Mercurial > hg > octave-shane > gnulib-hg
annotate lib/sha.c @ 2867:6d88857e7e6c
checkpoint
| author | Jim Meyering <jim@meyering.net> |
|---|---|
| date | Sun, 17 Sep 2000 12:54:25 +0000 |
| parents | 33ef979547bd |
| children | 665842f23067 |
| rev | line source |
|---|---|
| 2863 | 1 /* sha.c - Functions to compute the SHA1 hash (message-digest) of files |
| 2 or blocks of memory. Complies to the NIST specification FIPS-180-1. | |
| 3 | |
| 4 Copyright (C) 2000 Scott G. Miller | |
| 5 | |
| 6 Credits: | |
| 7 Robert Klep <robert@ilse.nl> -- Expansion function fix | |
| 8 */ | |
| 9 | |
| 10 #ifdef HAVE_CONFIG_H | |
| 11 # include <config.h> | |
| 12 #endif | |
| 13 | |
| 14 #include <sys/types.h> | |
| 15 | |
| 16 #if STDC_HEADERS || defined _LIBC | |
| 17 # include <stdlib.h> | |
| 18 # include <string.h> | |
| 19 #else | |
| 20 # ifndef HAVE_MEMCPY | |
| 21 # define memcpy(d, s, n) bcopy ((s), (d), (n)) | |
| 22 # endif | |
| 23 #endif | |
| 24 | |
| 25 #include "md5.h" | |
| 26 #include "sha.h" | |
| 27 | |
| 28 /* | |
| 29 Not-swap is a macro that does an endian swap on architectures that are | |
| 30 big-endian, as SHA needs some data in a little-endian format | |
| 31 */ | |
| 32 | |
| 33 #ifdef WORDS_BIGENDIAN | |
| 34 # define NOTSWAP(n) (n) | |
| 35 # define SWAP(n) \ | |
| 36 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24)) | |
| 37 #else | |
| 38 # define NOTSWAP(n) \ | |
| 39 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24)) | |
| 40 # define SWAP(n) (n) | |
| 41 #endif | |
| 42 | |
| 43 /* This array contains the bytes used to pad the buffer to the next | |
| 44 64-byte boundary. (RFC 1321, 3.1: Step 1) */ | |
| 45 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ }; | |
| 46 | |
| 47 | |
| 48 /* | |
| 49 Takes a pointer to a 160 bit block of data (five 32 bit ints) and | |
| 50 intializes it to the start constants of the SHA1 algorithm. This | |
| 51 must be called before using hash in the call to sha_hash | |
| 52 */ | |
| 53 void | |
| 54 sha_init_ctx (struct sha_ctx *ctx) | |
| 55 { | |
| 56 ctx->A = 0x67452301; | |
| 57 ctx->B = 0xefcdab89; | |
| 58 ctx->C = 0x98badcfe; | |
| 59 ctx->D = 0x10325476; | |
| 60 ctx->E = 0xc3d2e1f0; | |
| 61 | |
| 62 ctx->total[0] = ctx->total[1] = 0; | |
| 63 ctx->buflen = 0; | |
| 64 } | |
| 65 | |
| 66 /* Put result from CTX in first 20 bytes following RESBUF. The result | |
| 67 must be in little endian byte order. | |
| 68 | |
| 69 IMPORTANT: On some systems it is required that RESBUF is correctly | |
| 70 aligned for a 32 bits value. */ | |
| 71 void * | |
| 72 sha_read_ctx (const struct sha_ctx *ctx, void *resbuf) | |
| 73 { | |
| 74 ((md5_uint32 *) resbuf)[0] = NOTSWAP (ctx->A); | |
| 75 ((md5_uint32 *) resbuf)[1] = NOTSWAP (ctx->B); | |
| 76 ((md5_uint32 *) resbuf)[2] = NOTSWAP (ctx->C); | |
| 77 ((md5_uint32 *) resbuf)[3] = NOTSWAP (ctx->D); | |
| 78 ((md5_uint32 *) resbuf)[4] = NOTSWAP (ctx->E); | |
| 79 | |
| 80 return resbuf; | |
| 81 } | |
| 82 | |
| 83 /* Process the remaining bytes in the internal buffer and the usual | |
| 84 prolog according to the standard and write the result to RESBUF. | |
| 85 | |
| 86 IMPORTANT: On some systems it is required that RESBUF is correctly | |
| 87 aligned for a 32 bits value. */ | |
| 88 void * | |
| 89 sha_finish_ctx (struct sha_ctx *ctx, void *resbuf) | |
| 90 { | |
| 91 /* Take yet unprocessed bytes into account. */ | |
| 92 md5_uint32 bytes = ctx->buflen; | |
| 93 size_t pad; | |
| 94 | |
| 95 /* Now count remaining bytes. */ | |
| 96 ctx->total[0] += bytes; | |
| 97 if (ctx->total[0] < bytes) | |
| 98 ++ctx->total[1]; | |
| 99 | |
| 100 pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes; | |
| 101 memcpy (&ctx->buffer[bytes], fillbuf, pad); | |
| 102 | |
| 103 /* Put the 64-bit file length in *bits* at the end of the buffer. */ | |
| 104 *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = NOTSWAP (ctx->total[0] << 3); | |
| 105 *(md5_uint32 *) &ctx->buffer[bytes + pad] = NOTSWAP ((ctx->total[1] << 3) | | |
| 106 (ctx->total[0] >> 29)); | |
| 107 | |
| 108 /* Process last bytes. */ | |
| 109 sha_process_block (ctx->buffer, bytes + pad + 8, ctx); | |
| 110 | |
| 111 return sha_read_ctx (ctx, resbuf); | |
| 112 } | |
| 113 | |
| 114 /* Compute SHA1 message digest for bytes read from STREAM. The | |
| 115 resulting message digest number will be written into the 16 bytes | |
| 116 beginning at RESBLOCK. */ | |
| 117 int | |
| 118 sha_stream (FILE *stream, void *resblock) | |
| 119 { | |
| 120 /* Important: BLOCKSIZE must be a multiple of 64. */ | |
| 121 #define BLOCKSIZE 4096 | |
| 122 struct sha_ctx ctx; | |
| 123 char buffer[BLOCKSIZE + 72]; | |
| 124 size_t sum; | |
| 125 | |
| 126 /* Initialize the computation context. */ | |
| 127 sha_init_ctx (&ctx); | |
| 128 | |
| 129 /* Iterate over full file contents. */ | |
| 130 while (1) | |
| 131 { | |
| 132 /* We read the file in blocks of BLOCKSIZE bytes. One call of the | |
| 133 computation function processes the whole buffer so that with the | |
| 134 next round of the loop another block can be read. */ | |
| 135 size_t n; | |
| 136 sum = 0; | |
| 137 | |
| 138 /* Read block. Take care for partial reads. */ | |
| 139 do | |
| 140 { | |
| 141 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream); | |
| 142 | |
| 143 sum += n; | |
| 144 } | |
| 145 while (sum < BLOCKSIZE && n != 0); | |
| 146 if (n == 0 && ferror (stream)) | |
| 147 return 1; | |
| 148 | |
| 149 /* If end of file is reached, end the loop. */ | |
| 150 if (n == 0) | |
| 151 break; | |
| 152 | |
| 153 /* Process buffer with BLOCKSIZE bytes. Note that | |
| 154 BLOCKSIZE % 64 == 0 | |
| 155 */ | |
| 156 sha_process_block (buffer, BLOCKSIZE, &ctx); | |
| 157 } | |
| 158 | |
| 159 /* Add the last bytes if necessary. */ | |
| 160 if (sum > 0) | |
| 161 sha_process_bytes (buffer, sum, &ctx); | |
| 162 | |
| 163 /* Construct result in desired memory. */ | |
| 164 sha_finish_ctx (&ctx, resblock); | |
| 165 return 0; | |
| 166 } | |
| 167 | |
| 168 /* Compute MD5 message digest for LEN bytes beginning at BUFFER. The | |
| 169 result is always in little endian byte order, so that a byte-wise | |
| 170 output yields to the wanted ASCII representation of the message | |
| 171 digest. */ | |
| 172 void * | |
| 173 sha_buffer (const char *buffer, size_t len, void *resblock) | |
| 174 { | |
| 175 struct sha_ctx ctx; | |
| 176 | |
| 177 /* Initialize the computation context. */ | |
| 178 sha_init_ctx (&ctx); | |
| 179 | |
| 180 /* Process whole buffer but last len % 64 bytes. */ | |
| 181 sha_process_bytes (buffer, len, &ctx); | |
| 182 | |
| 183 /* Put result in desired memory area. */ | |
| 184 return sha_finish_ctx (&ctx, resblock); | |
| 185 } | |
| 186 | |
| 187 void | |
| 188 sha_process_bytes (const void *buffer, size_t len, struct sha_ctx *ctx) | |
| 189 { | |
| 190 /* When we already have some bits in our internal buffer concatenate | |
| 191 both inputs first. */ | |
| 192 if (ctx->buflen != 0) | |
| 193 { | |
| 194 size_t left_over = ctx->buflen; | |
| 195 size_t add = 128 - left_over > len ? len : 128 - left_over; | |
| 196 | |
| 197 memcpy (&ctx->buffer[left_over], buffer, add); | |
| 198 ctx->buflen += add; | |
| 199 | |
| 200 if (left_over + add > 64) | |
| 201 { | |
| 202 sha_process_block (ctx->buffer, (left_over + add) & ~63, ctx); | |
| 203 /* The regions in the following copy operation cannot overlap. */ | |
| 204 memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63], | |
| 205 (left_over + add) & 63); | |
| 206 ctx->buflen = (left_over + add) & 63; | |
| 207 } | |
| 208 | |
| 209 buffer = (const char *) buffer + add; | |
| 210 len -= add; | |
| 211 } | |
| 212 | |
| 213 /* Process available complete blocks. */ | |
| 214 if (len > 64) | |
| 215 { | |
| 216 sha_process_block (buffer, len & ~63, ctx); | |
| 217 buffer = (const char *) buffer + (len & ~63); | |
| 218 len &= 63; | |
| 219 } | |
| 220 | |
| 221 /* Move remaining bytes in internal buffer. */ | |
| 222 if (len > 0) | |
| 223 { | |
| 224 memcpy (ctx->buffer, buffer, len); | |
| 225 ctx->buflen = len; | |
| 226 } | |
| 227 } | |
| 228 | |
| 229 /* --- Code below is the primary difference between md5.c and sha.c --- */ | |
| 230 | |
| 231 /* SHA1 round constants */ | |
| 232 #define K1 0x5a827999L | |
| 233 #define K2 0x6ed9eba1L | |
| 234 #define K3 0x8f1bbcdcL | |
| 235 #define K4 0xca62c1d6L | |
| 236 | |
|
2864
26d60ac2d2ee
moving to gnupg's version of sha1.c
Jim Meyering <jim@meyering.net>
parents:
2863
diff
changeset
|
237 /* Round functions. Note that F2() is used in both rounds 2 and 4 */ |
|
26d60ac2d2ee
moving to gnupg's version of sha1.c
Jim Meyering <jim@meyering.net>
parents:
2863
diff
changeset
|
238 #define F1(B,C,D) ( D ^ ( B & ( C ^ D ) ) ) |
|
26d60ac2d2ee
moving to gnupg's version of sha1.c
Jim Meyering <jim@meyering.net>
parents:
2863
diff
changeset
|
239 #define F2(B,C,D) (B ^ C ^ D) |
|
26d60ac2d2ee
moving to gnupg's version of sha1.c
Jim Meyering <jim@meyering.net>
parents:
2863
diff
changeset
|
240 #define F3(B,C,D) ( ( B & C ) | ( D & ( B | C ) ) ) |
| 2863 | 241 |
| 242 /* Process LEN bytes of BUFFER, accumulating context into CTX. | |
| 243 It is assumed that LEN % 64 == 0. */ | |
| 244 | |
| 245 void | |
| 246 sha_process_block (const void *buffer, size_t len, struct sha_ctx *ctx) | |
| 247 { | |
| 248 const md5_uint32 *words = buffer; | |
| 249 size_t nwords = len / sizeof (md5_uint32); | |
| 250 const md5_uint32 *endp = words + nwords; | |
| 2867 | 251 md5_uint32 x[80]; |
| 252 md5_uint32 a = ctx->A; | |
| 253 md5_uint32 b = ctx->B; | |
| 254 md5_uint32 c = ctx->C; | |
| 255 md5_uint32 d = ctx->D; | |
| 256 md5_uint32 e = ctx->E; | |
| 2863 | 257 |
| 258 /* First increment the byte count. RFC 1321 specifies the possible | |
| 259 length of the file up to 2^64 bits. Here we only compute the | |
| 260 number of bytes. Do a double word increment. */ | |
| 261 ctx->total[0] += len; | |
| 262 if (ctx->total[0] < len) | |
| 263 ++ctx->total[1]; | |
| 264 | |
| 2867 | 265 #define M(i) ( tm = x[i&0x0f] ^ x[(i-14)&0x0f] \ |
| 266 ^ x[(i-8)&0x0f] ^ x[(i-3)&0x0f] \ | |
| 267 , (x[i&0x0f] = (tm << 1) | (tm >> 31)) ) | |
| 268 | |
| 269 #define R(a,b,c,d,e,f,k,m) do { e += rol( a, 5 ) \ | |
| 270 + f( b, c, d ) \ | |
| 271 + k \ | |
| 272 + m; \ | |
| 273 b = rol( b, 30 ); \ | |
| 274 } while(0) | |
| 275 | |
| 2863 | 276 while (words < endp) |
| 277 { | |
| 278 int t; | |
| 279 for (t = 0; t < 16; t++) | |
| 280 { | |
| 2867 | 281 x[t] = NOTSWAP (*words); |
| 2863 | 282 words++; |
| 283 } | |
| 284 | |
| 285 /* SHA1 Data expansion */ | |
| 286 for (t = 16; t < 80; t++) | |
| 287 { | |
| 2867 | 288 md5_uint32 tmp = x[t - 3] ^ x[t - 8] ^ x[t - 14] ^ x[t - 16]; |
| 289 x[t] = rol (tmp, 1); | |
| 2863 | 290 } |
| 291 | |
| 292 /* SHA1 main loop (t=0 to 79) | |
| 293 This is broken down into four subloops in order to use | |
| 294 the correct round function and constant */ | |
| 2867 | 295 #if 1 |
| 2863 | 296 for (t = 0; t < 20; t++) |
| 297 { | |
| 2867 | 298 md5_uint32 tmp = rol (a, 5) + F1 (b, c, d) + e + x[t] + K1; |
| 299 e = d; | |
| 300 d = c; | |
| 301 c = rol (b, 30); | |
| 302 b = a; | |
| 303 a = tmp; | |
| 2863 | 304 } |
| 2867 | 305 #else |
| 306 | |
| 307 #endif | |
| 2863 | 308 for (; t < 40; t++) |
| 309 { | |
| 2867 | 310 md5_uint32 tmp = rol (a, 5) + F2 (b, c, d) + e + x[t] + K2; |
| 311 e = d; | |
| 312 d = c; | |
| 313 c = rol (b, 30); | |
| 314 b = a; | |
| 315 a = tmp; | |
| 2863 | 316 } |
| 317 for (; t < 60; t++) | |
| 318 { | |
| 2867 | 319 md5_uint32 tmp = rol (a, 5) + F3 (b, c, d) + e + x[t] + K3; |
| 320 e = d; | |
| 321 d = c; | |
| 322 c = rol (b, 30); | |
| 323 b = a; | |
| 324 a = tmp; | |
| 2863 | 325 } |
| 326 for (; t < 80; t++) | |
| 327 { | |
| 2867 | 328 md5_uint32 tmp = rol (a, 5) + F2 (b, c, d) + e + x[t] + K4; |
| 329 e = d; | |
| 330 d = c; | |
| 331 c = rol (b, 30); | |
| 332 b = a; | |
| 333 a = tmp; | |
| 2863 | 334 } |
| 2867 | 335 a = ctx->A += a; |
| 336 b = ctx->B += b; | |
| 337 c = ctx->C += c; | |
| 338 d = ctx->D += d; | |
| 339 e = ctx->E += e; | |
| 2863 | 340 } |
| 341 } |