2 Copyright (C) Andrew Tridgell 1996
3 Copyright (C) Paul Mackerras 1996
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 int csum_length=2; /* initial value */
26 extern int checksum_seed;
27 extern int protocol_version;
30 a simple 32 bit checksum that can be upadted from either end
31 (inspired by Mark Adler's Adler-32 checksum)
33 uint32 get_checksum1(char *buf1,int len)
37 schar *buf = (schar *)buf1;
40 for (i = 0; i < (len-4); i+=4) {
41 s2 += 4*(s1 + buf[i]) + 3*buf[i+1] + 2*buf[i+2] + buf[i+3] +
43 s1 += (buf[i+0] + buf[i+1] + buf[i+2] + buf[i+3] + 4*CHAR_OFFSET);
45 for (; i < len; i++) {
46 s1 += (buf[i]+CHAR_OFFSET); s2 += s1;
48 return (s1 & 0xffff) + (s2 << 16);
52 void get_checksum2(char *buf,int len,char *sum)
61 buf1 = new_array(char, len+4);
63 if (!buf1) out_of_memory("get_checksum2");
70 SIVAL(buf1,len,checksum_seed);
74 for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
75 mdfour_update(&m, (uchar *)(buf1+i), CSUM_CHUNK);
78 * Prior to version 27 an incorrect MD4 checksum was computed
79 * by failing to call mdfour_tail() for block sizes that
80 * are multiples of 64. This is fixed by calling mdfour_update()
81 * even when there are no more bytes.
83 if (len - i > 0 || protocol_version >= 27) {
84 mdfour_update(&m, (uchar *)(buf1+i), (len-i));
87 mdfour_result(&m, (uchar *)sum);
91 void file_checksum(char *fname,char *sum,OFF_T size)
94 struct map_struct *buf;
99 memset(sum,0,MD4_SUM_LENGTH);
101 fd = do_open(fname, O_RDONLY, 0);
102 if (fd == -1) return;
104 buf = map_file(fd,size);
108 for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
109 mdfour_update(&m, (uchar *)map_ptr(buf, i, CSUM_CHUNK),
113 /* Prior to version 27 an incorrect MD4 checksum was computed
114 * by failing to call mdfour_tail() for block sizes that
115 * are multiples of 64. This is fixed by calling mdfour_update()
116 * even when there are no more bytes. */
117 if (len - i > 0 || protocol_version >= 27)
118 mdfour_update(&m, (uchar *)map_ptr(buf, i, len-i), len-i);
120 mdfour_result(&m, (uchar *)sum);
127 static int sumresidue;
128 static char sumrbuf[CSUM_CHUNK];
129 static struct mdfour md;
131 void sum_init(int seed)
141 * Feed data into an MD4 accumulator, md. The results may be
142 * retrieved using sum_end(). md is used for different purposes at
143 * different points during execution.
145 * @todo Perhaps get rid of md and just pass in the address each time.
146 * Very slightly clearer and slower.
148 void sum_update(char *p, int len)
151 if (len + sumresidue < CSUM_CHUNK) {
152 memcpy(sumrbuf+sumresidue, p, len);
158 i = MIN(CSUM_CHUNK-sumresidue,len);
159 memcpy(sumrbuf+sumresidue,p,i);
160 mdfour_update(&md, (uchar *)sumrbuf, (i+sumresidue));
165 for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
166 memcpy(sumrbuf,p+i,CSUM_CHUNK);
167 mdfour_update(&md, (uchar *)sumrbuf, CSUM_CHUNK);
172 memcpy(sumrbuf,p+i,sumresidue);
178 void sum_end(char *sum)
180 if (sumresidue || protocol_version >= 27) {
181 mdfour_update(&md, (uchar *)sumrbuf, sumresidue);
184 mdfour_result(&md, (uchar *)sum);