Editing: ssl.py
# Wrapper module for _ssl, providing some additional facilities # implemented in Python. Written by Bill Janssen. """This module provides some more Pythonic support for SSL. Object types: SSLSocket -- subtype of socket.socket which does SSL over the socket Exceptions: SSLError -- exception raised for I/O errors Functions: cert_time_to_seconds -- convert time string used for certificate notBefore and notAfter functions to integer seconds past the Epoch (the time values returned from time.time()) fetch_server_certificate (HOST, PORT) -- fetch the certificate provided by the server running on HOST at port PORT. No validation of the certificate is performed. Integer constants: SSL_ERROR_ZERO_RETURN SSL_ERROR_WANT_READ SSL_ERROR_WANT_WRITE SSL_ERROR_WANT_X509_LOOKUP SSL_ERROR_SYSCALL SSL_ERROR_SSL SSL_ERROR_WANT_CONNECT SSL_ERROR_EOF SSL_ERROR_INVALID_ERROR_CODE The following group define certificate requirements that one side is allowing/requiring from the other side: CERT_NONE - no certificates from the other side are required (or will be looked at if provided) CERT_OPTIONAL - certificates are not required, but if provided will be validated, and if validation fails, the connection will also fail CERT_REQUIRED - certificates are required, and will be validated, and if validation fails, the connection will also fail The following constants identify various SSL protocol variants: PROTOCOL_SSLv2 PROTOCOL_SSLv3 PROTOCOL_SSLv23 PROTOCOL_TLS PROTOCOL_TLSv1 PROTOCOL_TLSv1_1 PROTOCOL_TLSv1_2 The following constants identify various SSL alert message descriptions as per http://www.iana.org/assignments/tls-parameters/tls-parameters.xml#tls-parameters-6 ALERT_DESCRIPTION_CLOSE_NOTIFY ALERT_DESCRIPTION_UNEXPECTED_MESSAGE ALERT_DESCRIPTION_BAD_RECORD_MAC ALERT_DESCRIPTION_RECORD_OVERFLOW ALERT_DESCRIPTION_DECOMPRESSION_FAILURE ALERT_DESCRIPTION_HANDSHAKE_FAILURE ALERT_DESCRIPTION_BAD_CERTIFICATE ALERT_DESCRIPTION_UNSUPPORTED_CERTIFICATE ALERT_DESCRIPTION_CERTIFICATE_REVOKED ALERT_DESCRIPTION_CERTIFICATE_EXPIRED ALERT_DESCRIPTION_CERTIFICATE_UNKNOWN ALERT_DESCRIPTION_ILLEGAL_PARAMETER ALERT_DESCRIPTION_UNKNOWN_CA ALERT_DESCRIPTION_ACCESS_DENIED ALERT_DESCRIPTION_DECODE_ERROR ALERT_DESCRIPTION_DECRYPT_ERROR ALERT_DESCRIPTION_PROTOCOL_VERSION ALERT_DESCRIPTION_INSUFFICIENT_SECURITY ALERT_DESCRIPTION_INTERNAL_ERROR ALERT_DESCRIPTION_USER_CANCELLED ALERT_DESCRIPTION_NO_RENEGOTIATION ALERT_DESCRIPTION_UNSUPPORTED_EXTENSION ALERT_DESCRIPTION_CERTIFICATE_UNOBTAINABLE ALERT_DESCRIPTION_UNRECOGNIZED_NAME ALERT_DESCRIPTION_BAD_CERTIFICATE_STATUS_RESPONSE ALERT_DESCRIPTION_BAD_CERTIFICATE_HASH_VALUE ALERT_DESCRIPTION_UNKNOWN_PSK_IDENTITY """ import textwrap import re import sys import os from collections import namedtuple from contextlib import closing import _ssl # if we can't import it, let the error propagate from _ssl import OPENSSL_VERSION_NUMBER, OPENSSL_VERSION_INFO, OPENSSL_VERSION from _ssl import _SSLContext from _ssl import ( SSLError, SSLZeroReturnError, SSLWantReadError, SSLWantWriteError, SSLSyscallError, SSLEOFError, ) from _ssl import CERT_NONE, CERT_OPTIONAL, CERT_REQUIRED from _ssl import txt2obj as _txt2obj, nid2obj as _nid2obj from _ssl import RAND_status, RAND_add try: from _ssl import RAND_egd except ImportError: # LibreSSL does not provide RAND_egd pass def _import_symbols(prefix): for n in dir(_ssl): if n.startswith(prefix): globals()[n] = getattr(_ssl, n) _import_symbols('OP_') _import_symbols('ALERT_DESCRIPTION_') _import_symbols('SSL_ERROR_') _import_symbols('PROTOCOL_') _import_symbols('VERIFY_') from _ssl import HAS_SNI, HAS_ECDH, HAS_NPN, HAS_ALPN, HAS_TLSv1_3 from _ssl import _OPENSSL_API_VERSION _PROTOCOL_NAMES = {value: name for name, value in globals().items() if name.startswith('PROTOCOL_') and name != 'PROTOCOL_SSLv23'} PROTOCOL_SSLv23 = PROTOCOL_TLS try: _SSLv2_IF_EXISTS = PROTOCOL_SSLv2 except NameError: _SSLv2_IF_EXISTS = None from socket import socket, _fileobject, _delegate_methods, error as socket_error if sys.platform == "win32": from _ssl import enum_certificates, enum_crls from socket import socket, AF_INET, SOCK_STREAM, create_connection from socket import SOL_SOCKET, SO_TYPE import base64 # for DER-to-PEM translation import errno import warnings if _ssl.HAS_TLS_UNIQUE: CHANNEL_BINDING_TYPES = ['tls-unique'] else: CHANNEL_BINDING_TYPES = [] # Disable weak or insecure ciphers by default # (OpenSSL's default setting is 'DEFAULT:!aNULL:!eNULL') # Enable a better set of ciphers by default # This list has been explicitly chosen to: # * TLS 1.3 ChaCha20 and AES-GCM cipher suites # * Prefer cipher suites that offer perfect forward secrecy (DHE/ECDHE) # * Prefer ECDHE over DHE for better performance # * Prefer AEAD over CBC for better performance and security # * Prefer AES-GCM over ChaCha20 because most platforms have AES-NI # (ChaCha20 needs OpenSSL 1.1.0 or patched 1.0.2) # * Prefer any AES-GCM and ChaCha20 over any AES-CBC for better # performance and security # * Then Use HIGH cipher suites as a fallback # * Disable NULL authentication, NULL encryption, 3DES and MD5 MACs # for security reasons _DEFAULT_CIPHERS = ( 'TLS13-AES-256-GCM-SHA384:TLS13-CHACHA20-POLY1305-SHA256:' 'TLS13-AES-128-GCM-SHA256:' 'ECDH+AESGCM:ECDH+CHACHA20:DH+AESGCM:DH+CHACHA20:ECDH+AES256:DH+AES256:' 'ECDH+AES128:DH+AES:ECDH+HIGH:DH+HIGH:RSA+AESGCM:RSA+AES:RSA+HIGH:' '!aNULL:!eNULL:!MD5:!3DES' ) # Restricted and more secure ciphers for the server side # This list has been explicitly chosen to: # * TLS 1.3 ChaCha20 and AES-GCM cipher suites # * Prefer cipher suites that offer perfect forward secrecy (DHE/ECDHE) # * Prefer ECDHE over DHE for better performance # * Prefer AEAD over CBC for better performance and security # * Prefer AES-GCM over ChaCha20 because most platforms have AES-NI # * Prefer any AES-GCM and ChaCha20 over any AES-CBC for better # performance and security # * Then Use HIGH cipher suites as a fallback # * Disable NULL authentication, NULL encryption, MD5 MACs, DSS, RC4, and # 3DES for security reasons _RESTRICTED_SERVER_CIPHERS = ( 'TLS13-AES-256-GCM-SHA384:TLS13-CHACHA20-POLY1305-SHA256:' 'TLS13-AES-128-GCM-SHA256:' 'ECDH+AESGCM:ECDH+CHACHA20:DH+AESGCM:DH+CHACHA20:ECDH+AES256:DH+AES256:' 'ECDH+AES128:DH+AES:ECDH+HIGH:DH+HIGH:RSA+AESGCM:RSA+AES:RSA+HIGH:' '!aNULL:!eNULL:!MD5:!DSS:!RC4:!3DES' ) class CertificateError(ValueError): pass def _dnsname_match(dn, hostname, max_wildcards=1): """Matching according to RFC 6125, section 6.4.3 http://tools.ietf.org/html/rfc6125#section-6.4.3 """ pats = [] if not dn: return False pieces = dn.split(r'.') leftmost = pieces[0] remainder = pieces[1:] wildcards = leftmost.count('*') if wildcards > max_wildcards: # Issue #17980: avoid denials of service by refusing more # than one wildcard per fragment. A survery of established # policy among SSL implementations showed it to be a # reasonable choice. raise CertificateError( "too many wildcards in certificate DNS name: " + repr(dn)) # speed up common case w/o wildcards if not wildcards: return dn.lower() == hostname.lower() # RFC 6125, section 6.4.3, subitem 1. # The client SHOULD NOT attempt to match a presented identifier in which # the wildcard character comprises a label other than the left-most label. if leftmost == '*': # When '*' is a fragment by itself, it matches a non-empty dotless # fragment. pats.append('[^.]+') elif leftmost.startswith('xn--') or hostname.startswith('xn--'): # RFC 6125, section 6.4.3, subitem 3. # The client SHOULD NOT attempt to match a presented identifier # where the wildcard character is embedded within an A-label or # U-label of an internationalized domain name. pats.append(re.escape(leftmost)) else: # Otherwise, '*' matches any dotless string, e.g. www* pats.append(re.escape(leftmost).replace(r'\*', '[^.]*')) # add the remaining fragments, ignore any wildcards for frag in remainder: pats.append(re.escape(frag)) pat = re.compile(r'\A' + r'\.'.join(pats) + r'\Z', re.IGNORECASE) return pat.match(hostname) def match_hostname(cert, hostname): """Verify that *cert* (in decoded format as returned by SSLSocket.getpeercert()) matches the *hostname*. RFC 2818 and RFC 6125 rules are followed, but IP addresses are not accepted for *hostname*. CertificateError is raised on failure. On success, the function returns nothing. """ if not cert: raise ValueError("empty or no certificate, match_hostname needs a " "SSL socket or SSL context with either " "CERT_OPTIONAL or CERT_REQUIRED") dnsnames = [] san = cert.get('subjectAltName', ()) for key, value in san: if key == 'DNS': if _dnsname_match(value, hostname): return dnsnames.append(value) if not dnsnames: # The subject is only checked when there is no dNSName entry # in subjectAltName for sub in cert.get('subject', ()): for key, value in sub: # XXX according to RFC 2818, the most specific Common Name # must be used. if key == 'commonName': if _dnsname_match(value, hostname): return dnsnames.append(value) if len(dnsnames) > 1: raise CertificateError("hostname %r " "doesn't match either of %s" % (hostname, ', '.join(map(repr, dnsnames)))) elif len(dnsnames) == 1: raise CertificateError("hostname %r " "doesn't match %r" % (hostname, dnsnames[0])) else: raise CertificateError("no appropriate commonName or " "subjectAltName fields were found") DefaultVerifyPaths = namedtuple("DefaultVerifyPaths", "cafile capath openssl_cafile_env openssl_cafile openssl_capath_env " "openssl_capath") def get_default_verify_paths(): """Return paths to default cafile and capath. """ parts = _ssl.get_default_verify_paths() # environment vars shadow paths cafile = os.environ.get(parts[0], parts[1]) capath = os.environ.get(parts[2], parts[3]) return DefaultVerifyPaths(cafile if os.path.isfile(cafile) else None, capath if os.path.isdir(capath) else None, *parts) class _ASN1Object(namedtuple("_ASN1Object", "nid shortname longname oid")): """ASN.1 object identifier lookup """ __slots__ = () def __new__(cls, oid): return super(_ASN1Object, cls).__new__(cls, *_txt2obj(oid, name=False)) @classmethod def fromnid(cls, nid): """Create _ASN1Object from OpenSSL numeric ID """ return super(_ASN1Object, cls).__new__(cls, *_nid2obj(nid)) @classmethod def fromname(cls, name): """Create _ASN1Object from short name, long name or OID """ return super(_ASN1Object, cls).__new__(cls, *_txt2obj(name, name=True)) class Purpose(_ASN1Object): """SSLContext purpose flags with X509v3 Extended Key Usage objects """ Purpose.SERVER_AUTH = Purpose('1.3.6.1.5.5.7.3.1') Purpose.CLIENT_AUTH = Purpose('1.3.6.1.5.5.7.3.2') class SSLContext(_SSLContext): """An SSLContext holds various SSL-related configuration options and data, such as certificates and possibly a private key.""" __slots__ = ('protocol', '__weakref__') _windows_cert_stores = ("CA", "ROOT") def __new__(cls, protocol, *args, **kwargs): self = _SSLContext.__new__(cls, protocol) if protocol != _SSLv2_IF_EXISTS: self.set_ciphers(_DEFAULT_CIPHERS) return self def __init__(self, protocol): self.protocol = protocol def wrap_socket(self, sock, server_side=False, do_handshake_on_connect=True, suppress_ragged_eofs=True, server_hostname=None): return SSLSocket(sock=sock, server_side=server_side, do_handshake_on_connect=do_handshake_on_connect, suppress_ragged_eofs=suppress_ragged_eofs, server_hostname=server_hostname, _context=self) def set_npn_protocols(self, npn_protocols): protos = bytearray() for protocol in npn_protocols: b = protocol.encode('ascii') if len(b) == 0 or len(b) > 255: raise SSLError('NPN protocols must be 1 to 255 in length') protos.append(len(b)) protos.extend(b) self._set_npn_protocols(protos) def set_alpn_protocols(self, alpn_protocols): protos = bytearray() for protocol in alpn_protocols: b = protocol.encode('ascii') if len(b) == 0 or len(b) > 255: raise SSLError('ALPN protocols must be 1 to 255 in length') protos.append(len(b)) protos.extend(b) self._set_alpn_protocols(protos) def _load_windows_store_certs(self, storename, purpose): certs = bytearray() try: for cert, encoding, trust in enum_certificates(storename): # CA certs are never PKCS#7 encoded if encoding == "x509_asn": if trust is True or purpose.oid in trust: certs.extend(cert) except OSError: warnings.warn("unable to enumerate Windows certificate store") if certs: self.load_verify_locations(cadata=certs) return certs def load_default_certs(self, purpose=Purpose.SERVER_AUTH): if not isinstance(purpose, _ASN1Object): raise TypeError(purpose) if sys.platform == "win32": for storename in self._windows_cert_stores: self._load_windows_store_certs(storename, purpose) self.set_default_verify_paths() def create_default_context(purpose=Purpose.SERVER_AUTH, cafile=None, capath=None, cadata=None): """Create a SSLContext object with default settings. NOTE: The protocol and settings may change anytime without prior deprecation. The values represent a fair balance between maximum compatibility and security. """ if not isinstance(purpose, _ASN1Object): raise TypeError(purpose) # SSLContext sets OP_NO_SSLv2, OP_NO_SSLv3, OP_NO_COMPRESSION, # OP_CIPHER_SERVER_PREFERENCE, OP_SINGLE_DH_USE and OP_SINGLE_ECDH_USE # by default. context = SSLContext(PROTOCOL_TLS) if purpose == Purpose.SERVER_AUTH: # verify certs and host name in client mode context.verify_mode = CERT_REQUIRED context.check_hostname = True elif purpose == Purpose.CLIENT_AUTH: context.set_ciphers(_RESTRICTED_SERVER_CIPHERS) if cafile or capath or cadata: context.load_verify_locations(cafile, capath, cadata) elif context.verify_mode != CERT_NONE: # no explicit cafile, capath or cadata but the verify mode is # CERT_OPTIONAL or CERT_REQUIRED. Let's try to load default system # root CA certificates for the given purpose. This may fail silently. context.load_default_certs(purpose) return context def _create_unverified_context(protocol=PROTOCOL_TLS, cert_reqs=None, check_hostname=False, purpose=Purpose.SERVER_AUTH, certfile=None, keyfile=None, cafile=None, capath=None, cadata=None): """Create a SSLContext object for Python stdlib modules All Python stdlib modules shall use this function to create SSLContext objects in order to keep common settings in one place. The configuration is less restrict than create_default_context()'s to increase backward compatibility. """ if not isinstance(purpose, _ASN1Object): raise TypeError(purpose) # SSLContext sets OP_NO_SSLv2, OP_NO_SSLv3, OP_NO_COMPRESSION, # OP_CIPHER_SERVER_PREFERENCE, OP_SINGLE_DH_USE and OP_SINGLE_ECDH_USE # by default. context = SSLContext(protocol) if cert_reqs is not None: context.verify_mode = cert_reqs context.check_hostname = check_hostname if keyfile and not certfile: raise ValueError("certfile must be specified") if certfile or keyfile: context.load_cert_chain(certfile, keyfile) # load CA root certs if cafile or capath or cadata: context.load_verify_locations(cafile, capath, cadata) elif context.verify_mode != CERT_NONE: # no explicit cafile, capath or cadata but the verify mode is # CERT_OPTIONAL or CERT_REQUIRED. Let's try to load default system # root CA certificates for the given purpose. This may fail silently. context.load_default_certs(purpose) return context # Backwards compatibility alias, even though it's not a public name. _create_stdlib_context = _create_unverified_context # PEP 493: Verify HTTPS by default, but allow envvar to override that _https_verify_envvar = 'PYTHONHTTPSVERIFY' def _get_https_context_factory(): if not sys.flags.ignore_environment: config_setting = os.environ.get(_https_verify_envvar) if config_setting == '0': return _create_unverified_context return create_default_context _create_default_https_context = _get_https_context_factory() # PEP 493: "private" API to configure HTTPS defaults without monkeypatching def _https_verify_certificates(enable=True): """Verify server HTTPS certificates by default?""" global _create_default_https_context if enable: _create_default_https_context = create_default_context else: _create_default_https_context = _create_unverified_context class SSLSocket(socket): """This class implements a subtype of socket.socket that wraps the underlying OS socket in an SSL context when necessary, and provides read and write methods over that channel.""" def __init__(self, sock=None, keyfile=None, certfile=None, server_side=False, cert_reqs=CERT_NONE, ssl_version=PROTOCOL_TLS, ca_certs=None, do_handshake_on_connect=True, family=AF_INET, type=SOCK_STREAM, proto=0, fileno=None, suppress_ragged_eofs=True, npn_protocols=None, ciphers=None, server_hostname=None, _context=None): self._sslobj = None self._makefile_refs = 0 if _context: self._context = _context else: if server_side and not certfile: raise ValueError("certfile must be specified for server-side " "operations") if keyfile and not certfile: raise ValueError("certfile must be specified") if certfile and not keyfile: keyfile = certfile self._context = SSLContext(ssl_version) self._context.verify_mode = cert_reqs if ca_certs: self._context.load_verify_locations(ca_certs) if certfile: self._context.load_cert_chain(certfile, keyfile) if npn_protocols: self._context.set_npn_protocols(npn_protocols) if ciphers: self._context.set_ciphers(ciphers) self.keyfile = keyfile self.certfile = certfile self.cert_reqs = cert_reqs self.ssl_version = ssl_version self.ca_certs = ca_certs self.ciphers = ciphers # Can't use sock.type as other flags (such as SOCK_NONBLOCK) get # mixed in. if sock.getsockopt(SOL_SOCKET, SO_TYPE) != SOCK_STREAM: raise NotImplementedError("only stream sockets are supported") socket.__init__(self, _sock=sock._sock) # The initializer for socket overrides the methods send(), recv(), etc. # in the instancce, which we don't need -- but we want to provide the # methods defined in SSLSocket. for attr in _delegate_methods: try: delattr(self, attr) except AttributeError: pass if server_side and server_hostname: raise ValueError("server_hostname can only be specified " "in client mode") if self._context.check_hostname and not server_hostname: raise ValueError("check_hostname requires server_hostname") self.server_side = server_side self.server_hostname = server_hostname self.do_handshake_on_connect = do_handshake_on_connect self.suppress_ragged_eofs = suppress_ragged_eofs sock_timeout = sock.gettimeout() # See if we are connected try: self.getpeername() except socket_error as e: if e.errno != errno.ENOTCONN: raise connected = False blocking = (sock.gettimeout() != 0) self.setblocking(False) try: # We are not connected so this is not supposed to block, but # testing revealed otherwise on macOS and Windows so we do # the non-blocking dance regardless. Our raise when any data # is found means consuming the data is harmless. notconn_pre_handshake_data = self.recv(1) except socket_error as e: # EINVAL occurs for recv(1) on non-connected on unix sockets. if e.errno not in (errno.ENOTCONN, errno.EINVAL): raise notconn_pre_handshake_data = b'' self.setblocking(blocking) if notconn_pre_handshake_data: # This prevents pending data sent to the socket before it was # closed from escaping to the caller who could otherwise # presume it came through a successful TLS connection. reason = "Closed before TLS handshake with data in recv buffer" notconn_pre_handshake_data_error = SSLError(e.errno, reason) # Add the SSLError attributes that _ssl.c always adds. notconn_pre_handshake_data_error.reason = reason notconn_pre_handshake_data_error.library = None try: self.close() except OSError: pass try: raise notconn_pre_handshake_data_error finally: # Explicitly break the reference cycle. notconn_pre_handshake_data_error = None else: connected = True self.settimeout(sock_timeout) # Must come after setblocking() calls. self._closed = False self._sslobj = None self._connected = connected if connected: # create the SSL object try: self._sslobj = self._context._wrap_socket(self._sock, server_side, server_hostname, ssl_sock=self) if do_handshake_on_connect: timeout = self.gettimeout() if timeout == 0.0: # non-blocking raise ValueError("do_handshake_on_connect should not be specified for non-blocking sockets") self.do_handshake() except (OSError, ValueError): self.close() raise @property def context(self): return self._context @context.setter def context(self, ctx): self._context = ctx self._sslobj.context = ctx def dup(self): raise NotImplementedError("Can't dup() %s instances" % self.__class__.__name__) def _checkClosed(self, msg=None): # raise an exception here if you wish to check for spurious closes pass def _check_connected(self): if not self._connected: # getpeername() will raise ENOTCONN if the socket is really # not connected; note that we can be connected even without # _connected being set, e.g. if connect() first returned # EAGAIN. self.getpeername() def read(self, len=1024, buffer=None): """Read up to LEN bytes and return them. Return zero-length string on EOF.""" self._checkClosed() if not self._sslobj: raise ValueError("Read on closed or unwrapped SSL socket.") try: if buffer is not None: v = self._sslobj.read(len, buffer) else: v = self._sslobj.read(len) return v except SSLError as x: if x.args[0] == SSL_ERROR_EOF and self.suppress_ragged_eofs: if buffer is not None: return 0 else: return b'' else: raise def write(self, data): """Write DATA to the underlying SSL channel. Returns number of bytes of DATA actually transmitted.""" self._checkClosed() if not self._sslobj: raise ValueError("Write on closed or unwrapped SSL socket.") return self._sslobj.write(data) def getpeercert(self, binary_form=False): """Returns a formatted version of the data in the certificate provided by the other end of the SSL channel. Return None if no certificate was provided, {} if a certificate was provided, but not validated.""" self._checkClosed() self._check_connected() return self._sslobj.peer_certificate(binary_form) def selected_npn_protocol(self): self._checkClosed() if not self._sslobj or not _ssl.HAS_NPN: return None else: return self._sslobj.selected_npn_protocol() def selected_alpn_protocol(self): self._checkClosed() if not self._sslobj or not _ssl.HAS_ALPN: return None else: return self._sslobj.selected_alpn_protocol() def cipher(self): self._checkClosed() if not self._sslobj: return None else: return self._sslobj.cipher() def compression(self): self._checkClosed() if not self._sslobj: return None else: return self._sslobj.compression() def send(self, data, flags=0): self._checkClosed() if self._sslobj: if flags != 0: raise ValueError( "non-zero flags not allowed in calls to send() on %s" % self.__class__) try: v = self._sslobj.write(data) except SSLError as x: if x.args[0] == SSL_ERROR_WANT_READ: return 0 elif x.args[0] == SSL_ERROR_WANT_WRITE: return 0 else: raise else: return v else: return self._sock.send(data, flags) def sendto(self, data, flags_or_addr, addr=None): self._checkClosed() if self._sslobj: raise ValueError("sendto not allowed on instances of %s" % self.__class__) elif addr is None: return self._sock.sendto(data, flags_or_addr) else: return self._sock.sendto(data, flags_or_addr, addr) def sendall(self, data, flags=0): self._checkClosed() if self._sslobj: if flags != 0: raise ValueError( "non-zero flags not allowed in calls to sendall() on %s" % self.__class__) amount = len(data) count = 0 while (count < amount): v = self.send(data[count:]) count += v return amount else: return socket.sendall(self, data, flags) def recv(self, buflen=1024, flags=0): self._checkClosed() if self._sslobj: if flags != 0: raise ValueError( "non-zero flags not allowed in calls to recv() on %s" % self.__class__) return self.read(buflen) else: return self._sock.recv(buflen, flags) def recv_into(self, buffer, nbytes=None, flags=0): self._checkClosed() if buffer and (nbytes is None): nbytes = len(buffer) elif nbytes is None: nbytes = 1024 if self._sslobj: if flags != 0: raise ValueError( "non-zero flags not allowed in calls to recv_into() on %s" % self.__class__) return self.read(nbytes, buffer) else: return self._sock.recv_into(buffer, nbytes, flags) def recvfrom(self, buflen=1024, flags=0): self._checkClosed() if self._sslobj: raise ValueError("recvfrom not allowed on instances of %s" % self.__class__) else: return self._sock.recvfrom(buflen, flags) def recvfrom_into(self, buffer, nbytes=None, flags=0): self._checkClosed() if self._sslobj: raise ValueError("recvfrom_into not allowed on instances of %s" % self.__class__) else: return self._sock.recvfrom_into(buffer, nbytes, flags) def pending(self): self._checkClosed() if self._sslobj: return self._sslobj.pending() else: return 0 def shutdown(self, how): self._checkClosed() self._sslobj = None socket.shutdown(self, how) def close(self): if self._makefile_refs < 1: self._sslobj = None socket.close(self) else: self._makefile_refs -= 1 def unwrap(self): if self._sslobj: s = self._sslobj.shutdown() self._sslobj = None return s else: raise ValueError("No SSL wrapper around " + str(self)) def _real_close(self): self._sslobj = None socket._real_close(self) def do_handshake(self, block=False): """Perform a TLS/SSL handshake.""" self._check_connected() timeout = self.gettimeout() try: if timeout == 0.0 and block: self.settimeout(None) self._sslobj.do_handshake() finally: self.settimeout(timeout) if self.context.check_hostname: if not self.server_hostname: raise ValueError("check_hostname needs server_hostname " "argument") match_hostname(self.getpeercert(), self.server_hostname) def _real_connect(self, addr, connect_ex): if self.server_side: raise ValueError("can't connect in server-side mode") # Here we assume that the socket is client-side, and not # connected at the time of the call. We connect it, then wrap it. if self._connected: raise ValueError("attempt to connect already-connected SSLSocket!") self._sslobj = self.context._wrap_socket(self._sock, False, self.server_hostname, ssl_sock=self) try: if connect_ex: rc = socket.connect_ex(self, addr) else: rc = None socket.connect(self, addr) if not rc: self._connected = True if self.do_handshake_on_connect: self.do_handshake() return rc except (OSError, ValueError): self._sslobj = None raise def connect(self, addr): """Connects to remote ADDR, and then wraps the connection in an SSL channel.""" self._real_connect(addr, False) def connect_ex(self, addr): """Connects to remote ADDR, and then wraps the connection in an SSL channel.""" return self._real_connect(addr, True) def accept(self): """Accepts a new connection from a remote client, and returns a tuple containing that new connection wrapped with a server-side SSL channel, and the address of the remote client.""" newsock, addr = socket.accept(self) newsock = self.context.wrap_socket(newsock, do_handshake_on_connect=self.do_handshake_on_connect, suppress_ragged_eofs=self.suppress_ragged_eofs, server_side=True) return newsock, addr def makefile(self, mode='r', bufsize=-1): """Make and return a file-like object that works with the SSL connection. Just use the code from the socket module.""" self._makefile_refs += 1 # close=True so as to decrement the reference count when done with # the file-like object. return _fileobject(self, mode, bufsize, close=True) def get_channel_binding(self, cb_type="tls-unique"): """Get channel binding data for current connection. Raise ValueError if the requested `cb_type` is not supported. Return bytes of the data or None if the data is not available (e.g. before the handshake). """ if cb_type not in CHANNEL_BINDING_TYPES: raise ValueError("Unsupported channel binding type") if cb_type != "tls-unique": raise NotImplementedError( "{0} channel binding type not implemented" .format(cb_type)) if self._sslobj is None: return None return self._sslobj.tls_unique_cb() def version(self): """ Return a string identifying the protocol version used by the current SSL channel, or None if there is no established channel. """ if self._sslobj is None: return None return self._sslobj.version() def wrap_socket(sock, keyfile=None, certfile=None, server_side=False, cert_reqs=CERT_NONE, ssl_version=PROTOCOL_TLS, ca_certs=None, do_handshake_on_connect=True, suppress_ragged_eofs=True, ciphers=None): return SSLSocket(sock=sock, keyfile=keyfile, certfile=certfile, server_side=server_side, cert_reqs=cert_reqs, ssl_version=ssl_version, ca_certs=ca_certs, do_handshake_on_connect=do_handshake_on_connect, suppress_ragged_eofs=suppress_ragged_eofs, ciphers=ciphers) # some utility functions def cert_time_to_seconds(cert_time): """Return the time in seconds since the Epoch, given the timestring representing the "notBefore" or "notAfter" date from a certificate in ``"%b %d %H:%M:%S %Y %Z"`` strptime format (C locale). "notBefore" or "notAfter" dates must use UTC (RFC 5280). Month is one of: Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec UTC should be specified as GMT (see ASN1_TIME_print()) """ from time import strptime from calendar import timegm months = ( "Jan","Feb","Mar","Apr","May","Jun", "Jul","Aug","Sep","Oct","Nov","Dec" ) time_format = ' %d %H:%M:%S %Y GMT' # NOTE: no month, fixed GMT try: month_number = months.index(cert_time[:3].title()) + 1 except ValueError: raise ValueError('time data %r does not match ' 'format "%%b%s"' % (cert_time, time_format)) else: # found valid month tt = strptime(cert_time[3:], time_format) # return an integer, the previous mktime()-based implementation # returned a float (fractional seconds are always zero here). return timegm((tt[0], month_number) + tt[2:6]) PEM_HEADER = "-----BEGIN CERTIFICATE-----" PEM_FOOTER = "-----END CERTIFICATE-----" def DER_cert_to_PEM_cert(der_cert_bytes): """Takes a certificate in binary DER format and returns the PEM version of it as a string.""" f = base64.standard_b64encode(der_cert_bytes).decode('ascii') return (PEM_HEADER + '\n' + textwrap.fill(f, 64) + '\n' + PEM_FOOTER + '\n') def PEM_cert_to_DER_cert(pem_cert_string): """Takes a certificate in ASCII PEM format and returns the DER-encoded version of it as a byte sequence""" if not pem_cert_string.startswith(PEM_HEADER): raise ValueError("Invalid PEM encoding; must start with %s" % PEM_HEADER) if not pem_cert_string.strip().endswith(PEM_FOOTER): raise ValueError("Invalid PEM encoding; must end with %s" % PEM_FOOTER) d = pem_cert_string.strip()[len(PEM_HEADER):-len(PEM_FOOTER)] return base64.decodestring(d.encode('ASCII', 'strict')) def get_server_certificate(addr, ssl_version=PROTOCOL_TLS, ca_certs=None): """Retrieve the certificate from the server at the specified address, and return it as a PEM-encoded string. If 'ca_certs' is specified, validate the server cert against it. If 'ssl_version' is specified, use it in the connection attempt.""" host, port = addr if ca_certs is not None: cert_reqs = CERT_REQUIRED else: cert_reqs = CERT_NONE context = _create_stdlib_context(ssl_version, cert_reqs=cert_reqs, cafile=ca_certs) with closing(create_connection(addr)) as sock: with closing(context.wrap_socket(sock)) as sslsock: dercert = sslsock.getpeercert(True) return DER_cert_to_PEM_cert(dercert) def get_protocol_name(protocol_code): return _PROTOCOL_NAMES.get(protocol_code, '<unknown>') # a replacement for the old socket.ssl function def sslwrap_simple(sock, keyfile=None, certfile=None): """A replacement for the old socket.ssl function. Designed for compability with Python 2.5 and earlier. Will disappear in Python 3.0.""" if hasattr(sock, "_sock"): sock = sock._sock ctx = SSLContext(PROTOCOL_SSLv23) if keyfile or certfile: ctx.load_cert_chain(certfile, keyfile) ssl_sock = ctx._wrap_socket(sock, server_side=False) try: sock.getpeername() except socket_error: # no, no connection yet pass else: # yes, do the handshake ssl_sock.do_handshake() return ssl_sock
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