Adding some debug strings for cab parsing that existed in 0.99.2. Adding code that sterilizes garbage data that is read in as a string so it is not output to stderr when --debug is enabled.

8 years ago · 8dbf92a40f
parent b2f59861ee
commit 8dbf92a40f
2 changed files with 81 additions and 20 deletions
--- a/libclamav/libmspack-0.5alpha/mspack/cabd.c
+++ b/libclamav/libmspack-0.5alpha/mspack/cabd.c
@ -24,6 +24,7 @@
 #include <system.h>
 #include <cab.h>
 #include <assert.h>
+#include <ctype.h>

 /* Notes on compliance with cabinet specification:
 *
@ -295,6 +296,33 @@ static void cabd_close(struct mscab_decompressor *base,
  }
 }

+static int cab_chkname(
+           struct mspack_system *sys,
+           char *name,
+           int san)
+{
+  size_t i, len = 0;
+
+  if (NULL == sys || NULL == name) return 1;
+
+  len = strlen(name);
+
+  for (i = 0; i < len; i++)
+  {
+    if (!san && (strchr("%/*?|\\\"+=<>;:\t ", name[i]) || !isascii(name[i])))
+    {
+      sys->message(NULL, "cab_chkname: File name contains disallowed characters");
+      return 1;
+    }
+    else if (san && !isalnum(name[i]))
+    {
+      name[i] = '*';
+    }
+  }
+
+  return 0;
+}
+
 /***************************************
 * CABD_READ_HEADERS
 ***************************************
@ -307,7 +335,7 @@ static int cabd_read_headers(struct mspack_system *sys,
 			     struct mscabd_cabinet_p *cab,
 			     off_t offset, int quiet)
 {
-  unsigned int num_folders, num_files, folder_resv, i, x;
+  unsigned int num_folders, num_files, folder_resv, i, x, fidx;
  int read_string_errno = 0;
  struct mscabd_folder_p *fol, *linkfol = NULL;
  struct mscabd_file *file, *linkfile = NULL;
@ -392,14 +420,30 @@ static int cabd_read_headers(struct mspack_system *sys,
  /* read name and info of preceeding cabinet in set, if present */
  if (cab->base.flags & cfheadPREV_CABINET) {
    cab->base.prevname = cabd_read_string(sys, fh, &read_string_errno); if (read_string_errno) return read_string_errno;
+    if(cab_chkname(sys, cab->base.prevname, 0))
+        sys->message(NULL, "CAB: Invalid name of preceding cabinet");
+    else
+        sys->message(NULL, "CAB: Preceding cabinet name: %s", cab->base.prevname);
    cab->base.previnfo = cabd_read_string(sys, fh, &read_string_errno); if (read_string_errno) return read_string_errno;
+    if(cab_chkname(sys, cab->base.previnfo, 0))
+        sys->message(NULL, "CAB: Invalid info of preceding cabinet");
+    else
+        sys->message(NULL, "CAB: Preceding cabinet info: %s", cab->base.previnfo);
  }

  /* read name and info of next cabinet in set, if present */
  if (cab->base.flags & cfheadNEXT_CABINET) {
    cab->base.nextname = cabd_read_string(sys, fh, &read_string_errno); if (read_string_errno) return read_string_errno;
+    if(cab_chkname(sys, cab->base.nextname, 0))
+        sys->message(NULL, "CAB: Invalid name of next cabinet");
+    else
+        sys->message(NULL, "CAB: Next cabinet name: %s", cab->base.nextname);
    cab->base.nextinfo = cabd_read_string(sys, fh, &read_string_errno); if (read_string_errno) return read_string_errno;
-  }
+    if(cab_chkname(sys, cab->base.nextinfo, 0))
+        sys->message(NULL, "CAB: Invalid info of next cabinet");
+    else
+        sys->message(NULL, "CAB: Next cabinet info: %s", cab->base.nextinfo);
+}

  /* read folders */
  for (i = 0; i < num_folders; i++) {
@ -448,25 +492,24 @@ static int cabd_read_headers(struct mspack_system *sys,
    file->offset   = EndGetI32(&buf[cffile_FolderOffset]);

    /* set folder pointer */
-    x = EndGetI16(&buf[cffile_FolderIndex]);
-    if (x < num_folders) {
+    fidx = EndGetI16(&buf[cffile_FolderIndex]);
+    if (fidx < num_folders) {
      /* normal folder index; count up to the correct folder. the folder
       * pointer will be NULL if folder index is invalid */
      struct mscabd_folder *ifol = cab->base.folders; 
-      while (x--) if (ifol) ifol = ifol->next;
+      while (fidx--) if (ifol) ifol = ifol->next;
      file->folder = ifol;

      if (!ifol) {
 	sys->free(file);
-	sys->message(NULL, "invalid folder index: %d", x);
+	sys->message(NULL, "invalid folder index: %d", fidx);
 	return MSPACK_ERR_DATAFORMAT;
      }
    }
-    else if (x >= cffileCONTINUED_FROM_PREV) {
+    else if (fidx >= cffileCONTINUED_FROM_PREV) {
      /* either CONTINUED_TO_NEXT, CONTINUED_FROM_PREV or
       * CONTINUED_PREV_AND_NEXT */
-      if ((x == cffileCONTINUED_TO_NEXT) ||
-	  (x == cffileCONTINUED_PREV_AND_NEXT))
+      if ((fidx == cffileCONTINUED_TO_NEXT) || (fidx == cffileCONTINUED_PREV_AND_NEXT))
      {
 	/* get last folder */
 	struct mscabd_folder *ifol = cab->base.folders;
@ -478,8 +521,7 @@ static int cabd_read_headers(struct mspack_system *sys,
 	if (!fol->merge_next) fol->merge_next = file;
      }

-      if ((x == cffileCONTINUED_FROM_PREV) ||
-	  (x == cffileCONTINUED_PREV_AND_NEXT))
+      if ((fidx == cffileCONTINUED_FROM_PREV) || (fidx == cffileCONTINUED_PREV_AND_NEXT))
      {
 	/* get first folder */
 	file->folder = cab->base.folders;
@ -493,7 +535,7 @@ static int cabd_read_headers(struct mspack_system *sys,
      /* unexpected/invalid folder index */
      file->folder = NULL;
      sys->message(fh, "WARNING; cab header file %d of %d has invalid folder index (%d out of %d folders)", 
-        i + 1, num_files, x, num_folders);
+        i + 1, num_files, fidx, num_folders);
    }

    /* get time */
@ -515,8 +557,29 @@ static int cabd_read_headers(struct mspack_system *sys,
        file->filename = NULL;
        sys->message(fh, "WARNING; cab header file %d of %d has invalid filename", i + 1, num_files);
    }
+
+    /* sanitize the name, incase it contains invalid characters */
+	  cab_chkname(sys, file->filename, 1);
    
    if (file->folder && !read_string_errno) {
+        sys->message(NULL, "CAB: File record %u", i);
+        sys->message(NULL, "CAB: File name: %s", file->filename);
+        sys->message(NULL, "CAB: File offset: %u", (unsigned int) file->offset);
+        sys->message(NULL, "CAB: File folder index: %u", fidx);
+        sys->message(NULL, "CAB: File attribs: 0x%x", file->attribs);
+        if(file->attribs & 0x01)
+            sys->message(NULL, "CAB:   * file is read-only");
+        if(file->attribs & 0x02)
+            sys->message(NULL, "CAB:   * file is hidden");
+        if(file->attribs & 0x04)
+            sys->message(NULL, "CAB:   * file is a system file");
+        if(file->attribs & 0x20)
+            sys->message(NULL, "CAB:   * file modified since last backup");
+        if(file->attribs & 0x40)
+            sys->message(NULL, "CAB:   * file to be run after extraction");
+        if(file->attribs & 0x80)
+            sys->message(NULL, "CAB:   * file name contains UTF");
+    
        /* link file entry into file list */
        if (!linkfile) cab->base.files = file;
        else linkfile->next = file;
@ -529,7 +592,7 @@ static int cabd_read_headers(struct mspack_system *sys,
          file->filename = NULL;
        }
        sys->free(file);
-        sys->message(fh, "WARNING; omitting file %d of %d from file list", i, num_files);
+        sys->message(fh, "WARNING; omitting file %d of %d from file list.", i, num_files);
    }
  }

--- a/libclamav/libmspack.c
+++ b/libclamav/libmspack.c
@ -9,6 +9,7 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <stdarg.h>
+#include <stdio.h>

 #include <mspack.h>

@ -17,9 +18,6 @@
 #include "scanners.h"
 #include "others.h"

-#define DBG_PREFIX "LibClamAV debug: "
-#define DBG_BUFSIZ 1024
-
 enum mspack_type {
 	FILETYPE_DUNNO,
 	FILETYPE_FMAP,
@ -274,13 +272,13 @@ static void mspack_fmap_message(struct mspack_file *file, const char *fmt, ...)

 	if (UNLIKELY(cli_debug_flag)) {
 		va_list args;
-		char buff[DBG_BUFSIZ];
-		size_t len = sizeof(DBG_PREFIX) - 1;	
+		char buff[BUFSIZ];
+		size_t len = sizeof("LibClamAV debug: ") - 1;

-		memset(buff, 0, DBG_BUFSIZ);
+		memset(buff, 0, BUFSIZ);
 	
 		/* Add the prefix */
-		strncpy(buff, DBG_PREFIX, len);
+		strncpy(buff, "LibClamAV debug: ", len);
 		
 		va_start(args, fmt);
 		vsnprintf(buff + len, sizeof(buff) - len - 2, fmt, args);