Fail if /etc/doas.conf is g+w or o+w or is not owned by root. ok tedu

diff --git a/doas.c b/doas.c
index ec727df3931c02d2dac84efa3cf0c5aa6111c31e..47ae35ada88b03cd7aec9ba31d4599f256327a8b 100644 (file)
--- a/doas.c
+++ b/doas.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: doas.c,v 1.4 2015/07/16 21:57:54 deraadt Exp $ */
+/* $OpenBSD: doas.c,v 1.5 2015/07/16 22:11:01 nicm Exp $ */
 /*
  * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
  *
@@ -14,7 +14,9 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
+
 #include <sys/types.h>
+#include <sys/stat.h>
 
 #include <limits.h>
 #include <login_cap.h>
@@ -139,12 +141,21 @@ parseconfig(const char *filename)
 {
        extern FILE *yyfp;
        extern int yyparse(void);
+       struct stat sb;
 
        yyfp = fopen(filename, "r");
        if (!yyfp) {
                fprintf(stderr, "doas is not enabled.\n");
                exit(1);
        }
+
+       if (fstat(fileno(yyfp), &sb) != 0)
+               err(1, "fstat(\"%s\")", filename);
+       if ((sb.st_mode & (S_IWGRP|S_IWOTH)) != 0)
+               errx(1, "%s is writable by group or other", filename);
+       if (sb.st_uid != 0)
+               errx(1, "%s is not owned by root", filename);
+
        yyparse();
        fclose(yyfp);
 }