1 files changed, 86 insertions, 0 deletions
diff --git a/lib/util/secure_path.c b/lib/util/secure_path.c
new file mode 100644
index 0000000..b1d4415
--- /dev/null
+++ b/lib/util/secure_path.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2012, 2014-2016 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdio.h>
+#ifdef HAVE_STRING_H
+# include <string.h>
+#endif /* HAVE_STRING_H */
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif /* HAVE_STRINGS_H */
+#include <unistd.h>
+#include <errno.h>
+
+#include "sudo_compat.h"
+#include "sudo_util.h"
+#include "sudo_debug.h"
+
+/*
+ * Verify that path is the right type and not writable by other users.
+ */
+static int
+sudo_secure_path(const char *path, unsigned int type, uid_t uid, gid_t gid, struct stat *sbp)
+{
+    struct stat sb;
+    int ret = SUDO_PATH_MISSING;
+    debug_decl(sudo_secure_path, SUDO_DEBUG_UTIL)
+
+    if (path != NULL && stat(path, &sb) == 0) {
+	if ((sb.st_mode & _S_IFMT) != type) {
+	    ret = SUDO_PATH_BAD_TYPE;
+	} else if (uid != (uid_t)-1 && sb.st_uid != uid) {
+	    ret = SUDO_PATH_WRONG_OWNER;
+	} else if (sb.st_mode & S_IWOTH) {
+	    ret = SUDO_PATH_WORLD_WRITABLE;
+	} else if (ISSET(sb.st_mode, S_IWGRP) &&
+	    (gid == (gid_t)-1 || sb.st_gid != gid)) {
+	    ret = SUDO_PATH_GROUP_WRITABLE;
+	} else {
+	    ret = SUDO_PATH_SECURE;
+	}
+	if (sbp)
+	    (void) memcpy(sbp, &sb, sizeof(struct stat));
+    }
+
+    debug_return_int(ret);
+}
+
+/*
+ * Verify that path is a regular file and not writable by other users.
+ */
+int
+sudo_secure_file_v1(const char *path, uid_t uid, gid_t gid, struct stat *sbp)
+{
+    return sudo_secure_path(path, _S_IFREG, uid, gid, sbp);
+}
+
+/*
+ * Verify that path is a directory and not writable by other users.
+ */
+int
+sudo_secure_dir_v1(const char *path, uid_t uid, gid_t gid, struct stat *sbp)
+{
+    return sudo_secure_path(path, _S_IFDIR, uid, gid, sbp);
+}