[PATCH 08/18] insert: check folder name

[Peter Wang]

Don't accept folder names containing a ".." component,
to prevent writing outside of the maildir.
---
 notmuch-insert.c |   20 ++++++++++++++++++++
 1 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/notmuch-insert.c b/notmuch-insert.c
index 6398618..ee51a87 100644
--- a/notmuch-insert.c
+++ b/notmuch-insert.c
@@ -25,6 +25,22 @@
 #include <fcntl.h>
 
 static notmuch_bool_t
+check_folder_name (const char *folder)
+{
+    const char *p = folder;
+
+    /* Check ".." appears nowhere in the folder name. */
+    for (;;) {
+	if ((p[0] == '.') && (p[1] == '.') && (p[2] == '\0' || p[2] == '/'))
+	    return FALSE;
+	p = strchr (p, '/');
+	if (!p)
+	    return TRUE;
+	p++;
+    }
+}
+
+static notmuch_bool_t
 safe_gethostname (char *hostname, size_t hostname_size)
 {
     if (gethostname (hostname, hostname_size) == -1) {
@@ -232,6 +248,10 @@ notmuch_insert_command (void *ctx, int argc, char *argv[])
     db_path = notmuch_config_get_database_path (config);
 
     if (folder != NULL) {
+	if (! check_folder_name (folder)) {
+	    fprintf (stderr, "Error: bad folder name: %s\n", folder);
+	    return 1;
+	}
 	maildir = talloc_asprintf (ctx, "%s/%s", db_path, folder);
     } else {
 	maildir = talloc_asprintf (ctx, "%s", db_path);
-- 
1.7.4.4