C = S30(B);
433 B = A;
434 A = TEMP;
435 }
436 for (; t < 80; t++) {
437 TEMP = S5(A) + f3(B, C, D) + E + W[t] + SHA_K3;
438 E = D;
439 D = C;
440 C = S30(B);
441 B = A;
442 A = TEMP;
443 }
444
445 ctx->H[0] += A;
446 ctx->H[1] += B;
447 ctx->H[2] += C;
448 ctx->H[3] += D;
449 ctx->H[4] += E;
450 }
451
452 /* copy result into output buffer */
453 output[0] = be32_to_cpu(ctx->H[0]);
454 output[1] = be32_to_cpu(ctx->H[1]);
455 output[2] = be32_to_cpu(ctx->H[2]);
456 output[3] = be32_to_cpu(ctx->H[3]);
457 output[4] = be32_to_cpu(ctx->H[4]);
458
459 /* indicate that message buffer in context is empty */
460 ctx->octets_in_buffer = 0;
461
462 return;
463 }
464