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Diffstat (limited to 'python/urllib3/connection.py')
| -rw-r--r-- | python/urllib3/connection.py | 391 |
1 files changed, 391 insertions, 0 deletions
diff --git a/python/urllib3/connection.py b/python/urllib3/connection.py new file mode 100644 index 0000000..02b3665 --- /dev/null +++ b/python/urllib3/connection.py @@ -0,0 +1,391 @@ +from __future__ import absolute_import +import datetime +import logging +import os +import socket +from socket import error as SocketError, timeout as SocketTimeout +import warnings +from .packages import six +from .packages.six.moves.http_client import HTTPConnection as _HTTPConnection +from .packages.six.moves.http_client import HTTPException # noqa: F401 + +try: # Compiled with SSL? + import ssl + BaseSSLError = ssl.SSLError +except (ImportError, AttributeError): # Platform-specific: No SSL. + ssl = None + + class BaseSSLError(BaseException): + pass + + +try: # Python 3: + # Not a no-op, we're adding this to the namespace so it can be imported. + ConnectionError = ConnectionError +except NameError: # Python 2: + class ConnectionError(Exception): + pass + + +from .exceptions import ( + NewConnectionError, + ConnectTimeoutError, + SubjectAltNameWarning, + SystemTimeWarning, +) +from .packages.ssl_match_hostname import match_hostname, CertificateError + +from .util.ssl_ import ( + resolve_cert_reqs, + resolve_ssl_version, + assert_fingerprint, + create_urllib3_context, + ssl_wrap_socket +) + + +from .util import connection + +from ._collections import HTTPHeaderDict + +log = logging.getLogger(__name__) + +port_by_scheme = { + 'http': 80, + 'https': 443, +} + +# When updating RECENT_DATE, move it to within two years of the current date, +# and not less than 6 months ago. +# Example: if Today is 2018-01-01, then RECENT_DATE should be any date on or +# after 2016-01-01 (today - 2 years) AND before 2017-07-01 (today - 6 months) +RECENT_DATE = datetime.date(2017, 6, 30) + + +class DummyConnection(object): + """Used to detect a failed ConnectionCls import.""" + pass + + +class HTTPConnection(_HTTPConnection, object): + """ + Based on httplib.HTTPConnection but provides an extra constructor + backwards-compatibility layer between older and newer Pythons. + + Additional keyword parameters are used to configure attributes of the connection. + Accepted parameters include: + + - ``strict``: See the documentation on :class:`urllib3.connectionpool.HTTPConnectionPool` + - ``source_address``: Set the source address for the current connection. + - ``socket_options``: Set specific options on the underlying socket. If not specified, then + defaults are loaded from ``HTTPConnection.default_socket_options`` which includes disabling + Nagle's algorithm (sets TCP_NODELAY to 1) unless the connection is behind a proxy. + + For example, if you wish to enable TCP Keep Alive in addition to the defaults, + you might pass:: + + HTTPConnection.default_socket_options + [ + (socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1), + ] + + Or you may want to disable the defaults by passing an empty list (e.g., ``[]``). + """ + + default_port = port_by_scheme['http'] + + #: Disable Nagle's algorithm by default. + #: ``[(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)]`` + default_socket_options = [(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)] + + #: Whether this connection verifies the host's certificate. + is_verified = False + + def __init__(self, *args, **kw): + if six.PY3: # Python 3 + kw.pop('strict', None) + + # Pre-set source_address. + self.source_address = kw.get('source_address') + + #: The socket options provided by the user. If no options are + #: provided, we use the default options. + self.socket_options = kw.pop('socket_options', self.default_socket_options) + + _HTTPConnection.__init__(self, *args, **kw) + + @property + def host(self): + """ + Getter method to remove any trailing dots that indicate the hostname is an FQDN. + + In general, SSL certificates don't include the trailing dot indicating a + fully-qualified domain name, and thus, they don't validate properly when + checked against a domain name that includes the dot. In addition, some + servers may not expect to receive the trailing dot when provided. + + However, the hostname with trailing dot is critical to DNS resolution; doing a + lookup with the trailing dot will properly only resolve the appropriate FQDN, + whereas a lookup without a trailing dot will search the system's search domain + list. Thus, it's important to keep the original host around for use only in + those cases where it's appropriate (i.e., when doing DNS lookup to establish the + actual TCP connection across which we're going to send HTTP requests). + """ + return self._dns_host.rstrip('.') + + @host.setter + def host(self, value): + """ + Setter for the `host` property. + + We assume that only urllib3 uses the _dns_host attribute; httplib itself + only uses `host`, and it seems reasonable that other libraries follow suit. + """ + self._dns_host = value + + def _new_conn(self): + """ Establish a socket connection and set nodelay settings on it. + + :return: New socket connection. + """ + extra_kw = {} + if self.source_address: + extra_kw['source_address'] = self.source_address + + if self.socket_options: + extra_kw['socket_options'] = self.socket_options + + try: + conn = connection.create_connection( + (self._dns_host, self.port), self.timeout, **extra_kw) + + except SocketTimeout as e: + raise ConnectTimeoutError( + self, "Connection to %s timed out. (connect timeout=%s)" % + (self.host, self.timeout)) + + except SocketError as e: + raise NewConnectionError( + self, "Failed to establish a new connection: %s" % e) + + return conn + + def _prepare_conn(self, conn): + self.sock = conn + if self._tunnel_host: + # TODO: Fix tunnel so it doesn't depend on self.sock state. + self._tunnel() + # Mark this connection as not reusable + self.auto_open = 0 + + def connect(self): + conn = self._new_conn() + self._prepare_conn(conn) + + def request_chunked(self, method, url, body=None, headers=None): + """ + Alternative to the common request method, which sends the + body with chunked encoding and not as one block + """ + headers = HTTPHeaderDict(headers if headers is not None else {}) + skip_accept_encoding = 'accept-encoding' in headers + skip_host = 'host' in headers + self.putrequest( + method, + url, + skip_accept_encoding=skip_accept_encoding, + skip_host=skip_host + ) + for header, value in headers.items(): + self.putheader(header, value) + if 'transfer-encoding' not in headers: + self.putheader('Transfer-Encoding', 'chunked') + self.endheaders() + + if body is not None: + stringish_types = six.string_types + (bytes,) + if isinstance(body, stringish_types): + body = (body,) + for chunk in body: + if not chunk: + continue + if not isinstance(chunk, bytes): + chunk = chunk.encode('utf8') + len_str = hex(len(chunk))[2:] + self.send(len_str.encode('utf-8')) + self.send(b'\r\n') + self.send(chunk) + self.send(b'\r\n') + + # After the if clause, to always have a closed body + self.send(b'0\r\n\r\n') + + +class HTTPSConnection(HTTPConnection): + default_port = port_by_scheme['https'] + + ssl_version = None + + def __init__(self, host, port=None, key_file=None, cert_file=None, + strict=None, timeout=socket._GLOBAL_DEFAULT_TIMEOUT, + ssl_context=None, server_hostname=None, **kw): + + HTTPConnection.__init__(self, host, port, strict=strict, + timeout=timeout, **kw) + + self.key_file = key_file + self.cert_file = cert_file + self.ssl_context = ssl_context + self.server_hostname = server_hostname + + # Required property for Google AppEngine 1.9.0 which otherwise causes + # HTTPS requests to go out as HTTP. (See Issue #356) + self._protocol = 'https' + + def connect(self): + conn = self._new_conn() + self._prepare_conn(conn) + + if self.ssl_context is None: + self.ssl_context = create_urllib3_context( + ssl_version=resolve_ssl_version(None), + cert_reqs=resolve_cert_reqs(None), + ) + + self.sock = ssl_wrap_socket( + sock=conn, + keyfile=self.key_file, + certfile=self.cert_file, + ssl_context=self.ssl_context, + server_hostname=self.server_hostname + ) + + +class VerifiedHTTPSConnection(HTTPSConnection): + """ + Based on httplib.HTTPSConnection but wraps the socket with + SSL certification. + """ + cert_reqs = None + ca_certs = None + ca_cert_dir = None + ssl_version = None + assert_fingerprint = None + + def set_cert(self, key_file=None, cert_file=None, + cert_reqs=None, ca_certs=None, + assert_hostname=None, assert_fingerprint=None, + ca_cert_dir=None): + """ + This method should only be called once, before the connection is used. + """ + # If cert_reqs is not provided, we can try to guess. If the user gave + # us a cert database, we assume they want to use it: otherwise, if + # they gave us an SSL Context object we should use whatever is set for + # it. + if cert_reqs is None: + if ca_certs or ca_cert_dir: + cert_reqs = 'CERT_REQUIRED' + elif self.ssl_context is not None: + cert_reqs = self.ssl_context.verify_mode + + self.key_file = key_file + self.cert_file = cert_file + self.cert_reqs = cert_reqs + self.assert_hostname = assert_hostname + self.assert_fingerprint = assert_fingerprint + self.ca_certs = ca_certs and os.path.expanduser(ca_certs) + self.ca_cert_dir = ca_cert_dir and os.path.expanduser(ca_cert_dir) + + def connect(self): + # Add certificate verification + conn = self._new_conn() + hostname = self.host + + if self._tunnel_host: + self.sock = conn + # Calls self._set_hostport(), so self.host is + # self._tunnel_host below. + self._tunnel() + # Mark this connection as not reusable + self.auto_open = 0 + + # Override the host with the one we're requesting data from. + hostname = self._tunnel_host + + server_hostname = hostname + if self.server_hostname is not None: + server_hostname = self.server_hostname + + is_time_off = datetime.date.today() < RECENT_DATE + if is_time_off: + warnings.warn(( + 'System time is way off (before {0}). This will probably ' + 'lead to SSL verification errors').format(RECENT_DATE), + SystemTimeWarning + ) + + # Wrap socket using verification with the root certs in + # trusted_root_certs + if self.ssl_context is None: + self.ssl_context = create_urllib3_context( + ssl_version=resolve_ssl_version(self.ssl_version), + cert_reqs=resolve_cert_reqs(self.cert_reqs), + ) + + context = self.ssl_context + context.verify_mode = resolve_cert_reqs(self.cert_reqs) + self.sock = ssl_wrap_socket( + sock=conn, + keyfile=self.key_file, + certfile=self.cert_file, + ca_certs=self.ca_certs, + ca_cert_dir=self.ca_cert_dir, + server_hostname=server_hostname, + ssl_context=context) + + if self.assert_fingerprint: + assert_fingerprint(self.sock.getpeercert(binary_form=True), + self.assert_fingerprint) + elif context.verify_mode != ssl.CERT_NONE \ + and not getattr(context, 'check_hostname', False) \ + and self.assert_hostname is not False: + # While urllib3 attempts to always turn off hostname matching from + # the TLS library, this cannot always be done. So we check whether + # the TLS Library still thinks it's matching hostnames. + cert = self.sock.getpeercert() + if not cert.get('subjectAltName', ()): + warnings.warn(( + 'Certificate for {0} has no `subjectAltName`, falling back to check for a ' + '`commonName` for now. This feature is being removed by major browsers and ' + 'deprecated by RFC 2818. (See https://github.com/shazow/urllib3/issues/497 ' + 'for details.)'.format(hostname)), + SubjectAltNameWarning + ) + _match_hostname(cert, self.assert_hostname or server_hostname) + + self.is_verified = ( + context.verify_mode == ssl.CERT_REQUIRED or + self.assert_fingerprint is not None + ) + + +def _match_hostname(cert, asserted_hostname): + try: + match_hostname(cert, asserted_hostname) + except CertificateError as e: + log.error( + 'Certificate did not match expected hostname: %s. ' + 'Certificate: %s', asserted_hostname, cert + ) + # Add cert to exception and reraise so client code can inspect + # the cert when catching the exception, if they want to + e._peer_cert = cert + raise + + +if ssl: + # Make a copy for testing. + UnverifiedHTTPSConnection = HTTPSConnection + HTTPSConnection = VerifiedHTTPSConnection +else: + HTTPSConnection = DummyConnection |