2 * Routines to support checksumming of bytes.
4 * Copyright (C) 1996 Andrew Tridgell
5 * Copyright (C) 1996 Paul Mackerras
6 * Copyright (C) 2004-2018 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] +
116 s1 += (buf[i+0] + buf[i+1] + buf[i+2] + buf[i+3] + 4*CHAR_OFFSET);
118 for (; i < len; i++) {
119 s1 += (buf[i]+CHAR_OFFSET); s2 += s1;
121 return (s1 & 0xffff) + (s2 << 16);
124 void get_checksum2(char *buf, int32 len, char *sum)
128 switch (xfersum_type) {
132 if (proper_seed_order) {
134 SIVALu(seedbuf, 0, checksum_seed);
135 md5_update(&m, seedbuf, 4);
137 md5_update(&m, (uchar *)buf, len);
139 md5_update(&m, (uchar *)buf, len);
141 SIVALu(seedbuf, 0, checksum_seed);
142 md5_update(&m, seedbuf, 4);
145 md5_result(&m, (uchar *)sum);
150 case CSUM_MD4_BUSTED:
151 case CSUM_MD4_ARCHAIC: {
161 buf1 = new_array(char, len+4);
164 out_of_memory("get_checksum2");
167 memcpy(buf1, buf, len);
169 SIVAL(buf1,len,checksum_seed);
173 for (i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK)
174 mdfour_update(&m, (uchar *)(buf1+i), CSUM_CHUNK);
177 * Prior to version 27 an incorrect MD4 checksum was computed
178 * by failing to call mdfour_tail() for block sizes that
179 * are multiples of 64. This is fixed by calling mdfour_update()
180 * even when there are no more bytes.
182 if (len - i > 0 || xfersum_type > CSUM_MD4_BUSTED)
183 mdfour_update(&m, (uchar *)(buf1+i), len-i);
185 mdfour_result(&m, (uchar *)sum);
188 default: /* paranoia to prevent missing case values */
189 exit_cleanup(RERR_UNSUPPORTED);
193 void file_checksum(const char *fname, const STRUCT_STAT *st_p, char *sum)
195 struct map_struct *buf;
196 OFF_T i, len = st_p->st_size;
201 memset(sum, 0, MAX_DIGEST_LEN);
203 fd = do_open(fname, O_RDONLY, 0);
207 buf = map_file(fd, len, MAX_MAP_SIZE, CSUM_CHUNK);
209 switch (checksum_type) {
213 for (i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
214 md5_update(&m, (uchar *)map_ptr(buf, i, CSUM_CHUNK),
218 remainder = (int32)(len - i);
220 md5_update(&m, (uchar *)map_ptr(buf, i, remainder), remainder);
222 md5_result(&m, (uchar *)sum);
226 case CSUM_MD4_BUSTED:
227 case CSUM_MD4_ARCHAIC:
230 for (i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
231 mdfour_update(&m, (uchar *)map_ptr(buf, i, CSUM_CHUNK),
235 /* Prior to version 27 an incorrect MD4 checksum was computed
236 * by failing to call mdfour_tail() for block sizes that
237 * are multiples of 64. This is fixed by calling mdfour_update()
238 * even when there are no more bytes. */
239 remainder = (int32)(len - i);
240 if (remainder > 0 || checksum_type > CSUM_MD4_BUSTED)
241 mdfour_update(&m, (uchar *)map_ptr(buf, i, remainder), remainder);
243 mdfour_result(&m, (uchar *)sum);
246 rprintf(FERROR, "invalid checksum-choice for the --checksum option (%d)\n", checksum_type);
247 exit_cleanup(RERR_UNSUPPORTED);
254 static int32 sumresidue;
255 static md_context md;
256 static int cursum_type;
258 void sum_init(int csum_type, int seed)
263 csum_type = parse_csum_name(NULL, 0);
264 cursum_type = csum_type;
275 case CSUM_MD4_BUSTED:
276 case CSUM_MD4_ARCHAIC:
284 default: /* paranoia to prevent missing case values */
285 exit_cleanup(RERR_UNSUPPORTED);
290 * Feed data into an MD4 accumulator, md. The results may be
291 * retrieved using sum_end(). md is used for different purposes at
292 * different points during execution.
294 * @todo Perhaps get rid of md and just pass in the address each time.
295 * Very slightly clearer and slower.
297 void sum_update(const char *p, int32 len)
299 switch (cursum_type) {
301 md5_update(&md, (uchar *)p, len);
305 case CSUM_MD4_BUSTED:
306 case CSUM_MD4_ARCHAIC:
307 if (len + sumresidue < CSUM_CHUNK) {
308 memcpy(md.buffer + sumresidue, p, len);
314 int32 i = CSUM_CHUNK - sumresidue;
315 memcpy(md.buffer + sumresidue, p, i);
316 mdfour_update(&md, (uchar *)md.buffer, CSUM_CHUNK);
321 while (len >= CSUM_CHUNK) {
322 mdfour_update(&md, (uchar *)p, CSUM_CHUNK);
329 memcpy(md.buffer, p, sumresidue);
333 default: /* paranoia to prevent missing case values */
334 exit_cleanup(RERR_UNSUPPORTED);
338 /* NOTE: all the callers of sum_end() pass in a pointer to a buffer that is
339 * MAX_DIGEST_LEN in size, so even if the csum-len is shorter that that (i.e.
340 * CSUM_MD4_ARCHAIC), we don't have to worry about limiting the data we write
341 * into the "sum" buffer. */
342 int sum_end(char *sum)
344 switch (cursum_type) {
346 md5_result(&md, (uchar *)sum);
350 mdfour_update(&md, (uchar *)md.buffer, sumresidue);
351 mdfour_result(&md, (uchar *)sum);
353 case CSUM_MD4_BUSTED:
354 case CSUM_MD4_ARCHAIC:
356 mdfour_update(&md, (uchar *)md.buffer, sumresidue);
357 mdfour_result(&md, (uchar *)sum);
362 default: /* paranoia to prevent missing case values */
363 exit_cleanup(RERR_UNSUPPORTED);
366 return csum_len_for_type(cursum_type, 0);