diff options
Diffstat (limited to 'cloudinit/sources/helpers/azure.py')
| -rw-r--r-- | cloudinit/sources/helpers/azure.py | 109 |
1 files changed, 78 insertions, 31 deletions
diff --git a/cloudinit/sources/helpers/azure.py b/cloudinit/sources/helpers/azure.py index e5696b1f..2829dd20 100644 --- a/cloudinit/sources/helpers/azure.py +++ b/cloudinit/sources/helpers/azure.py @@ -138,9 +138,36 @@ class OpenSSLManager(object): self.certificate = certificate LOG.debug('New certificate generated.') - def parse_certificates(self, certificates_xml): - tag = ElementTree.fromstring(certificates_xml).find( - './/Data') + @staticmethod + def _run_x509_action(action, cert): + cmd = ['openssl', 'x509', '-noout', action] + result, _ = util.subp(cmd, data=cert) + return result + + def _get_ssh_key_from_cert(self, certificate): + pub_key = self._run_x509_action('-pubkey', certificate) + keygen_cmd = ['ssh-keygen', '-i', '-m', 'PKCS8', '-f', '/dev/stdin'] + ssh_key, _ = util.subp(keygen_cmd, data=pub_key) + return ssh_key + + def _get_fingerprint_from_cert(self, certificate): + """openssl x509 formats fingerprints as so: + 'SHA1 Fingerprint=07:3E:19:D1:4D:1C:79:92:24:C6:A0:FD:8D:DA:\ + B6:A8:BF:27:D4:73\n' + + Azure control plane passes that fingerprint as so: + '073E19D14D1C799224C6A0FD8DDAB6A8BF27D473' + """ + raw_fp = self._run_x509_action('-fingerprint', certificate) + eq = raw_fp.find('=') + octets = raw_fp[eq+1:-1].split(':') + return ''.join(octets) + + def _decrypt_certs_from_xml(self, certificates_xml): + """Decrypt the certificates XML document using the our private key; + return the list of certs and private keys contained in the doc. + """ + tag = ElementTree.fromstring(certificates_xml).find('.//Data') certificates_content = tag.text lines = [ b'MIME-Version: 1.0', @@ -151,32 +178,30 @@ class OpenSSLManager(object): certificates_content.encode('utf-8'), ] with cd(self.tmpdir): - with open('Certificates.p7m', 'wb') as f: - f.write(b'\n'.join(lines)) out, _ = util.subp( - 'openssl cms -decrypt -in Certificates.p7m -inkey' + 'openssl cms -decrypt -in /dev/stdin -inkey' ' {private_key} -recip {certificate} | openssl pkcs12 -nodes' ' -password pass:'.format(**self.certificate_names), - shell=True) - private_keys, certificates = [], [] + shell=True, data=b'\n'.join(lines)) + return out + + def parse_certificates(self, certificates_xml): + """Given the Certificates XML document, return a dictionary of + fingerprints and associated SSH keys derived from the certs.""" + out = self._decrypt_certs_from_xml(certificates_xml) current = [] + keys = {} for line in out.splitlines(): current.append(line) if re.match(r'[-]+END .*?KEY[-]+$', line): - private_keys.append('\n'.join(current)) + # ignore private_keys current = [] elif re.match(r'[-]+END .*?CERTIFICATE[-]+$', line): - certificates.append('\n'.join(current)) + certificate = '\n'.join(current) + ssh_key = self._get_ssh_key_from_cert(certificate) + fingerprint = self._get_fingerprint_from_cert(certificate) + keys[fingerprint] = ssh_key current = [] - keys = [] - for certificate in certificates: - with cd(self.tmpdir): - public_key, _ = util.subp( - 'openssl x509 -noout -pubkey |' - 'ssh-keygen -i -m PKCS8 -f /dev/stdin', - data=certificate, - shell=True) - keys.append(public_key) return keys @@ -206,7 +231,6 @@ class WALinuxAgentShim(object): self.dhcpoptions = dhcp_options self._endpoint = None self.openssl_manager = None - self.values = {} self.lease_file = fallback_lease_file def clean_up(self): @@ -328,8 +352,9 @@ class WALinuxAgentShim(object): LOG.debug('Azure endpoint found at %s', endpoint_ip_address) return endpoint_ip_address - def register_with_azure_and_fetch_data(self): - self.openssl_manager = OpenSSLManager() + def register_with_azure_and_fetch_data(self, pubkey_info=None): + if self.openssl_manager is None: + self.openssl_manager = OpenSSLManager() http_client = AzureEndpointHttpClient(self.openssl_manager.certificate) LOG.info('Registering with Azure...') attempts = 0 @@ -347,16 +372,37 @@ class WALinuxAgentShim(object): attempts += 1 LOG.debug('Successfully fetched GoalState XML.') goal_state = GoalState(response.contents, http_client) - public_keys = [] - if goal_state.certificates_xml is not None: + ssh_keys = [] + if goal_state.certificates_xml is not None and pubkey_info is not None: LOG.debug('Certificate XML found; parsing out public keys.') - public_keys = self.openssl_manager.parse_certificates( + keys_by_fingerprint = self.openssl_manager.parse_certificates( goal_state.certificates_xml) - data = { - 'public-keys': public_keys, - } + ssh_keys = self._filter_pubkeys(keys_by_fingerprint, pubkey_info) self._report_ready(goal_state, http_client) - return data + return {'public-keys': ssh_keys} + + def _filter_pubkeys(self, keys_by_fingerprint, pubkey_info): + """cloud-init expects a straightforward array of keys to be dropped + into the user's authorized_keys file. Azure control plane exposes + multiple public keys to the VM via wireserver. Select just the + user's key(s) and return them, ignoring any other certs. + """ + keys = [] + for pubkey in pubkey_info: + if 'value' in pubkey and pubkey['value']: + keys.append(pubkey['value']) + elif 'fingerprint' in pubkey and pubkey['fingerprint']: + fingerprint = pubkey['fingerprint'] + if fingerprint in keys_by_fingerprint: + keys.append(keys_by_fingerprint[fingerprint]) + else: + LOG.warning("ovf-env.xml specified PublicKey fingerprint " + "%s not found in goalstate XML", fingerprint) + else: + LOG.warning("ovf-env.xml specified PublicKey with neither " + "value nor fingerprint: %s", pubkey) + + return keys def _report_ready(self, goal_state, http_client): LOG.debug('Reporting ready to Azure fabric.') @@ -373,11 +419,12 @@ class WALinuxAgentShim(object): LOG.info('Reported ready to Azure fabric.') -def get_metadata_from_fabric(fallback_lease_file=None, dhcp_opts=None): +def get_metadata_from_fabric(fallback_lease_file=None, dhcp_opts=None, + pubkey_info=None): shim = WALinuxAgentShim(fallback_lease_file=fallback_lease_file, dhcp_options=dhcp_opts) try: - return shim.register_with_azure_and_fetch_data() + return shim.register_with_azure_and_fetch_data(pubkey_info=pubkey_info) finally: shim.clean_up() |