Add PKI API for compute nodes certificates

Treat the control node as a CA for certificates at compute nodes.
Upon joining a cluster, the compute node will request a certificate to
be created by generating a CSR and asking the control node to sign the
certificate.

This adds new config options for the compute private keys and
certificate locations in use.

Change-Id: I8e8b1a86cf7df752b6cb34cfdf65a87a72934ec5
This commit is contained in:
Billy Olsen 2021-10-15 09:39:57 -07:00
parent 03ad23de71
commit 872d04882b
6 changed files with 273 additions and 63 deletions

View File

@ -83,6 +83,10 @@ def _get_default_config():
f'{snap_common}/etc/ssl/certs/cert.pem',
'config.tls.key-path':
f'{snap_common}/etc/ssl/private/key.pem',
'config.tls.compute.cert-path':
f'{snap_common}/etc/ssl/certs/compute-cert.pem',
'config.tls.compute.key-path':
f'{snap_common}/etc/ssl/private/compute-key.pem',
}

View File

@ -136,6 +136,8 @@ setup:
tls_cacert_path: 'config.tls.cacert-path'
tls_cert_path: 'config.tls.cert-path'
tls_key_path: 'config.tls.key-path'
tls_compute_cert_path: 'config.tls.compute.cert-path'
tls_compute_key_path: 'config.tls.compute.key-path'
entry_points:
keystone-manage:
binary: "{snap}/bin/keystone-manage"

View File

@ -4,7 +4,10 @@ import sys
import urllib3
import json
from pathlib import Path
from cluster import shell
from init import tls
CLUSTER_SERVICE_PORT = 10002
@ -111,6 +114,66 @@ def join():
f.write(response_dict[tls_file])
shell.config_set(**{'config.tls.generate-self-signed': False})
compute_key_path = shell.config_get('config.tls.compute.key-path')
compute_key_path = Path(compute_key_path)
tls.create_or_get_private_key(compute_key_path)
csr = tls.create_csr(compute_key_path)
# Request CSRs for PKI settings
request_body = json.dumps({
'credential-id': credential_id,
'credential-secret': credential_secret,
'csr': csr.decode('utf-8')
})
try:
resp = conn_pool.urlopen(
'POST', '/pki/sign', retries=0, preload_content=True,
headers={
'API-VERSION': '1.0.0',
'Content-Type': 'application/json',
}, body=request_body)
except urllib3.exceptions.MaxRetryError as e:
if isinstance(e.reason, urllib3.exceptions.SSLError):
raise Exception(
'The actual clustering service certificate fingerprint'
' did not match the expected one, please make sure that: '
'(1) that a correct token was specified during initialization;'
' (2) a MITM attacks are not performed against HTTPS requests'
' (including transparent proxies).'
) from e.reason
raise Exception('Could not retrieve a response from the clustering'
' service.') from e
if resp.status == 401:
response_data = resp.data.decode('utf-8')
# TODO: this should be more bulletproof in case a proxy server
# returns this response - it will not have the expected format.
print('An authorization failure has occurred while joining the'
' the cluster: please make sure the connection string'
' was entered as returned by the "add-compute" command'
' and that it was used before its expiration time.',
file=sys.stderr)
if response_data:
message = json.loads(response_data)['message']
raise UnauthorizedRequestError(message)
raise UnauthorizedRequestError()
if resp.status != 200:
raise Exception('Unexpected response status received from the'
f' clustering service: {resp.status}')
# The API was introduced so there's a possibility that we get a 404
if resp.status == 404:
raise Exception('The control node does not support CSR.')
if not resp.data:
raise Exception('The clustering service did not return a certificate, '
'which is unexpected. Check its status and try again.')
compute_cert_path = shell.config_get('config.tls.compute.cert-path')
with open(compute_cert_path, 'wb+') as f:
f.write(resp.data)
if __name__ == '__main__':
join()

View File

@ -6,12 +6,15 @@ import semantic_version
import keystoneclient.exceptions as kc_exceptions
from flask import Flask, request, jsonify
from functools import wraps
from werkzeug.exceptions import BadRequest
from pathlib import Path
from cluster.shell import check_output
from cluster.shell import config_get
from init.tls import generate_cert_from_csr
from keystoneauth1.identity import v3
from keystoneauth1 import session
from keystoneclient.v3 import client as v3client
@ -151,55 +154,16 @@ def handle_unexpected_error(error):
return _handle_api_version_exception(error)
def join_info():
"""Generate the configuration information to return to a client."""
# TODO: be selective about what we return. For now, we just get everything.
info = {}
config = json.loads(check_output('snapctl', 'get', 'config'))
info['config'] = config
def require_auth(f):
"""Validates that proper authentication credentials are provided in the
request.
# Add the controller's TLS certificate data
tls_path_map = {
'cacert-path': 'tls_cacert',
'cert-path': 'tls_cert',
'key-path': 'tls_key',
}
for tls_config, tls_file in tls_path_map.items():
with open(config_get('config.tls.{}'.format(tls_config)), "r") as f:
info[tls_file] = f.read()
return info
@app.route('/join', methods=['POST'])
def join():
"""Authorize a client node and return relevant config."""
# Retrieve an API version from the request - it is a mandatory
# header for this API.
request_version = request.headers.get('API-Version')
if request_version is None:
logger.debug('The client has not specified the API-version header.')
raise APIVersionMissing()
else:
try:
api_version = semantic_version.Version(request_version)
except ValueError:
logger.debug('The client has specified an invalid API version.'
f': {request_version}')
raise APIVersionInvalid()
# Compare the API version used by the clustering service with the
# one specified in the request and return an appropriate response.
if api_version.major > API_VERSION.major:
logger.debug('The client requested a version that is not'
f' supported yet: {api_version}.')
raise APIVersionNotImplemented()
elif api_version.major < API_VERSION.major:
logger.debug('The client request version is no longer supported'
f': {api_version}.')
raise APIVersionDropped()
else:
Checks the provided request.json data to retrieve the credential_id and the
credential_secret and then validates the provided credentials and tokens
are valid tokens.
"""
@wraps(f)
def decorated_function(*args, **kwargs):
# Flask raises a BadRequest if the JSON content is invalid and
# returns None if the Content-Type header is missing or not set
# to application/json.
@ -293,6 +257,61 @@ def join():
' connecting to Keystone')
raise UnexpectedError()
return f(*args, **kwargs)
return decorated_function
def join_info():
"""Generate the configuration information to return to a client."""
# TODO: be selective about what we return. For now, we just get everything.
info = {}
config = json.loads(check_output('snapctl', 'get', 'config'))
info['config'] = config
# Add the controller's TLS certificate data
tls_path_map = {
'cacert-path': 'tls_cacert',
'cert-path': 'tls_cert',
'key-path': 'tls_key',
}
for tls_config, tls_file in tls_path_map.items():
with open(config_get('config.tls.{}'.format(tls_config)), "r") as f:
info[tls_file] = f.read()
return info
@app.route('/join', methods=['POST'])
@require_auth
def join():
"""Authorize a client node and return relevant config."""
# Retrieve an API version from the request - it is a mandatory
# header for this API.
request_version = request.headers.get('API-Version')
if request_version is None:
logger.debug('The client has not specified the API-version header.')
raise APIVersionMissing()
else:
try:
api_version = semantic_version.Version(request_version)
except ValueError:
logger.debug('The client has specified an invalid API version.'
f': {request_version}')
raise APIVersionInvalid()
# Compare the API version used by the clustering service with the
# one specified in the request and return an appropriate response.
if api_version.major > API_VERSION.major:
logger.debug('The client requested a version that is not'
f' supported yet: {api_version}.')
raise APIVersionNotImplemented()
elif api_version.major < API_VERSION.major:
logger.debug('The client request version is no longer supported'
f': {api_version}.')
raise APIVersionDropped()
else:
# We were able to authenticate against Keystone using the
# application credential and verify that it has not expired
# so the information for a compute node to join the cluster can
@ -300,6 +319,20 @@ def join():
return json.dumps(join_info())
@app.route('/pki/sign', methods=['POST'])
@require_auth
def sign_csr():
"""Signs the provided CSR."""
json_data = request.json
csr = bytes(json_data.get('csr'), 'utf-8')
key_path = Path(config_get('config.tls.key-path'))
ca_path = Path(config_get('config.tls.cacert-path'))
cert = generate_cert_from_csr(ca_path, key_path, csr)
return cert
@app.route('/')
def home():
status = {

View File

@ -92,6 +92,11 @@ class Clustering(Question):
role = shell.config_get('config.cluster.role')
# Generate the compute private key for all nodes since they all act as
# compute nodes.
compute_key_path = Path(shell.config_get('config.tls.compute.key-path'))
tls.create_or_get_private_key(compute_key_path)
if role == 'compute':
log.info('Setting up as a compute node.')
# Gets config info and sets local env vals.

View File

@ -5,6 +5,7 @@ from init.shell import check
from datetime import datetime
from dateutil.relativedelta import relativedelta
from pathlib import Path
import ipaddress
import socket
@ -18,6 +19,39 @@ from cryptography.x509.oid import NameOID
from init import shell
def create_or_get_private_key(key_path: Path) -> rsa.RSAPrivateKey:
"""Generate a local private key file.
:param key_path: path of the key
:type key_path: Path
:return: private key
:rtype: rs.RSAPrivateKey
"""
# If the key path exists, then attempt to load it in order to make sure
# it is a valid private key.
if key_path.exists():
with open(key_path, 'rb') as f:
key = serialization.load_pem_private_key(f.read(), None,
default_backend())
if not isinstance(key, rsa.RSAPrivateKey):
raise TypeError('Private key already exists but is not an '
'RSA key')
return key
key = rsa.generate_private_key(
public_exponent=65537,
key_size=2048,
backend=default_backend(),
)
serialized_key = key.private_bytes(
encoding=serialization.Encoding.PEM,
format=serialization.PrivateFormat.PKCS8,
encryption_algorithm=serialization.NoEncryption(),
)
key_path.write_bytes(serialized_key)
check('chmod', '600', str(key_path))
return key
def generate_self_signed(cert_path, key_path, ip=None,
fingerprint_config=None):
"""Generate a self-signed certificate with associated keys.
@ -34,15 +68,11 @@ def generate_self_signed(cert_path, key_path, ip=None,
"""
# Do not generate a new certificate and key if there is already an existing
# pair. TODO: improve this check and allow renewal.
if cert_path.exists() and key_path.exists():
if cert_path.exists():
return
key = rsa.generate_private_key(
public_exponent=65537,
key_size=2048,
backend=default_backend(),
)
cn = socket.gethostname()
key = create_or_get_private_key(key_path=key_path)
cn = socket.getfqdn()
common_name = x509.Name([
x509.NameAttribute(NameOID.COMMON_NAME, cn)
])
@ -74,12 +104,85 @@ def generate_self_signed(cert_path, key_path, ip=None,
shell.config_set(**{fingerprint_config: cert_fprint})
serialized_cert = cert.public_bytes(encoding=serialization.Encoding.PEM)
serialized_key = key.private_bytes(
encoding=serialization.Encoding.PEM,
format=serialization.PrivateFormat.PKCS8,
encryption_algorithm=serialization.NoEncryption(),
)
cert_path.write_bytes(serialized_cert)
key_path.write_bytes(serialized_key)
check('chmod', '644', str(cert_path))
check('chmod', '600', str(key_path))
def create_csr(key_path: Path, ip: str = None) -> \
x509.CertificateSigningRequest:
"""Creates a Certificate Signing Request (CSR) for the local node.
A CSR is created for the local node. The resulting CSR can be provided to
generate a Certificate in a PKI infrastructure. The CSR will be generated
using the local nodes hostname as the CN and SAN in the request. The CSR
generated will not request certificate authority.
:param key_path: the path to the local private key file
:type key_path: Path
:param ip: the ip address of the local node
:type str: the ip address of the local node
:returns: x509.CertificateSigningRequest object for the local node
:rtype: x509.CertificateSigningRequest
"""
with open(key_path, 'rb+') as f:
key = serialization.load_pem_private_key(f.read(), None,
default_backend())
hostname = socket.getfqdn()
cn = x509.NameAttribute(NameOID.COMMON_NAME, hostname)
if ip:
san = x509.SubjectAlternativeName(
[x509.DNSName(cn), x509.IPAddress(ipaddress.ip_address(ip))]
)
else:
san = x509.SubjectAlternativeName([x509.DNSName(hostname)])
not_ca = x509.BasicConstraints(ca=False, path_length=None)
builder = x509.CertificateSigningRequestBuilder()
builder = builder.subject_name(x509.Name([cn]))
builder = builder.add_extension(san, critical=False)
builder = builder.add_extension(not_ca, critical=True)
request = builder.sign(key, hashes.SHA256(), backend=default_backend())
return request.public_bytes(serialization.Encoding.PEM)
def generate_cert_from_csr(ca_path, key_path, client_csr):
"""Generates a certificate from a Certificate Signing Request (CSR).
:param ca_path: the path to the ca cert
:type ca_path: str or Path
:param key_path: the path to the ca cert key file
:type key_path: str or Path
:param client_csr: the certificate signing request from a client
:return: PEM encoded certificate
:rtype: bytes
"""
with open(ca_path, 'rb') as f:
cacert = x509.load_pem_x509_certificate(f.read(), default_backend())
with open(key_path, 'rb') as f:
key = serialization.load_pem_private_key(f.read(), None,
default_backend())
csr = x509.load_pem_x509_csr(client_csr, default_backend())
builder = (
x509.CertificateBuilder()
.subject_name(csr.subject)
.issuer_name(cacert.subject)
.public_key(csr.public_key())
.serial_number(x509.random_serial_number())
.not_valid_before(datetime.utcnow())
.not_valid_after(
# Set it to expire 2 days before our cacert does
cacert.not_valid_after - relativedelta(days=2)
)
)
# Add requested extensions
for extension in csr.extensions:
builder.add_extension(extension.value, extension.critical)
cert = builder.sign(key, hashes.SHA256(), default_backend())
return cert.public_bytes(encoding=serialization.Encoding.PEM)