Source code for Bcfg2.Server.Plugins.Cfg.CfgPrivateKeyCreator

""" The CfgPrivateKeyCreator creates SSH keys on the fly. """

import os
import shutil
import tempfile
import Bcfg2.Options
from Bcfg2.Utils import Executor
from Bcfg2.Server.Plugins.Cfg import XMLCfgCreator, CfgCreationError
from Bcfg2.Server.Plugins.Cfg.CfgPublicKeyCreator import CfgPublicKeyCreator


[docs]class CfgPrivateKeyCreator(XMLCfgCreator): """The CfgPrivateKeyCreator creates SSH keys on the fly. """ #: Different configurations for different clients/groups can be #: handled with Client and Group tags within privkey.xml __specific__ = False #: Handle XML specifications of private keys __basenames__ = ['privkey.xml'] cfg_section = "sshkeys" options = [ Bcfg2.Options.Option( cf=("sshkeys", "category"), dest="sshkeys_category", help="Metadata category that generated SSH keys are specific to"), Bcfg2.Options.Option( cf=("sshkeys", "passphrase"), dest="sshkeys_passphrase", help="Passphrase used to encrypt generated SSH private keys")] def __init__(self, fname): XMLCfgCreator.__init__(self, fname) pubkey_path = os.path.dirname(self.name) + ".pub" pubkey_name = os.path.join(pubkey_path, os.path.basename(pubkey_path)) self.pubkey_creator = CfgPublicKeyCreator(pubkey_name) self.cmd = Executor() def _gen_keypair(self, metadata, spec=None): """ Generate a keypair according to the given client medata and key specification. :param metadata: The client metadata to generate keys for :type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata :param spec: The key specification to follow when creating the keys. This should be an XML document that only contains key specification data that applies to the given client metadata, and may be obtained by doing ``self.XMLMatch(metadata)`` :type spec: lxml.etree._Element :returns: tuple - (private key data, public key data) """ if spec is None: spec = self.XMLMatch(metadata) # set key parameters ktype = "rsa" bits = None params = spec.find("Params") if params is not None: bits = params.get("bits") ktype = params.get("type", ktype) try: passphrase = spec.find("Passphrase").text except AttributeError: passphrase = '' tempdir = tempfile.mkdtemp() try: filename = os.path.join(tempdir, "privkey") # generate key pair cmd = ["ssh-keygen", "-f", filename, "-t", ktype] if bits: cmd.extend(["-b", bits]) cmd.append("-N") log_cmd = cmd[:] cmd.append(passphrase) if passphrase: log_cmd.append("******") else: log_cmd.append("''") self.debug_log("Cfg: Generating new SSH key pair: %s" % " ".join(log_cmd)) result = self.cmd.run(cmd) if not result.success: raise CfgCreationError("Cfg: Failed to generate SSH key pair " "at %s for %s: %s" % (filename, metadata.hostname, result.error)) elif result.stderr: self.logger.warning("Cfg: Generated SSH key pair at %s for %s " "with errors: %s" % (filename, metadata.hostname, result.stderr)) return (open(filename).read(), open(filename + ".pub").read()) finally: shutil.rmtree(tempdir) # pylint: disable=W0221
[docs] def create_data(self, entry, metadata): """ Create data for the given entry on the given client :param entry: The abstract entry to create data for. This will not be modified :type entry: lxml.etree._Element :param metadata: The client metadata to create data for :type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata :returns: string - The private key data """ spec = self.XMLMatch(metadata) specificity = self.get_specificity(metadata) privkey, pubkey = self._gen_keypair(metadata, spec) # write the public key, stripping the comment and # replacing it with a comment that specifies the filename. kdata = pubkey.split()[:2] kdata.append(self.pubkey_creator.get_filename(**specificity)) pubkey = " ".join(kdata) + "\n" self.pubkey_creator.write_data(pubkey, **specificity) # encrypt the private key, write to the proper place, and # return it self.write_data(privkey, **specificity) return privkey
# pylint: enable=W0221