| 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) 2000-2019 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 | } |