Add 'requests' library to third_party.

third_party/requests/packages/urllib3/util.py

+# urllib3/util.py
+# Copyright 2008-2013 Andrey Petrov and contributors (see CONTRIBUTORS.txt)
+#
+# This module is part of urllib3 and is released under
+# the MIT License: http://www.opensource.org/licenses/mit-license.php
+
+
+from base64 import b64encode
+from collections import namedtuple
+from socket import error as SocketError
+from hashlib import md5, sha1
+from binascii import hexlify, unhexlify
+
+try:
+    from select import poll, POLLIN
+except ImportError:  # `poll` doesn't exist on OSX and other platforms
+    poll = False
+    try:
+        from select import select
+    except ImportError:  # `select` doesn't exist on AppEngine.
+        select = False
+
+try:  # Test for SSL features
+    SSLContext = None
+    HAS_SNI = False
+
+    import ssl
+    from ssl import wrap_socket, CERT_NONE, PROTOCOL_SSLv23
+    from ssl import SSLContext  # Modern SSL?
+    from ssl import HAS_SNI  # Has SNI?
+except ImportError:
+    pass
+
+
+from .packages import six
+from .exceptions import LocationParseError, SSLError
+
+
+class Url(namedtuple('Url', ['scheme', 'auth', 'host', 'port', 'path', 'query', 'fragment'])):
+    """
+    Datastructure for representing an HTTP URL. Used as a return value for
+    :func:`parse_url`.
+    """
+    slots = ()
+
+    def __new__(cls, scheme=None, auth=None, host=None, port=None, path=None, query=None, fragment=None):
+        return super(Url, cls).__new__(cls, scheme, auth, host, port, path, query, fragment)
+
+    @property
+    def hostname(self):
+        """For backwards-compatibility with urlparse. We're nice like that."""
+        return self.host
+
+    @property
+    def request_uri(self):
+        """Absolute path including the query string."""
+        uri = self.path or '/'
+
+        if self.query is not None:
+            uri += '?' + self.query
+
+        return uri
+
+
+def split_first(s, delims):
+    """
+    Given a string and an iterable of delimiters, split on the first found
+    delimiter. Return two split parts and the matched delimiter.
+
+    If not found, then the first part is the full input string.
+
+    Example: ::
+
+        >>> split_first('foo/bar?baz', '?/=')
+        ('foo', 'bar?baz', '/')
+        >>> split_first('foo/bar?baz', '123')
+        ('foo/bar?baz', '', None)
+
+    Scales linearly with number of delims. Not ideal for large number of delims.
+    """
+    min_idx = None
+    min_delim = None
+    for d in delims:
+        idx = s.find(d)
+        if idx < 0:
+            continue
+
+        if min_idx is None or idx < min_idx:
+            min_idx = idx
+            min_delim = d
+
+    if min_idx is None or min_idx < 0:
+        return s, '', None
+
+    return s[:min_idx], s[min_idx+1:], min_delim
+
+
+def parse_url(url):
+    """
+    Given a url, return a parsed :class:`.Url` namedtuple. Best-effort is
+    performed to parse incomplete urls. Fields not provided will be None.
+
+    Partly backwards-compatible with :mod:`urlparse`.
+
+    Example: ::
+
+        >>> parse_url('http://google.com/mail/')
+        Url(scheme='http', host='google.com', port=None, path='/', ...)
+        >>> parse_url('google.com:80')
+        Url(scheme=None, host='google.com', port=80, path=None, ...)
+        >>> parse_url('/foo?bar')
+        Url(scheme=None, host=None, port=None, path='/foo', query='bar', ...)
+    """
+
+    # While this code has overlap with stdlib's urlparse, it is much
+    # simplified for our needs and less annoying.
+    # Additionally, this imeplementations does silly things to be optimal
+    # on CPython.
+
+    scheme = None
+    auth = None
+    host = None
+    port = None
+    path = None
+    fragment = None
+    query = None
+
+    # Scheme
+    if '://' in url:
+        scheme, url = url.split('://', 1)
+
+    # Find the earliest Authority Terminator
+    # (http://tools.ietf.org/html/rfc3986#section-3.2)
+    url, path_, delim = split_first(url, ['/', '?', '#'])
+
+    if delim:
+        # Reassemble the path
+        path = delim + path_
+
+    # Auth
+    if '@' in url:
+        auth, url = url.split('@', 1)
+
+    # IPv6
+    if url and url[0] == '[':
+        host, url = url[1:].split(']', 1)
+
+    # Port
+    if ':' in url:
+        _host, port = url.split(':', 1)
+
+        if not host:
+            host = _host
+
+        if not port.isdigit():
+            raise LocationParseError("Failed to parse: %s" % url)
+
+        port = int(port)
+
+    elif not host and url:
+        host = url
+
+    if not path:
+        return Url(scheme, auth, host, port, path, query, fragment)
+
+    # Fragment
+    if '#' in path:
+        path, fragment = path.split('#', 1)
+
+    # Query
+    if '?' in path:
+        path, query = path.split('?', 1)
+
+    return Url(scheme, auth, host, port, path, query, fragment)
+
+
+def get_host(url):
+    """
+    Deprecated. Use :func:`.parse_url` instead.
+    """
+    p = parse_url(url)
+    return p.scheme or 'http', p.hostname, p.port
+
+
+def make_headers(keep_alive=None, accept_encoding=None, user_agent=None,
+                 basic_auth=None):
+    """
+    Shortcuts for generating request headers.
+
+    :param keep_alive:
+        If ``True``, adds 'connection: keep-alive' header.
+
+    :param accept_encoding:
+        Can be a boolean, list, or string.
+        ``True`` translates to 'gzip,deflate'.
+        List will get joined by comma.
+        String will be used as provided.
+
+    :param user_agent:
+        String representing the user-agent you want, such as
+        "python-urllib3/0.6"
+
+    :param basic_auth:
+        Colon-separated username:password string for 'authorization: basic ...'
+        auth header.
+
+    Example: ::
+
+        >>> make_headers(keep_alive=True, user_agent="Batman/1.0")
+        {'connection': 'keep-alive', 'user-agent': 'Batman/1.0'}
+        >>> make_headers(accept_encoding=True)
+        {'accept-encoding': 'gzip,deflate'}
+    """
+    headers = {}
+    if accept_encoding:
+        if isinstance(accept_encoding, str):
+            pass
+        elif isinstance(accept_encoding, list):
+            accept_encoding = ','.join(accept_encoding)
+        else:
+            accept_encoding = 'gzip,deflate'
+        headers['accept-encoding'] = accept_encoding
+
+    if user_agent:
+        headers['user-agent'] = user_agent
+
+    if keep_alive:
+        headers['connection'] = 'keep-alive'
+
+    if basic_auth:
+        headers['authorization'] = 'Basic ' + \
+            b64encode(six.b(basic_auth)).decode('utf-8')
+
+    return headers
+
+
+def is_connection_dropped(conn):  # Platform-specific
+    """
+    Returns True if the connection is dropped and should be closed.
+
+    :param conn:
+        :class:`httplib.HTTPConnection` object.
+
+    Note: For platforms like AppEngine, this will always return ``False`` to
+    let the platform handle connection recycling transparently for us.
+    """
+    sock = getattr(conn, 'sock', False)
+    if not sock: # Platform-specific: AppEngine
+        return False
+
+    if not poll:
+        if not select: # Platform-specific: AppEngine
+            return False
+
+        try:
+            return select([sock], [], [], 0.0)[0]
+        except SocketError:
+            return True
+
+    # This version is better on platforms that support it.
+    p = poll()
+    p.register(sock, POLLIN)
+    for (fno, ev) in p.poll(0.0):
+        if fno == sock.fileno():
+            # Either data is buffered (bad), or the connection is dropped.
+            return True
+
+
+def resolve_cert_reqs(candidate):
+    """
+    Resolves the argument to a numeric constant, which can be passed to
+    the wrap_socket function/method from the ssl module.
+    Defaults to :data:`ssl.CERT_NONE`.
+    If given a string it is assumed to be the name of the constant in the
+    :mod:`ssl` module or its abbrevation.
+    (So you can specify `REQUIRED` instead of `CERT_REQUIRED`.
+    If it's neither `None` nor a string we assume it is already the numeric
+    constant which can directly be passed to wrap_socket.
+    """
+    if candidate is None:
+        return CERT_NONE
+
+    if isinstance(candidate, str):
+        res = getattr(ssl, candidate, None)
+        if res is None:
+            res = getattr(ssl, 'CERT_' + candidate)
+        return res
+
+    return candidate
+
+
+def resolve_ssl_version(candidate):
+    """
+    like resolve_cert_reqs
+    """
+    if candidate is None:
+        return PROTOCOL_SSLv23
+
+    if isinstance(candidate, str):
+        res = getattr(ssl, candidate, None)
+        if res is None:
+            res = getattr(ssl, 'PROTOCOL_' + candidate)
+        return res
+
+    return candidate
+
+
+def assert_fingerprint(cert, fingerprint):
+    """
+    Checks if given fingerprint matches the supplied certificate.
+
+    :param cert:
+        Certificate as bytes object.
+    :param fingerprint:
+        Fingerprint as string of hexdigits, can be interspersed by colons.
+    """
+
+    # Maps the length of a digest to a possible hash function producing
+    # this digest.
+    hashfunc_map = {
+        16: md5,
+        20: sha1
+    }
+
+    fingerprint = fingerprint.replace(':', '').lower()
+
+    digest_length, rest = divmod(len(fingerprint), 2)
+
+    if rest or digest_length not in hashfunc_map:
+        raise SSLError('Fingerprint is of invalid length.')
+
+    # We need encode() here for py32; works on py2 and p33.
+    fingerprint_bytes = unhexlify(fingerprint.encode())
+
+    hashfunc = hashfunc_map[digest_length]
+
+    cert_digest = hashfunc(cert).digest()
+
+    if not cert_digest == fingerprint_bytes:
+        raise SSLError('Fingerprints did not match. Expected "{0}", got "{1}".'
+                       .format(hexlify(fingerprint_bytes),
+                               hexlify(cert_digest)))
+
+
+if SSLContext is not None:  # Python 3.2+
+    def ssl_wrap_socket(sock, keyfile=None, certfile=None, cert_reqs=None,
+                        ca_certs=None, server_hostname=None,
+                        ssl_version=None):
+        """
+        All arguments except `server_hostname` have the same meaning as for
+        :func:`ssl.wrap_socket`
+
+        :param server_hostname:
+            Hostname of the expected certificate
+        """
+        context = SSLContext(ssl_version)
+        context.verify_mode = cert_reqs
+        if ca_certs:
+            try:
+                context.load_verify_locations(ca_certs)
+            # Py32 raises IOError
+            # Py33 raises FileNotFoundError
+            except Exception as e:  # Reraise as SSLError
+                raise SSLError(e)
+        if certfile:
+            # FIXME: This block needs a test.
+            context.load_cert_chain(certfile, keyfile)
+        if HAS_SNI:  # Platform-specific: OpenSSL with enabled SNI
+            return context.wrap_socket(sock, server_hostname=server_hostname)
+        return context.wrap_socket(sock)
+
+else:  # Python 3.1 and earlier
+    def ssl_wrap_socket(sock, keyfile=None, certfile=None, cert_reqs=None,
+                        ca_certs=None, server_hostname=None,
+                        ssl_version=None):
+        return wrap_socket(sock, keyfile=keyfile, certfile=certfile,
+                           ca_certs=ca_certs, cert_reqs=cert_reqs,
+                           ssl_version=ssl_version)