# Copyright 2007,2011 Google Inc. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # # This file is derived from # http://googleappengine.googlecode.com/svn-history/r136/trunk/python/google/appengine/tools/https_wrapper.py """Extensions to allow HTTPS requests with SSL certificate validation.""" import re import socket import ssl import boto from boto.compat import six, http_client class InvalidCertificateException(http_client.HTTPException): """Raised when a certificate is provided with an invalid hostname.""" def __init__(self, host, cert, reason): """Constructor. Args: host: The hostname the connection was made to. cert: The SSL certificate (as a dictionary) the host returned. """ http_client.HTTPException.__init__(self) self.host = host self.cert = cert self.reason = reason def __str__(self): return ('Host %s returned an invalid certificate (%s): %s' % (self.host, self.reason, self.cert)) def GetValidHostsForCert(cert): """Returns a list of valid host globs for an SSL certificate. Args: cert: A dictionary representing an SSL certificate. Returns: list: A list of valid host globs. """ if 'subjectAltName' in cert: return [x[1] for x in cert['subjectAltName'] if x[0].lower() == 'dns'] else: return [x[0][1] for x in cert['subject'] if x[0][0].lower() == 'commonname'] def ValidateCertificateHostname(cert, hostname): """Validates that a given hostname is valid for an SSL certificate. Args: cert: A dictionary representing an SSL certificate. hostname: The hostname to test. Returns: bool: Whether or not the hostname is valid for this certificate. """ hosts = GetValidHostsForCert(cert) boto.log.debug( "validating server certificate: hostname=%s, certificate hosts=%s", hostname, hosts) for host in hosts: host_re = host.replace('.', '\.').replace('*', '[^.]*') if re.search('^%s$' % (host_re,), hostname, re.I): return True return False class CertValidatingHTTPSConnection(http_client.HTTPConnection): """An HTTPConnection that connects over SSL and validates certificates.""" default_port = http_client.HTTPS_PORT def __init__(self, host, port=default_port, key_file=None, cert_file=None, ca_certs=None, strict=None, **kwargs): """Constructor. Args: host: The hostname. Can be in 'host:port' form. port: The port. Defaults to 443. key_file: A file containing the client's private key cert_file: A file containing the client's certificates ca_certs: A file contianing a set of concatenated certificate authority certs for validating the server against. strict: When true, causes BadStatusLine to be raised if the status line can't be parsed as a valid HTTP/1.0 or 1.1 status line. """ if six.PY2: # Python 3.2 and newer have deprecated and removed the strict # parameter. Since the params are supported as keyword arguments # we conditionally add it here. kwargs['strict'] = strict http_client.HTTPConnection.__init__(self, host=host, port=port, **kwargs) self.key_file = key_file self.cert_file = cert_file self.ca_certs = ca_certs def connect(self): "Connect to a host on a given (SSL) port." if hasattr(self, "timeout"): sock = socket.create_connection((self.host, self.port), self.timeout) else: sock = socket.create_connection((self.host, self.port)) msg = "wrapping ssl socket; " if self.ca_certs: msg += "CA certificate file=%s" % self.ca_certs else: msg += "using system provided SSL certs" boto.log.debug(msg) self.sock = ssl.wrap_socket(sock, keyfile=self.key_file, certfile=self.cert_file, cert_reqs=ssl.CERT_REQUIRED, ca_certs=self.ca_certs) cert = self.sock.getpeercert() hostname = self.host.split(':', 0)[0] if not ValidateCertificateHostname(cert, hostname): raise InvalidCertificateException(hostname, cert, 'remote hostname "%s" does not match ' 'certificate' % hostname)