1 /* sha1.c - Functions to compute SHA1 message digest of files or 2 memory blocks according to the NIST specification FIPS-180-1. 3 4 Copyright (C) 2000, 2001, 2003, 2004, 2005, 2006, 2008 Free Software 5 Foundation, Inc. 6 7 This program is free software; you can redistribute it and/or modify it 8 under the terms of the GNU General Public License as published by the 9 Free Software Foundation; either version 2, or (at your option) any 10 later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program; if not, write to the Free Software Foundation, 19 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ 20 21 /* Written by Scott G. Miller 22 Credits: 23 Robert Klep <robert@ilse.nl> -- Expansion function fix 24 */ 25 26 #include <config.h> 27 28 #include "sha1.h" 29 30 #include <stddef.h> 31 #include <string.h> 32 33 #if USE_UNLOCKED_IO 34 # include "unlocked-io.h" 35 #endif 36 37 #ifdef WORDS_BIGENDIAN 38 # define SWAP(n) (n) 39 #else 40 # define SWAP(n) \ 41 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24)) 42 #endif 43 44 #define BLOCKSIZE 4096 45 #if BLOCKSIZE % 64 != 0 46 # error "invalid BLOCKSIZE" 47 #endif 48 49 /* This array contains the bytes used to pad the buffer to the next 50 64-byte boundary. (RFC 1321, 3.1: Step 1) */ 51 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ }; 52 53 54 /* Take a pointer to a 160 bit block of data (five 32 bit ints) and 55 initialize it to the start constants of the SHA1 algorithm. This 56 must be called before using hash in the call to sha1_hash. */ 57 void 58 sha1_init_ctx (struct sha1_ctx *ctx) 59 { 60 ctx->A = 0x67452301; 61 ctx->B = 0xefcdab89; 62 ctx->C = 0x98badcfe; 63 ctx->D = 0x10325476; 64 ctx->E = 0xc3d2e1f0; 65 66 ctx->total[0] = ctx->total[1] = 0; 67 ctx->buflen = 0; 68 } 69 70 /* Put result from CTX in first 20 bytes following RESBUF. The result 71 must be in little endian byte order. 72 73 IMPORTANT: On some systems it is required that RESBUF is correctly 74 aligned for a 32-bit value. */ 75 void * 76 sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf) 77 { 78 ((sha1_uint32 *) resbuf)[0] = SWAP (ctx->A); 79 ((sha1_uint32 *) resbuf)[1] = SWAP (ctx->B); 80 ((sha1_uint32 *) resbuf)[2] = SWAP (ctx->C); 81 ((sha1_uint32 *) resbuf)[3] = SWAP (ctx->D); 82 ((sha1_uint32 *) resbuf)[4] = SWAP (ctx->E); 83 84 return resbuf; 85 } 86 87 /* Process the remaining bytes in the internal buffer and the usual 88 prolog according to the standard and write the result to RESBUF. 89 90 IMPORTANT: On some systems it is required that RESBUF is correctly 91 aligned for a 32-bit value. */ 92 void * 93 sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf) 94 { 95 /* Take yet unprocessed bytes into account. */ 96 sha1_uint32 bytes = ctx->buflen; 97 size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4; 98 99 /* Now count remaining bytes. */ 100 ctx->total[0] += bytes; 101 if (ctx->total[0] < bytes) 102 ++ctx->total[1]; 103 104 /* Put the 64-bit file length in *bits* at the end of the buffer. */ 105 ctx->buffer[size - 2] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29)); 106 ctx->buffer[size - 1] = SWAP (ctx->total[0] << 3); 107 108 memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes); 109 110 /* Process last bytes. */ 111 sha1_process_block (ctx->buffer, size * 4, ctx); 112 113 return sha1_read_ctx (ctx, resbuf); 114 } 115 116 /* Compute SHA1 message digest for bytes read from STREAM. The 117 resulting message digest number will be written into the 16 bytes 118 beginning at RESBLOCK. */ 119 int 120 sha1_stream (FILE *stream, void *resblock) 121 { 122 struct sha1_ctx ctx; 123 char buffer[BLOCKSIZE + 72]; 124 size_t sum; 125 126 /* Initialize the computation context. */ 127 sha1_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 while (1) 140 { 141 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream); 142 143 sum += n; 144 145 if (sum == BLOCKSIZE) 146 break; 147 148 if (n == 0) 149 { 150 /* Check for the error flag IFF N == 0, so that we don't 151 exit the loop after a partial read due to e.g., EAGAIN 152 or EWOULDBLOCK. */ 153 if (ferror (stream)) 154 return 1; 155 goto process_partial_block; 156 } 157 158 /* We've read at least one byte, so ignore errors. But always 159 check for EOF, since feof may be true even though N > 0. 160 Otherwise, we could end up calling fread after EOF. */ 161 if (feof (stream)) 162 goto process_partial_block; 163 } 164 165 /* Process buffer with BLOCKSIZE bytes. Note that 166 BLOCKSIZE % 64 == 0 167 */ 168 sha1_process_block (buffer, BLOCKSIZE, &ctx); 169 } 170 171 process_partial_block:; 172 173 /* Process any remaining bytes. */ 174 if (sum > 0) 175 sha1_process_bytes (buffer, sum, &ctx); 176 177 /* Construct result in desired memory. */ 178 sha1_finish_ctx (&ctx, resblock); 179 return 0; 180 } 181 182 /* Compute SHA1 message digest for LEN bytes beginning at BUFFER. The 183 result is always in little endian byte order, so that a byte-wise 184 output yields to the wanted ASCII representation of the message 185 digest. */ 186 void * 187 sha1_buffer (const char *buffer, size_t len, void *resblock) 188 { 189 struct sha1_ctx ctx; 190 191 /* Initialize the computation context. */ 192 sha1_init_ctx (&ctx); 193 194 /* Process whole buffer but last len % 64 bytes. */ 195 sha1_process_bytes (buffer, len, &ctx); 196 197 /* Put result in desired memory area. */ 198 return sha1_finish_ctx (&ctx, resblock); 199 } 200 201 void 202 sha1_process_bytes (const void *buffer, size_t len, struct sha1_ctx *ctx) 203 { 204 /* When we already have some bits in our internal buffer concatenate 205 both inputs first. */ 206 if (ctx->buflen != 0) 207 { 208 size_t left_over = ctx->buflen; 209 size_t add = 128 - left_over > len ? len : 128 - left_over; 210 211 memcpy (&((char *) ctx->buffer)[left_over], buffer, add); 212 ctx->buflen += add; 213 214 if (ctx->buflen > 64) 215 { 216 sha1_process_block (ctx->buffer, ctx->buflen & ~63, ctx); 217 218 ctx->buflen &= 63; 219 /* The regions in the following copy operation cannot overlap. */ 220 memcpy (ctx->buffer, 221 &((char *) ctx->buffer)[(left_over + add) & ~63], 222 ctx->buflen); 223 } 224 225 buffer = (const char *) buffer + add; 226 len -= add; 227 } 228 229 /* Process available complete blocks. */ 230 if (len >= 64) 231 { 232 #if !_STRING_ARCH_unaligned 233 # define alignof(type) offsetof (struct { char c; type x; }, x) 234 # define UNALIGNED_P(p) (((size_t) p) % alignof (sha1_uint32) != 0) 235 if (UNALIGNED_P (buffer)) 236 while (len > 64) 237 { 238 sha1_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx); 239 buffer = (const char *) buffer + 64; 240 len -= 64; 241 } 242 else 243 #endif 244 { 245 sha1_process_block (buffer, len & ~63, ctx); 246 buffer = (const char *) buffer + (len & ~63); 247 len &= 63; 248 } 249 } 250 251 /* Move remaining bytes in internal buffer. */ 252 if (len > 0) 253 { 254 size_t left_over = ctx->buflen; 255 256 memcpy (&((char *) ctx->buffer)[left_over], buffer, len); 257 left_over += len; 258 if (left_over >= 64) 259 { 260 sha1_process_block (ctx->buffer, 64, ctx); 261 left_over -= 64; 262 memcpy (ctx->buffer, &ctx->buffer[16], left_over); 263 } 264 ctx->buflen = left_over; 265 } 266 } 267 268 /* --- Code below is the primary difference between md5.c and sha1.c --- */ 269 270 /* SHA1 round constants */ 271 #define K1 0x5a827999 272 #define K2 0x6ed9eba1 273 #define K3 0x8f1bbcdc 274 #define K4 0xca62c1d6 275 276 /* Round functions. Note that F2 is the same as F4. */ 277 #define F1(B,C,D) ( D ^ ( B & ( C ^ D ) ) ) 278 #define F2(B,C,D) (B ^ C ^ D) 279 #define F3(B,C,D) ( ( B & C ) | ( D & ( B | C ) ) ) 280 #define F4(B,C,D) (B ^ C ^ D) 281 282 /* Process LEN bytes of BUFFER, accumulating context into CTX. 283 It is assumed that LEN % 64 == 0. 284 Most of this code comes from GnuPG's cipher/sha1.c. */ 285 286 void 287 sha1_process_block (const void *buffer, size_t len, struct sha1_ctx *ctx) 288 { 289 const sha1_uint32 *words = (const sha1_uint32*) buffer; 290 size_t nwords = len / sizeof (sha1_uint32); 291 const sha1_uint32 *endp = words + nwords; 292 sha1_uint32 x[16]; 293 sha1_uint32 a = ctx->A; 294 sha1_uint32 b = ctx->B; 295 sha1_uint32 c = ctx->C; 296 sha1_uint32 d = ctx->D; 297 sha1_uint32 e = ctx->E; 298 299 /* First increment the byte count. RFC 1321 specifies the possible 300 length of the file up to 2^64 bits. Here we only compute the 301 number of bytes. Do a double word increment. */ 302 ctx->total[0] += len; 303 if (ctx->total[0] < len) 304 ++ctx->total[1]; 305 306 #define rol(x, n) (((x) << (n)) | ((sha1_uint32) (x) >> (32 - (n)))) 307 308 #define M(I) ( tm = x[I&0x0f] ^ x[(I-14)&0x0f] \ 309 ^ x[(I-8)&0x0f] ^ x[(I-3)&0x0f] \ 310 , (x[I&0x0f] = rol(tm, 1)) ) 311 312 #define R(A,B,C,D,E,F,K,M) do { E += rol( A, 5 ) \ 313 + F( B, C, D ) \ 314 + K \ 315 + M; \ 316 B = rol( B, 30 ); \ 317 } while(0) 318 319 while (words < endp) 320 { 321 sha1_uint32 tm; 322 int t; 323 for (t = 0; t < 16; t++) 324 { 325 x[t] = SWAP (*words); 326 words++; 327 } 328 329 R( a, b, c, d, e, F1, K1, x[ 0] ); 330 R( e, a, b, c, d, F1, K1, x[ 1] ); 331 R( d, e, a, b, c, F1, K1, x[ 2] ); 332 R( c, d, e, a, b, F1, K1, x[ 3] ); 333 R( b, c, d, e, a, F1, K1, x[ 4] ); 334 R( a, b, c, d, e, F1, K1, x[ 5] ); 335 R( e, a, b, c, d, F1, K1, x[ 6] ); 336 R( d, e, a, b, c, F1, K1, x[ 7] ); 337 R( c, d, e, a, b, F1, K1, x[ 8] ); 338 R( b, c, d, e, a, F1, K1, x[ 9] ); 339 R( a, b, c, d, e, F1, K1, x[10] ); 340 R( e, a, b, c, d, F1, K1, x[11] ); 341 R( d, e, a, b, c, F1, K1, x[12] ); 342 R( c, d, e, a, b, F1, K1, x[13] ); 343 R( b, c, d, e, a, F1, K1, x[14] ); 344 R( a, b, c, d, e, F1, K1, x[15] ); 345 R( e, a, b, c, d, F1, K1, M(16) ); 346 R( d, e, a, b, c, F1, K1, M(17) ); 347 R( c, d, e, a, b, F1, K1, M(18) ); 348 R( b, c, d, e, a, F1, K1, M(19) ); 349 R( a, b, c, d, e, F2, K2, M(20) ); 350 R( e, a, b, c, d, F2, K2, M(21) ); 351 R( d, e, a, b, c, F2, K2, M(22) ); 352 R( c, d, e, a, b, F2, K2, M(23) ); 353 R( b, c, d, e, a, F2, K2, M(24) ); 354 R( a, b, c, d, e, F2, K2, M(25) ); 355 R( e, a, b, c, d, F2, K2, M(26) ); 356 R( d, e, a, b, c, F2, K2, M(27) ); 357 R( c, d, e, a, b, F2, K2, M(28) ); 358 R( b, c, d, e, a, F2, K2, M(29) ); 359 R( a, b, c, d, e, F2, K2, M(30) ); 360 R( e, a, b, c, d, F2, K2, M(31) ); 361 R( d, e, a, b, c, F2, K2, M(32) ); 362 R( c, d, e, a, b, F2, K2, M(33) ); 363 R( b, c, d, e, a, F2, K2, M(34) ); 364 R( a, b, c, d, e, F2, K2, M(35) ); 365 R( e, a, b, c, d, F2, K2, M(36) ); 366 R( d, e, a, b, c, F2, K2, M(37) ); 367 R( c, d, e, a, b, F2, K2, M(38) ); 368 R( b, c, d, e, a, F2, K2, M(39) ); 369 R( a, b, c, d, e, F3, K3, M(40) ); 370 R( e, a, b, c, d, F3, K3, M(41) ); 371 R( d, e, a, b, c, F3, K3, M(42) ); 372 R( c, d, e, a, b, F3, K3, M(43) ); 373 R( b, c, d, e, a, F3, K3, M(44) ); 374 R( a, b, c, d, e, F3, K3, M(45) ); 375 R( e, a, b, c, d, F3, K3, M(46) ); 376 R( d, e, a, b, c, F3, K3, M(47) ); 377 R( c, d, e, a, b, F3, K3, M(48) ); 378 R( b, c, d, e, a, F3, K3, M(49) ); 379 R( a, b, c, d, e, F3, K3, M(50) ); 380 R( e, a, b, c, d, F3, K3, M(51) ); 381 R( d, e, a, b, c, F3, K3, M(52) ); 382 R( c, d, e, a, b, F3, K3, M(53) ); 383 R( b, c, d, e, a, F3, K3, M(54) ); 384 R( a, b, c, d, e, F3, K3, M(55) ); 385 R( e, a, b, c, d, F3, K3, M(56) ); 386 R( d, e, a, b, c, F3, K3, M(57) ); 387 R( c, d, e, a, b, F3, K3, M(58) ); 388 R( b, c, d, e, a, F3, K3, M(59) ); 389 R( a, b, c, d, e, F4, K4, M(60) ); 390 R( e, a, b, c, d, F4, K4, M(61) ); 391 R( d, e, a, b, c, F4, K4, M(62) ); 392 R( c, d, e, a, b, F4, K4, M(63) ); 393 R( b, c, d, e, a, F4, K4, M(64) ); 394 R( a, b, c, d, e, F4, K4, M(65) ); 395 R( e, a, b, c, d, F4, K4, M(66) ); 396 R( d, e, a, b, c, F4, K4, M(67) ); 397 R( c, d, e, a, b, F4, K4, M(68) ); 398 R( b, c, d, e, a, F4, K4, M(69) ); 399 R( a, b, c, d, e, F4, K4, M(70) ); 400 R( e, a, b, c, d, F4, K4, M(71) ); 401 R( d, e, a, b, c, F4, K4, M(72) ); 402 R( c, d, e, a, b, F4, K4, M(73) ); 403 R( b, c, d, e, a, F4, K4, M(74) ); 404 R( a, b, c, d, e, F4, K4, M(75) ); 405 R( e, a, b, c, d, F4, K4, M(76) ); 406 R( d, e, a, b, c, F4, K4, M(77) ); 407 R( c, d, e, a, b, F4, K4, M(78) ); 408 R( b, c, d, e, a, F4, K4, M(79) ); 409 410 a = ctx->A += a; 411 b = ctx->B += b; 412 c = ctx->C += c; 413 d = ctx->D += d; 414 e = ctx->E += e; 415 } 416 } 417