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) 2000-2018 Free Software Foundation, Inc. 5 6 This program is free software; you can redistribute it and/or modify it 7 under the terms of the GNU General Public License as published by the 8 Free Software Foundation; either version 2, or (at your option) any 9 later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software Foundation, 18 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ 19 20 /* Written by Scott G. Miller 21 Credits: 22 Robert Klep <robert@ilse.nl> -- Expansion function fix 23 */ 24 25 #include <config.h> 26 27 #include "sha1.h" 28 29 #include <stddef.h> 30 #include <string.h> 31 32 #if USE_UNLOCKED_IO 33 # include "unlocked-io.h" 34 #endif 35 36 #ifdef WORDS_BIGENDIAN 37 # define SWAP(n) (n) 38 #else 39 # define SWAP(n) \ 40 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24)) 41 #endif 42 43 #define BLOCKSIZE 4096 44 #if BLOCKSIZE % 64 != 0 45 # error "invalid BLOCKSIZE" 46 #endif 47 48 /* This array contains the bytes used to pad the buffer to the next 49 64-byte boundary. (RFC 1321, 3.1: Step 1) */ 50 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ }; 51 52 53 /* Take a pointer to a 160 bit block of data (five 32 bit ints) and 54 initialize it to the start constants of the SHA1 algorithm. This 55 must be called before using hash in the call to sha1_hash. */ 56 void 57 sha1_init_ctx (struct sha1_ctx *ctx) 58 { 59 ctx->A = 0x67452301; 60 ctx->B = 0xefcdab89; 61 ctx->C = 0x98badcfe; 62 ctx->D = 0x10325476; 63 ctx->E = 0xc3d2e1f0; 64 65 ctx->total[0] = ctx->total[1] = 0; 66 ctx->buflen = 0; 67 } 68 69 /* Put result from CTX in first 20 bytes following RESBUF. The result 70 must be in little endian byte order. 71 72 IMPORTANT: On some systems it is required that RESBUF is correctly 73 aligned for a 32-bit value. */ 74 void * 75 sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf) 76 { 77 ((sha1_uint32 *) resbuf)[0] = SWAP (ctx->A); 78 ((sha1_uint32 *) resbuf)[1] = SWAP (ctx->B); 79 ((sha1_uint32 *) resbuf)[2] = SWAP (ctx->C); 80 ((sha1_uint32 *) resbuf)[3] = SWAP (ctx->D); 81 ((sha1_uint32 *) resbuf)[4] = SWAP (ctx->E); 82 83 return resbuf; 84 } 85 86 /* Process the remaining bytes in the internal buffer and the usual 87 prolog according to the standard and write the result to RESBUF. 88 89 IMPORTANT: On some systems it is required that RESBUF is correctly 90 aligned for a 32-bit value. */ 91 void * 92 sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf) 93 { 94 /* Take yet unprocessed bytes into account. */ 95 sha1_uint32 bytes = ctx->buflen; 96 size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4; 97 98 /* Now count remaining bytes. */ 99 ctx->total[0] += bytes; 100 if (ctx->total[0] < bytes) 101 ++ctx->total[1]; 102 103 /* Put the 64-bit file length in *bits* at the end of the buffer. */ 104 ctx->buffer[size - 2] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29)); 105 ctx->buffer[size - 1] = SWAP (ctx->total[0] << 3); 106 107 memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes); 108 109 /* Process last bytes. */ 110 sha1_process_block (ctx->buffer, size * 4, ctx); 111 112 return sha1_read_ctx (ctx, resbuf); 113 } 114 115 /* Compute SHA1 message digest for bytes read from STREAM. The 116 resulting message digest number will be written into the 16 bytes 117 beginning at RESBLOCK. */ 118 int 119 sha1_stream (FILE *stream, void *resblock) 120 { 121 struct sha1_ctx ctx; 122 char buffer[BLOCKSIZE + 72]; 123 size_t sum; 124 125 /* Initialize the computation context. */ 126 sha1_init_ctx (&ctx); 127 128 /* Iterate over full file contents. */ 129 while (1) 130 { 131 /* We read the file in blocks of BLOCKSIZE bytes. One call of the 132 computation function processes the whole buffer so that with the 133 next round of the loop another block can be read. */ 134 size_t n; 135 sum = 0; 136 137 /* Read block. Take care for partial reads. */ 138 while (1) 139 { 140 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream); 141 142 sum += n; 143 144 if (sum == BLOCKSIZE) 145 break; 146 147 if (n == 0) 148 { 149 /* Check for the error flag IFF N == 0, so that we don't 150 exit the loop after a partial read due to e.g., EAGAIN 151 or EWOULDBLOCK. */ 152 if (ferror (stream)) 153 return 1; 154 goto process_partial_block; 155 } 156 157 /* We've read at least one byte, so ignore errors. But always 158 check for EOF, since feof may be true even though N > 0. 159 Otherwise, we could end up calling fread after EOF. */ 160 if (feof (stream)) 161 goto process_partial_block; 162 } 163 164 /* Process buffer with BLOCKSIZE bytes. Note that 165 BLOCKSIZE % 64 == 0 166 */ 167 sha1_process_block (buffer, BLOCKSIZE, &ctx); 168 } 169 170 process_partial_block:; 171 172 /* Process any remaining bytes. */ 173 if (sum > 0) 174 sha1_process_bytes (buffer, sum, &ctx); 175 176 /* Construct result in desired memory. */ 177 sha1_finish_ctx (&ctx, resblock); 178 return 0; 179 } 180 181 /* Compute SHA1 message digest for LEN bytes beginning at BUFFER. The 182 result is always in little endian byte order, so that a byte-wise 183 output yields to the wanted ASCII representation of the message 184 digest. */ 185 void * 186 sha1_buffer (const char *buffer, size_t len, void *resblock) 187 { 188 struct sha1_ctx ctx; 189 190 /* Initialize the computation context. */ 191 sha1_init_ctx (&ctx); 192 193 /* Process whole buffer but last len % 64 bytes. */ 194 sha1_process_bytes (buffer, len, &ctx); 195 196 /* Put result in desired memory area. */ 197 return sha1_finish_ctx (&ctx, resblock); 198 } 199 200 void 201 sha1_process_bytes (const void *buffer, size_t len, struct sha1_ctx *ctx) 202 { 203 /* When we already have some bits in our internal buffer concatenate 204 both inputs first. */ 205 if (ctx->buflen != 0) 206 { 207 size_t left_over = ctx->buflen; 208 size_t add = 128 - left_over > len ? len : 128 - left_over; 209 210 memcpy (&((char *) ctx->buffer)[left_over], buffer, add); 211 ctx->buflen += add; 212 213 if (ctx->buflen > 64) 214 { 215 sha1_process_block (ctx->buffer, ctx->buflen & ~63, ctx); 216 217 ctx->buflen &= 63; 218 /* The regions in the following copy operation cannot overlap. */ 219 memcpy (ctx->buffer, 220 &((char *) ctx->buffer)[(left_over + add) & ~63], 221 ctx->buflen); 222 } 223 224 buffer = (const char *) buffer + add; 225 len -= add; 226 } 227 228 /* Process available complete blocks. */ 229 if (len >= 64) 230 { 231 #if !_STRING_ARCH_unaligned 232 # define alignof(type) offsetof (struct { char c; type x; }, x) 233 # define UNALIGNED_P(p) (((size_t) p) % alignof (sha1_uint32) != 0) 234 if (UNALIGNED_P (buffer)) 235 while (len > 64) 236 { 237 sha1_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx); 238 buffer = (const char *) buffer + 64; 239 len -= 64; 240 } 241 else 242 #endif 243 { 244 sha1_process_block (buffer, len & ~63, ctx); 245 buffer = (const char *) buffer + (len & ~63); 246 len &= 63; 247 } 248 } 249 250 /* Move remaining bytes in internal buffer. */ 251 if (len > 0) 252 { 253 size_t left_over = ctx->buflen; 254 255 memcpy (&((char *) ctx->buffer)[left_over], buffer, len); 256 left_over += len; 257 if (left_over >= 64) 258 { 259 sha1_process_block (ctx->buffer, 64, ctx); 260 left_over -= 64; 261 memcpy (ctx->buffer, &ctx->buffer[16], left_over); 262 } 263 ctx->buflen = left_over; 264 } 265 } 266 267 /* --- Code below is the primary difference between md5.c and sha1.c --- */ 268 269 /* SHA1 round constants */ 270 #define K1 0x5a827999 271 #define K2 0x6ed9eba1 272 #define K3 0x8f1bbcdc 273 #define K4 0xca62c1d6 274 275 /* Round functions. Note that F2 is the same as F4. */ 276 #define F1(B,C,D) ( D ^ ( B & ( C ^ D ) ) ) 277 #define F2(B,C,D) (B ^ C ^ D) 278 #define F3(B,C,D) ( ( B & C ) | ( D & ( B | C ) ) ) 279 #define F4(B,C,D) (B ^ C ^ D) 280 281 /* Process LEN bytes of BUFFER, accumulating context into CTX. 282 It is assumed that LEN % 64 == 0. 283 Most of this code comes from GnuPG's cipher/sha1.c. */ 284 285 void 286 sha1_process_block (const void *buffer, size_t len, struct sha1_ctx *ctx) 287 { 288 const sha1_uint32 *words = (const sha1_uint32*) buffer; 289 size_t nwords = len / sizeof (sha1_uint32); 290 const sha1_uint32 *endp = words + nwords; 291 sha1_uint32 x[16]; 292 sha1_uint32 a = ctx->A; 293 sha1_uint32 b = ctx->B; 294 sha1_uint32 c = ctx->C; 295 sha1_uint32 d = ctx->D; 296 sha1_uint32 e = ctx->E; 297 298 /* First increment the byte count. RFC 1321 specifies the possible 299 length of the file up to 2^64 bits. Here we only compute the 300 number of bytes. Do a double word increment. */ 301 ctx->total[0] += len; 302 ctx->total[1] += ((len >> 31) >> 1) + (ctx->total[0] < len); 303 304 #define rol(x, n) (((x) << (n)) | ((sha1_uint32) (x) >> (32 - (n)))) 305 306 #define M(I) ( tm = x[I&0x0f] ^ x[(I-14)&0x0f] \ 307 ^ x[(I-8)&0x0f] ^ x[(I-3)&0x0f] \ 308 , (x[I&0x0f] = rol(tm, 1)) ) 309 310 #define R(A,B,C,D,E,F,K,M) do { E += rol( A, 5 ) \ 311 + F( B, C, D ) \ 312 + K \ 313 + M; \ 314 B = rol( B, 30 ); \ 315 } while(0) 316 317 while (words < endp) 318 { 319 sha1_uint32 tm; 320 int t; 321 for (t = 0; t < 16; t++) 322 { 323 x[t] = SWAP (*words); 324 words++; 325 } 326 327 R( a, b, c, d, e, F1, K1, x[ 0] ); 328 R( e, a, b, c, d, F1, K1, x[ 1] ); 329 R( d, e, a, b, c, F1, K1, x[ 2] ); 330 R( c, d, e, a, b, F1, K1, x[ 3] ); 331 R( b, c, d, e, a, F1, K1, x[ 4] ); 332 R( a, b, c, d, e, F1, K1, x[ 5] ); 333 R( e, a, b, c, d, F1, K1, x[ 6] ); 334 R( d, e, a, b, c, F1, K1, x[ 7] ); 335 R( c, d, e, a, b, F1, K1, x[ 8] ); 336 R( b, c, d, e, a, F1, K1, x[ 9] ); 337 R( a, b, c, d, e, F1, K1, x[10] ); 338 R( e, a, b, c, d, F1, K1, x[11] ); 339 R( d, e, a, b, c, F1, K1, x[12] ); 340 R( c, d, e, a, b, F1, K1, x[13] ); 341 R( b, c, d, e, a, F1, K1, x[14] ); 342 R( a, b, c, d, e, F1, K1, x[15] ); 343 R( e, a, b, c, d, F1, K1, M(16) ); 344 R( d, e, a, b, c, F1, K1, M(17) ); 345 R( c, d, e, a, b, F1, K1, M(18) ); 346 R( b, c, d, e, a, F1, K1, M(19) ); 347 R( a, b, c, d, e, F2, K2, M(20) ); 348 R( e, a, b, c, d, F2, K2, M(21) ); 349 R( d, e, a, b, c, F2, K2, M(22) ); 350 R( c, d, e, a, b, F2, K2, M(23) ); 351 R( b, c, d, e, a, F2, K2, M(24) ); 352 R( a, b, c, d, e, F2, K2, M(25) ); 353 R( e, a, b, c, d, F2, K2, M(26) ); 354 R( d, e, a, b, c, F2, K2, M(27) ); 355 R( c, d, e, a, b, F2, K2, M(28) ); 356 R( b, c, d, e, a, F2, K2, M(29) ); 357 R( a, b, c, d, e, F2, K2, M(30) ); 358 R( e, a, b, c, d, F2, K2, M(31) ); 359 R( d, e, a, b, c, F2, K2, M(32) ); 360 R( c, d, e, a, b, F2, K2, M(33) ); 361 R( b, c, d, e, a, F2, K2, M(34) ); 362 R( a, b, c, d, e, F2, K2, M(35) ); 363 R( e, a, b, c, d, F2, K2, M(36) ); 364 R( d, e, a, b, c, F2, K2, M(37) ); 365 R( c, d, e, a, b, F2, K2, M(38) ); 366 R( b, c, d, e, a, F2, K2, M(39) ); 367 R( a, b, c, d, e, F3, K3, M(40) ); 368 R( e, a, b, c, d, F3, K3, M(41) ); 369 R( d, e, a, b, c, F3, K3, M(42) ); 370 R( c, d, e, a, b, F3, K3, M(43) ); 371 R( b, c, d, e, a, F3, K3, M(44) ); 372 R( a, b, c, d, e, F3, K3, M(45) ); 373 R( e, a, b, c, d, F3, K3, M(46) ); 374 R( d, e, a, b, c, F3, K3, M(47) ); 375 R( c, d, e, a, b, F3, K3, M(48) ); 376 R( b, c, d, e, a, F3, K3, M(49) ); 377 R( a, b, c, d, e, F3, K3, M(50) ); 378 R( e, a, b, c, d, F3, K3, M(51) ); 379 R( d, e, a, b, c, F3, K3, M(52) ); 380 R( c, d, e, a, b, F3, K3, M(53) ); 381 R( b, c, d, e, a, F3, K3, M(54) ); 382 R( a, b, c, d, e, F3, K3, M(55) ); 383 R( e, a, b, c, d, F3, K3, M(56) ); 384 R( d, e, a, b, c, F3, K3, M(57) ); 385 R( c, d, e, a, b, F3, K3, M(58) ); 386 R( b, c, d, e, a, F3, K3, M(59) ); 387 R( a, b, c, d, e, F4, K4, M(60) ); 388 R( e, a, b, c, d, F4, K4, M(61) ); 389 R( d, e, a, b, c, F4, K4, M(62) ); 390 R( c, d, e, a, b, F4, K4, M(63) ); 391 R( b, c, d, e, a, F4, K4, M(64) ); 392 R( a, b, c, d, e, F4, K4, M(65) ); 393 R( e, a, b, c, d, F4, K4, M(66) ); 394 R( d, e, a, b, c, F4, K4, M(67) ); 395 R( c, d, e, a, b, F4, K4, M(68) ); 396 R( b, c, d, e, a, F4, K4, M(69) ); 397 R( a, b, c, d, e, F4, K4, M(70) ); 398 R( e, a, b, c, d, F4, K4, M(71) ); 399 R( d, e, a, b, c, F4, K4, M(72) ); 400 R( c, d, e, a, b, F4, K4, M(73) ); 401 R( b, c, d, e, a, F4, K4, M(74) ); 402 R( a, b, c, d, e, F4, K4, M(75) ); 403 R( e, a, b, c, d, F4, K4, M(76) ); 404 R( d, e, a, b, c, F4, K4, M(77) ); 405 R( c, d, e, a, b, F4, K4, M(78) ); 406 R( b, c, d, e, a, F4, K4, M(79) ); 407 408 a = ctx->A += a; 409 b = ctx->B += b; 410 c = ctx->C += c; 411 d = ctx->D += d; 412 e = ctx->E += e; 413 } 414 } 415