improve handling of archives with unusual headers

git-svn: trunk@2593

clamav-devel/ChangeLog

@@ -1,3 +1,7 @@
+Sun Jan  7 01:24:21 CET 2007 (tk)
+---------------------------------
+  * libclamav/unzip.c: improve handling of archives with unusual headers
+
 Sat Jan  6 17:45:49 CET 2007 (tk)
 ---------------------------------
   * clamd: s/DetectPhishing/PhishingSignatures

clamav-devel/libclamav/unzip.c

@@ -168,14 +168,15 @@ int __zip_find_disk_trailer(int fd, off_t filesize, struct zip_disk_trailer *tra
 int __zip_parse_root_directory(int fd, struct zip_disk_trailer *trailer, zip_dir_hdr **hdr_return, off_t start)
 {
 	struct zip_root_dirent dirent, *d;
-	zip_dir_hdr *hdr, *hdr0;
+	zip_dir_hdr *hdr, *hdr0, *prev_hdr;
 	uint16_t *p_reclen = NULL, entries;
 	uint32_t offset;
 	struct stat sb;
 	uint16_t u_entries  = EC16(trailer->z_entries);   
 	uint32_t u_rootsize = EC32(trailer->z_rootsize);  
 	uint32_t u_rootseek = EC32(trailer->z_rootseek) + start;
-        uint16_t u_extras, u_comment, u_namlen, u_flags;
+	uint16_t u_extras, u_comment, u_namlen, u_flags;
+	uint8_t clone_entry;
 	char *pt;
 
 
@@ -196,6 +197,8 @@ int __zip_parse_root_directory(int fd, struct zip_disk_trailer *trailer, zip_dir
     hdr = hdr0;
 
     for(entries = u_entries, offset = 0; entries > 0; entries--) {
+	clone_entry = 0;
+
 	if(lseek(fd, u_rootseek + offset, SEEK_SET) < 0) {
 	    free(hdr0);
 	    cli_errmsg("Unzip: __zip_parse_root_directory: Can't lseek descriptor %d\n", fd);
@@ -244,6 +247,7 @@ int __zip_parse_root_directory(int fd, struct zip_disk_trailer *trailer, zip_dir
 	    cli_dbgmsg("Unzip: __zip_parse_root_directory: File claims to be deflated but csize == usize\n");
 	    cli_dbgmsg("Unzip: __zip_parse_root_directory: Assuming method 'stored'\n");
 	    hdr->d_compr = 0;
+	    clone_entry = 1;
 	}
 
 	hdr->d_flags = u_flags;
@@ -274,7 +278,20 @@ int __zip_parse_root_directory(int fd, struct zip_disk_trailer *trailer, zip_dir
 	hdr->d_reclen = (uint16_t) (pt - (char *) hdr);
 	p_reclen = &hdr->d_reclen;
 
+	prev_hdr = hdr;
 	hdr = (zip_dir_hdr *) ((char *) hdr + hdr->d_reclen);
+
+	if(clone_entry) {
+	    hdr0 = (zip_dir_hdr *) cli_realloc(hdr0, u_rootsize + *p_reclen);
+	    if(!hdr0)
+		return CL_EMEM;
+	    memcpy((zip_dir_hdr *) hdr, (zip_dir_hdr *) prev_hdr, *p_reclen);
+	    hdr->d_compr = 8;
+	    if(u_namlen)
+		hdr->d_name[strlen(hdr->d_name) - 1]++;
+	    p_reclen = &hdr->d_reclen;
+	    hdr = (zip_dir_hdr *) ((char *) hdr + hdr->d_reclen);
+	}
     }
 
     if(p_reclen) {