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) 2000-2020 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 # if defined(__clang__) || defined(__GNUC__) 233 # define alignof(type) __alignof__(type) 234 # else 235 # define alignof(type) offsetof (struct { char c; type x; }, x) 236 # endif 237 # define UNALIGNED_P(p) (((size_t) p) % alignof (sha1_uint32) != 0) 238 if (UNALIGNED_P (buffer)) 239 while (len > 64) 240 { 241 sha1_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx); 242 buffer = (const char *) buffer + 64; 243 len -= 64; 244 } 245 else 246 #endif 247 { 248 sha1_process_block (buffer, len & ~63, ctx); 249 buffer = (const char *) buffer + (len & ~63); 250 len &= 63; 251 } 252 } 253 254 /* Move remaining bytes in internal buffer. */ 255 if (len > 0) 256 { 257 size_t left_over = ctx->buflen; 258 259 memcpy (&((char *) ctx->buffer)[left_over], buffer, len); 260 left_over += len; 261 if (left_over >= 64) 262 { 263 sha1_process_block (ctx->buffer, 64, ctx); 264 left_over -= 64; 265 memcpy (ctx->buffer, &ctx->buffer[16], left_over); 266 } 267 ctx->buflen = left_over; 268 } 269 } 270 271 /* --- Code below is the primary difference between md5.c and sha1.c --- */ 272 273 /* SHA1 round constants */ 274 #define K1 0x5a827999 275 #define K2 0x6ed9eba1 276 #define K3 0x8f1bbcdc 277 #define K4 0xca62c1d6 278 279 /* Round functions. Note that F2 is the same as F4. */ 280 #define F1(B,C,D) ( D ^ ( B & ( C ^ D ) ) ) 281 #define F2(B,C,D) (B ^ C ^ D) 282 #define F3(B,C,D) ( ( B & C ) | ( D & ( B | C ) ) ) 283 #define F4(B,C,D) (B ^ C ^ D) 284 285 /* Process LEN bytes of BUFFER, accumulating context into CTX. 286 It is assumed that LEN % 64 == 0. 287 Most of this code comes from GnuPG's cipher/sha1.c. */ 288 289 void 290 sha1_process_block (const void *buffer, size_t len, struct sha1_ctx *ctx) 291 { 292 const sha1_uint32 *words = (const sha1_uint32*) buffer; 293 size_t nwords = len / sizeof (sha1_uint32); 294 const sha1_uint32 *endp = words + nwords; 295 sha1_uint32 x[16]; 296 sha1_uint32 a = ctx->A; 297 sha1_uint32 b = ctx->B; 298 sha1_uint32 c = ctx->C; 299 sha1_uint32 d = ctx->D; 300 sha1_uint32 e = ctx->E; 301 302 /* First increment the byte count. RFC 1321 specifies the possible 303 length of the file up to 2^64 bits. Here we only compute the 304 number of bytes. Do a double word increment. */ 305 ctx->total[0] += len; 306 ctx->total[1] += ((len >> 31) >> 1) + (ctx->total[0] < len); 307 308 #define rol(x, n) (((x) << (n)) | ((sha1_uint32) (x) >> (32 - (n)))) 309 310 #define M(I) ( tm = x[I&0x0f] ^ x[(I-14)&0x0f] \ 311 ^ x[(I-8)&0x0f] ^ x[(I-3)&0x0f] \ 312 , (x[I&0x0f] = rol(tm, 1)) ) 313 314 #define R(A,B,C,D,E,F,K,M) do { E += rol( A, 5 ) \ 315 + F( B, C, D ) \ 316 + K \ 317 + M; \ 318 B = rol( B, 30 ); \ 319 } while(0) 320 321 while (words < endp) 322 { 323 sha1_uint32 tm; 324 int t; 325 for (t = 0; t < 16; t++) 326 { 327 x[t] = SWAP (*words); 328 words++; 329 } 330 331 R( a, b, c, d, e, F1, K1, x[ 0] ); 332 R( e, a, b, c, d, F1, K1, x[ 1] ); 333 R( d, e, a, b, c, F1, K1, x[ 2] ); 334 R( c, d, e, a, b, F1, K1, x[ 3] ); 335 R( b, c, d, e, a, F1, K1, x[ 4] ); 336 R( a, b, c, d, e, F1, K1, x[ 5] ); 337 R( e, a, b, c, d, F1, K1, x[ 6] ); 338 R( d, e, a, b, c, F1, K1, x[ 7] ); 339 R( c, d, e, a, b, F1, K1, x[ 8] ); 340 R( b, c, d, e, a, F1, K1, x[ 9] ); 341 R( a, b, c, d, e, F1, K1, x[10] ); 342 R( e, a, b, c, d, F1, K1, x[11] ); 343 R( d, e, a, b, c, F1, K1, x[12] ); 344 R( c, d, e, a, b, F1, K1, x[13] ); 345 R( b, c, d, e, a, F1, K1, x[14] ); 346 R( a, b, c, d, e, F1, K1, x[15] ); 347 R( e, a, b, c, d, F1, K1, M(16) ); 348 R( d, e, a, b, c, F1, K1, M(17) ); 349 R( c, d, e, a, b, F1, K1, M(18) ); 350 R( b, c, d, e, a, F1, K1, M(19) ); 351 R( a, b, c, d, e, F2, K2, M(20) ); 352 R( e, a, b, c, d, F2, K2, M(21) ); 353 R( d, e, a, b, c, F2, K2, M(22) ); 354 R( c, d, e, a, b, F2, K2, M(23) ); 355 R( b, c, d, e, a, F2, K2, M(24) ); 356 R( a, b, c, d, e, F2, K2, M(25) ); 357 R( e, a, b, c, d, F2, K2, M(26) ); 358 R( d, e, a, b, c, F2, K2, M(27) ); 359 R( c, d, e, a, b, F2, K2, M(28) ); 360 R( b, c, d, e, a, F2, K2, M(29) ); 361 R( a, b, c, d, e, F2, K2, M(30) ); 362 R( e, a, b, c, d, F2, K2, M(31) ); 363 R( d, e, a, b, c, F2, K2, M(32) ); 364 R( c, d, e, a, b, F2, K2, M(33) ); 365 R( b, c, d, e, a, F2, K2, M(34) ); 366 R( a, b, c, d, e, F2, K2, M(35) ); 367 R( e, a, b, c, d, F2, K2, M(36) ); 368 R( d, e, a, b, c, F2, K2, M(37) ); 369 R( c, d, e, a, b, F2, K2, M(38) ); 370 R( b, c, d, e, a, F2, K2, M(39) ); 371 R( a, b, c, d, e, F3, K3, M(40) ); 372 R( e, a, b, c, d, F3, K3, M(41) ); 373 R( d, e, a, b, c, F3, K3, M(42) ); 374 R( c, d, e, a, b, F3, K3, M(43) ); 375 R( b, c, d, e, a, F3, K3, M(44) ); 376 R( a, b, c, d, e, F3, K3, M(45) ); 377 R( e, a, b, c, d, F3, K3, M(46) ); 378 R( d, e, a, b, c, F3, K3, M(47) ); 379 R( c, d, e, a, b, F3, K3, M(48) ); 380 R( b, c, d, e, a, F3, K3, M(49) ); 381 R( a, b, c, d, e, F3, K3, M(50) ); 382 R( e, a, b, c, d, F3, K3, M(51) ); 383 R( d, e, a, b, c, F3, K3, M(52) ); 384 R( c, d, e, a, b, F3, K3, M(53) ); 385 R( b, c, d, e, a, F3, K3, M(54) ); 386 R( a, b, c, d, e, F3, K3, M(55) ); 387 R( e, a, b, c, d, F3, K3, M(56) ); 388 R( d, e, a, b, c, F3, K3, M(57) ); 389 R( c, d, e, a, b, F3, K3, M(58) ); 390 R( b, c, d, e, a, F3, K3, M(59) ); 391 R( a, b, c, d, e, F4, K4, M(60) ); 392 R( e, a, b, c, d, F4, K4, M(61) ); 393 R( d, e, a, b, c, F4, K4, M(62) ); 394 R( c, d, e, a, b, F4, K4, M(63) ); 395 R( b, c, d, e, a, F4, K4, M(64) ); 396 R( a, b, c, d, e, F4, K4, M(65) ); 397 R( e, a, b, c, d, F4, K4, M(66) ); 398 R( d, e, a, b, c, F4, K4, M(67) ); 399 R( c, d, e, a, b, F4, K4, M(68) ); 400 R( b, c, d, e, a, F4, K4, M(69) ); 401 R( a, b, c, d, e, F4, K4, M(70) ); 402 R( e, a, b, c, d, F4, K4, M(71) ); 403 R( d, e, a, b, c, F4, K4, M(72) ); 404 R( c, d, e, a, b, F4, K4, M(73) ); 405 R( b, c, d, e, a, F4, K4, M(74) ); 406 R( a, b, c, d, e, F4, K4, M(75) ); 407 R( e, a, b, c, d, F4, K4, M(76) ); 408 R( d, e, a, b, c, F4, K4, M(77) ); 409 R( c, d, e, a, b, F4, K4, M(78) ); 410 R( b, c, d, e, a, F4, K4, M(79) ); 411 412 a = ctx->A += a; 413 b = ctx->B += b; 414 c = ctx->C += c; 415 d = ctx->D += d; 416 e = ctx->E += e; 417 } 418 } 419