| 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) 2007 Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of the GNU Binutils. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify it |
| 9 | under the terms of the GNU General Public License as published by the |
| 10 | Free Software Foundation; either version 3, or (at your option) any |
| 11 | later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software Foundation, |
| 20 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ |
| 21 | |
| 22 | /* Written by Scott G. Miller |
| 23 | Credits: |
| 24 | Robert Klep <robert@ilse.nl> -- Expansion function fix */ |
| 25 | |
| 26 | #include <config.h> |
| 27 | #include "sha1.h" |
| 28 | #include <stddef.h> |
| 29 | #include <string.h> |
| 30 | |
| 31 | #if USE_UNLOCKED_IO |
| 32 | # include "unlocked-io.h" |
| 33 | #endif |
| 34 | |
| 35 | #ifdef WORDS_BIGENDIAN |
| 36 | # define SWAP(n) (n) |
| 37 | #else |
| 38 | # define SWAP(n) \ |
| 39 | (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24)) |
| 40 | #endif |
| 41 | |
| 42 | #define BLOCKSIZE 4096 |
| 43 | #if BLOCKSIZE % 64 != 0 |
| 44 | # error "invalid BLOCKSIZE" |
| 45 | #endif |
| 46 | |
| 47 | /* This array contains the bytes used to pad the buffer to the next |
| 48 | 64-byte boundary. (RFC 1321, 3.1: Step 1) */ |
| 49 | static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ }; |
| 50 | |
| 51 | |
| 52 | /* Take a pointer to a 160 bit block of data (five 32 bit ints) and |
| 53 | initialize it to the start constants of the SHA1 algorithm. This |
| 54 | must be called before using hash in the call to sha1_hash. */ |
| 55 | |
| 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 | |
| 75 | void * |
| 76 | sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf) |
| 77 | { |
| 78 | ((uint32_t *) resbuf)[0] = SWAP (ctx->A); |
| 79 | ((uint32_t *) resbuf)[1] = SWAP (ctx->B); |
| 80 | ((uint32_t *) resbuf)[2] = SWAP (ctx->C); |
| 81 | ((uint32_t *) resbuf)[3] = SWAP (ctx->D); |
| 82 | ((uint32_t *) 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 | |
| 93 | void * |
| 94 | sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf) |
| 95 | { |
| 96 | /* Take yet unprocessed bytes into account. */ |
| 97 | uint32_t bytes = ctx->buflen; |
| 98 | size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4; |
| 99 | |
| 100 | /* Now count remaining bytes. */ |
| 101 | ctx->total[0] += bytes; |
| 102 | if (ctx->total[0] < bytes) |
| 103 | ++ctx->total[1]; |
| 104 | |
| 105 | /* Put the 64-bit file length in *bits* at the end of the buffer. */ |
| 106 | ctx->buffer[size - 2] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29)); |
| 107 | ctx->buffer[size - 1] = SWAP (ctx->total[0] << 3); |
| 108 | |
| 109 | memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes); |
| 110 | |
| 111 | /* Process last bytes. */ |
| 112 | sha1_process_block (ctx->buffer, size * 4, ctx); |
| 113 | |
| 114 | return sha1_read_ctx (ctx, resbuf); |
| 115 | } |
| 116 | |
| 117 | /* Compute SHA1 message digest for bytes read from STREAM. The |
| 118 | resulting message digest number will be written into the 16 bytes |
| 119 | beginning at RESBLOCK. */ |
| 120 | |
| 121 | int |
| 122 | sha1_stream (FILE *stream, void *resblock) |
| 123 | { |
| 124 | struct sha1_ctx ctx; |
| 125 | char buffer[BLOCKSIZE + 72]; |
| 126 | size_t sum; |
| 127 | |
| 128 | /* Initialize the computation context. */ |
| 129 | sha1_init_ctx (&ctx); |
| 130 | |
| 131 | /* Iterate over full file contents. */ |
| 132 | while (1) |
| 133 | { |
| 134 | /* We read the file in blocks of BLOCKSIZE bytes. One call of the |
| 135 | computation function processes the whole buffer so that with the |
| 136 | next round of the loop another block can be read. */ |
| 137 | size_t n; |
| 138 | sum = 0; |
| 139 | |
| 140 | /* Read block. Take care for partial reads. */ |
| 141 | while (1) |
| 142 | { |
| 143 | n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream); |
| 144 | |
| 145 | sum += n; |
| 146 | |
| 147 | if (sum == BLOCKSIZE) |
| 148 | break; |
| 149 | |
| 150 | if (n == 0) |
| 151 | { |
| 152 | /* Check for the error flag IFF N == 0, so that we don't |
| 153 | exit the loop after a partial read due to e.g., EAGAIN |
| 154 | or EWOULDBLOCK. */ |
| 155 | if (ferror (stream)) |
| 156 | return 1; |
| 157 | goto process_partial_block; |
| 158 | } |
| 159 | |
| 160 | /* We've read at least one byte, so ignore errors. But always |
| 161 | check for EOF, since feof may be true even though N > 0. |
| 162 | Otherwise, we could end up calling fread after EOF. */ |
| 163 | if (feof (stream)) |
| 164 | goto process_partial_block; |
| 165 | } |
| 166 | |
| 167 | /* Process buffer with BLOCKSIZE bytes. Note that |
| 168 | BLOCKSIZE % 64 == 0. */ |
| 169 | sha1_process_block (buffer, BLOCKSIZE, &ctx); |
| 170 | } |
| 171 | |
| 172 | process_partial_block:; |
| 173 | |
| 174 | /* Process any remaining bytes. */ |
| 175 | if (sum > 0) |
| 176 | sha1_process_bytes (buffer, sum, &ctx); |
| 177 | |
| 178 | /* Construct result in desired memory. */ |
| 179 | sha1_finish_ctx (&ctx, resblock); |
| 180 | return 0; |
| 181 | } |
| 182 | |
| 183 | /* Compute SHA1 message digest for LEN bytes beginning at BUFFER. The |
| 184 | result is always in little endian byte order, so that a byte-wise |
| 185 | output yields to the wanted ASCII representation of the message |
| 186 | digest. */ |
| 187 | |
| 188 | void * |
| 189 | sha1_buffer (const char *buffer, size_t len, void *resblock) |
| 190 | { |
| 191 | struct sha1_ctx ctx; |
| 192 | |
| 193 | /* Initialize the computation context. */ |
| 194 | sha1_init_ctx (&ctx); |
| 195 | |
| 196 | /* Process whole buffer but last len % 64 bytes. */ |
| 197 | sha1_process_bytes (buffer, len, &ctx); |
| 198 | |
| 199 | /* Put result in desired memory area. */ |
| 200 | return sha1_finish_ctx (&ctx, resblock); |
| 201 | } |
| 202 | |
| 203 | void |
| 204 | sha1_process_bytes (const void *buffer, size_t len, struct sha1_ctx *ctx) |
| 205 | { |
| 206 | /* When we already have some bits in our internal buffer concatenate |
| 207 | both inputs first. */ |
| 208 | if (ctx->buflen != 0) |
| 209 | { |
| 210 | size_t left_over = ctx->buflen; |
| 211 | size_t add = 128 - left_over > len ? len : 128 - left_over; |
| 212 | |
| 213 | memcpy (&((char *) ctx->buffer)[left_over], buffer, add); |
| 214 | ctx->buflen += add; |
| 215 | |
| 216 | if (ctx->buflen > 64) |
| 217 | { |
| 218 | sha1_process_block (ctx->buffer, ctx->buflen & ~63, ctx); |
| 219 | |
| 220 | ctx->buflen &= 63; |
| 221 | /* The regions in the following copy operation cannot overlap. */ |
| 222 | memcpy (ctx->buffer, |
| 223 | &((char *) ctx->buffer)[(left_over + add) & ~63], |
| 224 | ctx->buflen); |
| 225 | } |
| 226 | |
| 227 | buffer = (const char *) buffer + add; |
| 228 | len -= add; |
| 229 | } |
| 230 | |
| 231 | /* Process available complete blocks. */ |
| 232 | if (len >= 64) |
| 233 | { |
| 234 | #if !_STRING_ARCH_unaligned |
| 235 | # define alignof(type) offsetof (struct { char c; type x; }, x) |
| 236 | # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0) |
| 237 | if (UNALIGNED_P (buffer)) |
| 238 | while (len > 64) |
| 239 | { |
| 240 | sha1_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx); |
| 241 | buffer = (const char *) buffer + 64; |
| 242 | len -= 64; |
| 243 | } |
| 244 | else |
| 245 | #endif |
| 246 | { |
| 247 | sha1_process_block (buffer, len & ~63, ctx); |
| 248 | buffer = (const char *) buffer + (len & ~63); |
| 249 | len &= 63; |
| 250 | } |
| 251 | } |
| 252 | |
| 253 | /* Move remaining bytes in internal buffer. */ |
| 254 | if (len > 0) |
| 255 | { |
| 256 | size_t left_over = ctx->buflen; |
| 257 | |
| 258 | memcpy (&((char *) ctx->buffer)[left_over], buffer, len); |
| 259 | left_over += len; |
| 260 | if (left_over >= 64) |
| 261 | { |
| 262 | sha1_process_block (ctx->buffer, 64, ctx); |
| 263 | left_over -= 64; |
| 264 | memcpy (ctx->buffer, &ctx->buffer[16], left_over); |
| 265 | } |
| 266 | ctx->buflen = left_over; |
| 267 | } |
| 268 | } |
| 269 | |
| 270 | /* --- Code below is the primary difference between md5.c and sha1.c --- */ |
| 271 | |
| 272 | /* SHA1 round constants. */ |
| 273 | #define K1 0x5a827999 |
| 274 | #define K2 0x6ed9eba1 |
| 275 | #define K3 0x8f1bbcdc |
| 276 | #define K4 0xca62c1d6 |
| 277 | |
| 278 | /* Round functions. Note that F2 is the same as F4. */ |
| 279 | #define F1(B,C,D) (D ^ (B & (C ^ D))) |
| 280 | #define F2(B,C,D) (B ^ C ^ D) |
| 281 | #define F3(B,C,D) ((B & C) | (D & (B | C))) |
| 282 | #define F4(B,C,D) (B ^ C ^ D) |
| 283 | |
| 284 | /* Process LEN bytes of BUFFER, accumulating context into CTX. |
| 285 | It is assumed that LEN % 64 == 0. |
| 286 | Most of this code comes from GnuPG's cipher/sha1.c. */ |
| 287 | |
| 288 | void |
| 289 | sha1_process_block (const void *buffer, size_t len, struct sha1_ctx *ctx) |
| 290 | { |
| 291 | const uint32_t *words = buffer; |
| 292 | size_t nwords = len / sizeof (uint32_t); |
| 293 | const uint32_t *endp = words + nwords; |
| 294 | uint32_t x[16]; |
| 295 | uint32_t a = ctx->A; |
| 296 | uint32_t b = ctx->B; |
| 297 | uint32_t c = ctx->C; |
| 298 | uint32_t d = ctx->D; |
| 299 | uint32_t e = ctx->E; |
| 300 | |
| 301 | /* First increment the byte count. RFC 1321 specifies the possible |
| 302 | length of the file up to 2^64 bits. Here we only compute the |
| 303 | number of bytes. Do a double word increment. */ |
| 304 | ctx->total[0] += len; |
| 305 | if (ctx->total[0] < len) |
| 306 | ++ctx->total[1]; |
| 307 | |
| 308 | #define rol(x, n) (((x) << (n)) | ((uint32_t) (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) \ |
| 315 | do \ |
| 316 | { \ |
| 317 | E += rol (A, 5) \ |
| 318 | + F (B, C, D) \ |
| 319 | + K \ |
| 320 | + M; \ |
| 321 | B = rol (B, 30); \ |
| 322 | } \ |
| 323 | while (0) |
| 324 | |
| 325 | while (words < endp) |
| 326 | { |
| 327 | uint32_t tm; |
| 328 | int t; |
| 329 | |
| 330 | for (t = 0; t < 16; t++) |
| 331 | { |
| 332 | x[t] = SWAP (*words); |
| 333 | words++; |
| 334 | } |
| 335 | |
| 336 | R (a, b, c, d, e, F1, K1, x[ 0]); |
| 337 | R (e, a, b, c, d, F1, K1, x[ 1]); |
| 338 | R (d, e, a, b, c, F1, K1, x[ 2]); |
| 339 | R (c, d, e, a, b, F1, K1, x[ 3]); |
| 340 | R (b, c, d, e, a, F1, K1, x[ 4]); |
| 341 | R (a, b, c, d, e, F1, K1, x[ 5]); |
| 342 | R (e, a, b, c, d, F1, K1, x[ 6]); |
| 343 | R (d, e, a, b, c, F1, K1, x[ 7]); |
| 344 | R (c, d, e, a, b, F1, K1, x[ 8]); |
| 345 | R (b, c, d, e, a, F1, K1, x[ 9]); |
| 346 | R (a, b, c, d, e, F1, K1, x[10]); |
| 347 | R (e, a, b, c, d, F1, K1, x[11]); |
| 348 | R (d, e, a, b, c, F1, K1, x[12]); |
| 349 | R (c, d, e, a, b, F1, K1, x[13]); |
| 350 | R (b, c, d, e, a, F1, K1, x[14]); |
| 351 | R (a, b, c, d, e, F1, K1, x[15]); |
| 352 | R (e, a, b, c, d, F1, K1, M(16)); |
| 353 | R (d, e, a, b, c, F1, K1, M(17)); |
| 354 | R (c, d, e, a, b, F1, K1, M(18)); |
| 355 | R (b, c, d, e, a, F1, K1, M(19)); |
| 356 | R (a, b, c, d, e, F2, K2, M(20)); |
| 357 | R (e, a, b, c, d, F2, K2, M(21)); |
| 358 | R (d, e, a, b, c, F2, K2, M(22)); |
| 359 | R (c, d, e, a, b, F2, K2, M(23)); |
| 360 | R (b, c, d, e, a, F2, K2, M(24)); |
| 361 | R (a, b, c, d, e, F2, K2, M(25)); |
| 362 | R (e, a, b, c, d, F2, K2, M(26)); |
| 363 | R (d, e, a, b, c, F2, K2, M(27)); |
| 364 | R (c, d, e, a, b, F2, K2, M(28)); |
| 365 | R (b, c, d, e, a, F2, K2, M(29)); |
| 366 | R (a, b, c, d, e, F2, K2, M(30)); |
| 367 | R (e, a, b, c, d, F2, K2, M(31)); |
| 368 | R (d, e, a, b, c, F2, K2, M(32)); |
| 369 | R (c, d, e, a, b, F2, K2, M(33)); |
| 370 | R (b, c, d, e, a, F2, K2, M(34)); |
| 371 | R (a, b, c, d, e, F2, K2, M(35)); |
| 372 | R (e, a, b, c, d, F2, K2, M(36)); |
| 373 | R (d, e, a, b, c, F2, K2, M(37)); |
| 374 | R (c, d, e, a, b, F2, K2, M(38)); |
| 375 | R (b, c, d, e, a, F2, K2, M(39)); |
| 376 | R (a, b, c, d, e, F3, K3, M(40)); |
| 377 | R (e, a, b, c, d, F3, K3, M(41)); |
| 378 | R (d, e, a, b, c, F3, K3, M(42)); |
| 379 | R (c, d, e, a, b, F3, K3, M(43)); |
| 380 | R (b, c, d, e, a, F3, K3, M(44)); |
| 381 | R (a, b, c, d, e, F3, K3, M(45)); |
| 382 | R (e, a, b, c, d, F3, K3, M(46)); |
| 383 | R (d, e, a, b, c, F3, K3, M(47)); |
| 384 | R (c, d, e, a, b, F3, K3, M(48)); |
| 385 | R (b, c, d, e, a, F3, K3, M(49)); |
| 386 | R (a, b, c, d, e, F3, K3, M(50)); |
| 387 | R (e, a, b, c, d, F3, K3, M(51)); |
| 388 | R (d, e, a, b, c, F3, K3, M(52)); |
| 389 | R (c, d, e, a, b, F3, K3, M(53)); |
| 390 | R (b, c, d, e, a, F3, K3, M(54)); |
| 391 | R (a, b, c, d, e, F3, K3, M(55)); |
| 392 | R (e, a, b, c, d, F3, K3, M(56)); |
| 393 | R (d, e, a, b, c, F3, K3, M(57)); |
| 394 | R (c, d, e, a, b, F3, K3, M(58)); |
| 395 | R (b, c, d, e, a, F3, K3, M(59)); |
| 396 | R (a, b, c, d, e, F4, K4, M(60)); |
| 397 | R (e, a, b, c, d, F4, K4, M(61)); |
| 398 | R (d, e, a, b, c, F4, K4, M(62)); |
| 399 | R (c, d, e, a, b, F4, K4, M(63)); |
| 400 | R (b, c, d, e, a, F4, K4, M(64)); |
| 401 | R (a, b, c, d, e, F4, K4, M(65)); |
| 402 | R (e, a, b, c, d, F4, K4, M(66)); |
| 403 | R (d, e, a, b, c, F4, K4, M(67)); |
| 404 | R (c, d, e, a, b, F4, K4, M(68)); |
| 405 | R (b, c, d, e, a, F4, K4, M(69)); |
| 406 | R (a, b, c, d, e, F4, K4, M(70)); |
| 407 | R (e, a, b, c, d, F4, K4, M(71)); |
| 408 | R (d, e, a, b, c, F4, K4, M(72)); |
| 409 | R (c, d, e, a, b, F4, K4, M(73)); |
| 410 | R (b, c, d, e, a, F4, K4, M(74)); |
| 411 | R (a, b, c, d, e, F4, K4, M(75)); |
| 412 | R (e, a, b, c, d, F4, K4, M(76)); |
| 413 | R (d, e, a, b, c, F4, K4, M(77)); |
| 414 | R (c, d, e, a, b, F4, K4, M(78)); |
| 415 | R (b, c, d, e, a, F4, K4, M(79)); |
| 416 | |
| 417 | a = ctx->A += a; |
| 418 | b = ctx->B += b; |
| 419 | c = ctx->C += c; |
| 420 | d = ctx->D += d; |
| 421 | e = ctx->E += e; |
| 422 | } |
| 423 | } |