client.py
| 57.2 KB | Satir:
0
| py
Geri
r"""HTTP/1.1 client library <intro stuff goes here> <other stuff, too> HTTPConnection goes through a number of "states", which define when a client may legally make another request or fetch the response for a particular request. This diagram details these state transitions: (null) | | HTTPConnection() v Idle | | putrequest() v Request-started | | ( putheader() )* endheaders() v Request-sent |\_____________________________ | | getresponse() raises | response = getresponse() | ConnectionError v v Unread-response Idle [Response-headers-read] |\____________________ | | | response.read() | putrequest() v v Idle Req-started-unread-response ______/| / | response.read() | | ( putheader() )* endheaders() v v Request-started Req-sent-unread-response | | response.read() v Request-sent This diagram presents the following rules: -- a second request may not be started until {response-headers-read} -- a response [object] cannot be retrieved until {request-sent} -- there is no differentiation between an unread response body and a partially read response body Note: this enforcement is applied by the HTTPConnection class. The HTTPResponse class does not enforce this state machine, which implies sophisticated clients may accelerate the request/response pipeline. Caution should be taken, though: accelerating the states beyond the above pattern may imply knowledge of the server's connection-close behavior for certain requests. For example, it is impossible to tell whether the server will close the connection UNTIL the response headers have been read; this means that further requests cannot be placed into the pipeline until it is known that the server will NOT be closing the connection. Logical State __state __response ------------- ------- ---------- Idle _CS_IDLE None Request-started _CS_REQ_STARTED None Request-sent _CS_REQ_SENT None Unread-response _CS_IDLE <response_class> Req-started-unread-response _CS_REQ_STARTED <response_class> Req-sent-unread-response _CS_REQ_SENT <response_class> """ import email.parser import email.message import errno import http import io import re import socket import sys import collections.abc from urllib.parse import urlsplit # HTTPMessage, parse_headers(), and the HTTP status code constants are # intentionally omitted for simplicity __all__ = ["HTTPResponse", "HTTPConnection", "HTTPException", "NotConnected", "UnknownProtocol", "UnknownTransferEncoding", "UnimplementedFileMode", "IncompleteRead", "InvalidURL", "ImproperConnectionState", "CannotSendRequest", "CannotSendHeader", "ResponseNotReady", "BadStatusLine", "LineTooLong", "RemoteDisconnected", "error", "responses"] HTTP_PORT = 80 HTTPS_PORT = 443 _UNKNOWN = 'UNKNOWN' # connection states _CS_IDLE = 'Idle' _CS_REQ_STARTED = 'Request-started' _CS_REQ_SENT = 'Request-sent' # hack to maintain backwards compatibility globals().update(http.HTTPStatus.__members__) # another hack to maintain backwards compatibility # Mapping status codes to official W3C names responses = {v: v.phrase for v in http.HTTPStatus.__members__.values()} # maximal line length when calling readline(). _MAXLINE = 65536 _MAXHEADERS = 100 # Data larger than this will be read in chunks, to prevent extreme # overallocation. _MIN_READ_BUF_SIZE = 1 << 20 # Header name/value ABNF (http://tools.ietf.org/html/rfc7230#section-3.2) # # VCHAR = %x21-7E # obs-text = %x80-FF # header-field = field-name ":" OWS field-value OWS # field-name = token # field-value = *( field-content / obs-fold ) # field-content = field-vchar [ 1*( SP / HTAB ) field-vchar ] # field-vchar = VCHAR / obs-text # # obs-fold = CRLF 1*( SP / HTAB ) # ; obsolete line folding # ; see Section 3.2.4 # token = 1*tchar # # tchar = "!" / "#" / "$" / "%" / "&" / "'" / "*" # / "+" / "-" / "." / "^" / "_" / "`" / "|" / "~" # / DIGIT / ALPHA # ; any VCHAR, except delimiters # # VCHAR defined in http://tools.ietf.org/html/rfc5234#appendix-B.1 # the patterns for both name and value are more lenient than RFC # definitions to allow for backwards compatibility _is_legal_header_name = re.compile(rb'[^:\s][^:\r\n]*').fullmatch _is_illegal_header_value = re.compile(rb'\n(?![ \t])|\r(?![ \t\n])').search # These characters are not allowed within HTTP URL paths. # See https://tools.ietf.org/html/rfc3986#section-3.3 and the # https://tools.ietf.org/html/rfc3986#appendix-A pchar definition. # Prevents CVE-2019-9740. Includes control characters such as \r\n. # We don't restrict chars above \x7f as putrequest() limits us to ASCII. _contains_disallowed_url_pchar_re = re.compile('[\x00-\x20\x7f]') # Arguably only these _should_ allowed: # _is_allowed_url_pchars_re = re.compile(r"^[/!$&'()*+,;=:@%a-zA-Z0-9._~-]+$") # We are more lenient for assumed real world compatibility purposes. # These characters are not allowed within HTTP method names # to prevent http header injection. _contains_disallowed_method_pchar_re = re.compile('[\x00-\x1f]') # We always set the Content-Length header for these methods because some # servers will otherwise respond with a 411 _METHODS_EXPECTING_BODY = {'PATCH', 'POST', 'PUT'} def _encode(data, name='data'): """Call data.encode("latin-1") but show a better error message.""" try: return data.encode("latin-1") except UnicodeEncodeError as err: raise UnicodeEncodeError( err.encoding, err.object, err.start, err.end, "%s (%.20r) is not valid Latin-1. Use %s.encode('utf-8') " "if you want to send it encoded in UTF-8." % (name.title(), data[err.start:err.end], name)) from None def _strip_ipv6_iface(enc_name: bytes) -> bytes: """Remove interface scope from IPv6 address.""" enc_name, percent, _ = enc_name.partition(b"%") if percent: assert enc_name.startswith(b'['), enc_name enc_name += b']' return enc_name class HTTPMessage(email.message.Message): # XXX The only usage of this method is in # http.server.CGIHTTPRequestHandler. Maybe move the code there so # that it doesn't need to be part of the public API. The API has # never been defined so this could cause backwards compatibility # issues. def getallmatchingheaders(self, name): """Find all header lines matching a given header name. Look through the list of headers and find all lines matching a given header name (and their continuation lines). A list of the lines is returned, without interpretation. If the header does not occur, an empty list is returned. If the header occurs multiple times, all occurrences are returned. Case is not important in the header name. """ name = name.lower() + ':' n = len(name) lst = [] hit = 0 for line in self.keys(): if line[:n].lower() == name: hit = 1 elif not line[:1].isspace(): hit = 0 if hit: lst.append(line) return lst def _read_headers(fp): """Reads potential header lines into a list from a file pointer. Length of line is limited by _MAXLINE, and number of headers is limited by _MAXHEADERS. """ headers = [] while True: line = fp.readline(_MAXLINE + 1) if len(line) > _MAXLINE: raise LineTooLong("header line") headers.append(line) if len(headers) > _MAXHEADERS: raise HTTPException("got more than %d headers" % _MAXHEADERS) if line in (b'\r\n', b'\n', b''): break return headers def _parse_header_lines(header_lines, _class=HTTPMessage): """ Parses only RFC2822 headers from header lines. email Parser wants to see strings rather than bytes. But a TextIOWrapper around self.rfile would buffer too many bytes from the stream, bytes which we later need to read as bytes. So we read the correct bytes here, as bytes, for email Parser to parse. """ hstring = b''.join(header_lines).decode('iso-8859-1') return email.parser.Parser(_class=_class).parsestr(hstring) def parse_headers(fp, _class=HTTPMessage): """Parses only RFC2822 headers from a file pointer.""" headers = _read_headers(fp) return _parse_header_lines(headers, _class) class HTTPResponse(io.BufferedIOBase): # See RFC 2616 sec 19.6 and RFC 1945 sec 6 for details. # The bytes from the socket object are iso-8859-1 strings. # See RFC 2616 sec 2.2 which notes an exception for MIME-encoded # text following RFC 2047. The basic status line parsing only # accepts iso-8859-1. def __init__(self, sock, debuglevel=0, method=None, url=None): # If the response includes a content-length header, we need to # make sure that the client doesn't read more than the # specified number of bytes. If it does, it will block until # the server times out and closes the connection. This will # happen if a self.fp.read() is done (without a size) whether # self.fp is buffered or not. So, no self.fp.read() by # clients unless they know what they are doing. self.fp = sock.makefile("rb") self.debuglevel = debuglevel self._method = method # The HTTPResponse object is returned via urllib. The clients # of http and urllib expect different attributes for the # headers. headers is used here and supports urllib. msg is # provided as a backwards compatibility layer for http # clients. self.headers = self.msg = None # from the Status-Line of the response self.version = _UNKNOWN # HTTP-Version self.status = _UNKNOWN # Status-Code self.reason = _UNKNOWN # Reason-Phrase self.chunked = _UNKNOWN # is "chunked" being used? self.chunk_left = _UNKNOWN # bytes left to read in current chunk self.length = _UNKNOWN # number of bytes left in response self.will_close = _UNKNOWN # conn will close at end of response def _read_status(self): line = str(self.fp.readline(_MAXLINE + 1), "iso-8859-1") if len(line) > _MAXLINE: raise LineTooLong("status line") if self.debuglevel > 0: print("reply:", repr(line)) if not line: # Presumably, the server closed the connection before # sending a valid response. raise RemoteDisconnected("Remote end closed connection without" " response") try: version, status, reason = line.split(None, 2) except ValueError: try: version, status = line.split(None, 1) reason = "" except ValueError: # empty version will cause next test to fail. version = "" if not version.startswith("HTTP/"): self._close_conn() raise BadStatusLine(line) # The status code is a three-digit number try: status = int(status) if status < 100 or status > 999: raise BadStatusLine(line) except ValueError: raise BadStatusLine(line) return version, status, reason def begin(self): if self.headers is not None: # we've already started reading the response return # read until we get a non-100 response while True: version, status, reason = self._read_status() if status != CONTINUE: break # skip the header from the 100 response skipped_headers = _read_headers(self.fp) if self.debuglevel > 0: print("headers:", skipped_headers) del skipped_headers self.code = self.status = status self.reason = reason.strip() if version in ("HTTP/1.0", "HTTP/0.9"): # Some servers might still return "0.9", treat it as 1.0 anyway self.version = 10 elif version.startswith("HTTP/1."): self.version = 11 # use HTTP/1.1 code for HTTP/1.x where x>=1 else: raise UnknownProtocol(version) self.headers = self.msg = parse_headers(self.fp) if self.debuglevel > 0: for hdr, val in self.headers.items(): print("header:", hdr + ":", val) # are we using the chunked-style of transfer encoding? tr_enc = self.headers.get("transfer-encoding") if tr_enc and tr_enc.lower() == "chunked": self.chunked = True self.chunk_left = None else: self.chunked = False # will the connection close at the end of the response? self.will_close = self._check_close() # do we have a Content-Length? # NOTE: RFC 2616, S4.4, #3 says we ignore this if tr_enc is "chunked" self.length = None length = self.headers.get("content-length") if length and not self.chunked: try: self.length = int(length) except ValueError: self.length = None else: if self.length < 0: # ignore nonsensical negative lengths self.length = None else: self.length = None # does the body have a fixed length? (of zero) if (status == NO_CONTENT or status == NOT_MODIFIED or 100 <= status < 200 or # 1xx codes self._method == "HEAD"): self.length = 0 # if the connection remains open, and we aren't using chunked, and # a content-length was not provided, then assume that the connection # WILL close. if (not self.will_close and not self.chunked and self.length is None): self.will_close = True def _check_close(self): conn = self.headers.get("connection") if self.version == 11: # An HTTP/1.1 proxy is assumed to stay open unless # explicitly closed. if conn and "close" in conn.lower(): return True return False # Some HTTP/1.0 implementations have support for persistent # connections, using rules different than HTTP/1.1. # For older HTTP, Keep-Alive indicates persistent connection. if self.headers.get("keep-alive"): return False # At least Akamai returns a "Connection: Keep-Alive" header, # which was supposed to be sent by the client. if conn and "keep-alive" in conn.lower(): return False # Proxy-Connection is a netscape hack. pconn = self.headers.get("proxy-connection") if pconn and "keep-alive" in pconn.lower(): return False # otherwise, assume it will close return True def _close_conn(self): fp = self.fp self.fp = None fp.close() def close(self): try: super().close() # set "closed" flag finally: if self.fp: self._close_conn() # These implementations are for the benefit of io.BufferedReader. # XXX This class should probably be revised to act more like # the "raw stream" that BufferedReader expects. def flush(self): super().flush() if self.fp: self.fp.flush() def readable(self): """Always returns True""" return True # End of "raw stream" methods def isclosed(self): """True if the connection is closed.""" # NOTE: it is possible that we will not ever call self.close(). This # case occurs when will_close is TRUE, length is None, and we # read up to the last byte, but NOT past it. # # IMPLIES: if will_close is FALSE, then self.close() will ALWAYS be # called, meaning self.isclosed() is meaningful. return self.fp is None def read(self, amt=None): """Read and return the response body, or up to the next amt bytes.""" if self.fp is None: return b"" if self._method == "HEAD": self._close_conn() return b"" if self.chunked: return self._read_chunked(amt) if amt is not None and amt >= 0: if self.length is not None and amt > self.length: # clip the read to the "end of response" amt = self.length s = self.fp.read(amt) if not s and amt: # Ideally, we would raise IncompleteRead if the content-length # wasn't satisfied, but it might break compatibility. self._close_conn() elif self.length is not None: self.length -= len(s) if not self.length: self._close_conn() return s else: # Amount is not given (unbounded read) so we must check self.length if self.length is None: s = self.fp.read() else: try: s = self._safe_read(self.length) except IncompleteRead: self._close_conn() raise self.length = 0 self._close_conn() # we read everything return s def readinto(self, b): """Read up to len(b) bytes into bytearray b and return the number of bytes read. """ if self.fp is None: return 0 if self._method == "HEAD": self._close_conn() return 0 if self.chunked: return self._readinto_chunked(b) if self.length is not None: if len(b) > self.length: # clip the read to the "end of response" b = memoryview(b)[0:self.length] # we do not use _safe_read() here because this may be a .will_close # connection, and the user is reading more bytes than will be provided # (for example, reading in 1k chunks) n = self.fp.readinto(b) if not n and b: # Ideally, we would raise IncompleteRead if the content-length # wasn't satisfied, but it might break compatibility. self._close_conn() elif self.length is not None: self.length -= n if not self.length: self._close_conn() return n def _read_next_chunk_size(self): # Read the next chunk size from the file line = self.fp.readline(_MAXLINE + 1) if len(line) > _MAXLINE: raise LineTooLong("chunk size") i = line.find(b";") if i >= 0: line = line[:i] # strip chunk-extensions try: return int(line, 16) except ValueError: # close the connection as protocol synchronisation is # probably lost self._close_conn() raise def _read_and_discard_trailer(self): # read and discard trailer up to the CRLF terminator ### note: we shouldn't have any trailers! while True: line = self.fp.readline(_MAXLINE + 1) if len(line) > _MAXLINE: raise LineTooLong("trailer line") if not line: # a vanishingly small number of sites EOF without # sending the trailer break if line in (b'\r\n', b'\n', b''): break def _get_chunk_left(self): # return self.chunk_left, reading a new chunk if necessary. # chunk_left == 0: at the end of the current chunk, need to close it # chunk_left == None: No current chunk, should read next. # This function returns non-zero or None if the last chunk has # been read. chunk_left = self.chunk_left if not chunk_left: # Can be 0 or None if chunk_left is not None: # We are at the end of chunk, discard chunk end self._safe_read(2) # toss the CRLF at the end of the chunk try: chunk_left = self._read_next_chunk_size() except ValueError: raise IncompleteRead(b'') if chunk_left == 0: # last chunk: 1*("0") [ chunk-extension ] CRLF self._read_and_discard_trailer() # we read everything; close the "file" self._close_conn() chunk_left = None self.chunk_left = chunk_left return chunk_left def _read_chunked(self, amt=None): assert self.chunked != _UNKNOWN if amt is not None and amt < 0: amt = None value = [] try: while (chunk_left := self._get_chunk_left()) is not None: if amt is not None and amt <= chunk_left: value.append(self._safe_read(amt)) self.chunk_left = chunk_left - amt break value.append(self._safe_read(chunk_left)) if amt is not None: amt -= chunk_left self.chunk_left = 0 return b''.join(value) except IncompleteRead as exc: raise IncompleteRead(b''.join(value)) from exc def _readinto_chunked(self, b): assert self.chunked != _UNKNOWN total_bytes = 0 mvb = memoryview(b) try: while True: chunk_left = self._get_chunk_left() if chunk_left is None: return total_bytes if len(mvb) <= chunk_left: n = self._safe_readinto(mvb) self.chunk_left = chunk_left - n return total_bytes + n temp_mvb = mvb[:chunk_left] n = self._safe_readinto(temp_mvb) mvb = mvb[n:] total_bytes += n self.chunk_left = 0 except IncompleteRead: raise IncompleteRead(bytes(b[0:total_bytes])) def _safe_read(self, amt): """Read the number of bytes requested. This function should be used when <amt> bytes "should" be present for reading. If the bytes are truly not available (due to EOF), then the IncompleteRead exception can be used to detect the problem. """ cursize = min(amt, _MIN_READ_BUF_SIZE) data = self.fp.read(cursize) if len(data) >= amt: return data if len(data) < cursize: raise IncompleteRead(data, amt - len(data)) data = io.BytesIO(data) data.seek(0, 2) while True: # This is a geometric increase in read size (never more than # doubling out the current length of data per loop iteration). delta = min(cursize, amt - cursize) data.write(self.fp.read(delta)) if data.tell() >= amt: return data.getvalue() cursize += delta if data.tell() < cursize: raise IncompleteRead(data.getvalue(), amt - data.tell()) def _safe_readinto(self, b): """Same as _safe_read, but for reading into a buffer.""" amt = len(b) n = self.fp.readinto(b) if n < amt: raise IncompleteRead(bytes(b[:n]), amt-n) return n def read1(self, n=-1): """Read with at most one underlying system call. If at least one byte is buffered, return that instead. """ if self.fp is None or self._method == "HEAD": return b"" if self.chunked: return self._read1_chunked(n) if self.length is not None and (n < 0 or n > self.length): n = self.length result = self.fp.read1(n) if not result and n: self._close_conn() elif self.length is not None: self.length -= len(result) if not self.length: self._close_conn() return result def peek(self, n=-1): # Having this enables IOBase.readline() to read more than one # byte at a time if self.fp is None or self._method == "HEAD": return b"" if self.chunked: return self._peek_chunked(n) return self.fp.peek(n) def readline(self, limit=-1): if self.fp is None or self._method == "HEAD": return b"" if self.chunked: # Fallback to IOBase readline which uses peek() and read() return super().readline(limit) if self.length is not None and (limit < 0 or limit > self.length): limit = self.length result = self.fp.readline(limit) if not result and limit: self._close_conn() elif self.length is not None: self.length -= len(result) if not self.length: self._close_conn() return result def _read1_chunked(self, n): # Strictly speaking, _get_chunk_left() may cause more than one read, # but that is ok, since that is to satisfy the chunked protocol. chunk_left = self._get_chunk_left() if chunk_left is None or n == 0: return b'' if not (0 <= n <= chunk_left): n = chunk_left # if n is negative or larger than chunk_left read = self.fp.read1(n) self.chunk_left -= len(read) if not read: raise IncompleteRead(b"") return read def _peek_chunked(self, n): # Strictly speaking, _get_chunk_left() may cause more than one read, # but that is ok, since that is to satisfy the chunked protocol. try: chunk_left = self._get_chunk_left() except IncompleteRead: return b'' # peek doesn't worry about protocol if chunk_left is None: return b'' # eof # peek is allowed to return more than requested. Just request the # entire chunk, and truncate what we get. return self.fp.peek(chunk_left)[:chunk_left] def fileno(self): return self.fp.fileno() def getheader(self, name, default=None): '''Returns the value of the header matching *name*. If there are multiple matching headers, the values are combined into a single string separated by commas and spaces. If no matching header is found, returns *default* or None if the *default* is not specified. If the headers are unknown, raises http.client.ResponseNotReady. ''' if self.headers is None: raise ResponseNotReady() headers = self.headers.get_all(name) or default if isinstance(headers, str) or not hasattr(headers, '__iter__'): return headers else: return ', '.join(headers) def getheaders(self): """Return list of (header, value) tuples.""" if self.headers is None: raise ResponseNotReady() return list(self.headers.items()) # We override IOBase.__iter__ so that it doesn't check for closed-ness def __iter__(self): return self # For compatibility with old-style urllib responses. def info(self): '''Returns an instance of the class mimetools.Message containing meta-information associated with the URL. When the method is HTTP, these headers are those returned by the server at the head of the retrieved HTML page (including Content-Length and Content-Type). When the method is FTP, a Content-Length header will be present if (as is now usual) the server passed back a file length in response to the FTP retrieval request. A Content-Type header will be present if the MIME type can be guessed. When the method is local-file, returned headers will include a Date representing the file's last-modified time, a Content-Length giving file size, and a Content-Type containing a guess at the file's type. See also the description of the mimetools module. ''' return self.headers def geturl(self): '''Return the real URL of the page. In some cases, the HTTP server redirects a client to another URL. The urlopen() function handles this transparently, but in some cases the caller needs to know which URL the client was redirected to. The geturl() method can be used to get at this redirected URL. ''' return self.url def getcode(self): '''Return the HTTP status code that was sent with the response, or None if the URL is not an HTTP URL. ''' return self.status def _create_https_context(http_version): # Function also used by urllib.request to be able to set the check_hostname # attribute on a context object. context = ssl._create_default_https_context() # send ALPN extension to indicate HTTP/1.1 protocol if http_version == 11: context.set_alpn_protocols(['http/1.1']) # enable PHA for TLS 1.3 connections if available if context.post_handshake_auth is not None: context.post_handshake_auth = True return context class HTTPConnection: _http_vsn = 11 _http_vsn_str = 'HTTP/1.1' response_class = HTTPResponse default_port = HTTP_PORT auto_open = 1 debuglevel = 0 @staticmethod def _is_textIO(stream): """Test whether a file-like object is a text or a binary stream. """ return isinstance(stream, io.TextIOBase) @staticmethod def _get_content_length(body, method): """Get the content-length based on the body. If the body is None, we set Content-Length: 0 for methods that expect a body (RFC 7230, Section 3.3.2). We also set the Content-Length for any method if the body is a str or bytes-like object and not a file. """ if body is None: # do an explicit check for not None here to distinguish # between unset and set but empty if method.upper() in _METHODS_EXPECTING_BODY: return 0 else: return None if hasattr(body, 'read'): # file-like object. return None try: # does it implement the buffer protocol (bytes, bytearray, array)? mv = memoryview(body) return mv.nbytes except TypeError: pass if isinstance(body, str): return len(body) return None def __init__(self, host, port=None, timeout=socket._GLOBAL_DEFAULT_TIMEOUT, source_address=None, blocksize=8192): self.timeout = timeout self.source_address = source_address self.blocksize = blocksize self.sock = None self._buffer = [] self.__response = None self.__state = _CS_IDLE self._method = None self._tunnel_host = None self._tunnel_port = None self._tunnel_headers = {} self._raw_proxy_headers = None (self.host, self.port) = self._get_hostport(host, port) self._validate_host(self.host) # This is stored as an instance variable to allow unit # tests to replace it with a suitable mockup self._create_connection = socket.create_connection def set_tunnel(self, host, port=None, headers=None): """Set up host and port for HTTP CONNECT tunnelling. In a connection that uses HTTP CONNECT tunnelling, the host passed to the constructor is used as a proxy server that relays all communication to the endpoint passed to `set_tunnel`. This done by sending an HTTP CONNECT request to the proxy server when the connection is established. This method must be called before the HTTP connection has been established. The headers argument should be a mapping of extra HTTP headers to send with the CONNECT request. As HTTP/1.1 is used for HTTP CONNECT tunnelling request, as per the RFC (https://tools.ietf.org/html/rfc7231#section-4.3.6), a HTTP Host: header must be provided, matching the authority-form of the request target provided as the destination for the CONNECT request. If a HTTP Host: header is not provided via the headers argument, one is generated and transmitted automatically. """ if self.sock: raise RuntimeError("Can't set up tunnel for established connection") self._tunnel_host, self._tunnel_port = self._get_hostport(host, port) if headers: self._tunnel_headers = headers.copy() else: self._tunnel_headers.clear() if not any(header.lower() == "host" for header in self._tunnel_headers): encoded_host = self._tunnel_host.encode("idna").decode("ascii") self._tunnel_headers["Host"] = "%s:%d" % ( encoded_host, self._tunnel_port) def _get_hostport(self, host, port): if port is None: i = host.rfind(':') j = host.rfind(']') # ipv6 addresses have [...] if i > j: try: port = int(host[i+1:]) except ValueError: if host[i+1:] == "": # http://foo.com:/ == http://foo.com/ port = self.default_port else: raise InvalidURL("nonnumeric port: '%s'" % host[i+1:]) host = host[:i] else: port = self.default_port if host and host[0] == '[' and host[-1] == ']': host = host[1:-1] return (host, port) def set_debuglevel(self, level): self.debuglevel = level def _wrap_ipv6(self, ip): if b':' in ip and ip[0] != b'['[0]: return b"[" + ip + b"]" return ip def _tunnel(self): if _contains_disallowed_url_pchar_re.search(self._tunnel_host): raise ValueError('Tunnel host can\'t contain control characters %r' % (self._tunnel_host,)) connect = b"CONNECT %s:%d %s\r\n" % ( self._wrap_ipv6(self._tunnel_host.encode("idna")), self._tunnel_port, self._http_vsn_str.encode("ascii")) headers = [connect] for header, value in self._tunnel_headers.items(): header_bytes = header.encode("latin-1") value_bytes = value.encode("latin-1") if not _is_legal_header_name(header_bytes): raise ValueError('Invalid header name %r' % (header_bytes,)) if _is_illegal_header_value(value_bytes): raise ValueError('Invalid header value %r' % (value_bytes,)) headers.append(b"%s: %s\r\n" % (header_bytes, value_bytes)) headers.append(b"\r\n") # Making a single send() call instead of one per line encourages # the host OS to use a more optimal packet size instead of # potentially emitting a series of small packets. self.send(b"".join(headers)) del headers response = self.response_class(self.sock, method=self._method) try: (version, code, message) = response._read_status() self._raw_proxy_headers = _read_headers(response.fp) if self.debuglevel > 0: for header in self._raw_proxy_headers: print('header:', header.decode()) if code != http.HTTPStatus.OK: self.close() raise OSError(f"Tunnel connection failed: {code} {message.strip()}") finally: response.close() def get_proxy_response_headers(self): """ Returns a dictionary with the headers of the response received from the proxy server to the CONNECT request sent to set the tunnel. If the CONNECT request was not sent, the method returns None. """ return ( _parse_header_lines(self._raw_proxy_headers) if self._raw_proxy_headers is not None else None ) def connect(self): """Connect to the host and port specified in __init__.""" sys.audit("http.client.connect", self, self.host, self.port) self.sock = self._create_connection( (self.host,self.port), self.timeout, self.source_address) # Might fail in OSs that don't implement TCP_NODELAY try: self.sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1) except OSError as e: if e.errno != errno.ENOPROTOOPT: raise if self._tunnel_host: self._tunnel() def close(self): """Close the connection to the HTTP server.""" self.__state = _CS_IDLE try: sock = self.sock if sock: self.sock = None sock.close() # close it manually... there may be other refs finally: response = self.__response if response: self.__response = None response.close() def send(self, data): """Send `data' to the server. ``data`` can be a string object, a bytes object, an array object, a file-like object that supports a .read() method, or an iterable object. """ if self.sock is None: if self.auto_open: self.connect() else: raise NotConnected() if self.debuglevel > 0: print("send:", repr(data)) if hasattr(data, "read") : if self.debuglevel > 0: print("sending a readable") encode = self._is_textIO(data) if encode and self.debuglevel > 0: print("encoding file using iso-8859-1") while datablock := data.read(self.blocksize): if encode: datablock = datablock.encode("iso-8859-1") sys.audit("http.client.send", self, datablock) self.sock.sendall(datablock) return sys.audit("http.client.send", self, data) try: self.sock.sendall(data) except TypeError: if isinstance(data, collections.abc.Iterable): for d in data: self.sock.sendall(d) else: raise TypeError("data should be a bytes-like object " "or an iterable, got %r" % type(data)) def _output(self, s): """Add a line of output to the current request buffer. Assumes that the line does *not* end with \\r\\n. """ self._buffer.append(s) def _read_readable(self, readable): if self.debuglevel > 0: print("reading a readable") encode = self._is_textIO(readable) if encode and self.debuglevel > 0: print("encoding file using iso-8859-1") while datablock := readable.read(self.blocksize): if encode: datablock = datablock.encode("iso-8859-1") yield datablock def _send_output(self, message_body=None, encode_chunked=False): """Send the currently buffered request and clear the buffer. Appends an extra \\r\\n to the buffer. A message_body may be specified, to be appended to the request. """ self._buffer.extend((b"", b"")) msg = b"\r\n".join(self._buffer) del self._buffer[:] self.send(msg) if message_body is not None: # create a consistent interface to message_body if hasattr(message_body, 'read'): # Let file-like take precedence over byte-like. This # is needed to allow the current position of mmap'ed # files to be taken into account. chunks = self._read_readable(message_body) else: try: # this is solely to check to see if message_body # implements the buffer API. it /would/ be easier # to capture if PyObject_CheckBuffer was exposed # to Python. memoryview(message_body) except TypeError: try: chunks = iter(message_body) except TypeError: raise TypeError("message_body should be a bytes-like " "object or an iterable, got %r" % type(message_body)) else: # the object implements the buffer interface and # can be passed directly into socket methods chunks = (message_body,) for chunk in chunks: if not chunk: if self.debuglevel > 0: print('Zero length chunk ignored') continue if encode_chunked and self._http_vsn == 11: # chunked encoding chunk = f'{len(chunk):X}\r\n'.encode('ascii') + chunk \ + b'\r\n' self.send(chunk) if encode_chunked and self._http_vsn == 11: # end chunked transfer self.send(b'0\r\n\r\n') def putrequest(self, method, url, skip_host=False, skip_accept_encoding=False): """Send a request to the server. `method' specifies an HTTP request method, e.g. 'GET'. `url' specifies the object being requested, e.g. '/index.html'. `skip_host' if True does not add automatically a 'Host:' header `skip_accept_encoding' if True does not add automatically an 'Accept-Encoding:' header """ # if a prior response has been completed, then forget about it. if self.__response and self.__response.isclosed(): self.__response = None # in certain cases, we cannot issue another request on this connection. # this occurs when: # 1) we are in the process of sending a request. (_CS_REQ_STARTED) # 2) a response to a previous request has signalled that it is going # to close the connection upon completion. # 3) the headers for the previous response have not been read, thus # we cannot determine whether point (2) is true. (_CS_REQ_SENT) # # if there is no prior response, then we can request at will. # # if point (2) is true, then we will have passed the socket to the # response (effectively meaning, "there is no prior response"), and # will open a new one when a new request is made. # # Note: if a prior response exists, then we *can* start a new request. # We are not allowed to begin fetching the response to this new # request, however, until that prior response is complete. # if self.__state == _CS_IDLE: self.__state = _CS_REQ_STARTED else: raise CannotSendRequest(self.__state) self._validate_method(method) # Save the method for use later in the response phase self._method = method url = url or '/' self._validate_path(url) request = '%s %s %s' % (method, url, self._http_vsn_str) self._output(self._encode_request(request)) if self._http_vsn == 11: # Issue some standard headers for better HTTP/1.1 compliance if not skip_host: # this header is issued *only* for HTTP/1.1 # connections. more specifically, this means it is # only issued when the client uses the new # HTTPConnection() class. backwards-compat clients # will be using HTTP/1.0 and those clients may be # issuing this header themselves. we should NOT issue # it twice; some web servers (such as Apache) barf # when they see two Host: headers # If we need a non-standard port,include it in the # header. If the request is going through a proxy, # but the host of the actual URL, not the host of the # proxy. netloc = '' if url.startswith('http'): nil, netloc, nil, nil, nil = urlsplit(url) if netloc: try: netloc_enc = netloc.encode("ascii") except UnicodeEncodeError: netloc_enc = netloc.encode("idna") self.putheader('Host', _strip_ipv6_iface(netloc_enc)) else: if self._tunnel_host: host = self._tunnel_host port = self._tunnel_port else: host = self.host port = self.port try: host_enc = host.encode("ascii") except UnicodeEncodeError: host_enc = host.encode("idna") # As per RFC 273, IPv6 address should be wrapped with [] # when used as Host header host_enc = self._wrap_ipv6(host_enc) if ":" in host: host_enc = _strip_ipv6_iface(host_enc) if port == self.default_port: self.putheader('Host', host_enc) else: host_enc = host_enc.decode("ascii") self.putheader('Host', "%s:%s" % (host_enc, port)) # note: we are assuming that clients will not attempt to set these # headers since *this* library must deal with the # consequences. this also means that when the supporting # libraries are updated to recognize other forms, then this # code should be changed (removed or updated). # we only want a Content-Encoding of "identity" since we don't # support encodings such as x-gzip or x-deflate. if not skip_accept_encoding: self.putheader('Accept-Encoding', 'identity') # we can accept "chunked" Transfer-Encodings, but no others # NOTE: no TE header implies *only* "chunked" #self.putheader('TE', 'chunked') # if TE is supplied in the header, then it must appear in a # Connection header. #self.putheader('Connection', 'TE') else: # For HTTP/1.0, the server will assume "not chunked" pass def _encode_request(self, request): # ASCII also helps prevent CVE-2019-9740. return request.encode('ascii') def _validate_method(self, method): """Validate a method name for putrequest.""" # prevent http header injection match = _contains_disallowed_method_pchar_re.search(method) if match: raise ValueError( f"method can't contain control characters. {method!r} " f"(found at least {match.group()!r})") def _validate_path(self, url): """Validate a url for putrequest.""" # Prevent CVE-2019-9740. match = _contains_disallowed_url_pchar_re.search(url) if match: raise InvalidURL(f"URL can't contain control characters. {url!r} " f"(found at least {match.group()!r})") def _validate_host(self, host): """Validate a host so it doesn't contain control characters.""" # Prevent CVE-2019-18348. match = _contains_disallowed_url_pchar_re.search(host) if match: raise InvalidURL(f"URL can't contain control characters. {host!r} " f"(found at least {match.group()!r})") def putheader(self, header, *values): """Send a request header line to the server. For example: h.putheader('Accept', 'text/html') """ if self.__state != _CS_REQ_STARTED: raise CannotSendHeader() if hasattr(header, 'encode'): header = header.encode('ascii') if not _is_legal_header_name(header): raise ValueError('Invalid header name %r' % (header,)) values = list(values) for i, one_value in enumerate(values): if hasattr(one_value, 'encode'): values[i] = one_value.encode('latin-1') elif isinstance(one_value, int): values[i] = str(one_value).encode('ascii') if _is_illegal_header_value(values[i]): raise ValueError('Invalid header value %r' % (values[i],)) value = b'\r\n\t'.join(values) header = header + b': ' + value self._output(header) def endheaders(self, message_body=None, *, encode_chunked=False): """Indicate that the last header line has been sent to the server. This method sends the request to the server. The optional message_body argument can be used to pass a message body associated with the request. """ if self.__state == _CS_REQ_STARTED: self.__state = _CS_REQ_SENT else: raise CannotSendHeader() self._send_output(message_body, encode_chunked=encode_chunked) def request(self, method, url, body=None, headers={}, *, encode_chunked=False): """Send a complete request to the server.""" self._send_request(method, url, body, headers, encode_chunked) def _send_request(self, method, url, body, headers, encode_chunked): # Honor explicitly requested Host: and Accept-Encoding: headers. header_names = frozenset(k.lower() for k in headers) skips = {} if 'host' in header_names: skips['skip_host'] = 1 if 'accept-encoding' in header_names: skips['skip_accept_encoding'] = 1 self.putrequest(method, url, **skips) # chunked encoding will happen if HTTP/1.1 is used and either # the caller passes encode_chunked=True or the following # conditions hold: # 1. content-length has not been explicitly set # 2. the body is a file or iterable, but not a str or bytes-like # 3. Transfer-Encoding has NOT been explicitly set by the caller if 'content-length' not in header_names: # only chunk body if not explicitly set for backwards # compatibility, assuming the client code is already handling the # chunking if 'transfer-encoding' not in header_names: # if content-length cannot be automatically determined, fall # back to chunked encoding encode_chunked = False content_length = self._get_content_length(body, method) if content_length is None: if body is not None: if self.debuglevel > 0: print('Unable to determine size of %r' % body) encode_chunked = True self.putheader('Transfer-Encoding', 'chunked') else: self.putheader('Content-Length', str(content_length)) else: encode_chunked = False for hdr, value in headers.items(): self.putheader(hdr, value) if isinstance(body, str): # RFC 2616 Section 3.7.1 says that text default has a # default charset of iso-8859-1. body = _encode(body, 'body') self.endheaders(body, encode_chunked=encode_chunked) def getresponse(self): """Get the response from the server. If the HTTPConnection is in the correct state, returns an instance of HTTPResponse or of whatever object is returned by the response_class variable. If a request has not been sent or if a previous response has not be handled, ResponseNotReady is raised. If the HTTP response indicates that the connection should be closed, then it will be closed before the response is returned. When the connection is closed, the underlying socket is closed. """ # if a prior response has been completed, then forget about it. if self.__response and self.__response.isclosed(): self.__response = None # if a prior response exists, then it must be completed (otherwise, we # cannot read this response's header to determine the connection-close # behavior) # # note: if a prior response existed, but was connection-close, then the # socket and response were made independent of this HTTPConnection # object since a new request requires that we open a whole new # connection # # this means the prior response had one of two states: # 1) will_close: this connection was reset and the prior socket and # response operate independently # 2) persistent: the response was retained and we await its # isclosed() status to become true. # if self.__state != _CS_REQ_SENT or self.__response: raise ResponseNotReady(self.__state) if self.debuglevel > 0: response = self.response_class(self.sock, self.debuglevel, method=self._method) else: response = self.response_class(self.sock, method=self._method) try: try: response.begin() except ConnectionError: self.close() raise assert response.will_close != _UNKNOWN self.__state = _CS_IDLE if response.will_close: # this effectively passes the connection to the response self.close() else: # remember this, so we can tell when it is complete self.__response = response return response except: response.close() raise try: import ssl except ImportError: pass else: class HTTPSConnection(HTTPConnection): "This class allows communication via SSL." default_port = HTTPS_PORT def __init__(self, host, port=None, *, timeout=socket._GLOBAL_DEFAULT_TIMEOUT, source_address=None, context=None, blocksize=8192): super(HTTPSConnection, self).__init__(host, port, timeout, source_address, blocksize=blocksize) if context is None: context = _create_https_context(self._http_vsn) self._context = context def connect(self): "Connect to a host on a given (SSL) port." super().connect() if self._tunnel_host: server_hostname = self._tunnel_host else: server_hostname = self.host self.sock = self._context.wrap_socket(self.sock, server_hostname=server_hostname) __all__.append("HTTPSConnection") class HTTPException(Exception): # Subclasses that define an __init__ must call Exception.__init__ # or define self.args. Otherwise, str() will fail. pass class NotConnected(HTTPException): pass class InvalidURL(HTTPException): pass class UnknownProtocol(HTTPException): def __init__(self, version): self.args = version, self.version = version class UnknownTransferEncoding(HTTPException): pass class UnimplementedFileMode(HTTPException): pass class IncompleteRead(HTTPException): def __init__(self, partial, expected=None): self.args = partial, self.partial = partial self.expected = expected def __repr__(self): if self.expected is not None: e = ', %i more expected' % self.expected else: e = '' return '%s(%i bytes read%s)' % (self.__class__.__name__, len(self.partial), e) __str__ = object.__str__ class ImproperConnectionState(HTTPException): pass class CannotSendRequest(ImproperConnectionState): pass class CannotSendHeader(ImproperConnectionState): pass class ResponseNotReady(ImproperConnectionState): pass class BadStatusLine(HTTPException): def __init__(self, line): if not line: line = repr(line) self.args = line, self.line = line class LineTooLong(HTTPException): def __init__(self, line_type): HTTPException.__init__(self, "got more than %d bytes when reading %s" % (_MAXLINE, line_type)) class RemoteDisconnected(ConnectionResetError, BadStatusLine): def __init__(self, *pos, **kw): BadStatusLine.__init__(self, "") ConnectionResetError.__init__(self, *pos, **kw) # for backwards compatibility error = HTTPException
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