- djm@cvs.openbsd.org 2010/01/13 23:47:26

     [auth.c]
     when using ChrootDirectory, make sure we test for the existence of the
     user's shell inside the chroot; bz #1679, patch from alex AT rtfs.hu;
     ok dtucker

1 files changed, 23 insertions, 3 deletions

diff --git a/auth.c b/auth.c
index 3dc116907..da87807a8 100644
--- a/auth.c
+++ b/auth.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth.c,v 1.82 2010/01/13 00:19:04 dtucker Exp $ */
+/* $OpenBSD: auth.c,v 1.83 2010/01/13 23:47:26 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -95,7 +95,7 @@ allowed_user(struct passwd * pw)
 {
 	struct stat st;
 	const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL;
-	char *shell;
+	char *shell, *tmp, *chroot_path;
 	u_int i;
 #ifdef USE_SHADOW
 	struct spwd *spw = NULL;
@@ -156,20 +156,40 @@ allowed_user(struct passwd * pw)
 	 * Get the shell from the password data.  An empty shell field is
 	 * legal, and means /bin/sh.
 	 */
-	shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
+	shell = xstrdup((pw->pw_shell[0] == '\0') ?
+	    _PATH_BSHELL : pw->pw_shell);
+
+	/*
+	 * Amend shell if chroot is requested.
+	 */
+	if (options.chroot_directory != NULL &&
+	    strcasecmp(options.chroot_directory, "none") != 0) {
+		tmp = tilde_expand_filename(options.chroot_directory,
+		    pw->pw_uid);
+		chroot_path = percent_expand(tmp, "h", pw->pw_dir,
+		    "u", pw->pw_name, (char *)NULL);
+		xfree(tmp);
+		xasprintf(&tmp, "%s/%s", chroot_path, shell);
+		xfree(shell);
+		shell = tmp;
+		free(chroot_path);
+	}
 
 	/* deny if shell does not exists or is not executable */
 	if (stat(shell, &st) != 0) {
 		logit("User %.100s not allowed because shell %.100s does not exist",
 		    pw->pw_name, shell);
+		xfree(shell);
 		return 0;
 	}
 	if (S_ISREG(st.st_mode) == 0 ||
 	    (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) {
 		logit("User %.100s not allowed because shell %.100s is not executable",
 		    pw->pw_name, shell);
+		xfree(shell);
 		return 0;
 	}
+	xfree(shell);
 
 	if (options.num_deny_users > 0 || options.num_allow_users > 0 ||
 	    options.num_deny_groups > 0 || options.num_allow_groups > 0) {