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1 /***************************************************************************/
2 /* sha.c */
3 /* */
4 /* Public domain SHA-1 implementation. */
5 /* */
6 /* Taken from the SHA implementation by Peter C. Gutmann of 9/2/1992 */
7 /* and modified by Carl Ellison to be SHA-1. */
8 /***************************************************************************/
9
10 /*
11 ** Note regarding apg_* namespace: this avoids potential conflicts
12 ** with libraries.
13 */
14
15 #include <string.h>
16 #include "sha.h"
17
18 /* The SHA f()-functions */
19
20 #define f1(x,y,z) ( ( x & y ) | ( ~x & z ) ) /* Rounds 0-19 */
21 #define f2(x,y,z) ( x ^ y ^ z ) /* Rounds 20-39 */
22 #define f3(x,y,z) ( ( x & y ) | ( x & z ) | ( y & z ) ) /* Rounds 40-59 */
23 #define f4(x,y,z) ( x ^ y ^ z ) /* Rounds 60-79 */
24
25 /* The SHA Mysterious Constants */
26
27 #define K1 0x5A827999L /* Rounds 0-19 */
28 #define K2 0x6ED9EBA1L /* Rounds 20-39 */
29 #define K3 0x8F1BBCDCL /* Rounds 40-59 */
30 #define K4 0xCA62C1D6L /* Rounds 60-79 */
31
32 /* SHA initial values */
33
34 #define h0init 0x67452301L
35 #define h1init 0xEFCDAB89L
36 #define h2init 0x98BADCFEL
37 #define h3init 0x10325476L
38 #define h4init 0xC3D2E1F0L
39
40 /* 32-bit rotate - kludged with shifts */
41
42 typedef unsigned long UL ; /* to save space */
43
44 #define S(n,X) ( ( ((UL)X) << n ) | ( ((UL)X) >> ( 32 - n ) ) )
45
46 /* The initial expanding function */
47
48 #define expand(count) W[ count ] = S(1,(W[ count - 3 ] ^ W[ count - 8 ] ^ W[ count - 14 ] ^ W[ count - 16 ])) /* to make this SHA-1 */
49
50 /* The four SHA sub-rounds */
51
52 #define subRound1(count) \
53 { \
54 temp = S( 5, A ) + f1( B, C, D ) + E + W[ count ] + K1; \
55 E = D; \
56 D = C; \
57 C = S( 30, B ); \
58 B = A; \
59 A = temp; \
60 }
61
62 #define subRound2(count) \
63 { \
64 temp = S( 5, A ) + f2( B, C, D ) + E + W[ count ] + K2; \
65 E = D; \
66 D = C; \
67 C = S( 30, B ); \
68 B = A; \
69 A = temp; \
70 }
71
72 #define subRound3(count) \
73 { \
74 temp = S( 5, A ) + f3( B, C, D ) + E + W[ count ] + K3; \
75 E = D; \
76 D = C; \
77 C = S( 30, B ); \
78 B = A; \
79 A = temp; \
80 }
81
82 #define subRound4(count) \
83 { \
84 temp = S( 5, A ) + f4( B, C, D ) + E + W[ count ] + K4; \
85 E = D; \
86 D = C; \
87 C = S( 30, B ); \
88 B = A; \
89 A = temp; \
90 }
91
92 /* The two buffers of 5 32-bit words */
93
94 LONG h0, h1, h2, h3, h4;
95 LONG A, B, C, D, E;
96
97 /***************************************************************************/
98 /* apg_shaInit */
99 /* */
100 /* Initialize the SHA values */
101 /***************************************************************************/
102
103 void apg_shaInit( apg_SHA_INFO *shaInfo )
104 {
105 /* Set the h-vars to their initial values */
106 shaInfo->digest[ 0 ] = h0init;
107 shaInfo->digest[ 1 ] = h1init;
108 shaInfo->digest[ 2 ] = h2init;
109 shaInfo->digest[ 3 ] = h3init;
110 shaInfo->digest[ 4 ] = h4init;
111
112 /* Initialise bit count */
113 shaInfo->countLo = shaInfo->countHi = 0L;
114 shaInfo->slop = 0 ; /* no data saved yet in data[] */
115 } /* apg_shaInit */
116
117 /***************************************************************************/
118 /* shaTransform */
119 /* */
120 /* Perform the SHA transformation over one input block. */
121 /***************************************************************************/
122
123 static void shaTransform( apg_SHA_INFO *shaInfo )
124 {
125 LONG W[ 80 ], temp;
126 int i;
127
128 /* Step A. Copy the data buffer into the local work buffer */
129 for( i = 0; i < 16; i++ )
130 W[ i ] = shaInfo->data[ i ];
131
132 /* Step B. Expand the 16 words into 64 temporary data words */
133 expand( 16 ); expand( 17 ); expand( 18 ); expand( 19 ); expand( 20 );
134 expand( 21 ); expand( 22 ); expand( 23 ); expand( 24 ); expand( 25 );
135 expand( 26 ); expand( 27 ); expand( 28 ); expand( 29 ); expand( 30 );
136 expand( 31 ); expand( 32 ); expand( 33 ); expand( 34 ); expand( 35 );
137 expand( 36 ); expand( 37 ); expand( 38 ); expand( 39 ); expand( 40 );
138 expand( 41 ); expand( 42 ); expand( 43 ); expand( 44 ); expand( 45 );
139 expand( 46 ); expand( 47 ); expand( 48 ); expand( 49 ); expand( 50 );
140 expand( 51 ); expand( 52 ); expand( 53 ); expand( 54 ); expand( 55 );
141 expand( 56 ); expand( 57 ); expand( 58 ); expand( 59 ); expand( 60 );
142 expand( 61 ); expand( 62 ); expand( 63 ); expand( 64 ); expand( 65 );
143 expand( 66 ); expand( 67 ); expand( 68 ); expand( 69 ); expand( 70 );
144 expand( 71 ); expand( 72 ); expand( 73 ); expand( 74 ); expand( 75 );
145 expand( 76 ); expand( 77 ); expand( 78 ); expand( 79 );
146
147 /* Step C. Set up first buffer */
148 A = shaInfo->digest[ 0 ];
149 B = shaInfo->digest[ 1 ];
150 C = shaInfo->digest[ 2 ];
151 D = shaInfo->digest[ 3 ];
152 E = shaInfo->digest[ 4 ];
153
154 /* Step D. Serious mangling, divided into four sub-rounds */
155 subRound1( 0 ); subRound1( 1 ); subRound1( 2 ); subRound1( 3 );
156 subRound1( 4 ); subRound1( 5 ); subRound1( 6 ); subRound1( 7 );
157 subRound1( 8 ); subRound1( 9 ); subRound1( 10 ); subRound1( 11 );
158 subRound1( 12 ); subRound1( 13 ); subRound1( 14 ); subRound1( 15 );
159 subRound1( 16 ); subRound1( 17 ); subRound1( 18 ); subRound1( 19 );
160 subRound2( 20 ); subRound2( 21 ); subRound2( 22 ); subRound2( 23 );
161 subRound2( 24 ); subRound2( 25 ); subRound2( 26 ); subRound2( 27 );
162 subRound2( 28 ); subRound2( 29 ); subRound2( 30 ); subRound2( 31 );
163 subRound2( 32 ); subRound2( 33 ); subRound2( 34 ); subRound2( 35 );
164 subRound2( 36 ); subRound2( 37 ); subRound2( 38 ); subRound2( 39 );
165 subRound3( 40 ); subRound3( 41 ); subRound3( 42 ); subRound3( 43 );
166 subRound3( 44 ); subRound3( 45 ); subRound3( 46 ); subRound3( 47 );
167 subRound3( 48 ); subRound3( 49 ); subRound3( 50 ); subRound3( 51 );
168 subRound3( 52 ); subRound3( 53 ); subRound3( 54 ); subRound3( 55 );
169 subRound3( 56 ); subRound3( 57 ); subRound3( 58 ); subRound3( 59 );
170 subRound4( 60 ); subRound4( 61 ); subRound4( 62 ); subRound4( 63 );
171 subRound4( 64 ); subRound4( 65 ); subRound4( 66 ); subRound4( 67 );
172 subRound4( 68 ); subRound4( 69 ); subRound4( 70 ); subRound4( 71 );
173 subRound4( 72 ); subRound4( 73 ); subRound4( 74 ); subRound4( 75 );
174 subRound4( 76 ); subRound4( 77 ); subRound4( 78 ); subRound4( 79 );
175
176 /* Step E. Build message digest */
177 shaInfo->digest[ 0 ] += A;
178 shaInfo->digest[ 1 ] += B;
179 shaInfo->digest[ 2 ] += C;
180 shaInfo->digest[ 3 ] += D;
181 shaInfo->digest[ 4 ] += E;
182 } /* shaTransform */
183
184 #ifdef APG_LITTLE_ENDIAN
185
186 /***************************************************************************/
187 /* byteReverse */
188 /* */
189 /* When run on a little-endian CPU we need to perform byte reversal on an */
190 /* array of longwords. It is possible to make the code endianness- */
191 /* independant by fiddling around with data at the byte level, but this */
192 /* makes for very slow code, so we rely on the user to sort out endianness */
193 /* at compile time. */
194 /***************************************************************************/
195
196 static void byteReverse( LONG *buffer, int byteCount )
197 {
198 LONG value;
199 int count;
200
201 byteCount /= sizeof( LONG );
202 for( count = 0; count < byteCount; count++ )
203 {
204 value = ( buffer[ count ] << 16 ) | ( buffer[ count ] >> 16 );
205 buffer[ count ] = ( ( value & 0xFF00FF00L ) >> 8 ) | ( ( value & 0x00FF00FFL ) << 8 );
206 } /* for */
207 } /* byteReverse */
208 #endif /* APG_LITTLE_ENDIAN */
209
210 /***************************************************************************/
211 /* apg_shaUpdate */
212 /* */
213 /* Update SHA for a block of data. */
214 /* Use any data already in the SHA_INFO structure and leave any partial */
215 /* data block there. */
216 /***************************************************************************/
217
218 void apg_shaUpdate( apg_SHA_INFO *shaInfo, BYTE *buffer, int count )
219 {
220 BYTE *db ;
221
222 db = (BYTE *) &(shaInfo->data[0]) ;
223
224 /* Update bitcount */
225 if( ( shaInfo->countLo + ( ( LONG ) count << 3 ) ) < shaInfo->countLo )
226 shaInfo->countHi++; /* Carry from low to high bitCount */
227 shaInfo->countLo += ( ( LONG ) count << 3 );
228 shaInfo->countHi += ( ( LONG ) count >> 29 );
229
230 /* Process data in SHA_BLOCKSIZE chunks */
231 while ( count-- > 0 )
232 {
233 db[ shaInfo->slop++ ] = *(buffer++) ;
234 if (shaInfo->slop == SHA_BLOCKSIZE)
235 { /* transform this one block */
236 #ifdef APG_LITTLE_ENDIAN
237 byteReverse( shaInfo->data, SHA_BLOCKSIZE );
238 #endif /* APG_LITTLE_ENDIAN */
239 shaTransform( shaInfo );
240 shaInfo->slop = 0 ; /* no slop left */
241 } /* if */
242 } /* while */
243 } /* apg_shaUpdate */
244
245 /***************************************************************************/
246 /* apg_shaFinal */
247 /* */
248 /* Handle the last piece of data -- if any is left over in the data */
249 /* buffer -- and append padding and a bit count for the last block */
250 /* to process. Having transformed that block, pull the digest out */
251 /* as a byte array. */
252 /***************************************************************************/
253
254 void apg_shaFinal( apg_SHA_INFO *shaInfo, BYTE hash[SHA_DIGESTSIZE] )
255 {
256 int count;
257 LONG lowBitcount = shaInfo->countLo, highBitcount = shaInfo->countHi;
258
259 /* Compute number of bytes mod 64 */
260 count = ( int ) ( ( shaInfo->countLo >> 3 ) & 0x3F );
261
262 /* Set the first char of padding to 0x80. This is safe since there is
263 always at least one byte free */
264 ( ( BYTE * ) shaInfo->data )[ count++ ] = 0x80;
265
266 /* Pad out to 56 mod 64 */
267 if( count > 56 )
268 {
269 /* Two lots of padding: Pad the first block to 64 bytes */
270 memset( ( BYTE * ) &shaInfo->data + count, 0, 64 - count );
271 #ifdef APG_LITTLE_ENDIAN
272 byteReverse( shaInfo->data, SHA_BLOCKSIZE );
273 #endif /* APG_LITTLE_ENDIAN */
274 shaTransform( shaInfo );
275
276 /* Now fill the next block with 56 bytes */
277 memset( &shaInfo->data, 0, 56 );
278 }
279 else
280 /* Pad block to 56 bytes */
281 memset( ( BYTE * ) &shaInfo->data + count, 0, 56 - count );
282 #ifdef APG_LITTLE_ENDIAN
283 byteReverse( shaInfo->data, SHA_BLOCKSIZE );
284 #endif /* APG_LITTLE_ENDIAN */
285
286 /* Append length in bits and transform */
287 shaInfo->data[ 14 ] = highBitcount;
288 shaInfo->data[ 15 ] = lowBitcount;
289
290 shaTransform( shaInfo );
291 #ifdef APG_LITTLE_ENDIAN
292 byteReverse( shaInfo->data, SHA_DIGESTSIZE );
293 #endif /* APG_LITTLE_ENDIAN */
294
295 for (count=0; count<SHA_DIGESTSIZE; count++)
296 hash[count] = (BYTE) ((shaInfo->digest[count>>2]) >> (8*(3-(count & 0x3)))) & 0xff ;
297 } /* apg_shaFinal */