Use m_temp instead of mutt_mktemp in compress code

This patch remove the static set_path() function which was used only twice.
in:
- mutt_open_read_compressed()
  We just create a temporary file and open it, so this is more secure
  against symlink attacks and then just call decompression cmd normaly
- mutt_open_append_compressed()
  Instead of creating the file if (cond), unlink() it if (!cond).

Signed-off-by: Julien Danjou <julien@danjou.info>
Signed-off-by: Pierre Habouzit <madcoder@debian.org>

diff --git a/lib-mx/compress.c b/lib-mx/compress.c
index 044392e..9e44f34 100644 (file)
--- a/lib-mx/compress.c
+++ b/lib-mx/compress.c
@@ -45,7 +45,7 @@ static int mbox_lock_compressed (CONTEXT * ctx, FILE * fp, int excl, int retry)
     return 0;
   }
 
-  return (r);
+  return r;
 }
 
 static void mbox_unlock_compressed (CONTEXT * ctx, FILE * fp)
@@ -60,7 +60,7 @@ static void mbox_unlock_compressed (CONTEXT * ctx, FILE * fp)
 
 static int is_new (const char *path)
 {
-  return (access (path, W_OK) != 0 && errno == ENOENT) ? 1 : 0;
+  return (access (path, W_OK) && errno == ENOENT);
 }
 
 static const char *find_compress_hook (int type, const char *path)
@@ -113,25 +113,13 @@ static compress_info *set_compress_info (CONTEXT * ctx)
   return (ctx->cinfo = ci);
 }
 
-static void set_path (CONTEXT * ctx)
-{
-  char tmppath[_POSIX_PATH_MAX];
-
-  /* Setup the right paths */
-  ctx->realpath = ctx->path;
-
-  /* Uncompress to /tmp */
-  mutt_mktemp (tmppath);
-  ctx->path = p_dupstr(tmppath, m_strlen(tmppath));
-}
-
 static int get_size (const char *path)
 {
   struct stat sb;
 
   if (stat (path, &sb) != 0)
     return 0;
-  return (sb.st_size);
+  return sb.st_size;
 }
 
 static const char *
@@ -156,7 +144,7 @@ compresshook_format_str(char *dest, ssize_t destlen,
     snprintf (dest, destlen, tmp, ctx->path);
     break;
   }
-  return (src);
+  return src;
 }
 
 /* check that the command has both %f and %t
@@ -181,9 +169,9 @@ int mutt_check_mailbox_compressed (CONTEXT * ctx)
     p_delete(&ctx->realpath);
     mutt_error _("Mailbox was corrupted!");
 
-    return (-1);
+    return -1;
   }
-  return (0);
+  return 0;
 }
 
 int mutt_open_read_compressed (CONTEXT * ctx)
@@ -191,18 +179,34 @@ int mutt_open_read_compressed (CONTEXT * ctx)
   char *cmd;
   FILE *fp;
   int rc;
+  char tmppath[_POSIX_PATH_MAX];
+  int tmpfd;
 
   compress_info *ci = set_compress_info (ctx);
 
   if (!ci->open) {
     ctx->magic = 0;
     p_delete(&ctx->cinfo);
-    return (-1);
+    return -1;
   }
   if (!ci->close || access (ctx->path, W_OK) != 0)
     ctx->readonly = 1;
 
-  set_path (ctx);
+  /* Setup the right paths */
+  ctx->realpath = ctx->path;
+
+  /* Uncompress to /tmp */
+  tmpfd = m_tempfd(tmppath, sizeof(tmppath), NONULL(Tempdir), NULL);
+  /* If we cannot open tempfile, that means the file already exists (!?)
+   * or we are following a symlink, which is bad and insecure.
+   */
+  if(!tmpfd) {
+      return -1;
+  }
+  close(tmpfd);
+  
+  ctx->path = p_dupstr(tmppath, m_strlen(tmppath));
+
   ctx->cinfo->size = get_size(ctx->realpath);
 
   if (!ctx->quiet)
@@ -210,12 +214,12 @@ int mutt_open_read_compressed (CONTEXT * ctx)
 
   cmd = get_compression_cmd (ci->open, ctx);
   if (cmd == NULL)
-    return (-1);
+    return -1;
 
   if ((fp = fopen (ctx->realpath, "r")) == NULL) {
     mutt_perror (ctx->realpath);
     p_delete(&cmd);
-    return (-1);
+    return -1;
   }
   mutt_block_signals ();
   if (mbox_lock_compressed (ctx, fp, 0, 1) == -1) {
@@ -224,7 +228,7 @@ int mutt_open_read_compressed (CONTEXT * ctx)
     mutt_error _("Unable to lock mailbox!");
 
     p_delete(&cmd);
-    return (-1);
+    return -1;
   }
 
   endwin ();
@@ -244,14 +248,14 @@ int mutt_open_read_compressed (CONTEXT * ctx)
   }
   p_delete(&cmd);
   if (rc)
-    return (-1);
+    return -1;
 
   if (mutt_check_mailbox_compressed (ctx))
-    return (-1);
+    return -1;
 
   ctx->magic = mx_get_magic (ctx->path);
 
-  return (0);
+  return 0;
 }
 
 static void restore_path (CONTEXT * ctx)
@@ -271,27 +275,36 @@ int mutt_open_append_compressed (CONTEXT * ctx)
 {
   FILE *fh;
   compress_info *ci = set_compress_info (ctx);
+  char tmppath[_POSIX_PATH_MAX];
 
   if (!get_append_command (ctx->path, ctx)) {
     if (ci->open && ci->close)
-      return (mutt_open_read_compressed (ctx));
+      return mutt_open_read_compressed (ctx);
 
     ctx->magic = 0;
     p_delete(&ctx->cinfo);
-    return (-1);
+    return -1;
   }
 
-  set_path (ctx);
+  /* Setup the right paths */
+  ctx->realpath = ctx->path;
+
+  /* Uncompress to /tmp */
+  fh = m_tempfile(tmppath, sizeof(tmppath), NONULL(Tempdir), NULL);
+  m_fclose(&fh);
+
+  ctx->path = p_dupstr(tmppath, m_strlen(tmppath));
 
   ctx->magic = DefaultMagic;
 
-  if (!is_new (ctx->realpath))
-    if (ctx->magic == M_MBOX || ctx->magic == M_MMDF)
-      if ((fh = safe_fopen (ctx->path, "w")))
-        m_fclose(&fh);
+  if (is_new (ctx->realpath) || 
+      (ctx->magic != M_MBOX &&
+       ctx->magic != M_MMDF))
+      unlink(tmppath);
+
   /* No error checking - the parent function will catch it */
 
-  return (0);
+  return 0;
 }
 
 /* close a compressed mailbox */
@@ -323,12 +336,12 @@ int mutt_sync_compressed (CONTEXT * ctx)
 
   cmd = get_compression_cmd (ctx->cinfo->close, ctx);
   if (cmd == NULL)
-    return (-1);
+    return -1;
 
   if ((fp = fopen (ctx->realpath, "a")) == NULL) {
     mutt_perror (ctx->realpath);
     p_delete(&cmd);
-    return (-1);
+    return -1;
   }
   mutt_block_signals ();
   if (mbox_lock_compressed (ctx, fp, 1, 1) == -1) {
@@ -339,7 +352,7 @@ int mutt_sync_compressed (CONTEXT * ctx)
     ctx->cinfo->size = get_size(ctx->realpath);
 
     p_delete(&cmd);
-    return (-1);
+    return -1;
   }
 
   endwin ();
@@ -362,7 +375,7 @@ int mutt_sync_compressed (CONTEXT * ctx)
 
   ctx->cinfo->size = get_size(ctx->realpath);
 
-  return (rc);
+  return rc;
 }
 
 int mutt_slow_close_compressed (CONTEXT * ctx)
@@ -377,7 +390,7 @@ int mutt_slow_close_compressed (CONTEXT * ctx)
       /* if we can not or should not append, we only have to remove the
          compressed info, because sync was already called */
     mutt_fast_close_compressed (ctx);
-    return (0);
+    return 0;
   }
 
   m_fclose(&ctx->fp);
@@ -391,12 +404,12 @@ int mutt_slow_close_compressed (CONTEXT * ctx)
 
   cmd = get_compression_cmd (append, ctx);
   if (cmd == NULL)
-    return (-1);
+    return -1;
 
   if ((fp = fopen (ctx->realpath, "a")) == NULL) {
     mutt_perror (ctx->realpath);
     p_delete(&cmd);
-    return (-1);
+    return -1;
   }
   mutt_block_signals ();
   if (mbox_lock_compressed (ctx, fp, 1, 1) == -1) {
@@ -405,7 +418,7 @@ int mutt_slow_close_compressed (CONTEXT * ctx)
     mutt_error _("Unable to lock mailbox!");
 
     p_delete(&cmd);
-    return (-1);
+    return -1;
   }
 
   endwin ();
@@ -426,7 +439,7 @@ int mutt_slow_close_compressed (CONTEXT * ctx)
     mbox_unlock_compressed (ctx, fp);
     mutt_unblock_signals ();
     m_fclose(&fp);
-    return (-1);
+    return -1;
   }
 
   mbox_unlock_compressed (ctx, fp);
@@ -437,7 +450,7 @@ int mutt_slow_close_compressed (CONTEXT * ctx)
   p_delete(&cmd);
   p_delete(&ctx->cinfo);
 
-  return (0);
+  return 0;
 }
 
 mx_t const compress_mx = {