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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) 2001-2006, 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 
48 #include "sha1.h"
49 
50 debug_module_t mod_sha1 = {
51   0,                 /* debugging is off by default */
52   "sha-1"            /* printable module name       */
53 };
54 
55 /* SN == Rotate left N bits */
56 #define S1(X)  ((X << 1)  | (X >> 31))
57 #define S5(X)  ((X << 5)  | (X >> 27))
58 #define S30(X) ((X << 30) | (X >> 2))
59 
60 #define f0(B,C,D) ((B & C) | (~B & D))
61 #define f1(B,C,D) (B ^ C ^ D)
62 #define f2(B,C,D) ((B & C) | (B & D) | (C & D))
63 #define f3(B,C,D) (B ^ C ^ D)
64 
65 /*
66  * nota bene: the variable K0 appears in the curses library, so we
67  * give longer names to these variables to avoid spurious warnings
68  * on systems that uses curses
69  */
70 
71 uint32_t SHA_K0 = 0x5A827999;   /* Kt for 0  <= t <= 19 */
72 uint32_t SHA_K1 = 0x6ED9EBA1;   /* Kt for 20 <= t <= 39 */
73 uint32_t SHA_K2 = 0x8F1BBCDC;   /* Kt for 40 <= t <= 59 */
74 uint32_t SHA_K3 = 0xCA62C1D6;   /* Kt for 60 <= t <= 79 */
75 
76 void
sha1(const uint8_t * msg,int octets_in_msg,uint32_t hash_value[5])77 sha1(const uint8_t *msg,  int octets_in_msg, uint32_t hash_value[5]) {
78   sha1_ctx_t ctx;
79 
80   sha1_init(&ctx);
81   sha1_update(&ctx, msg, octets_in_msg);
82   sha1_final(&ctx, hash_value);
83 
84 }
85 
86 /*
87  *  sha1_core(M, H) computes the core compression function, where M is
88  *  the next part of the message (in network byte order) and H is the
89  *  intermediate state { H0, H1, ...} (in host byte order)
90  *
91  *  this function does not do any of the padding required in the
92  *  complete SHA1 function
93  *
94  *  this function is used in the SEAL 3.0 key setup routines
95  *  (crypto/cipher/seal.c)
96  */
97 
98 void
sha1_core(const uint32_t M[16],uint32_t hash_value[5])99 sha1_core(const uint32_t M[16], uint32_t hash_value[5]) {
100   uint32_t H0;
101   uint32_t H1;
102   uint32_t H2;
103   uint32_t H3;
104   uint32_t H4;
105   uint32_t W[80];
106   uint32_t A, B, C, D, E, TEMP;
107   int t;
108 
109   /* copy hash_value into H0, H1, H2, H3, H4 */
110   H0 = hash_value[0];
111   H1 = hash_value[1];
112   H2 = hash_value[2];
113   H3 = hash_value[3];
114   H4 = hash_value[4];
115 
116   /* copy/xor message into array */
117 
118   W[0]  = be32_to_cpu(M[0]);
119   W[1]  = be32_to_cpu(M[1]);
120   W[2]  = be32_to_cpu(M[2]);
121   W[3]  = be32_to_cpu(M[3]);
122   W[4]  = be32_to_cpu(M[4]);
123   W[5]  = be32_to_cpu(M[5]);
124   W[6]  = be32_to_cpu(M[6]);
125   W[7]  = be32_to_cpu(M[7]);
126   W[8]  = be32_to_cpu(M[8]);
127   W[9]  = be32_to_cpu(M[9]);
128   W[10] = be32_to_cpu(M[10]);
129   W[11] = be32_to_cpu(M[11]);
130   W[12] = be32_to_cpu(M[12]);
131   W[13] = be32_to_cpu(M[13]);
132   W[14] = be32_to_cpu(M[14]);
133   W[15] = be32_to_cpu(M[15]);
134   TEMP = W[13] ^ W[8]  ^ W[2]  ^ W[0];  W[16] = S1(TEMP);
135   TEMP = W[14] ^ W[9]  ^ W[3]  ^ W[1];  W[17] = S1(TEMP);
136   TEMP = W[15] ^ W[10] ^ W[4]  ^ W[2];  W[18] = S1(TEMP);
137   TEMP = W[16] ^ W[11] ^ W[5]  ^ W[3];  W[19] = S1(TEMP);
138   TEMP = W[17] ^ W[12] ^ W[6]  ^ W[4];  W[20] = S1(TEMP);
139   TEMP = W[18] ^ W[13] ^ W[7]  ^ W[5];  W[21] = S1(TEMP);
140   TEMP = W[19] ^ W[14] ^ W[8]  ^ W[6];  W[22] = S1(TEMP);
141   TEMP = W[20] ^ W[15] ^ W[9]  ^ W[7];  W[23] = S1(TEMP);
142   TEMP = W[21] ^ W[16] ^ W[10] ^ W[8];  W[24] = S1(TEMP);
143   TEMP = W[22] ^ W[17] ^ W[11] ^ W[9];  W[25] = S1(TEMP);
144   TEMP = W[23] ^ W[18] ^ W[12] ^ W[10]; W[26] = S1(TEMP);
145   TEMP = W[24] ^ W[19] ^ W[13] ^ W[11]; W[27] = S1(TEMP);
146   TEMP = W[25] ^ W[20] ^ W[14] ^ W[12]; W[28] = S1(TEMP);
147   TEMP = W[26] ^ W[21] ^ W[15] ^ W[13]; W[29] = S1(TEMP);
148   TEMP = W[27] ^ W[22] ^ W[16] ^ W[14]; W[30] = S1(TEMP);
149   TEMP = W[28] ^ W[23] ^ W[17] ^ W[15]; W[31] = S1(TEMP);
150 
151   /* process the remainder of the array */
152   for (t=32; t < 80; t++) {
153     TEMP = W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16];
154     W[t] = S1(TEMP);
155   }
156 
157   A = H0; B = H1; C = H2; D = H3; E = H4;
158 
159   for (t=0; t < 20; t++) {
160     TEMP = S5(A) + f0(B,C,D) + E + W[t] + SHA_K0;
161     E = D; D = C; C = S30(B); B = A; A = TEMP;
162   }
163   for (   ; t < 40; t++) {
164     TEMP = S5(A) + f1(B,C,D) + E + W[t] + SHA_K1;
165     E = D; D = C; C = S30(B); B = A; A = TEMP;
166   }
167   for (   ; t < 60; t++) {
168     TEMP = S5(A) + f2(B,C,D) + E + W[t] + SHA_K2;
169     E = D; D = C; C = S30(B); B = A; A = TEMP;
170   }
171   for (   ; t < 80; t++) {
172     TEMP = S5(A) + f3(B,C,D) + E + W[t] + SHA_K3;
173     E = D; D = C; C = S30(B); B = A; A = TEMP;
174   }
175 
176   hash_value[0] = H0 + A;
177   hash_value[1] = H1 + B;
178   hash_value[2] = H2 + C;
179   hash_value[3] = H3 + D;
180   hash_value[4] = H4 + E;
181 
182   return;
183 }
184 
185 void
sha1_init(sha1_ctx_t * ctx)186 sha1_init(sha1_ctx_t *ctx) {
187 
188   /* initialize state vector */
189   ctx->H[0] = 0x67452301;
190   ctx->H[1] = 0xefcdab89;
191   ctx->H[2] = 0x98badcfe;
192   ctx->H[3] = 0x10325476;
193   ctx->H[4] = 0xc3d2e1f0;
194 
195   /* indicate that message buffer is empty */
196   ctx->octets_in_buffer = 0;
197 
198   /* reset message bit-count to zero */
199   ctx->num_bits_in_msg = 0;
200 
201 }
202 
203 void
sha1_update(sha1_ctx_t * ctx,const uint8_t * msg,int octets_in_msg)204 sha1_update(sha1_ctx_t *ctx, const uint8_t *msg, int octets_in_msg) {
205   int i;
206   uint8_t *buf = (uint8_t *)ctx->M;
207 
208   /* update message bit-count */
209   ctx->num_bits_in_msg += octets_in_msg * 8;
210 
211   /* loop over 16-word blocks of M */
212   while (octets_in_msg > 0) {
213 
214     if (octets_in_msg + ctx->octets_in_buffer >= 64) {
215 
216       /*
217        * copy words of M into msg buffer until that buffer is full,
218        * converting them into host byte order as needed
219        */
220       octets_in_msg -= (64 - ctx->octets_in_buffer);
221       for (i=ctx->octets_in_buffer; i < 64; i++)
222 	buf[i] = *msg++;
223       ctx->octets_in_buffer = 0;
224 
225       /* process a whole block */
226 
227       debug_print(mod_sha1, "(update) running sha1_core()", NULL);
228 
229       sha1_core(ctx->M, ctx->H);
230 
231     } else {
232 
233       debug_print(mod_sha1, "(update) not running sha1_core()", NULL);
234 
235       for (i=ctx->octets_in_buffer;
236 	   i < (ctx->octets_in_buffer + octets_in_msg); i++)
237 	buf[i] = *msg++;
238       ctx->octets_in_buffer += octets_in_msg;
239       octets_in_msg = 0;
240     }
241 
242   }
243 
244 }
245 
246 /*
247  * sha1_final(ctx, output) computes the result for ctx and copies it
248  * into the twenty octets located at *output
249  */
250 
251 void
sha1_final(sha1_ctx_t * ctx,uint32_t * output)252 sha1_final(sha1_ctx_t *ctx, uint32_t *output) {
253   uint32_t A, B, C, D, E, TEMP;
254   uint32_t W[80];
255   int i, t;
256 
257   /*
258    * process the remaining octets_in_buffer, padding and terminating as
259    * necessary
260    */
261   {
262     int tail = ctx->octets_in_buffer % 4;
263 
264     /* copy/xor message into array */
265     for (i=0; i < (ctx->octets_in_buffer+3)/4; i++)
266       W[i]  = be32_to_cpu(ctx->M[i]);
267 
268     /* set the high bit of the octet immediately following the message */
269     switch (tail) {
270     case (3):
271       W[i-1] = (be32_to_cpu(ctx->M[i-1]) & 0xffffff00) | 0x80;
272       W[i] = 0x0;
273       break;
274     case (2):
275       W[i-1] = (be32_to_cpu(ctx->M[i-1]) & 0xffff0000) | 0x8000;
276       W[i] = 0x0;
277       break;
278     case (1):
279       W[i-1] = (be32_to_cpu(ctx->M[i-1]) & 0xff000000) | 0x800000;
280       W[i] = 0x0;
281       break;
282     case (0):
283       W[i] = 0x80000000;
284       break;
285     }
286 
287     /* zeroize remaining words */
288     for (i++   ; i < 15; i++)
289       W[i] = 0x0;
290 
291     /*
292      * if there is room at the end of the word array, then set the
293      * last word to the bit-length of the message; otherwise, set that
294      * word to zero and then we need to do one more run of the
295      * compression algo.
296      */
297     if (ctx->octets_in_buffer < 56)
298       W[15] = ctx->num_bits_in_msg;
299     else if (ctx->octets_in_buffer < 60)
300       W[15] = 0x0;
301 
302     /* process the word array */
303     for (t=16; t < 80; t++) {
304       TEMP = W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16];
305       W[t] = S1(TEMP);
306     }
307 
308     A = ctx->H[0];
309     B = ctx->H[1];
310     C = ctx->H[2];
311     D = ctx->H[3];
312     E = ctx->H[4];
313 
314     for (t=0; t < 20; t++) {
315       TEMP = S5(A) + f0(B,C,D) + E + W[t] + SHA_K0;
316       E = D; D = C; C = S30(B); B = A; A = TEMP;
317     }
318     for (   ; t < 40; t++) {
319       TEMP = S5(A) + f1(B,C,D) + E + W[t] + SHA_K1;
320       E = D; D = C; C = S30(B); B = A; A = TEMP;
321     }
322     for (   ; t < 60; t++) {
323       TEMP = S5(A) + f2(B,C,D) + E + W[t] + SHA_K2;
324       E = D; D = C; C = S30(B); B = A; A = TEMP;
325     }
326     for (   ; t < 80; t++) {
327       TEMP = S5(A) + f3(B,C,D) + E + W[t] + SHA_K3;
328       E = D; D = C; C = S30(B); B = A; A = TEMP;
329     }
330 
331     ctx->H[0] += A;
332     ctx->H[1] += B;
333     ctx->H[2] += C;
334     ctx->H[3] += D;
335     ctx->H[4] += E;
336 
337   }
338 
339   debug_print(mod_sha1, "(final) running sha1_core()", NULL);
340 
341   if (ctx->octets_in_buffer >= 56) {
342 
343     debug_print(mod_sha1, "(final) running sha1_core() again", NULL);
344 
345     /* we need to do one final run of the compression algo */
346 
347     /*
348      * set initial part of word array to zeros, and set the
349      * final part to the number of bits in the message
350      */
351     for (i=0; i < 15; i++)
352       W[i] = 0x0;
353     W[15] = ctx->num_bits_in_msg;
354 
355     /* process the word array */
356     for (t=16; t < 80; t++) {
357       TEMP = W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16];
358       W[t] = S1(TEMP);
359     }
360 
361     A = ctx->H[0];
362     B = ctx->H[1];
363     C = ctx->H[2];
364     D = ctx->H[3];
365     E = ctx->H[4];
366 
367     for (t=0; t < 20; t++) {
368       TEMP = S5(A) + f0(B,C,D) + E + W[t] + SHA_K0;
369       E = D; D = C; C = S30(B); B = A; A = TEMP;
370     }
371     for (   ; t < 40; t++) {
372       TEMP = S5(A) + f1(B,C,D) + E + W[t] + SHA_K1;
373       E = D; D = C; C = S30(B); B = A; A = TEMP;
374     }
375     for (   ; t < 60; t++) {
376       TEMP = S5(A) + f2(B,C,D) + E + W[t] + SHA_K2;
377       E = D; D = C; C = S30(B); B = A; A = TEMP;
378     }
379     for (   ; t < 80; t++) {
380       TEMP = S5(A) + f3(B,C,D) + E + W[t] + SHA_K3;
381       E = D; D = C; C = S30(B); B = A; A = TEMP;
382     }
383 
384     ctx->H[0] += A;
385     ctx->H[1] += B;
386     ctx->H[2] += C;
387     ctx->H[3] += D;
388     ctx->H[4] += E;
389   }
390 
391   /* copy result into output buffer */
392   output[0] = be32_to_cpu(ctx->H[0]);
393   output[1] = be32_to_cpu(ctx->H[1]);
394   output[2] = be32_to_cpu(ctx->H[2]);
395   output[3] = be32_to_cpu(ctx->H[3]);
396   output[4] = be32_to_cpu(ctx->H[4]);
397 
398   /* indicate that message buffer in context is empty */
399   ctx->octets_in_buffer = 0;
400 
401   return;
402 }
403 
404 
405 
406