1 files changed, 146 insertions, 0 deletions
diff --git a/lib/libpam/openpam_check_owner_perms.c b/lib/libpam/openpam_check_owner_perms.c
new file mode 100644
index 0000000..d3b2ca9
--- /dev/null
+++ b/lib/libpam/openpam_check_owner_perms.c
@@ -0,0 +1,146 @@
+/*-
+ * Copyright (c) 2011 Dag-Erling Smørgrav
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer
+ *    in this position and unchanged.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $Id: openpam_check_owner_perms.c 543 2012-03-31 22:11:34Z des $
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <security/pam_appl.h>
+
+#include "openpam_impl.h"
+
+/*
+ * OpenPAM internal
+ *
+ * Verify that the file or directory referenced by the given descriptor is
+ * owned by either root or the arbitrator and that it is not writable by
+ * group or other.
+ */
+
+int
+openpam_check_desc_owner_perms(const char *name, int fd)
+{
+	uid_t root, arbitrator;
+	struct stat sb;
+	int serrno;
+
+	root = 0;
+	arbitrator = geteuid();
+	if (fstat(fd, &sb) != 0) {
+		serrno = errno;
+		openpam_log(PAM_LOG_ERROR, "%s: %m", name);
+		errno = serrno;
+		return (-1);
+	}
+	if (!S_ISREG(sb.st_mode)) {
+		openpam_log(PAM_LOG_ERROR,
+		    "%s: not a regular file", name);
+		errno = EINVAL;
+		return (-1);
+	}
+	if ((sb.st_uid != root && sb.st_uid != arbitrator) ||
+	    (sb.st_mode & (S_IWGRP|S_IWOTH)) != 0) {
+		openpam_log(PAM_LOG_ERROR,
+		    "%s: insecure ownership or permissions", name);
+		errno = EPERM;
+		return (-1);
+	}
+	return (0);
+}
+
+/*
+ * OpenPAM internal
+ *
+ * Verify that a file or directory and all components of the path leading
+ * up to it are owned by either root or the arbitrator and that they are
+ * not writable by group or other.
+ *
+ * Note that openpam_check_desc_owner_perms() should be used instead if
+ * possible to avoid a race between the ownership / permission check and
+ * the actual open().
+ */
+
+int
+openpam_check_path_owner_perms(const char *path)
+{
+	uid_t root, arbitrator;
+	char pathbuf[PATH_MAX];
+	struct stat sb;
+	int len, serrno, tip;
+
+	tip = 1;
+	root = 0;
+	arbitrator = geteuid();
+	if (realpath(path, pathbuf) == NULL)
+		return (-1);
+	len = strlen(pathbuf);
+	while (len > 0) {
+		if (stat(pathbuf, &sb) != 0) {
+			if (errno != ENOENT) {
+				serrno = errno;
+				openpam_log(PAM_LOG_ERROR, "%s: %m", pathbuf);
+				errno = serrno;
+			}
+			return (-1);
+		}
+		if (tip && !S_ISREG(sb.st_mode)) {
+			openpam_log(PAM_LOG_ERROR,
+			    "%s: not a regular file", pathbuf);
+			errno = EINVAL;
+			return (-1);
+		}
+		if ((sb.st_uid != root && sb.st_uid != arbitrator) ||
+		    (sb.st_mode & (S_IWGRP|S_IWOTH)) != 0) {
+			openpam_log(PAM_LOG_ERROR,
+			    "%s: insecure ownership or permissions", pathbuf);
+			errno = EPERM;
+			return (-1);
+		}
+		while (--len > 0 && pathbuf[len] != '/')
+			pathbuf[len] = '\0';
+		tip = 0;
+	}
+	return (0);
+}
+
+/*
+ * NOPARSE
+ */