2 * Routines to support checksumming of bytes.
4 * Copyright (C) 1996 Andrew Tridgell
5 * Copyright (C) 1996 Paul Mackerras
6 * Copyright (C) 2004-2019 Wayne Davison
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 3 of the License, or
11 * (at your option) any later version.
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.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, visit the http://fsf.org website.
24 extern int checksum_seed;
25 extern int protocol_version;
26 extern int proper_seed_order;
27 extern char *checksum_choice;
30 #define CSUM_MD4_ARCHAIC 1
31 #define CSUM_MD4_BUSTED 2
32 #define CSUM_MD4_OLD 3
36 int xfersum_type = 0; /* used for the file transfer checksums */
37 int checksum_type = 0; /* used for the pre-transfer (--checksum) checksums */
39 /* Returns 1 if --whole-file must be enabled. */
40 int parse_checksum_choice(void)
42 char *cp = checksum_choice ? strchr(checksum_choice, ',') : NULL;
44 xfersum_type = parse_csum_name(checksum_choice, cp - checksum_choice);
45 checksum_type = parse_csum_name(cp+1, -1);
47 xfersum_type = checksum_type = parse_csum_name(checksum_choice, -1);
48 return xfersum_type == CSUM_NONE;
51 int parse_csum_name(const char *name, int len)
56 if (!name || (len == 4 && strncasecmp(name, "auto", 4) == 0)) {
57 if (protocol_version >= 30)
59 if (protocol_version >= 27)
61 if (protocol_version >= 21)
62 return CSUM_MD4_BUSTED;
63 return CSUM_MD4_ARCHAIC;
65 if (len == 3 && strncasecmp(name, "md4", 3) == 0)
67 if (len == 3 && strncasecmp(name, "md5", 3) == 0)
69 if (len == 4 && strncasecmp(name, "none", 4) == 0)
72 rprintf(FERROR, "unknown checksum name: %s\n", name);
73 exit_cleanup(RERR_UNSUPPORTED);
76 int csum_len_for_type(int cst, BOOL flist_csum)
81 case CSUM_MD4_ARCHAIC:
82 /* The oldest checksum code is rather weird: the file-list code only sent
83 * 2-byte checksums, but all other checksums were full MD4 length. */
84 return flist_csum ? 2 : MD4_DIGEST_LEN;
88 return MD4_DIGEST_LEN;
90 return MD5_DIGEST_LEN;
91 default: /* paranoia to prevent missing case values */
92 exit_cleanup(RERR_UNSUPPORTED);
97 int canonical_checksum(int csum_type)
99 return csum_type >= CSUM_MD4 ? 1 : 0;
103 a simple 32 bit checksum that can be upadted from either end
104 (inspired by Mark Adler's Adler-32 checksum)
106 uint32 get_checksum1(char *buf1, int32 len)
110 schar *buf = (schar *)buf1;
113 for (i = 0; i < (len-4); i+=4) {
114 s2 += 4*(s1 + buf[i]) + 3*buf[i+1] + 2*buf[i+2] + buf[i+3] + 10*CHAR_OFFSET;
115 s1 += (buf[i+0] + buf[i+1] + buf[i+2] + buf[i+3] + 4*CHAR_OFFSET);
117 for (; i < len; i++) {
118 s1 += (buf[i]+CHAR_OFFSET); s2 += s1;
120 return (s1 & 0xffff) + (s2 << 16);
123 void get_checksum2(char *buf, int32 len, char *sum)
127 switch (xfersum_type) {
131 if (proper_seed_order) {
133 SIVALu(seedbuf, 0, checksum_seed);
134 md5_update(&m, seedbuf, 4);
136 md5_update(&m, (uchar *)buf, len);
138 md5_update(&m, (uchar *)buf, len);
140 SIVALu(seedbuf, 0, checksum_seed);
141 md5_update(&m, seedbuf, 4);
144 md5_result(&m, (uchar *)sum);
149 case CSUM_MD4_BUSTED:
150 case CSUM_MD4_ARCHAIC: {
160 buf1 = new_array(char, len+4);
163 out_of_memory("get_checksum2");
166 memcpy(buf1, buf, len);
168 SIVAL(buf1,len,checksum_seed);
172 for (i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK)
173 mdfour_update(&m, (uchar *)(buf1+i), CSUM_CHUNK);
176 * Prior to version 27 an incorrect MD4 checksum was computed
177 * by failing to call mdfour_tail() for block sizes that
178 * are multiples of 64. This is fixed by calling mdfour_update()
179 * even when there are no more bytes.
181 if (len - i > 0 || xfersum_type > CSUM_MD4_BUSTED)
182 mdfour_update(&m, (uchar *)(buf1+i), len-i);
184 mdfour_result(&m, (uchar *)sum);
187 default: /* paranoia to prevent missing case values */
188 exit_cleanup(RERR_UNSUPPORTED);
192 void file_checksum(const char *fname, const STRUCT_STAT *st_p, char *sum)
194 struct map_struct *buf;
195 OFF_T i, len = st_p->st_size;
200 memset(sum, 0, MAX_DIGEST_LEN);
202 fd = do_open(fname, O_RDONLY, 0);
206 buf = map_file(fd, len, MAX_MAP_SIZE, CSUM_CHUNK);
208 switch (checksum_type) {
212 for (i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
213 md5_update(&m, (uchar *)map_ptr(buf, i, CSUM_CHUNK),
217 remainder = (int32)(len - i);
219 md5_update(&m, (uchar *)map_ptr(buf, i, remainder), remainder);
221 md5_result(&m, (uchar *)sum);
225 case CSUM_MD4_BUSTED:
226 case CSUM_MD4_ARCHAIC:
229 for (i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
230 mdfour_update(&m, (uchar *)map_ptr(buf, i, CSUM_CHUNK), CSUM_CHUNK);
233 /* Prior to version 27 an incorrect MD4 checksum was computed
234 * by failing to call mdfour_tail() for block sizes that
235 * are multiples of 64. This is fixed by calling mdfour_update()
236 * even when there are no more bytes. */
237 remainder = (int32)(len - i);
238 if (remainder > 0 || checksum_type > CSUM_MD4_BUSTED)
239 mdfour_update(&m, (uchar *)map_ptr(buf, i, remainder), remainder);
241 mdfour_result(&m, (uchar *)sum);
244 rprintf(FERROR, "invalid checksum-choice for the --checksum option (%d)\n", checksum_type);
245 exit_cleanup(RERR_UNSUPPORTED);
252 static int32 sumresidue;
253 static md_context md;
254 static int cursum_type;
256 void sum_init(int csum_type, int seed)
261 csum_type = parse_csum_name(NULL, 0);
262 cursum_type = csum_type;
273 case CSUM_MD4_BUSTED:
274 case CSUM_MD4_ARCHAIC:
282 default: /* paranoia to prevent missing case values */
283 exit_cleanup(RERR_UNSUPPORTED);
288 * Feed data into an MD4 accumulator, md. The results may be
289 * retrieved using sum_end(). md is used for different purposes at
290 * different points during execution.
292 * @todo Perhaps get rid of md and just pass in the address each time.
293 * Very slightly clearer and slower.
295 void sum_update(const char *p, int32 len)
297 switch (cursum_type) {
299 md5_update(&md, (uchar *)p, len);
303 case CSUM_MD4_BUSTED:
304 case CSUM_MD4_ARCHAIC:
305 if (len + sumresidue < CSUM_CHUNK) {
306 memcpy(md.buffer + sumresidue, p, len);
312 int32 i = CSUM_CHUNK - sumresidue;
313 memcpy(md.buffer + sumresidue, p, i);
314 mdfour_update(&md, (uchar *)md.buffer, CSUM_CHUNK);
319 while (len >= CSUM_CHUNK) {
320 mdfour_update(&md, (uchar *)p, CSUM_CHUNK);
327 memcpy(md.buffer, p, sumresidue);
331 default: /* paranoia to prevent missing case values */
332 exit_cleanup(RERR_UNSUPPORTED);
336 /* NOTE: all the callers of sum_end() pass in a pointer to a buffer that is
337 * MAX_DIGEST_LEN in size, so even if the csum-len is shorter that that (i.e.
338 * CSUM_MD4_ARCHAIC), we don't have to worry about limiting the data we write
339 * into the "sum" buffer. */
340 int sum_end(char *sum)
342 switch (cursum_type) {
344 md5_result(&md, (uchar *)sum);
348 mdfour_update(&md, (uchar *)md.buffer, sumresidue);
349 mdfour_result(&md, (uchar *)sum);
351 case CSUM_MD4_BUSTED:
352 case CSUM_MD4_ARCHAIC:
354 mdfour_update(&md, (uchar *)md.buffer, sumresidue);
355 mdfour_result(&md, (uchar *)sum);
360 default: /* paranoia to prevent missing case values */
361 exit_cleanup(RERR_UNSUPPORTED);
364 return csum_len_for_type(cursum_type, 0);