"""A library for integrating pyOpenSSL with CherryPy. The OpenSSL module must be importable for SSL functionality. You can obtain it from `here `_. To use this module, set CherryPyWSGIServer.ssl_adapter to an instance of SSLAdapter. There are two ways to use SSL: Method One ---------- * ``ssl_adapter.context``: an instance of SSL.Context. If this is not None, it is assumed to be an SSL.Context instance, and will be passed to SSL.Connection on bind(). The developer is responsible for forming a valid Context object. This approach is to be preferred for more flexibility, e.g. if the cert and key are streams instead of files, or need decryption, or SSL.SSLv3_METHOD is desired instead of the default SSL.SSLv23_METHOD, etc. Consult the pyOpenSSL documentation for complete options. Method Two (shortcut) --------------------- * ``ssl_adapter.certificate``: the filename of the server SSL certificate. * ``ssl_adapter.private_key``: the filename of the server's private key file. Both are None by default. If ssl_adapter.context is None, but .private_key and .certificate are both given and valid, they will be read, and the context will be automatically created from them. """ import socket import threading import time from cherrypy import wsgiserver try: from OpenSSL import SSL from OpenSSL import crypto except ImportError: SSL = None class SSL_fileobject(wsgiserver.CP_fileobject): """SSL file object attached to a socket object.""" ssl_timeout = 3 ssl_retry = .01 def _safe_call(self, is_reader, call, *args, **kwargs): """Wrap the given call with SSL error-trapping. is_reader: if False EOF errors will be raised. If True, EOF errors will return "" (to emulate normal sockets). """ start = time.time() while True: try: return call(*args, **kwargs) except SSL.WantReadError: # Sleep and try again. This is dangerous, because it means # the rest of the stack has no way of differentiating # between a "new handshake" error and "client dropped". # Note this isn't an endless loop: there's a timeout below. time.sleep(self.ssl_retry) except SSL.WantWriteError: time.sleep(self.ssl_retry) except SSL.SysCallError, e: if is_reader and e.args == (-1, 'Unexpected EOF'): return "" errnum = e.args[0] if is_reader and errnum in wsgiserver.socket_errors_to_ignore: return "" raise socket.error(errnum) except SSL.Error, e: if is_reader and e.args == (-1, 'Unexpected EOF'): return "" thirdarg = None try: thirdarg = e.args[0][0][2] except IndexError: pass if thirdarg == 'http request': # The client is talking HTTP to an HTTPS server. raise wsgiserver.NoSSLError() raise wsgiserver.FatalSSLAlert(*e.args) except: raise if time.time() - start > self.ssl_timeout: raise socket.timeout("timed out") def recv(self, size): return self._safe_call(True, super(SSL_fileobject, self).recv, size) def sendall(self, *args, **kwargs): return self._safe_call(False, super(SSL_fileobject, self).sendall, *args, **kwargs) def send(self, *args, **kwargs): return self._safe_call(False, super(SSL_fileobject, self).send, *args, **kwargs) class SSLConnection: """A thread-safe wrapper for an SSL.Connection. ``*args``: the arguments to create the wrapped ``SSL.Connection(*args)``. """ def __init__(self, *args): self._ssl_conn = SSL.Connection(*args) self._lock = threading.RLock() for f in ('get_context', 'pending', 'send', 'write', 'recv', 'read', 'renegotiate', 'bind', 'listen', 'connect', 'accept', 'setblocking', 'fileno', 'close', 'get_cipher_list', 'getpeername', 'getsockname', 'getsockopt', 'setsockopt', 'makefile', 'get_app_data', 'set_app_data', 'state_string', 'sock_shutdown', 'get_peer_certificate', 'want_read', 'want_write', 'set_connect_state', 'set_accept_state', 'connect_ex', 'sendall', 'settimeout', 'gettimeout'): exec("""def %s(self, *args): self._lock.acquire() try: return self._ssl_conn.%s(*args) finally: self._lock.release() """ % (f, f)) def shutdown(self, *args): self._lock.acquire() try: # pyOpenSSL.socket.shutdown takes no args return self._ssl_conn.shutdown() finally: self._lock.release() class pyOpenSSLAdapter(wsgiserver.SSLAdapter): """A wrapper for integrating pyOpenSSL with CherryPy.""" context = None """An instance of SSL.Context.""" certificate = None """The filename of the server SSL certificate.""" private_key = None """The filename of the server's private key file.""" certificate_chain = None """Optional. The filename of CA's intermediate certificate bundle. This is needed for cheaper "chained root" SSL certificates, and should be left as None if not required.""" def __init__(self, certificate, private_key, certificate_chain=None): if SSL is None: raise ImportError("You must install pyOpenSSL to use HTTPS.") self.context = None self.certificate = certificate self.private_key = private_key self.certificate_chain = certificate_chain self._environ = None def bind(self, sock): """Wrap and return the given socket.""" if self.context is None: self.context = self.get_context() conn = SSLConnection(self.context, sock) self._environ = self.get_environ() return conn def wrap(self, sock): """Wrap and return the given socket, plus WSGI environ entries.""" return sock, self._environ.copy() def get_context(self): """Return an SSL.Context from self attributes.""" # See http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/442473 c = SSL.Context(SSL.SSLv23_METHOD) c.use_privatekey_file(self.private_key) if self.certificate_chain: c.load_verify_locations(self.certificate_chain) c.use_certificate_file(self.certificate) return c def get_environ(self): """Return WSGI environ entries to be merged into each request.""" ssl_environ = { "HTTPS": "on", # pyOpenSSL doesn't provide access to any of these AFAICT # 'SSL_PROTOCOL': 'SSLv2', # SSL_CIPHER string The cipher specification name # SSL_VERSION_INTERFACE string The mod_ssl program version # SSL_VERSION_LIBRARY string The OpenSSL program version } if self.certificate: # Server certificate attributes cert = open(self.certificate, 'rb').read() cert = crypto.load_certificate(crypto.FILETYPE_PEM, cert) ssl_environ.update({ 'SSL_SERVER_M_VERSION': cert.get_version(), 'SSL_SERVER_M_SERIAL': cert.get_serial_number(), # 'SSL_SERVER_V_START': # Validity of server's certificate (start time), # 'SSL_SERVER_V_END': # Validity of server's certificate (end time), }) for prefix, dn in [("I", cert.get_issuer()), ("S", cert.get_subject())]: # X509Name objects don't seem to have a way to get the # complete DN string. Use str() and slice it instead, # because str(dn) == "" dnstr = str(dn)[18:-2] wsgikey = 'SSL_SERVER_%s_DN' % prefix ssl_environ[wsgikey] = dnstr # The DN should be of the form: /k1=v1/k2=v2, but we must allow # for any value to contain slashes itself (in a URL). while dnstr: pos = dnstr.rfind("=") dnstr, value = dnstr[:pos], dnstr[pos + 1:] pos = dnstr.rfind("/") dnstr, key = dnstr[:pos], dnstr[pos + 1:] if key and value: wsgikey = 'SSL_SERVER_%s_DN_%s' % (prefix, key) ssl_environ[wsgikey] = value return ssl_environ def makefile(self, sock, mode='r', bufsize=-1): if SSL and isinstance(sock, SSL.ConnectionType): timeout = sock.gettimeout() f = SSL_fileobject(sock, mode, bufsize) f.ssl_timeout = timeout return f else: return wsgiserver.CP_fileobject(sock, mode, bufsize)