File Content: cc_ssh_authkey_fingerprints.py # Copyright (C) 2012 Yahoo! Inc. # # Author: Joshua Harlow <harlowja@yahoo-inc.com> # # This file is part of cloud-init. See LICENSE file for license information. """ SSH Authkey Fingerprints ------------------------ **Summary:** log fingerprints of user ssh keys Write fingerprints of authorized keys for each user to log. This is enabled by default, but can be disabled using ``no_ssh_fingerprints``. The hash type for the keys can be specified, but defaults to ``md5``. **Internal name:** `` cc_ssh_authkey_fingerprints`` **Module frequency:** per instance **Supported distros:** all **Config keys**:: no_ssh_fingerprints: <true/false> authkey_hash: <hash type> """ import base64 import hashlib from cloudinit.simpletable import SimpleTable from cloudinit.distros import ug_util from cloudinit import ssh_util from cloudinit import util def _split_hash(bin_hash): split_up = [] for i in range(0, len(bin_hash), 2): split_up.append(bin_hash[i:i + 2]) return split_up def _gen_fingerprint(b64_text, hash_meth='md5'): if not b64_text: return '' # TBD(harlowja): Maybe we should feed this into 'ssh -lf'? try: hasher = hashlib.new(hash_meth) hasher.update(base64.b64decode(b64_text)) return ":".join(_split_hash(hasher.hexdigest())) except (TypeError, ValueError): # Raised when b64 not really b64... # or when the hash type is not really # a known/supported hash type... return '?' def _is_printable_key(entry): if any([entry.keytype, entry.base64, entry.comment, entry.options]): if (entry.keytype and entry.keytype.lower().strip() in ['ssh-dss', 'ssh-rsa']): return True return False def _pprint_key_entries(user, key_fn, key_entries, hash_meth='md5', prefix='ci-info: '): if not key_entries: message = ("%sno authorized ssh keys fingerprints found for user %s.\n" % (prefix, user)) util.multi_log(message) return tbl_fields = ['Keytype', 'Fingerprint (%s)' % (hash_meth), 'Options', 'Comment'] tbl = SimpleTable(tbl_fields) for entry in key_entries: if _is_printable_key(entry): row = [entry.keytype or '-', _gen_fingerprint(entry.base64, hash_meth) or '-', entry.options or '-', entry.comment or '-'] tbl.add_row(row) authtbl_s = tbl.get_string() authtbl_lines = authtbl_s.splitlines() max_len = len(max(authtbl_lines, key=len)) lines = [ util.center("Authorized keys from %s for user %s" % (key_fn, user), "+", max_len), ] lines.extend(authtbl_lines) for line in lines: util.multi_log(text="%s%s\n" % (prefix, line), stderr=False, console=True) def handle(name, cfg, cloud, log, _args): if util.is_true(cfg.get('no_ssh_fingerprints', False)): log.debug(("Skipping module named %s, " "logging of ssh fingerprints disabled"), name) return hash_meth = util.get_cfg_option_str(cfg, "authkey_hash", "md5") (users, _groups) = ug_util.normalize_users_groups(cfg, cloud.distro) for (user_name, _cfg) in users.items(): (key_fn, key_entries) = ssh_util.extract_authorized_keys(user_name) _pprint_key_entries(user_name, key_fn, key_entries, hash_meth) # vi: ts=4 expandtab Submit