-/*
- Copyright (C) Andrew Tridgell 1996
- Copyright (C) Paul Mackerras 1996
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
+/*
+ * Routines to support checksumming of bytes.
+ *
+ * Copyright (C) 1996 Andrew Tridgell
+ * Copyright (C) 1996 Paul Mackerras
+ * Copyright (C) 2004, 2005 Wayne Davison
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
#include "rsync.h"
+int csum_length=2; /* initial value */
+
+#define CSUM_CHUNK 64
+
+extern int checksum_seed;
+extern int protocol_version;
/*
a simple 32 bit checksum that can be upadted from either end
(inspired by Mark Adler's Adler-32 checksum)
*/
-uint32 get_checksum1(char *buf,int len)
+uint32 get_checksum1(char *buf1, int32 len)
{
- int i;
+ int32 i;
uint32 s1, s2;
+ schar *buf = (schar *)buf1;
s1 = s2 = 0;
- for (i = 0; i < len; i++) {
- s1 += buf[i];
- s2 += s1;
+ for (i = 0; i < (len-4); i+=4) {
+ s2 += 4*(s1 + buf[i]) + 3*buf[i+1] + 2*buf[i+2] + buf[i+3] +
+ 10*CHAR_OFFSET;
+ s1 += (buf[i+0] + buf[i+1] + buf[i+2] + buf[i+3] + 4*CHAR_OFFSET);
+ }
+ for (; i < len; i++) {
+ s1 += (buf[i]+CHAR_OFFSET); s2 += s1;
}
return (s1 & 0xffff) + (s2 << 16);
}
-void get_checksum2(char *buf,int len,char *sum)
+void get_checksum2(char *buf, int32 len, char *sum)
{
- char buf2[64];
- int i;
- MDstruct MD;
-
- MDbegin(&MD);
- for(i = 0; i + 64 <= len; i += 64) {
- bcopy(buf+i,buf2,64);
- MDupdate(&MD, buf2, 512);
- }
- bcopy(buf+i,buf2,len-i);
- MDupdate(&MD, buf2, (len-i)*8);
- SIVAL(sum,0,MD.buffer[0]);
- SIVAL(sum,4,MD.buffer[1]);
- SIVAL(sum,8,MD.buffer[2]);
- SIVAL(sum,12,MD.buffer[3]);
+ int32 i;
+ static char *buf1;
+ static int32 len1;
+ struct mdfour m;
+
+ if (len > len1) {
+ if (buf1)
+ free(buf1);
+ buf1 = new_array(char, len+4);
+ len1 = len;
+ if (!buf1)
+ out_of_memory("get_checksum2");
+ }
+
+ mdfour_begin(&m);
+
+ memcpy(buf1,buf,len);
+ if (checksum_seed) {
+ SIVAL(buf1,len,checksum_seed);
+ len += 4;
+ }
+
+ for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
+ mdfour_update(&m, (uchar *)(buf1+i), CSUM_CHUNK);
+ }
+ /*
+ * Prior to version 27 an incorrect MD4 checksum was computed
+ * by failing to call mdfour_tail() for block sizes that
+ * are multiples of 64. This is fixed by calling mdfour_update()
+ * even when there are no more bytes.
+ */
+ if (len - i > 0 || protocol_version >= 27) {
+ mdfour_update(&m, (uchar *)(buf1+i), (len-i));
+ }
+
+ mdfour_result(&m, (uchar *)sum);
}
-void file_checksum(char *fname,char *sum,off_t size)
+
+void file_checksum(char *fname,char *sum,OFF_T size)
{
- char *buf;
- int fd;
- bzero(sum,SUM_LENGTH);
-
- fd = open(fname,O_RDONLY);
- if (fd == -1) return;
-
- buf = map_file(fd,size);
- if (!buf) {
- close(fd);
- return;
- }
-
- get_checksum2(buf,size,sum);
- close(fd);
- unmap_file(buf,size);
+ OFF_T i;
+ struct map_struct *buf;
+ int fd;
+ OFF_T len = size;
+ struct mdfour m;
+
+ memset(sum,0,MD4_SUM_LENGTH);
+
+ fd = do_open(fname, O_RDONLY, 0);
+ if (fd == -1)
+ return;
+
+ buf = map_file(fd, size, MAX_MAP_SIZE, CSUM_CHUNK);
+
+ mdfour_begin(&m);
+
+ for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
+ mdfour_update(&m, (uchar *)map_ptr(buf, i, CSUM_CHUNK),
+ CSUM_CHUNK);
+ }
+
+ /* Prior to version 27 an incorrect MD4 checksum was computed
+ * by failing to call mdfour_tail() for block sizes that
+ * are multiples of 64. This is fixed by calling mdfour_update()
+ * even when there are no more bytes. */
+ if (len - i > 0 || protocol_version >= 27)
+ mdfour_update(&m, (uchar *)map_ptr(buf, i, len-i), len-i);
+
+ mdfour_result(&m, (uchar *)sum);
+
+ close(fd);
+ unmap_file(buf);
+}
+
+
+static int32 sumresidue;
+static char sumrbuf[CSUM_CHUNK];
+static struct mdfour md;
+
+void sum_init(int seed)
+{
+ char s[4];
+ mdfour_begin(&md);
+ sumresidue = 0;
+ SIVAL(s, 0, seed);
+ sum_update(s, 4);
+}
+
+/**
+ * Feed data into an MD4 accumulator, md. The results may be
+ * retrieved using sum_end(). md is used for different purposes at
+ * different points during execution.
+ *
+ * @todo Perhaps get rid of md and just pass in the address each time.
+ * Very slightly clearer and slower.
+ **/
+void sum_update(char *p, int32 len)
+{
+ if (len + sumresidue < CSUM_CHUNK) {
+ memcpy(sumrbuf + sumresidue, p, len);
+ sumresidue += len;
+ return;
+ }
+
+ if (sumresidue) {
+ int32 i = CSUM_CHUNK - sumresidue;
+ memcpy(sumrbuf + sumresidue, p, i);
+ mdfour_update(&md, (uchar *)sumrbuf, CSUM_CHUNK);
+ len -= i;
+ p += i;
+ }
+
+ while (len >= CSUM_CHUNK) {
+ mdfour_update(&md, (uchar *)p, CSUM_CHUNK);
+ len -= CSUM_CHUNK;
+ p += CSUM_CHUNK;
+ }
+
+ sumresidue = len;
+ if (sumresidue)
+ memcpy(sumrbuf, p, sumresidue);
+}
+
+void sum_end(char *sum)
+{
+ if (sumresidue || protocol_version >= 27)
+ mdfour_update(&md, (uchar *)sumrbuf, sumresidue);
+
+ mdfour_result(&md, (uchar *)sum);
}
Matt McCutchen's Web Site / rsync / rsync.git / blobdiff