diff options
Diffstat (limited to 'cloudinit/config/cc_ssh.py')
| -rwxr-xr-x | cloudinit/config/cc_ssh.py | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/cloudinit/config/cc_ssh.py b/cloudinit/config/cc_ssh.py index f8f7cb35..53f69399 100755 --- a/cloudinit/config/cc_ssh.py +++ b/cloudinit/config/cc_ssh.py @@ -91,6 +91,9 @@ public keys. ssh_authorized_keys: - ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAGEA3FSyQwBI6Z+nCSjUU ... - ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA3I7VUf2l5gSn5uavROsc5HRDpZ ... + ssh_publish_hostkeys: + enabled: <true/false> (Defaults to true) + blacklist: <list of key types> (Defaults to [dsa]) """ import glob @@ -104,6 +107,10 @@ from cloudinit import util GENERATE_KEY_NAMES = ['rsa', 'dsa', 'ecdsa', 'ed25519'] KEY_FILE_TPL = '/etc/ssh/ssh_host_%s_key' +PUBLISH_HOST_KEYS = True +# Don't publish the dsa hostkey by default since OpenSSH recommends not using +# it. +HOST_KEY_PUBLISH_BLACKLIST = ['dsa'] CONFIG_KEY_TO_FILE = {} PRIV_TO_PUB = {} @@ -176,6 +183,23 @@ def handle(_name, cfg, cloud, log, _args): util.logexc(log, "Failed generating key type %s to " "file %s", keytype, keyfile) + if "ssh_publish_hostkeys" in cfg: + host_key_blacklist = util.get_cfg_option_list( + cfg["ssh_publish_hostkeys"], "blacklist", + HOST_KEY_PUBLISH_BLACKLIST) + publish_hostkeys = util.get_cfg_option_bool( + cfg["ssh_publish_hostkeys"], "enabled", PUBLISH_HOST_KEYS) + else: + host_key_blacklist = HOST_KEY_PUBLISH_BLACKLIST + publish_hostkeys = PUBLISH_HOST_KEYS + + if publish_hostkeys: + hostkeys = get_public_host_keys(blacklist=host_key_blacklist) + try: + cloud.datasource.publish_host_keys(hostkeys) + except Exception as e: + util.logexc(log, "Publishing host keys failed!") + try: (users, _groups) = ug_util.normalize_users_groups(cfg, cloud.distro) (user, _user_config) = ug_util.extract_default(users) @@ -209,4 +233,35 @@ def apply_credentials(keys, user, disable_root, disable_root_opts): ssh_util.setup_user_keys(keys, 'root', options=key_prefix) + +def get_public_host_keys(blacklist=None): + """Read host keys from /etc/ssh/*.pub files and return them as a list. + + @param blacklist: List of key types to ignore. e.g. ['dsa', 'rsa'] + @returns: List of keys, each formatted as a two-element tuple. + e.g. [('ssh-rsa', 'AAAAB3Nz...'), ('ssh-ed25519', 'AAAAC3Nx...')] + """ + public_key_file_tmpl = '%s.pub' % (KEY_FILE_TPL,) + key_list = [] + blacklist_files = [] + if blacklist: + # Convert blacklist to filenames: + # 'dsa' -> '/etc/ssh/ssh_host_dsa_key.pub' + blacklist_files = [public_key_file_tmpl % (key_type,) + for key_type in blacklist] + # Get list of public key files and filter out blacklisted files. + file_list = [hostfile for hostfile + in glob.glob(public_key_file_tmpl % ('*',)) + if hostfile not in blacklist_files] + + # Read host key files, retrieve first two fields as a tuple and + # append that tuple to key_list. + for file_name in file_list: + file_contents = util.load_file(file_name) + key_data = file_contents.split() + if key_data and len(key_data) > 1: + key_list.append(tuple(key_data[:2])) + return key_list + + # vi: ts=4 expandtab |