X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/7ae359c331afedbab7a9d572cf78495b2bf92dbf..b3bf9b9df95137a3a43248be9599d919b04877af:/checksum.c

diff --git a/checksum.c b/checksum.c
index edc844f2..811b5b60 100644
--- a/checksum.c
+++ b/checksum.c
@@ -1,46 +1,44 @@
-/* 
-   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) 2004-2009 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 3 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, visit the http://fsf.org website.
+ */
 
 #include "rsync.h"
 
-int csum_length=2; /* initial value */
-
-#define CSUM_CHUNK 64
-
-int checksum_seed = 0;
-extern int remote_version;
+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 *buf1,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-4); i+=4) {
-	s2 += 4*(s1 + buf[i]) + 3*buf[i+1] + 2*buf[i+2] + buf[i+3] + 
+	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); 
+	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;
@@ -49,132 +47,177 @@ uint32 get_checksum1(char *buf1,int len)
 }
 
 
-void get_checksum2(char *buf,int len,char *sum)
+void get_checksum2(char *buf, int32 len, char *sum)
 {
-	int i;
-	static char *buf1;
-	static int len1;
-	struct mdfour m;
-
-	if (len > len1) {
-		if (buf1) free(buf1);
-		buf1 = (char *)malloc(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);
-	}
-	if (len - i > 0) {
-		mdfour_update(&m, (uchar *)(buf1+i), (len-i));
+	md_context m;
+
+	if (protocol_version >= 30) {
+		uchar seedbuf[4];
+		md5_begin(&m);
+		md5_update(&m, (uchar *)buf, len);
+		if (checksum_seed) {
+			SIVAL(seedbuf, 0, checksum_seed);
+			md5_update(&m, seedbuf, 4);
+		}
+		md5_result(&m, (uchar *)sum);
+	} else {
+		int32 i;
+		static char *buf1;
+		static int32 len1;
+
+		mdfour_begin(&m);
+
+		if (len > len1) {
+			if (buf1)
+				free(buf1);
+			buf1 = new_array(char, len+4);
+			len1 = len;
+			if (!buf1)
+				out_of_memory("get_checksum2");
+		}
+
+		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);
 	}
-	
-	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)
 {
-	OFF_T i;
 	struct map_struct *buf;
+	OFF_T i, len = size;
+	md_context m;
+	int32 remainder;
 	int fd;
-	OFF_T len = size;
-	char tmpchunk[CSUM_CHUNK];
-	struct mdfour m;
-	
-	memset(sum,0,csum_length);
-	
-	fd = open(fname,O_RDONLY);
-	if (fd == -1) return;
-	
-	buf = map_file(fd,size);
-	
-	mdfour_begin(&m);
-
-	for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
-		memcpy(tmpchunk, map_ptr(buf,i,CSUM_CHUNK), CSUM_CHUNK);
-		mdfour_update(&m, (uchar *)tmpchunk, CSUM_CHUNK);
-	}
 
-	if (len - i > 0) {
-		memcpy(tmpchunk, map_ptr(buf,i,len-i), len-i);
-		mdfour_update(&m, (uchar *)tmpchunk, (len-i));
-	}
+	memset(sum, 0, MAX_DIGEST_LEN);
 
-	mdfour_result(&m, (uchar *)sum);
+	fd = do_open(fname, O_RDONLY, 0);
+	if (fd == -1)
+		return;
 
-	close(fd);
-	unmap_file(buf);
-}
+	buf = map_file(fd, size, MAX_MAP_SIZE, CSUM_CHUNK);
 
+	if (protocol_version >= 30) {
+		md5_begin(&m);
 
-void checksum_init(void)
-{
-  if (remote_version >= 14)
-    csum_length = 2; /* adaptive */
-  else
-    csum_length = SUM_LENGTH;
-}
+		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);
+}
 
-static int sumresidue;
-static char sumrbuf[CSUM_CHUNK];
-static struct mdfour md;
+static int32 sumresidue;
+static md_context md;
 
-void sum_init(void)
+void sum_init(int seed)
 {
 	char s[4];
-	mdfour_begin(&md);
-	sumresidue=0;
-	SIVAL(s,0,checksum_seed);
-	sum_update(s,4);
+
+	if (protocol_version >= 30)
+		md5_begin(&md);
+	else {
+		mdfour_begin(&md);
+		sumresidue = 0;
+		SIVAL(s, 0, seed);
+		sum_update(s, 4);
+	}
 }
 
-void sum_update(char *p,int len)
+/**
+ * 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(const char *p, int32 len)
 {
-	int i;
+	if (protocol_version >= 30) {
+		md5_update(&md, (uchar *)p, len);
+		return;
+	}
+
 	if (len + sumresidue < CSUM_CHUNK) {
-		memcpy(sumrbuf+sumresidue, p, len);
+		memcpy(md.buffer + sumresidue, p, len);
 		sumresidue += len;
 		return;
 	}
 
 	if (sumresidue) {
-		i = MIN(CSUM_CHUNK-sumresidue,len);
-		memcpy(sumrbuf+sumresidue,p,i);
-		mdfour_update(&md, (uchar *)sumrbuf, (i+sumresidue));
+		int32 i = CSUM_CHUNK - sumresidue;
+		memcpy(md.buffer + sumresidue, p, i);
+		mdfour_update(&md, (uchar *)md.buffer, CSUM_CHUNK);
 		len -= i;
 		p += i;
 	}
 
-	for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
-		memcpy(sumrbuf,p+i,CSUM_CHUNK);
-		mdfour_update(&md, (uchar *)sumrbuf, CSUM_CHUNK);
+	while (len >= CSUM_CHUNK) {
+		mdfour_update(&md, (uchar *)p, CSUM_CHUNK);
+		len -= CSUM_CHUNK;
+		p += CSUM_CHUNK;
 	}
 
-	if (len - i > 0) {
-		sumresidue = len-i;
-		memcpy(sumrbuf,p+i,sumresidue);
-	} else {
-		sumresidue = 0;    
-	}
+	sumresidue = len;
+	if (sumresidue)
+		memcpy(md.buffer, p, sumresidue);
 }
 
-void sum_end(char *sum)
+int sum_end(char *sum)
 {
-	if (sumresidue) {
-		mdfour_update(&md, (uchar *)sumrbuf, sumresidue);
+	if (protocol_version >= 30) {
+		md5_result(&md, (uchar *)sum);
+		return MD5_DIGEST_LEN;
 	}
 
+	if (sumresidue || protocol_version >= 27)
+		mdfour_update(&md, (uchar *)md.buffer, sumresidue);
+
 	mdfour_result(&md, (uchar *)sum);
+
+	return MD4_DIGEST_LEN;
 }