Usage: ./ssh_scan_keys.py /home /export/home

ssh_scan_keys.py

#!/usr/bin/env python
# coding: utf-8
# vim: set ts=4 sts=4 sw=4 si ai et ft=python:
# author: Paul Tötterman <[email protected]>
#
# Copyright (c) 2013, ZenRobotics Ltd.
#
# Permission to use, copy, modify, and/or 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.

"""Scan for unencrypted SSH private keys."""


import os
import socket
import stat
import sys


HEADER = '-----BEGIN RSA PRIVATE KEY-----'
HOSTNAME = socket.gethostname()


def is_encrypted(filename):
    """Return true if the file contains an encrypted SSH private key."""
    with open(filename, 'rb') as infile:
        lines = infile.readlines()
        enc_lines = [line for line in lines if 'ENCRYPTED' in line]
        return bool(enc_lines)


def detect_rsa_pem(filename):
    """Return true if the file beings with a RSA private key header."""
    with open(filename, 'rb') as infile:
        start = infile.read(len(HEADER))
        if start == HEADER:
            return True
    return False


def main(args):
    """Main function."""
    for path in args[1:]:
        for root, _, files in os.walk(path):
            for filename in files:
                try:
                    abspath = os.path.join(root, filename)

                    if os.path.islink(abspath):
                        continue

                    mode = os.stat(abspath).st_mode
                    if not stat.S_ISREG(mode):
                        continue

                    if detect_rsa_pem(abspath):
                        if not is_encrypted(abspath):
                            print 'Unencrypted rsa pem file: %s:%s' % (HOSTNAME,
                                                                       abspath)
                except IOError:
                    continue


if __name__ == '__main__':
    main(sys.argv)