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# 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_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 ipaddress import textwrap import re import sys import os from collections import namedtuple from enum import Enum as _Enum, IntEnum as _IntEnum 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, MemoryBIO 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, RAND_bytes, RAND_pseudo_bytes 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('VERIFY_') from _ssl import HAS_SNI, HAS_ECDH, HAS_NPN, HAS_ALPN from _ssl import _OPENSSL_API_VERSION _IntEnum._convert( '_SSLMethod', __name__, lambda name: name.startswith('PROTOCOL_'), source=_ssl) _PROTOCOL_NAMES = {value: name for name, value in _SSLMethod.__members__.items()} try: _SSLv2_IF_EXISTS = PROTOCOL_SSLv2 except NameError: _SSLv2_IF_EXISTS = None 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 socket_error = OSError # keep that public name in module namespace 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: # * Prefer cipher suites that offer perfect forward secrecy (DHE/ECDHE) # * Prefer ECDHE over DHE for better performance # * Prefer any AES-GCM over any AES-CBC for better performance and security # * Then Use HIGH cipher suites as a fallback # * Then Use 3DES as fallback which is secure but slow # * Disable NULL authentication, NULL encryption, and MD5 MACs for security # reasons _DEFAULT_CIPHERS = ( 'ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:ECDH+HIGH:' 'DH+HIGH:ECDH+3DES:DH+3DES:RSA+AESGCM:RSA+AES:RSA+HIGH:RSA+3DES:!aNULL:' '!eNULL:!MD5' ) # Restricted and more secure ciphers for the server side # This list has been explicitly chosen to: # * Prefer cipher suites that offer perfect forward secrecy (DHE/ECDHE) # * Prefer ECDHE over DHE for better performance # * Prefer any AES-GCM over any AES-CBC for better performance and security # * Then Use HIGH cipher suites as a fallback # * Then Use 3DES as fallback which is secure but slow # * Disable NULL authentication, NULL encryption, MD5 MACs, DSS, and RC4 for # security reasons _RESTRICTED_SERVER_CIPHERS = ( 'ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:ECDH+HIGH:' 'DH+HIGH:ECDH+3DES:DH+3DES:RSA+AESGCM:RSA+AES:RSA+HIGH:RSA+3DES:!aNULL:' '!eNULL:!MD5:!DSS:!RC4' ) 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 leftmost, *remainder = dn.split(r'.') wildcards = leftmost.count('*') if wildcards > max_wildcards: # Issue #17980: avoid denials of service by refusing more # than one wildcard per fragment. A survey 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 _ipaddress_match(ipname, host_ip): """Exact matching of IP addresses. RFC 6125 explicitly doesn't define an algorithm for this (section 1.7.2 - "Out of Scope"). """ # OpenSSL may add a trailing newline to a subjectAltName's IP address ip = ipaddress.ip_address(ipname.rstrip()) return ip == host_ip 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") try: host_ip = ipaddress.ip_address(hostname) except ValueError: # Not an IP address (common case) host_ip = None dnsnames = [] san = cert.get('subjectAltName', ()) for key, value in san: if key == 'DNS': if host_ip is None and _dnsname_match(value, hostname): return dnsnames.append(value) elif key == 'IP Address': if host_ip is not None and _ipaddress_match(value, host_ip): 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().__new__(cls, *_txt2obj(oid, name=False)) @classmethod def fromnid(cls, nid): """Create _ASN1Object from OpenSSL numeric ID """ return super().__new__(cls, *_nid2obj(nid)) @classmethod def fromname(cls, name): """Create _ASN1Object from short name, long name or OID """ return super().__new__(cls, *_txt2obj(name, name=True)) class Purpose(_ASN1Object, _Enum): """SSLContext purpose flags with X509v3 Extended Key Usage objects """ SERVER_AUTH = '1.3.6.1.5.5.7.3.1' CLIENT_AUTH = '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 wrap_bio(self, incoming, outgoing, server_side=False, server_hostname=None): sslobj = self._wrap_bio(incoming, outgoing, server_side=server_side, server_hostname=server_hostname) return SSLObject(sslobj) def set_npn_protocols(self, npn_protocols): protos = bytearray() for protocol in npn_protocols: b = bytes(protocol, '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 = bytes(protocol, '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 PermissionError: 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) context = SSLContext(PROTOCOL_SSLv23) # SSLv2 considered harmful. context.options |= OP_NO_SSLv2 # SSLv3 has problematic security and is only required for really old # clients such as IE6 on Windows XP context.options |= OP_NO_SSLv3 # disable compression to prevent CRIME attacks (OpenSSL 1.0+) context.options |= getattr(_ssl, "OP_NO_COMPRESSION", 0) 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: # Prefer the server's ciphers by default so that we get stronger # encryption context.options |= getattr(_ssl, "OP_CIPHER_SERVER_PREFERENCE", 0) # Use single use keys in order to improve forward secrecy context.options |= getattr(_ssl, "OP_SINGLE_DH_USE", 0) context.options |= getattr(_ssl, "OP_SINGLE_ECDH_USE", 0) # disallow ciphers with known vulnerabilities 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_SSLv23, *, 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) context = SSLContext(protocol) # SSLv2 considered harmful. context.options |= OP_NO_SSLv2 # SSLv3 has problematic security and is only required for really old # clients such as IE6 on Windows XP context.options |= OP_NO_SSLv3 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 # Used by http.client if no context is explicitly passed. _create_default_https_context = create_default_context # Backwards compatibility alias, even though it's not a public name. _create_stdlib_context = _create_unverified_context class SSLObject: """This class implements an interface on top of a low-level SSL object as implemented by OpenSSL. This object captures the state of an SSL connection but does not provide any network IO itself. IO needs to be performed through separate "BIO" objects which are OpenSSL's IO abstraction layer. This class does not have a public constructor. Instances are returned by ``SSLContext.wrap_bio``. This class is typically used by framework authors that want to implement asynchronous IO for SSL through memory buffers. When compared to ``SSLSocket``, this object lacks the following features: * Any form of network IO incluging methods such as ``recv`` and ``send``. * The ``do_handshake_on_connect`` and ``suppress_ragged_eofs`` machinery. """ def __init__(self, sslobj, owner=None): self._sslobj = sslobj # Note: _sslobj takes a weak reference to owner self._sslobj.owner = owner or self @property def context(self): """The SSLContext that is currently in use.""" return self._sslobj.context @context.setter def context(self, ctx): self._sslobj.context = ctx @property def server_side(self): """Whether this is a server-side socket.""" return self._sslobj.server_side @property def server_hostname(self): """The currently set server hostname (for SNI), or ``None`` if no server hostame is set.""" return self._sslobj.server_hostname def read(self, len=1024, buffer=None): """Read up to 'len' bytes from the SSL object and return them. If 'buffer' is provided, read into this buffer and return the number of bytes read. """ if buffer is not None: v = self._sslobj.read(len, buffer) else: v = self._sslobj.read(len) return v def write(self, data): """Write 'data' to the SSL object and return the number of bytes written. The 'data' argument must support the buffer interface. """ 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. """ return self._sslobj.peer_certificate(binary_form) def selected_npn_protocol(self): """Return the currently selected NPN protocol as a string, or ``None`` if a next protocol was not negotiated or if NPN is not supported by one of the peers.""" if _ssl.HAS_NPN: return self._sslobj.selected_npn_protocol() def selected_alpn_protocol(self): """Return the currently selected ALPN protocol as a string, or ``None`` if a next protocol was not negotiated or if ALPN is not supported by one of the peers.""" if _ssl.HAS_ALPN: return self._sslobj.selected_alpn_protocol() def cipher(self): """Return the currently selected cipher as a 3-tuple ``(name, ssl_version, secret_bits)``.""" return self._sslobj.cipher() def shared_ciphers(self): """Return a list of ciphers shared by the client during the handshake or None if this is not a valid server connection. """ return self._sslobj.shared_ciphers() def compression(self): """Return the current compression algorithm in use, or ``None`` if compression was not negotiated or not supported by one of the peers.""" return self._sslobj.compression() def pending(self): """Return the number of bytes that can be read immediately.""" return self._sslobj.pending() def do_handshake(self): """Start the SSL/TLS handshake.""" self._sslobj.do_handshake() 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 unwrap(self): """Start the SSL shutdown handshake.""" return self._sslobj.shutdown() 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)) return self._sslobj.tls_unique_cb() def version(self): """Return a string identifying the protocol version used by the current SSL channel. """ return self._sslobj.version() 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_SSLv23, 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): 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") 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 if sock is not None: socket.__init__(self, family=sock.family, type=sock.type, proto=sock.proto, fileno=sock.fileno()) self.settimeout(sock.gettimeout()) sock.detach() elif fileno is not None: socket.__init__(self, fileno=fileno) else: socket.__init__(self, family=family, type=type, proto=proto) # See if we are connected try: self.getpeername() except OSError as e: if e.errno != errno.ENOTCONN: raise connected = False else: connected = True self._closed = False self._sslobj = None self._connected = connected if connected: # create the SSL object try: sslobj = self._context._wrap_socket(self, server_side, server_hostname) self._sslobj = SSLObject(sslobj, owner=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 NotImplemented("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: return self._sslobj.read(len, buffer) 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.getpeercert(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 shared_ciphers(self): self._checkClosed() if not self._sslobj: return None return self._sslobj.shared_ciphers() 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__) return self._sslobj.write(data) else: return socket.send(self, 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 socket.sendto(self, data, flags_or_addr) else: return socket.sendto(self, data, flags_or_addr, addr) def sendmsg(self, *args, **kwargs): # Ensure programs don't send data unencrypted if they try to # use this method. raise NotImplementedError("sendmsg not allowed on instances of %s" % self.__class__) 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 sendfile(self, file, offset=0, count=None): """Send a file, possibly by using os.sendfile() if this is a clear-text socket. Return the total number of bytes sent. """ if self._sslobj is None: # os.sendfile() works with plain sockets only return super().sendfile(file, offset, count) else: return self._sendfile_use_send(file, offset, count) 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 socket.recv(self, 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 socket.recv_into(self, 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 socket.recvfrom(self, 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 socket.recvfrom_into(self, buffer, nbytes, flags) def recvmsg(self, *args, **kwargs): raise NotImplementedError("recvmsg not allowed on instances of %s" % self.__class__) def recvmsg_into(self, *args, **kwargs): raise NotImplementedError("recvmsg_into not allowed on instances of " "%s" % self.__class__) 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 unwrap(self): if self._sslobj: s = self._sslobj.unwrap() 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) 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!") sslobj = self.context._wrap_socket(self, False, self.server_hostname) self._sslobj = SSLObject(sslobj, owner=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 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 self._sslobj is None: return None return self._sslobj.get_channel_binding(cb_type) 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_SSLv23, 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 = str(base64.standard_b64encode(der_cert_bytes), 'ASCII', 'strict') 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.decodebytes(d.encode('ASCII', 'strict')) def get_server_certificate(addr, ssl_version=PROTOCOL_SSLv23, 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 create_connection(addr) as sock: with 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>')