3 * The compression function of the sha1 hash function.
6 /* nettle, low-level cryptographics library
8 * Copyright (C) 2001, 2004 Peter Gutmann, Andrew Kuchling, Niels Möller
10 * The nettle library is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU Lesser General Public License as published by
12 * the Free Software Foundation; either version 2.1 of the License, or (at your
13 * option) any later version.
15 * The nettle library is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
17 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
18 * License for more details.
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with the nettle library; see the file COPYING.LIB. If not, write to
22 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
26 /* Here's the first paragraph of Peter Gutmann's posting,
27 * <30ajo5$oe8@ccu2.auckland.ac.nz>:
29 * The following is my SHA (FIPS 180) code updated to allow use of the "fixed"
30 * SHA, thanks to Jim Gillogly and an anonymous contributor for the information on
31 * what's changed in the new version. The fix is a simple change which involves
32 * adding a single rotate in the initial expansion function. It is unknown
33 * whether this is an optimal solution to the problem which was discovered in the
34 * SHA or whether it's simply a bandaid which fixes the problem with a minimum of
35 * effort (for example the reengineering of a great many Capstone chips).
49 fprintf(stderr, "%2d: %8x %8x %8x %8x %8x\n", i, A, B, C, D ,E)
62 /* A block, treated as a sequence of 32-bit words. */
63 #define SHA1_DATA_LENGTH 16
65 /* The SHA f()-functions. The f1 and f3 functions can be optimized to
66 save one boolean operation each - thanks to Rich Schroeppel,
67 rcs@cs.arizona.edu for discovering this */
69 /* FIXME: Can save a temporary in f3 by using ( (x & y) + (z & (x ^
70 y)) ), and then, in the round, compute one of the terms and add it
71 into the destination word before computing the second term. Credits
72 to George Spelvin for pointing this out. Unfortunately, gcc
73 doesn't seem to be smart enough to take advantage of this. */
75 /* #define f1(x,y,z) ( ( x & y ) | ( ~x & z ) ) Rounds 0-19 */
76 #define f1(x,y,z) ( z ^ ( x & ( y ^ z ) ) ) /* Rounds 0-19 */
77 #define f2(x,y,z) ( x ^ y ^ z ) /* Rounds 20-39 */
78 /* #define f3(x,y,z) ( ( x & y ) | ( x & z ) | ( y & z ) ) Rounds 40-59 */
79 #define f3(x,y,z) ( ( x & y ) | ( z & ( x | y ) ) ) /* Rounds 40-59 */
82 /* The SHA Mysterious Constants */
84 #define K1 0x5A827999L /* Rounds 0-19 */
85 #define K2 0x6ED9EBA1L /* Rounds 20-39 */
86 #define K3 0x8F1BBCDCL /* Rounds 40-59 */
87 #define K4 0xCA62C1D6L /* Rounds 60-79 */
89 /* 32-bit rotate left - kludged with shifts */
91 #define ROTL(n,X) ( ( (X) << (n) ) | ( (X) >> ( 32 - (n) ) ) )
93 /* The initial expanding function. The hash function is defined over an
94 80-word expanded input array W, where the first 16 are copies of the input
95 data, and the remaining 64 are defined by
97 W[ i ] = W[ i - 16 ] ^ W[ i - 14 ] ^ W[ i - 8 ] ^ W[ i - 3 ]
99 This implementation generates these values on the fly in a circular
100 buffer - thanks to Colin Plumb, colin@nyx10.cs.du.edu for this
103 The updated SHA changes the expanding function by adding a rotate of 1
104 bit. Thanks to Jim Gillogly, jim@rand.org, and an anonymous contributor
105 for this information */
107 #define expand(W,i) ( W[ i & 15 ] = \
108 ROTL( 1, ( W[ i & 15 ] ^ W[ (i - 14) & 15 ] ^ \
109 W[ (i - 8) & 15 ] ^ W[ (i - 3) & 15 ] ) ) )
112 /* The prototype SHA sub-round. The fundamental sub-round is:
114 a' = e + ROTL( 5, a ) + f( b, c, d ) + k + data;
120 but this is implemented by unrolling the loop 5 times and renaming the
121 variables ( e, a, b, c, d ) = ( a', b', c', d', e' ) each iteration.
122 This code is then replicated 20 times for each of the 4 functions, using
123 the next 20 values from the W[] array each time */
125 #define subRound(a, b, c, d, e, f, k, data) \
126 ( e += ROTL( 5, a ) + f( b, c, d ) + k + data, b = ROTL( 30, b ) )
128 /* Perform the SHA transformation. Note that this code, like MD5, seems to
129 break some optimizing compilers due to the complexity of the expressions
130 and the size of the basic block. It may be necessary to split it into
131 sections, e.g. based on the four subrounds. */
134 _nettle_sha1_compress(uint32_t *state, const uint8_t *input)
136 uint32_t data[SHA1_DATA_LENGTH];
137 uint32_t A, B, C, D, E; /* Local vars */
140 for (i = 0; i < SHA1_DATA_LENGTH; i++, input+= 4)
142 data[i] = READ_UINT32(input);
145 /* Set up first buffer and local data buffer */
153 /* Heavy mangling, in 4 sub-rounds of 20 interations each. */
154 subRound( A, B, C, D, E, f1, K1, data[ 0] ); DEBUG(0);
155 subRound( E, A, B, C, D, f1, K1, data[ 1] ); DEBUG(1);
156 subRound( D, E, A, B, C, f1, K1, data[ 2] );
157 subRound( C, D, E, A, B, f1, K1, data[ 3] );
158 subRound( B, C, D, E, A, f1, K1, data[ 4] );
159 subRound( A, B, C, D, E, f1, K1, data[ 5] );
160 subRound( E, A, B, C, D, f1, K1, data[ 6] );
161 subRound( D, E, A, B, C, f1, K1, data[ 7] );
162 subRound( C, D, E, A, B, f1, K1, data[ 8] );
163 subRound( B, C, D, E, A, f1, K1, data[ 9] );
164 subRound( A, B, C, D, E, f1, K1, data[10] );
165 subRound( E, A, B, C, D, f1, K1, data[11] );
166 subRound( D, E, A, B, C, f1, K1, data[12] );
167 subRound( C, D, E, A, B, f1, K1, data[13] );
168 subRound( B, C, D, E, A, f1, K1, data[14] );
169 subRound( A, B, C, D, E, f1, K1, data[15] ); DEBUG(15);
170 subRound( E, A, B, C, D, f1, K1, expand( data, 16 ) ); DEBUG(16);
171 subRound( D, E, A, B, C, f1, K1, expand( data, 17 ) ); DEBUG(17);
172 subRound( C, D, E, A, B, f1, K1, expand( data, 18 ) ); DEBUG(18);
173 subRound( B, C, D, E, A, f1, K1, expand( data, 19 ) ); DEBUG(19);
175 subRound( A, B, C, D, E, f2, K2, expand( data, 20 ) ); DEBUG(20);
176 subRound( E, A, B, C, D, f2, K2, expand( data, 21 ) ); DEBUG(21);
177 subRound( D, E, A, B, C, f2, K2, expand( data, 22 ) );
178 subRound( C, D, E, A, B, f2, K2, expand( data, 23 ) );
179 subRound( B, C, D, E, A, f2, K2, expand( data, 24 ) );
180 subRound( A, B, C, D, E, f2, K2, expand( data, 25 ) );
181 subRound( E, A, B, C, D, f2, K2, expand( data, 26 ) );
182 subRound( D, E, A, B, C, f2, K2, expand( data, 27 ) );
183 subRound( C, D, E, A, B, f2, K2, expand( data, 28 ) );
184 subRound( B, C, D, E, A, f2, K2, expand( data, 29 ) );
185 subRound( A, B, C, D, E, f2, K2, expand( data, 30 ) );
186 subRound( E, A, B, C, D, f2, K2, expand( data, 31 ) );
187 subRound( D, E, A, B, C, f2, K2, expand( data, 32 ) );
188 subRound( C, D, E, A, B, f2, K2, expand( data, 33 ) );
189 subRound( B, C, D, E, A, f2, K2, expand( data, 34 ) );
190 subRound( A, B, C, D, E, f2, K2, expand( data, 35 ) );
191 subRound( E, A, B, C, D, f2, K2, expand( data, 36 ) );
192 subRound( D, E, A, B, C, f2, K2, expand( data, 37 ) );
193 subRound( C, D, E, A, B, f2, K2, expand( data, 38 ) ); DEBUG(38);
194 subRound( B, C, D, E, A, f2, K2, expand( data, 39 ) ); DEBUG(39);
196 subRound( A, B, C, D, E, f3, K3, expand( data, 40 ) ); DEBUG(40);
197 subRound( E, A, B, C, D, f3, K3, expand( data, 41 ) ); DEBUG(41);
198 subRound( D, E, A, B, C, f3, K3, expand( data, 42 ) );
199 subRound( C, D, E, A, B, f3, K3, expand( data, 43 ) );
200 subRound( B, C, D, E, A, f3, K3, expand( data, 44 ) );
201 subRound( A, B, C, D, E, f3, K3, expand( data, 45 ) );
202 subRound( E, A, B, C, D, f3, K3, expand( data, 46 ) );
203 subRound( D, E, A, B, C, f3, K3, expand( data, 47 ) );
204 subRound( C, D, E, A, B, f3, K3, expand( data, 48 ) );
205 subRound( B, C, D, E, A, f3, K3, expand( data, 49 ) );
206 subRound( A, B, C, D, E, f3, K3, expand( data, 50 ) );
207 subRound( E, A, B, C, D, f3, K3, expand( data, 51 ) );
208 subRound( D, E, A, B, C, f3, K3, expand( data, 52 ) );
209 subRound( C, D, E, A, B, f3, K3, expand( data, 53 ) );
210 subRound( B, C, D, E, A, f3, K3, expand( data, 54 ) );
211 subRound( A, B, C, D, E, f3, K3, expand( data, 55 ) );
212 subRound( E, A, B, C, D, f3, K3, expand( data, 56 ) );
213 subRound( D, E, A, B, C, f3, K3, expand( data, 57 ) );
214 subRound( C, D, E, A, B, f3, K3, expand( data, 58 ) ); DEBUG(58);
215 subRound( B, C, D, E, A, f3, K3, expand( data, 59 ) ); DEBUG(59);
217 subRound( A, B, C, D, E, f4, K4, expand( data, 60 ) ); DEBUG(60);
218 subRound( E, A, B, C, D, f4, K4, expand( data, 61 ) ); DEBUG(61);
219 subRound( D, E, A, B, C, f4, K4, expand( data, 62 ) );
220 subRound( C, D, E, A, B, f4, K4, expand( data, 63 ) );
221 subRound( B, C, D, E, A, f4, K4, expand( data, 64 ) );
222 subRound( A, B, C, D, E, f4, K4, expand( data, 65 ) );
223 subRound( E, A, B, C, D, f4, K4, expand( data, 66 ) );
224 subRound( D, E, A, B, C, f4, K4, expand( data, 67 ) );
225 subRound( C, D, E, A, B, f4, K4, expand( data, 68 ) );
226 subRound( B, C, D, E, A, f4, K4, expand( data, 69 ) );
227 subRound( A, B, C, D, E, f4, K4, expand( data, 70 ) );
228 subRound( E, A, B, C, D, f4, K4, expand( data, 71 ) );
229 subRound( D, E, A, B, C, f4, K4, expand( data, 72 ) );
230 subRound( C, D, E, A, B, f4, K4, expand( data, 73 ) );
231 subRound( B, C, D, E, A, f4, K4, expand( data, 74 ) );
232 subRound( A, B, C, D, E, f4, K4, expand( data, 75 ) );
233 subRound( E, A, B, C, D, f4, K4, expand( data, 76 ) );
234 subRound( D, E, A, B, C, f4, K4, expand( data, 77 ) );
235 subRound( C, D, E, A, B, f4, K4, expand( data, 78 ) ); DEBUG(78);
236 subRound( B, C, D, E, A, f4, K4, expand( data, 79 ) ); DEBUG(79);
238 /* Build message digest */
246 fprintf(stderr, "99: %8x %8x %8x %8x %8x\n",
247 state[0], state[1], state[2], state[3], state[4]);