Source code for tornado.httputil

#
# Copyright 2009 Facebook
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

"""HTTP utility code shared by clients and servers.

This module also defines the `HTTPServerRequest` class which is exposed
via `tornado.web.RequestHandler.request`.
"""

from __future__ import absolute_import, division, print_function

import calendar
import collections
import copy
import dataclasses
import datetime
import email.utils
import numbers
import re
import time
import unicodedata
import warnings

from tornado.escape import native_str, parse_qs_bytes, utf8
from tornado.log import gen_log
from tornado.util import ObjectDict, PY3, unicode_type

if PY3:
    import http.cookies as Cookie
    from http.client import responses
    from urllib.parse import urlencode, urlparse, urlunparse, parse_qsl
else:
    import Cookie
    from httplib import responses
    from urllib import urlencode
    from urlparse import urlparse, urlunparse, parse_qsl


# responses is unused in this file, but we re-export it to other files.
# Reference it so pyflakes doesn't complain.
responses

try:
    from ssl import SSLError
except ImportError:
    # ssl is unavailable on app engine.
    class _SSLError(Exception):
        pass
    # Hack around a mypy limitation. We can't simply put "type: ignore"
    # on the class definition itself; must go through an assignment.
    SSLError = _SSLError  # type: ignore

try:
    import typing  # noqa: F401
except ImportError:
    pass


class _ABNF:
    """Class that holds a subset of ABNF rules from RFC 9110 and friends.

    Class attributes are re.Pattern objects, with the same name as in the RFC
    (with hyphens changed to underscores). Currently contains only the subset
    we use (which is why this class is not public). Unfortunately the fields
    cannot be alphabetized as they are in the RFCs because of dependencies.
    """

    # RFC 5234 (ABNF)
    VCHAR = re.compile(r"[\x21-\x7E]")

    # RFC 9110 (HTTP Semantics)
    obs_text = re.compile(r"[\x80-\xFF]")
    tchar = re.compile(r"[!#$%&'*+\-.^_`|~0-9A-Za-z]")
    token = re.compile(rf"{tchar.pattern}+")
    field_name = token

    # RFC 9112 (HTTP/1.1)
    HTTP_version = re.compile(r"HTTP/[0-9]\.[0-9]")
    reason_phrase = re.compile(rf"(?:[\t ]|{VCHAR.pattern}|{obs_text.pattern})+")
    status_code = re.compile(r"[0-9]{3}")
    status_line = re.compile(
        rf"({HTTP_version.pattern}) ({status_code.pattern}) ({reason_phrase.pattern})?"
    )


# RFC 7230 section 3.5: a recipient MAY recognize a single LF as a line
# terminator and ignore any preceding CR.
_CRLF_RE = re.compile(r'\r?\n')


class _NormalizedHeaderCache(dict):
    """Dynamic cached mapping of header names to Http-Header-Case.

    Implemented as a dict subclass so that cache hits are as fast as a
    normal dict lookup, without the overhead of a python function
    call.

    >>> normalized_headers = _NormalizedHeaderCache(10)
    >>> normalized_headers["coNtent-TYPE"]
    'Content-Type'
    """
    def __init__(self, size):
        super(_NormalizedHeaderCache, self).__init__()
        self.size = size
        self.queue = collections.deque()

    def __missing__(self, key):
        normalized = "-".join([w.capitalize() for w in key.split("-")])
        self[key] = normalized
        self.queue.append(key)
        if len(self.queue) > self.size:
            # Limit the size of the cache.  LRU would be better, but this
            # simpler approach should be fine.  In Python 2.7+ we could
            # use OrderedDict (or in 3.2+, @functools.lru_cache).
            old_key = self.queue.popleft()
            del self[old_key]
        return normalized


_normalized_headers = _NormalizedHeaderCache(1000)


[docs]class HTTPHeaders(collections.MutableMapping): """A dictionary that maintains ``Http-Header-Case`` for all keys. Supports multiple values per key via a pair of new methods, `add()` and `get_list()`. The regular dictionary interface returns a single value per key, with multiple values joined by a comma. >>> h = HTTPHeaders({"content-type": "text/html"}) >>> list(h.keys()) ['Content-Type'] >>> h["Content-Type"] 'text/html' >>> h.add("Set-Cookie", "A=B") >>> h.add("Set-Cookie", "C=D") >>> h["set-cookie"] 'A=B,C=D' >>> h.get_list("set-cookie") ['A=B', 'C=D'] >>> for (k,v) in sorted(h.get_all()): ... print('%s: %s' % (k,v)) ... Content-Type: text/html Set-Cookie: A=B Set-Cookie: C=D """ def __init__(self, *args, **kwargs): # Formally, HTTP headers are a mapping from a field name to a "combined field value", # which may be constructed from multiple field lines by joining them with commas. # In practice, however, some headers (notably Set-Cookie) do not follow this convention, # so we maintain a mapping from field name to a list of field lines in self._as_list. # self._combined_cache is a cache of the combined field values derived from self._as_list # on demand (and cleared whenever the list is modified). self._as_list = {} self._combined_cache = {} self._last_key = None if (len(args) == 1 and len(kwargs) == 0 and isinstance(args[0], HTTPHeaders)): # Copy constructor for k, v in args[0].get_all(): self.add(k, v) else: # Dict-style initialization self.update(*args, **kwargs) # new public methods
[docs] def add(self, name, value): # type: (str, str) -> None """Adds a new value for the given key.""" if not _ABNF.token.fullmatch(name): raise HTTPInputError("Invalid header name %r" % name) norm_name = _normalized_headers[name] self._last_key = norm_name if norm_name in self: self._combined_cache.pop(norm_name, None) self._as_list[norm_name].append(value) else: self[norm_name] = value
[docs] def get_list(self, name): """Returns all values for the given header as a list.""" norm_name = _normalized_headers[name] return self._as_list.get(norm_name, [])
[docs] def get_all(self): # type: () -> typing.Iterable[typing.Tuple[str, str]] """Returns an iterable of all (name, value) pairs. If a header has multiple values, multiple pairs will be returned with the same name. """ for name, values in self._as_list.items(): for value in values: yield (name, value)
[docs] def parse_line(self, line): """Updates the dictionary with a single header line. >>> h = HTTPHeaders() >>> h.parse_line("Content-Type: text/html") >>> h.get('content-type') 'text/html' """ if line[0].isspace(): # continuation of a multi-line header if self._last_key is None: raise HTTPInputError("first header line cannot start with whitespace") new_part = ' ' + line.lstrip() self._as_list[self._last_key][-1] += new_part self._combined_cache.pop(self._last_key, None) else: try: name, value = line.split(":", 1) except ValueError: raise HTTPInputError("no colon in header line") self.add(name, value.strip())
[docs] @classmethod def parse(cls, headers): """Returns a dictionary from HTTP header text. >>> h = HTTPHeaders.parse("Content-Type: text/html\\r\\nContent-Length: 42\\r\\n") >>> sorted(h.items()) [('Content-Length', '42'), ('Content-Type', 'text/html')] .. versionchanged:: 5.1 Raises `HTTPInputError` on malformed headers instead of a mix of `KeyError`, and `ValueError`. """ h = cls() for line in _CRLF_RE.split(headers): if line: h.parse_line(line) return h
# MutableMapping abstract method implementations. def __setitem__(self, name, value): norm_name = _normalized_headers[name] self._combined_cache[norm_name] = value self._as_list[norm_name] = [value] def __contains__(self, name): # This is an important optimization to avoid the expensive concatenation # in __getitem__ when it's not needed. if not isinstance(name, str): return False norm_name = _normalized_headers[name] return norm_name in self._as_list def __getitem__(self, name): # type: (str) -> str header = _normalized_headers[name] if header not in self._combined_cache: self._combined_cache[header] = ",".join(self._as_list[header]) return self._combined_cache[header] def __delitem__(self, name): norm_name = _normalized_headers[name] del self._combined_cache[norm_name] del self._as_list[norm_name] def __len__(self): return len(self._as_list) def __iter__(self): return iter(self._as_list) def copy(self): # defined in dict but not in MutableMapping. return HTTPHeaders(self) # Use our overridden copy method for the copy.copy module. # This makes shallow copies one level deeper, but preserves # the appearance that HTTPHeaders is a single container. __copy__ = copy def __str__(self): lines = [] for name, value in self.get_all(): lines.append("%s: %s\n" % (name, value)) return "".join(lines) __unicode__ = __str__
[docs]class HTTPServerRequest(object): """A single HTTP request. All attributes are type `str` unless otherwise noted. .. attribute:: method HTTP request method, e.g. "GET" or "POST" .. attribute:: uri The requested uri. .. attribute:: path The path portion of `uri` .. attribute:: query The query portion of `uri` .. attribute:: version HTTP version specified in request, e.g. "HTTP/1.1" .. attribute:: headers `.HTTPHeaders` dictionary-like object for request headers. Acts like a case-insensitive dictionary with additional methods for repeated headers. .. attribute:: body Request body, if present, as a byte string. .. attribute:: remote_ip Client's IP address as a string. If ``HTTPServer.xheaders`` is set, will pass along the real IP address provided by a load balancer in the ``X-Real-Ip`` or ``X-Forwarded-For`` header. .. versionchanged:: 3.1 The list format of ``X-Forwarded-For`` is now supported. .. attribute:: protocol The protocol used, either "http" or "https". If ``HTTPServer.xheaders`` is set, will pass along the protocol used by a load balancer if reported via an ``X-Scheme`` header. .. attribute:: host The requested hostname, usually taken from the ``Host`` header. .. attribute:: arguments GET/POST arguments are available in the arguments property, which maps arguments names to lists of values (to support multiple values for individual names). Names are of type `str`, while arguments are byte strings. Note that this is different from `.RequestHandler.get_argument`, which returns argument values as unicode strings. .. attribute:: query_arguments Same format as ``arguments``, but contains only arguments extracted from the query string. .. versionadded:: 3.2 .. attribute:: body_arguments Same format as ``arguments``, but contains only arguments extracted from the request body. .. versionadded:: 3.2 .. attribute:: files File uploads are available in the files property, which maps file names to lists of `.HTTPFile`. .. attribute:: connection An HTTP request is attached to a single HTTP connection, which can be accessed through the "connection" attribute. Since connections are typically kept open in HTTP/1.1, multiple requests can be handled sequentially on a single connection. .. versionchanged:: 4.0 Moved from ``tornado.httpserver.HTTPRequest``. """ def __init__(self, method=None, uri=None, version="HTTP/1.0", headers=None, body=None, host=None, files=None, connection=None, start_line=None, server_connection=None): if start_line is not None: method, uri, version = start_line self.method = method self.uri = uri self.version = version self.headers = headers or HTTPHeaders() self.body = body or b"" # set remote IP and protocol context = getattr(connection, 'context', None) self.remote_ip = getattr(context, 'remote_ip', None) self.protocol = getattr(context, 'protocol', "http") self.host = host or self.headers.get("Host") or "127.0.0.1" self.host_name = split_host_and_port(self.host.lower())[0] self.files = files or {} self.connection = connection self.server_connection = server_connection self._start_time = time.time() self._finish_time = None self.path, sep, self.query = uri.partition('?') self.arguments = parse_qs_bytes(self.query, keep_blank_values=True) self.query_arguments = copy.deepcopy(self.arguments) self.body_arguments = {}
[docs] def supports_http_1_1(self): """Returns True if this request supports HTTP/1.1 semantics. .. deprecated:: 4.0 Applications are less likely to need this information with the introduction of `.HTTPConnection`. If you still need it, access the ``version`` attribute directly. This method will be removed in Tornado 6.0. """ warnings.warn("supports_http_1_1() is deprecated, use request.version instead", DeprecationWarning) return self.version == "HTTP/1.1"
@property def cookies(self): """A dictionary of Cookie.Morsel objects.""" if not hasattr(self, "_cookies"): self._cookies = Cookie.SimpleCookie() if "Cookie" in self.headers: try: parsed = parse_cookie(self.headers["Cookie"]) except Exception: pass else: for k, v in parsed.items(): try: self._cookies[k] = v except Exception: # SimpleCookie imposes some restrictions on keys; # parse_cookie does not. Discard any cookies # with disallowed keys. pass return self._cookies
[docs] def write(self, chunk, callback=None): """Writes the given chunk to the response stream. .. deprecated:: 4.0 Use ``request.connection`` and the `.HTTPConnection` methods to write the response. This method will be removed in Tornado 6.0. """ warnings.warn("req.write deprecated, use req.connection.write and write_headers instead", DeprecationWarning) assert isinstance(chunk, bytes) assert self.version.startswith("HTTP/1."), \ "deprecated interface only supported in HTTP/1.x" self.connection.write(chunk, callback=callback)
[docs] def finish(self): """Finishes this HTTP request on the open connection. .. deprecated:: 4.0 Use ``request.connection`` and the `.HTTPConnection` methods to write the response. This method will be removed in Tornado 6.0. """ warnings.warn("req.finish deprecated, use req.connection.finish instead", DeprecationWarning) self.connection.finish() self._finish_time = time.time()
[docs] def full_url(self): """Reconstructs the full URL for this request.""" return self.protocol + "://" + self.host + self.uri
[docs] def request_time(self): """Returns the amount of time it took for this request to execute.""" if self._finish_time is None: return time.time() - self._start_time else: return self._finish_time - self._start_time
[docs] def get_ssl_certificate(self, binary_form=False): """Returns the client's SSL certificate, if any. To use client certificates, the HTTPServer's `ssl.SSLContext.verify_mode` field must be set, e.g.:: ssl_ctx = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH) ssl_ctx.load_cert_chain("foo.crt", "foo.key") ssl_ctx.load_verify_locations("cacerts.pem") ssl_ctx.verify_mode = ssl.CERT_REQUIRED server = HTTPServer(app, ssl_options=ssl_ctx) By default, the return value is a dictionary (or None, if no client certificate is present). If ``binary_form`` is true, a DER-encoded form of the certificate is returned instead. See SSLSocket.getpeercert() in the standard library for more details. http://docs.python.org/library/ssl.html#sslsocket-objects """ try: return self.connection.stream.socket.getpeercert( binary_form=binary_form) except SSLError: return None
def _parse_body(self): parse_body_arguments( self.headers.get("Content-Type", ""), self.body, self.body_arguments, self.files, self.headers) for k, v in self.body_arguments.items(): self.arguments.setdefault(k, []).extend(v) def __repr__(self): attrs = ("protocol", "host", "method", "uri", "version", "remote_ip") args = ", ".join(["%s=%r" % (n, getattr(self, n)) for n in attrs]) return "%s(%s)" % (self.__class__.__name__, args)
[docs]class HTTPInputError(Exception): """Exception class for malformed HTTP requests or responses from remote sources. .. versionadded:: 4.0 """ pass
[docs]class HTTPOutputError(Exception): """Exception class for errors in HTTP output. .. versionadded:: 4.0 """ pass
[docs]class HTTPServerConnectionDelegate(object): """Implement this interface to handle requests from `.HTTPServer`. .. versionadded:: 4.0 """
[docs] def start_request(self, server_conn, request_conn): """This method is called by the server when a new request has started. :arg server_conn: is an opaque object representing the long-lived (e.g. tcp-level) connection. :arg request_conn: is a `.HTTPConnection` object for a single request/response exchange. This method should return a `.HTTPMessageDelegate`. """ raise NotImplementedError()
[docs] def on_close(self, server_conn): """This method is called when a connection has been closed. :arg server_conn: is a server connection that has previously been passed to ``start_request``. """ pass
[docs]class HTTPMessageDelegate(object): """Implement this interface to handle an HTTP request or response. .. versionadded:: 4.0 """
[docs] def headers_received(self, start_line, headers): """Called when the HTTP headers have been received and parsed. :arg start_line: a `.RequestStartLine` or `.ResponseStartLine` depending on whether this is a client or server message. :arg headers: a `.HTTPHeaders` instance. Some `.HTTPConnection` methods can only be called during ``headers_received``. May return a `.Future`; if it does the body will not be read until it is done. """ pass
[docs] def data_received(self, chunk): """Called when a chunk of data has been received. May return a `.Future` for flow control. """ pass
[docs] def finish(self): """Called after the last chunk of data has been received.""" pass
[docs] def on_connection_close(self): """Called if the connection is closed without finishing the request. If ``headers_received`` is called, either ``finish`` or ``on_connection_close`` will be called, but not both. """ pass
[docs]class HTTPConnection(object): """Applications use this interface to write their responses. .. versionadded:: 4.0 """
[docs] def write_headers(self, start_line, headers, chunk=None, callback=None): """Write an HTTP header block. :arg start_line: a `.RequestStartLine` or `.ResponseStartLine`. :arg headers: a `.HTTPHeaders` instance. :arg chunk: the first (optional) chunk of data. This is an optimization so that small responses can be written in the same call as their headers. :arg callback: a callback to be run when the write is complete. The ``version`` field of ``start_line`` is ignored. Returns a `.Future` if no callback is given. .. deprecated:: 5.1 The ``callback`` argument is deprecated and will be removed in Tornado 6.0. """ raise NotImplementedError()
[docs] def write(self, chunk, callback=None): """Writes a chunk of body data. The callback will be run when the write is complete. If no callback is given, returns a Future. .. deprecated:: 5.1 The ``callback`` argument is deprecated and will be removed in Tornado 6.0. """ raise NotImplementedError()
[docs] def finish(self): """Indicates that the last body data has been written. """ raise NotImplementedError()
[docs]def url_concat(url, args): """Concatenate url and arguments regardless of whether url has existing query parameters. ``args`` may be either a dictionary or a list of key-value pairs (the latter allows for multiple values with the same key. >>> url_concat("http://example.com/foo", dict(c="d")) 'http://example.com/foo?c=d' >>> url_concat("http://example.com/foo?a=b", dict(c="d")) 'http://example.com/foo?a=b&c=d' >>> url_concat("http://example.com/foo?a=b", [("c", "d"), ("c", "d2")]) 'http://example.com/foo?a=b&c=d&c=d2' """ if args is None: return url parsed_url = urlparse(url) if isinstance(args, dict): parsed_query = parse_qsl(parsed_url.query, keep_blank_values=True) parsed_query.extend(args.items()) elif isinstance(args, list) or isinstance(args, tuple): parsed_query = parse_qsl(parsed_url.query, keep_blank_values=True) parsed_query.extend(args) else: err = "'args' parameter should be dict, list or tuple. Not {0}".format( type(args)) raise TypeError(err) final_query = urlencode(parsed_query) url = urlunparse(( parsed_url[0], parsed_url[1], parsed_url[2], parsed_url[3], final_query, parsed_url[5])) return url
[docs]class HTTPFile(ObjectDict): """Represents a file uploaded via a form. For backwards compatibility, its instance attributes are also accessible as dictionary keys. * ``filename`` * ``body`` * ``content_type`` """ pass
def _parse_request_range(range_header): """Parses a Range header. Returns either ``None`` or tuple ``(start, end)``. Note that while the HTTP headers use inclusive byte positions, this method returns indexes suitable for use in slices. >>> start, end = _parse_request_range("bytes=1-2") >>> start, end (1, 3) >>> [0, 1, 2, 3, 4][start:end] [1, 2] >>> _parse_request_range("bytes=6-") (6, None) >>> _parse_request_range("bytes=-6") (-6, None) >>> _parse_request_range("bytes=-0") (None, 0) >>> _parse_request_range("bytes=") (None, None) >>> _parse_request_range("foo=42") >>> _parse_request_range("bytes=1-2,6-10") Note: only supports one range (ex, ``bytes=1-2,6-10`` is not allowed). See [0] for the details of the range header. [0]: http://greenbytes.de/tech/webdav/draft-ietf-httpbis-p5-range-latest.html#byte.ranges """ unit, _, value = range_header.partition("=") unit, value = unit.strip(), value.strip() if unit != "bytes": return None start_b, _, end_b = value.partition("-") try: start = _int_or_none(start_b) end = _int_or_none(end_b) except ValueError: return None if end is not None: if start is None: if end != 0: start = -end end = None else: end += 1 return (start, end) def _get_content_range(start, end, total): """Returns a suitable Content-Range header: >>> print(_get_content_range(None, 1, 4)) bytes 0-0/4 >>> print(_get_content_range(1, 3, 4)) bytes 1-2/4 >>> print(_get_content_range(None, None, 4)) bytes 0-3/4 """ start = start or 0 end = (end or total) - 1 return "bytes %s-%s/%s" % (start, end, total) def _int_or_none(val): val = val.strip() if val == "": return None return int(val)
[docs]@dataclasses.dataclass class ParseMultipartConfig: """This class configures the parsing of ``multipart/form-data`` request bodies. Its primary purpose is to place limits on the size and complexity of request messages to avoid potential denial-of-service attacks. .. versionadded:: 6.5.5 """ enabled: bool = True """Set this to false to disable the parsing of ``multipart/form-data`` requests entirely. This may be desirable for applications that do not need to handle this format, since multipart request have a history of DoS vulnerabilities in Tornado. Multipart requests are used primarily for ``<input type="file">`` in HTML forms, or in APIs that mimic this format. File uploads that use the HTTP ``PUT`` method generally do not use the multipart format. """ max_parts: int = 100 """The maximum number of parts accepted in a multipart request. Each ``<input>`` element in an HTML form corresponds to at least one "part". """ max_part_header_size: int = 10 * 1024 """The maximum size of the headers for each part of a multipart request. The header for a part contains the name of the form field and optionally the filename and content type of the uploaded file. """
[docs]@dataclasses.dataclass class ParseBodyConfig: """This class configures the parsing of request bodies. .. versionadded:: 6.5.5 """ multipart: ParseMultipartConfig = dataclasses.field( default_factory=ParseMultipartConfig ) """Configuration for ``multipart/form-data`` request bodies."""
_DEFAULT_PARSE_BODY_CONFIG = ParseBodyConfig()
[docs]def set_parse_body_config(config): r"""Sets the **global** default configuration for parsing request bodies. This global setting is provided as a stopgap for applications that need to raise the limits introduced in Tornado 6.5.5, or who wish to disable the parsing of multipart/form-data bodies entirely. Non-global configuration for this functionality will be introduced in a future release. >>> content_type = "multipart/form-data; boundary=foo" >>> multipart_body = b"--foo--\r\n" >>> parse_body_arguments(content_type, multipart_body, {}, {}) >>> multipart_config = ParseMultipartConfig(enabled=False) >>> config = ParseBodyConfig(multipart=multipart_config) >>> set_parse_body_config(config) >>> set_parse_body_config(ParseBodyConfig()) # reset to defaults .. versionadded:: 6.5.5 """ global _DEFAULT_PARSE_BODY_CONFIG _DEFAULT_PARSE_BODY_CONFIG = config
[docs]def parse_body_arguments(content_type, body, arguments, files, headers=None, *, config = None): """Parses a form request body. Supports ``application/x-www-form-urlencoded`` and ``multipart/form-data``. The ``content_type`` parameter should be a string and ``body`` should be a byte string. The ``arguments`` and ``files`` parameters are dictionaries that will be updated with the parsed contents. """ if config is None: config = _DEFAULT_PARSE_BODY_CONFIG if headers and 'Content-Encoding' in headers: gen_log.warning("Unsupported Content-Encoding: %s", headers['Content-Encoding']) return if content_type.startswith("application/x-www-form-urlencoded"): try: uri_arguments = parse_qs_bytes(native_str(body), keep_blank_values=True) except Exception as e: gen_log.warning('Invalid x-www-form-urlencoded body: %s', e) uri_arguments = {} for name, values in uri_arguments.items(): if values: arguments.setdefault(name, []).extend(values) elif content_type.startswith("multipart/form-data"): try: fields = content_type.split(";") if fields[0].strip() != "multipart/form-data": # This catches "Content-Type: multipart/form-dataxyz" raise HTTPInputError("Invalid content type") for field in fields: k, sep, v = field.strip().partition("=") if k == "boundary" and v: parse_multipart_form_data( utf8(v), body, arguments, files, config=config.multipart ) break else: raise ValueError("multipart boundary not found") except Exception as e: gen_log.warning("Invalid multipart/form-data: %s", e)
[docs]def parse_multipart_form_data(boundary, data, arguments, files, *, config = None): """Parses a ``multipart/form-data`` body. The ``boundary`` and ``data`` parameters are both byte strings. The dictionaries given in the arguments and files parameters will be updated with the contents of the body. .. versionchanged:: 5.1 Now recognizes non-ASCII filenames in RFC 2231/5987 (``filename*=``) format. """ if config is None: config = _DEFAULT_PARSE_BODY_CONFIG.multipart if not config.enabled: raise HTTPInputError("multipart/form-data parsing is disabled") # The standard allows for the boundary to be quoted in the header, # although it's rare (it happens at least for google app engine # xmpp). I think we're also supposed to handle backslash-escapes # here but I'll save that until we see a client that uses them # in the wild. if boundary.startswith(b'"') and boundary.endswith(b'"'): boundary = boundary[1:-1] final_boundary_index = data.rfind(b"--" + boundary + b"--") if final_boundary_index == -1: gen_log.warning("Invalid multipart/form-data: no final boundary") return parts = data[:final_boundary_index].split(b"--" + boundary + b"\r\n") if len(parts) > config.max_parts: raise HTTPInputError("multipart/form-data has too many parts") for part in parts: if not part: continue eoh = part.find(b"\r\n\r\n") if eoh == -1: gen_log.warning("multipart/form-data missing headers") continue if eoh > config.max_part_header_size: raise HTTPInputError("multipart/form-data part header too large") headers = HTTPHeaders.parse(part[:eoh].decode("utf-8")) disp_header = headers.get("Content-Disposition", "") disposition, disp_params = _parse_header(disp_header) if disposition != "form-data" or not part.endswith(b"\r\n"): gen_log.warning("Invalid multipart/form-data") continue value = part[eoh + 4:-2] if not disp_params.get("name"): gen_log.warning("multipart/form-data value missing name") continue name = disp_params["name"] if disp_params.get("filename"): ctype = headers.get("Content-Type", "application/unknown") files.setdefault(name, []).append(HTTPFile( # type: ignore filename=disp_params["filename"], body=value, content_type=ctype)) else: arguments.setdefault(name, []).append(value)
[docs]def format_timestamp(ts): """Formats a timestamp in the format used by HTTP. The argument may be a numeric timestamp as returned by `time.time`, a time tuple as returned by `time.gmtime`, or a `datetime.datetime` object. >>> format_timestamp(1359312200) 'Sun, 27 Jan 2013 18:43:20 GMT' """ if isinstance(ts, numbers.Real): pass elif isinstance(ts, (tuple, time.struct_time)): ts = calendar.timegm(ts) elif isinstance(ts, datetime.datetime): ts = calendar.timegm(ts.utctimetuple()) else: raise TypeError("unknown timestamp type: %r" % ts) return email.utils.formatdate(ts, usegmt=True)
RequestStartLine = collections.namedtuple( 'RequestStartLine', ['method', 'path', 'version'])
[docs]def parse_request_start_line(line): """Returns a (method, path, version) tuple for an HTTP 1.x request line. The response is a `collections.namedtuple`. >>> parse_request_start_line("GET /foo HTTP/1.1") RequestStartLine(method='GET', path='/foo', version='HTTP/1.1') """ try: method, path, version = line.split(" ") except ValueError: # https://tools.ietf.org/html/rfc7230#section-3.1.1 # invalid request-line SHOULD respond with a 400 (Bad Request) raise HTTPInputError("Malformed HTTP request line") if not _ABNF.HTTP_version.fullmatch(version): raise HTTPInputError( "Malformed HTTP version in HTTP Request-Line: %r" % version) if not version.startswith("HTTP/1"): # HTTP/2 and above doesn't use parse_request_start_line. # This could be folded into the regex but we don't want to deviate # from the ABNF in the RFCs. raise HTTPInputError("Unexpected HTTP version %r" % version) return RequestStartLine(method, path, version)
ResponseStartLine = collections.namedtuple( 'ResponseStartLine', ['version', 'code', 'reason'])
[docs]def parse_response_start_line(line): """Returns a (version, code, reason) tuple for an HTTP 1.x response line. The response is a `collections.namedtuple`. >>> parse_response_start_line("HTTP/1.1 200 OK") ResponseStartLine(version='HTTP/1.1', code=200, reason='OK') """ match = _ABNF.status_line.fullmatch(line) if not match: raise HTTPInputError("Error parsing response start line") r = ResponseStartLine(match.group(1), int(match.group(2)), match.group(3)) if not r.version.startswith("HTTP/1"): # HTTP/2 and above doesn't use parse_response_start_line. raise HTTPInputError("Unexpected HTTP version %r" % r.version) return r
# _parseparam and _parse_header are copied and modified from python2.7's cgi.py # The original 2.7 version of this code did not correctly support some # combinations of semicolons and double quotes. # It has also been modified to support valueless parameters as seen in # websocket extension negotiations, and to support non-ascii values in # RFC 2231/5987 format. # # _parseparam has been further modified with the logic from # https://github.com/python/cpython/pull/136072/files # to avoid quadratic behavior when parsing semicolons in quoted strings. # # TODO: See if we can switch to email.message.Message for this functionality. # This is the suggested replacement for the cgi.py module now that cgi has # been removed from recent versions of Python. We need to verify that # the email module is consistent with our existing behavior (and all relevant # RFCs for multipart/form-data) before making this change. def _parseparam(s): start = 0 while s.find(";", start) == start: start += 1 end = s.find(";", start) ind, diff = start, 0 while end > 0: diff += s.count('"', ind, end) - s.count('\\"', ind, end) if diff % 2 == 0: break end, ind = ind, s.find(";", end + 1) if end < 0: end = len(s) f = s[start:end] yield f.strip() start = end def _parse_header(line): r"""Parse a Content-type like header. Return the main content-type and a dictionary of options. >>> d = "form-data; foo=\"b\\\\a\\\"r\"; file*=utf-8''T%C3%A4st" >>> ct, d = _parse_header(d) >>> ct 'form-data' >>> d['file'] == r'T\u00e4st'.encode('ascii').decode('unicode_escape') True >>> d['foo'] 'b\\a"r' """ parts = _parseparam(';' + line) key = next(parts) # decode_params treats first argument special, but we already stripped key params = [('Dummy', 'value')] for p in parts: i = p.find('=') if i >= 0: name = p[:i].strip().lower() value = p[i + 1:].strip() params.append((name, native_str(value))) params = email.utils.decode_params(params) params.pop(0) # get rid of the dummy again pdict = {} for name, value in params: value = email.utils.collapse_rfc2231_value(value) if len(value) >= 2 and value[0] == '"' and value[-1] == '"': value = value[1:-1] pdict[name] = value return key, pdict def _encode_header(key, pdict): """Inverse of _parse_header. >>> _encode_header('permessage-deflate', ... {'client_max_window_bits': 15, 'client_no_context_takeover': None}) 'permessage-deflate; client_max_window_bits=15; client_no_context_takeover' """ if not pdict: return key out = [key] # Sort the parameters just to make it easy to test. for k, v in sorted(pdict.items()): if v is None: out.append(k) else: # TODO: quote if necessary. out.append('%s=%s' % (k, v)) return '; '.join(out)
[docs]def encode_username_password(username, password): """Encodes a username/password pair in the format used by HTTP auth. The return value is a byte string in the form ``username:password``. .. versionadded:: 5.1 """ if isinstance(username, unicode_type): username = unicodedata.normalize('NFC', username) if isinstance(password, unicode_type): password = unicodedata.normalize('NFC', password) return utf8(username) + b":" + utf8(password)
def doctests(): import doctest return doctest.DocTestSuite()
[docs]def split_host_and_port(netloc): """Returns ``(host, port)`` tuple from ``netloc``. Returned ``port`` will be ``None`` if not present. .. versionadded:: 4.1 """ match = re.match(r'^(.+):(\d+)$', netloc) if match: host = match.group(1) port = int(match.group(2)) else: host = netloc port = None return (host, port)
[docs]def qs_to_qsl(qs): """Generator converting a result of ``parse_qs`` back to name-value pairs. .. versionadded:: 5.0 """ for k, vs in qs.items(): for v in vs: yield (k, v)
_unquote_sub = re.compile(r"\\(?:([0-3][0-7][0-7])|(.))").sub def _unquote_replace(m: re.Match) -> str: if m[1]: return chr(int(m[1], 8)) else: return m[2] def _unquote_cookie(str): """Handle double quotes and escaping in cookie values. This method is copied verbatim from the Python 3.13 standard library (http.cookies._unquote) so we don't have to depend on non-public interfaces. """ # If there aren't any doublequotes, # then there can't be any special characters. See RFC 2109. if str is None or len(str) < 2: return str if str[0] != '"' or str[-1] != '"': return str # We have to assume that we must decode this string. # Down to work. # Remove the "s str = str[1:-1] # Check for special sequences. Examples: # \012 --> \n # \" --> " # return _unquote_sub(_unquote_replace, str)