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) 2000-2023 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 (dest: &((char *) ctx->buffer)[bytes], src: fillbuf, n: (size - 2) * 4 - bytes); |
108 | |
109 | /* Process last bytes. */ |
110 | sha1_process_block (buffer: ctx->buffer, len: 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: &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 (ptr: buffer + sum, size: 1, BLOCKSIZE - sum, stream: 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: 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: 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: &ctx); |
168 | } |
169 | |
170 | process_partial_block:; |
171 | |
172 | /* Process any remaining bytes. */ |
173 | if (sum > 0) |
174 | sha1_process_bytes (buffer, len: sum, ctx: &ctx); |
175 | |
176 | /* Construct result in desired memory. */ |
177 | sha1_finish_ctx (ctx: &ctx, resbuf: 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: &ctx); |
192 | |
193 | /* Process whole buffer but last len % 64 bytes. */ |
194 | sha1_process_bytes (buffer, len, ctx: &ctx); |
195 | |
196 | /* Put result in desired memory area. */ |
197 | return sha1_finish_ctx (ctx: &ctx, resbuf: 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 (dest: &((char *) ctx->buffer)[left_over], src: buffer, n: add); |
211 | ctx->buflen += add; |
212 | |
213 | if (ctx->buflen > 64) |
214 | { |
215 | sha1_process_block (buffer: ctx->buffer, len: ctx->buflen & ~63, ctx); |
216 | |
217 | ctx->buflen &= 63; |
218 | /* The regions in the following copy operation cannot overlap. */ |
219 | memcpy (dest: ctx->buffer, |
220 | src: &((char *) ctx->buffer)[(left_over + add) & ~63], |
221 | n: 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 (buffer: memcpy (dest: ctx->buffer, src: buffer, n: 64), len: 64, ctx); |
238 | buffer = (const char *) buffer + 64; |
239 | len -= 64; |
240 | } |
241 | else |
242 | #endif |
243 | { |
244 | sha1_process_block (buffer, len: 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 (dest: &((char *) ctx->buffer)[left_over], src: buffer, n: len); |
256 | left_over += len; |
257 | if (left_over >= 64) |
258 | { |
259 | sha1_process_block (buffer: ctx->buffer, len: 64, ctx); |
260 | left_over -= 64; |
261 | memmove (dest: ctx->buffer, src: &ctx->buffer[16], n: 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 | |