- int i;
- MDstruct MD;
- static char *buf1 = NULL;
- static int len1 = 0;
-
- if (len > len1) {
- if (buf1) free(buf1);
- buf1 = (char *)malloc(len+4);
- len1 = len;
- if (!buf1) out_of_memory("get_checksum2");
- }
-
- MDbegin(&MD);
-
- bcopy(buf,buf1,len);
- if (checksum_seed) {
- SIVAL(buf1,len,checksum_seed);
- len += 4;
- }
-
- for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
- MDupdate(&MD, buf1+i, CSUM_CHUNK*8);
- }
- MDupdate(&MD, buf1+i, (len-i)*8);
-
- sum_put(&MD,sum);
+ struct map_struct *buf;
+ OFF_T i, len = size;
+ md_context m;
+ int32 remainder;
+ int fd;
+
+ memset(sum, 0, MAX_DIGEST_LEN);
+
+ fd = do_open(fname, O_RDONLY, 0);
+ if (fd == -1)
+ return;
+
+ buf = map_file(fd, size, MAX_MAP_SIZE, CSUM_CHUNK);
+
+ if (protocol_version >= 30) {
+ md5_begin(&m);
+
+ for (i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
+ md5_update(&m, (uchar *)map_ptr(buf, i, CSUM_CHUNK),
+ CSUM_CHUNK);
+ }
+
+ remainder = (int32)(len - i);
+ if (remainder > 0)
+ md5_update(&m, (uchar *)map_ptr(buf, i, remainder), remainder);
+
+ md5_result(&m, (uchar *)sum);
+ } else {
+ 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. */
+ remainder = (int32)(len - i);
+ if (remainder > 0 || protocol_version >= 27)
+ mdfour_update(&m, (uchar *)map_ptr(buf, i, remainder), remainder);
+
+ mdfour_result(&m, (uchar *)sum);
+ }
+
+ close(fd);
+ unmap_file(buf);