[gq-commit] gq/src configfile.c,1.26,1.27

[<sta...@us...>]

Update of /cvsroot/gqclient/gq/src
In directory usw-pr-cvs1:/tmp/cvs-serv2484

Modified Files:
	configfile.c 
Log Message:
* Fixed a potential buffer overflow situation as indicated by an original
  source comment of Bert
* Modified saving of the condiguration to be robust against problems during 
  writing of the configuration (write to .gq.new, rename .gq.new to .gq).
  Might need add'l changes to catch all i/o related errors.


Index: configfile.c
===================================================================
RCS file: /cvsroot/gqclient/gq/src/configfile.c,v
retrieving revision 1.26
retrieving revision 1.27
diff -C2 -d -r1.26 -r1.27
*** configfile.c	23 Jul 2002 13:50:06 -0000	1.26
--- configfile.c	18 Sep 2002 09:42:13 -0000	1.27
***************
*** 627,634 ****
  }
  
! 
! char *filename_config(int context)
  {
!      static char rcpath[128];
       char *home;
  
--- 627,636 ----
  }
  
! /* filename_config returns the name of the config file. The returned
!    pointer must g_free'd. */
! gchar *filename_config(int context)
  {
!      gchar *rcpath = NULL;
! /*       static char rcpath[128]; */
       char *home;
  
***************
*** 639,643 ****
       }
  
!      snprintf(rcpath, sizeof(rcpath), "%s/%s", home, RCFILE);
       free(home);
  
--- 641,648 ----
       }
  
!      /* need add'l "/", thus add some extra chars */
!      rcpath = g_malloc(strlen(home) + strlen(RCFILE) + 3);
! 
!      sprintf(rcpath, "%s/%s", home, RCFILE);
       free(home);
  
***************
*** 668,684 ****
  	  config.config_version = CURRENT_CONFIG_VERSION;
  	  config.asked_version = CURRENT_CONFIG_VERSION;
  	  return;
       }
  
       /* refuse to read config file if world readable (bind passwords) */
!      if( (sfile.st_mode & ~S_IFMT) != 00600 ) {
  	  snprintf(errstr, sizeof(errstr), 
! 		   _("%s is group and/or world readable.\n"
  		     "This file can contain passwords in cleartext,\n"
! 		     "and should be mode 0600.\n\n"
  		     "Continuing with default settings...\n"),
  		   rcpath);
  	  error_push(load_context, errstr);
  	  error_flush(load_context);
  	  return;
       }
--- 673,691 ----
  	  config.config_version = CURRENT_CONFIG_VERSION;
  	  config.asked_version = CURRENT_CONFIG_VERSION;
+ 	  g_free(rcpath);
  	  return;
       }
  
       /* refuse to read config file if world readable (bind passwords) */
!      if( ((sfile.st_mode & ~S_IFMT) & (S_IRWXG|S_IRWXO)) != 0 ) {
  	  snprintf(errstr, sizeof(errstr), 
! 		   _("%s is group and/or world readable or writeable.\n"
  		     "This file can contain passwords in cleartext,\n"
! 		     "and is recommended to have mode 0600.\n\n"
  		     "Continuing with default settings...\n"),
  		   rcpath);
  	  error_push(load_context, errstr);
  	  error_flush(load_context);
+ 	  g_free(rcpath);
  	  return;
       }
***************
*** 691,694 ****
--- 698,702 ----
  	  fclose(rcfd);
       }
+      g_free(rcpath);
  
       process_rcfile(rcfile);
***************
*** 737,759 ****
  void config_write_string(struct writeconfig *wc, char *value, char *entity)
  {
!      int i, p;
!      char outstr[1024];
! 
!      snprintf(outstr, sizeof(outstr), "<%s>", entity);
  
       /* quick-and-dirty escape < and > */
       for(i = 0; value[i]; i++) {
  	  if(value[i] == '<' || value[i] == '>') {
! 	       strcat(outstr, "\\"); /* FIXME: Buffer overflow probs  */
  	  }
! 	  p = strlen(outstr);
! 	  outstr[p++] = value[i];
! 	  outstr[p] = '\0';
       }
  
!      strcat(outstr, "</");
!      strcat(outstr, entity);
!      strcat(outstr, ">\n");
!      config_write(wc, outstr);
  }
  
--- 745,764 ----
  void config_write_string(struct writeconfig *wc, char *value, char *entity)
  {
!      int i;
!      GString *outstr = g_string_sized_new(1024);
!      g_string_sprintf(outstr, "<%s>", entity);
  
       /* quick-and-dirty escape < and > */
       for(i = 0; value[i]; i++) {
  	  if(value[i] == '<' || value[i] == '>') {
! 	       g_string_append(outstr, "\\");
  	  }
! 	  g_string_append_c(outstr, value[i]);
       }
  
!      g_string_append(outstr, "</");
!      g_string_append(outstr, entity);
!      g_string_append(outstr, ">\n");
!      config_write(wc, outstr->str);
  }
  
***************
*** 776,780 ****
       struct writeconfig *wc;
       int write_context;
!      char *rcpath, errstr[256];
  
       write_context = error_new_context(_("Error writing configfile"));
--- 781,788 ----
       struct writeconfig *wc;
       int write_context;
!      char *rcpath, errstr[1024];
!      char *tmprcpath;
!      struct stat sfile;
!      int mode = S_IRUSR|S_IWUSR;
  
       write_context = error_new_context(_("Error writing configfile"));
***************
*** 796,801 ****
  	  return;
       }
  
!      wc->outfile = fopen(rcpath, "w");
       if(!wc->outfile) {
  	  snprintf(errstr, sizeof(errstr), 
--- 804,819 ----
  	  return;
       }
+      /* write to temp file... */
+      tmprcpath = g_malloc(strlen(rcpath) + 10);
+      strcpy(tmprcpath, rcpath);
+      strcat(tmprcpath, ".new");
+ 
+      /* check mode of original file. Do not overwrite without write
+         permission. */
+      if(stat(rcpath, &sfile) == 0) {
+ 	  mode = sfile.st_mode & (S_IRUSR|S_IWUSR);
+      }
  
!      wc->outfile = fopen(tmprcpath, "w");
       if(!wc->outfile) {
  	  snprintf(errstr, sizeof(errstr), 
***************
*** 804,810 ****
  	  error_push(write_context, errstr);
  	  error_flush(write_context);
  	  return;
       }
!      fchmod(fileno(wc->outfile), S_IRUSR|S_IWUSR);
  
       config_write(wc, "<?xml version=\"1.0\" standalone=\"yes\"?>\n");
--- 822,830 ----
  	  error_push(write_context, errstr);
  	  error_flush(write_context);
+ 	  g_free(tmprcpath);
+ 	  g_free(rcpath);
  	  return;
       }
!      fchmod(fileno(wc->outfile), mode);
  
       config_write(wc, "<?xml version=\"1.0\" standalone=\"yes\"?>\n");
***************
*** 927,932 ****
--- 947,968 ----
       FREE(wc, "struct writeconfig");
  
+      /* rename temp to final config file */
+ 
+      if (rename(tmprcpath, rcpath) != 0) {
+ 	  snprintf(errstr, sizeof(errstr), 
+ 		   _("Could not replace old configuration (%s) with the new one (%s):\n%s\n"), rcpath, tmprcpath,
+ 		   strerror(errno));
+ 	  error_push(write_context, errstr);
+ 	  error_flush(write_context);
+ 	  
+ 	  g_free(tmprcpath);
+ 	  g_free(rcpath);
+ 	  return;
+      }
+ 
       error_flush(write_context);
  
+      g_free(tmprcpath);
+      g_free(rcpath);
  }