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wg-backend-django/dell-env/lib/python3.11/site-packages/werkzeug/http.py

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Add iptable-parser as submodule
2023-10-30 03:40:43 -04:00
import base64
import email.utils
import re
import typing
import typing as t
import warnings
from datetime import date
from datetime import datetime
from datetime import time
from datetime import timedelta
from datetime import timezone
from enum import Enum
from hashlib import sha1
from time import mktime
from time import struct_time
from urllib.parse import unquote_to_bytes as _unquote
from urllib.request import parse_http_list as _parse_list_header
from ._internal import _cookie_quote
from ._internal import _dt_as_utc
from ._internal import _make_cookie_domain
from ._internal import _to_bytes
from ._internal import _to_str
from ._internal import _wsgi_decoding_dance
if t.TYPE_CHECKING:
from _typeshed.wsgi import WSGIEnvironment
# for explanation of "media-range", etc. see Sections 5.3.{1,2} of RFC 7231
_accept_re = re.compile(
r"""
( # media-range capturing-parenthesis
[^\s;,]+ # type/subtype
(?:[ \t]*;[ \t]* # ";"
(?: # parameter non-capturing-parenthesis
[^\s;,q][^\s;,]* # token that doesn't start with "q"
| # or
q[^\s;,=][^\s;,]* # token that is more than just "q"
)
)* # zero or more parameters
) # end of media-range
(?:[ \t]*;[ \t]*q= # weight is a "q" parameter
(\d*(?:\.\d+)?) # qvalue capturing-parentheses
[^,]* # "extension" accept params: who cares?
)? # accept params are optional
""",
re.VERBOSE,
)
_token_chars = frozenset(
"!#$%&'*+-.0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ^_`abcdefghijklmnopqrstuvwxyz|~"
)
_etag_re = re.compile(r'([Ww]/)?(?:"(.*?)"|(.*?))(?:\s*,\s*|$)')
_option_header_piece_re = re.compile(
r"""
;\s*,?\s* # newlines were replaced with commas
(?P<key>
"[^"\\]*(?:\\.[^"\\]*)*" # quoted string
|
[^\s;,=*]+ # token
)
(?:\*(?P<count>\d+))? # *1, optional continuation index
\s*
(?: # optionally followed by =value
(?: # equals sign, possibly with encoding
\*\s*=\s* # * indicates extended notation
(?: # optional encoding
(?P<encoding>[^\s]+?)
'(?P<language>[^\s]*?)'
)?
|
=\s* # basic notation
)
(?P<value>
"[^"\\]*(?:\\.[^"\\]*)*" # quoted string
|
[^;,]+ # token
)?
)?
\s*
""",
flags=re.VERBOSE,
)
_option_header_start_mime_type = re.compile(r",\s*([^;,\s]+)([;,]\s*.+)?")
_entity_headers = frozenset(
[
"allow",
"content-encoding",
"content-language",
"content-length",
"content-location",
"content-md5",
"content-range",
"content-type",
"expires",
"last-modified",
]
)
_hop_by_hop_headers = frozenset(
[
"connection",
"keep-alive",
"proxy-authenticate",
"proxy-authorization",
"te",
"trailer",
"transfer-encoding",
"upgrade",
]
)
HTTP_STATUS_CODES = {
100: "Continue",
101: "Switching Protocols",
102: "Processing",
103: "Early Hints", # see RFC 8297
200: "OK",
201: "Created",
202: "Accepted",
203: "Non Authoritative Information",
204: "No Content",
205: "Reset Content",
206: "Partial Content",
207: "Multi Status",
208: "Already Reported", # see RFC 5842
226: "IM Used", # see RFC 3229
300: "Multiple Choices",
301: "Moved Permanently",
302: "Found",
303: "See Other",
304: "Not Modified",
305: "Use Proxy",
306: "Switch Proxy", # unused
307: "Temporary Redirect",
308: "Permanent Redirect",
400: "Bad Request",
401: "Unauthorized",
402: "Payment Required", # unused
403: "Forbidden",
404: "Not Found",
405: "Method Not Allowed",
406: "Not Acceptable",
407: "Proxy Authentication Required",
408: "Request Timeout",
409: "Conflict",
410: "Gone",
411: "Length Required",
412: "Precondition Failed",
413: "Request Entity Too Large",
414: "Request URI Too Long",
415: "Unsupported Media Type",
416: "Requested Range Not Satisfiable",
417: "Expectation Failed",
418: "I'm a teapot", # see RFC 2324
421: "Misdirected Request", # see RFC 7540
422: "Unprocessable Entity",
423: "Locked",
424: "Failed Dependency",
425: "Too Early", # see RFC 8470
426: "Upgrade Required",
428: "Precondition Required", # see RFC 6585
429: "Too Many Requests",
431: "Request Header Fields Too Large",
449: "Retry With", # proprietary MS extension
451: "Unavailable For Legal Reasons",
500: "Internal Server Error",
501: "Not Implemented",
502: "Bad Gateway",
503: "Service Unavailable",
504: "Gateway Timeout",
505: "HTTP Version Not Supported",
506: "Variant Also Negotiates", # see RFC 2295
507: "Insufficient Storage",
508: "Loop Detected", # see RFC 5842
510: "Not Extended",
511: "Network Authentication Failed",
}
class COEP(Enum):
"""Cross Origin Embedder Policies"""
UNSAFE_NONE = "unsafe-none"
REQUIRE_CORP = "require-corp"
class COOP(Enum):
"""Cross Origin Opener Policies"""
UNSAFE_NONE = "unsafe-none"
SAME_ORIGIN_ALLOW_POPUPS = "same-origin-allow-popups"
SAME_ORIGIN = "same-origin"
def _is_extended_parameter(key: str) -> bool:
"""Per RFC 5987/8187, "extended" values may *not* be quoted.
This is in keeping with browser implementations. So we test
using this function to see if the key indicates this parameter
follows the `ext-parameter` syntax (using a trailing '*').
"""
return key.strip().endswith("*")
def quote_header_value(
value: t.Union[str, int], extra_chars: str = "", allow_token: bool = True
) -> str:
"""Quote a header value if necessary.
.. versionadded:: 0.5
:param value: the value to quote.
:param extra_chars: a list of extra characters to skip quoting.
:param allow_token: if this is enabled token values are returned
unchanged.
"""
if isinstance(value, bytes):
value = value.decode("latin1")
value = str(value)
if allow_token:
token_chars = _token_chars | set(extra_chars)
if set(value).issubset(token_chars):
return value
value = value.replace("\\", "\\\\").replace('"', '\\"')
return f'"{value}"'
def unquote_header_value(value: str, is_filename: bool = False) -> str:
r"""Unquotes a header value. (Reversal of :func:`quote_header_value`).
This does not use the real unquoting but what browsers are actually
using for quoting.
.. versionadded:: 0.5
:param value: the header value to unquote.
:param is_filename: The value represents a filename or path.
"""
if value and value[0] == value[-1] == '"':
# this is not the real unquoting, but fixing this so that the
# RFC is met will result in bugs with internet explorer and
# probably some other browsers as well. IE for example is
# uploading files with "C:\foo\bar.txt" as filename
value = value[1:-1]
# if this is a filename and the starting characters look like
# a UNC path, then just return the value without quotes. Using the
# replace sequence below on a UNC path has the effect of turning
# the leading double slash into a single slash and then
# _fix_ie_filename() doesn't work correctly. See #458.
if not is_filename or value[:2] != "\\\\":
return value.replace("\\\\", "\\").replace('\\"', '"')
return value
def dump_options_header(
header: t.Optional[str], options: t.Mapping[str, t.Optional[t.Union[str, int]]]
) -> str:
"""The reverse function to :func:`parse_options_header`.
:param header: the header to dump
:param options: a dict of options to append.
"""
segments = []
if header is not None:
segments.append(header)
for key, value in options.items():
if value is None:
segments.append(key)
elif _is_extended_parameter(key):
segments.append(f"{key}={value}")
else:
segments.append(f"{key}={quote_header_value(value)}")
return "; ".join(segments)
def dump_header(
iterable: t.Union[t.Dict[str, t.Union[str, int]], t.Iterable[str]],
allow_token: bool = True,
) -> str:
"""Dump an HTTP header again. This is the reversal of
:func:`parse_list_header`, :func:`parse_set_header` and
:func:`parse_dict_header`. This also quotes strings that include an
equals sign unless you pass it as dict of key, value pairs.
>>> dump_header({'foo': 'bar baz'})
'foo="bar baz"'
>>> dump_header(('foo', 'bar baz'))
'foo, "bar baz"'
:param iterable: the iterable or dict of values to quote.
:param allow_token: if set to `False` tokens as values are disallowed.
See :func:`quote_header_value` for more details.
"""
if isinstance(iterable, dict):
items = []
for key, value in iterable.items():
if value is None:
items.append(key)
elif _is_extended_parameter(key):
items.append(f"{key}={value}")
else:
items.append(
f"{key}={quote_header_value(value, allow_token=allow_token)}"
)
else:
items = [quote_header_value(x, allow_token=allow_token) for x in iterable]
return ", ".join(items)
def dump_csp_header(header: "ds.ContentSecurityPolicy") -> str:
"""Dump a Content Security Policy header.
These are structured into policies such as "default-src 'self';
script-src 'self'".
.. versionadded:: 1.0.0
Support for Content Security Policy headers was added.
"""
return "; ".join(f"{key} {value}" for key, value in header.items())
def parse_list_header(value: str) -> t.List[str]:
"""Parse lists as described by RFC 2068 Section 2.
In particular, parse comma-separated lists where the elements of
the list may include quoted-strings. A quoted-string could
contain a comma. A non-quoted string could have quotes in the
middle. Quotes are removed automatically after parsing.
It basically works like :func:`parse_set_header` just that items
may appear multiple times and case sensitivity is preserved.
The return value is a standard :class:`list`:
>>> parse_list_header('token, "quoted value"')
['token', 'quoted value']
To create a header from the :class:`list` again, use the
:func:`dump_header` function.
:param value: a string with a list header.
:return: :class:`list`
"""
result = []
for item in _parse_list_header(value):
if item[:1] == item[-1:] == '"':
item = unquote_header_value(item[1:-1])
result.append(item)
return result
def parse_dict_header(value: str, cls: t.Type[dict] = dict) -> t.Dict[str, str]:
"""Parse lists of key, value pairs as described by RFC 2068 Section 2 and
convert them into a python dict (or any other mapping object created from
the type with a dict like interface provided by the `cls` argument):
>>> d = parse_dict_header('foo="is a fish", bar="as well"')
>>> type(d) is dict
True
>>> sorted(d.items())
[('bar', 'as well'), ('foo', 'is a fish')]
If there is no value for a key it will be `None`:
>>> parse_dict_header('key_without_value')
{'key_without_value': None}
To create a header from the :class:`dict` again, use the
:func:`dump_header` function.
.. versionchanged:: 0.9
Added support for `cls` argument.
:param value: a string with a dict header.
:param cls: callable to use for storage of parsed results.
:return: an instance of `cls`
"""
result = cls()
if isinstance(value, bytes):
value = value.decode("latin1")
for item in _parse_list_header(value):
if "=" not in item:
result[item] = None
continue
name, value = item.split("=", 1)
if value[:1] == value[-1:] == '"':
value = unquote_header_value(value[1:-1])
result[name] = value
return result
def parse_options_header(value: t.Optional[str]) -> t.Tuple[str, t.Dict[str, str]]:
"""Parse a ``Content-Type``-like header into a tuple with the
value and any options:
>>> parse_options_header('text/html; charset=utf8')
('text/html', {'charset': 'utf8'})
This should is not for ``Cache-Control``-like headers, which use a
different format. For those, use :func:`parse_dict_header`.
:param value: The header value to parse.
.. versionchanged:: 2.2
Option names are always converted to lowercase.
.. versionchanged:: 2.1
The ``multiple`` parameter is deprecated and will be removed in
Werkzeug 2.2.
.. versionchanged:: 0.15
:rfc:`2231` parameter continuations are handled.
.. versionadded:: 0.5
"""
if not value:
return "", {}
result: t.List[t.Any] = []
value = "," + value.replace("\n", ",")
while value:
match = _option_header_start_mime_type.match(value)
if not match:
break
result.append(match.group(1)) # mimetype
options: t.Dict[str, str] = {}
# Parse options
rest = match.group(2)
encoding: t.Optional[str]
continued_encoding: t.Optional[str] = None
while rest:
optmatch = _option_header_piece_re.match(rest)
if not optmatch:
break
option, count, encoding, language, option_value = optmatch.groups()
# Continuations don't have to supply the encoding after the
# first line. If we're in a continuation, track the current
# encoding to use for subsequent lines. Reset it when the
# continuation ends.
if not count:
continued_encoding = None
else:
if not encoding:
encoding = continued_encoding
continued_encoding = encoding
option = unquote_header_value(option).lower()
if option_value is not None:
option_value = unquote_header_value(option_value, option == "filename")
if encoding is not None:
option_value = _unquote(option_value).decode(encoding)
if count:
# Continuations append to the existing value. For
# simplicity, this ignores the possibility of
# out-of-order indices, which shouldn't happen anyway.
if option_value is not None:
options[option] = options.get(option, "") + option_value
else:
options[option] = option_value # type: ignore[assignment]
rest = rest[optmatch.end() :]
result.append(options)
return tuple(result) # type: ignore[return-value]
return tuple(result) if result else ("", {}) # type: ignore[return-value]
_TAnyAccept = t.TypeVar("_TAnyAccept", bound="ds.Accept")
@typing.overload
def parse_accept_header(value: t.Optional[str]) -> "ds.Accept":
...
@typing.overload
def parse_accept_header(
value: t.Optional[str], cls: t.Type[_TAnyAccept]
) -> _TAnyAccept:
...
def parse_accept_header(
value: t.Optional[str], cls: t.Optional[t.Type[_TAnyAccept]] = None
) -> _TAnyAccept:
"""Parses an HTTP Accept-* header. This does not implement a complete
valid algorithm but one that supports at least value and quality
extraction.
Returns a new :class:`Accept` object (basically a list of ``(value, quality)``
tuples sorted by the quality with some additional accessor methods).
The second parameter can be a subclass of :class:`Accept` that is created
with the parsed values and returned.
:param value: the accept header string to be parsed.
:param cls: the wrapper class for the return value (can be
:class:`Accept` or a subclass thereof)
:return: an instance of `cls`.
"""
if cls is None:
cls = t.cast(t.Type[_TAnyAccept], ds.Accept)
if not value:
return cls(None)
result = []
for match in _accept_re.finditer(value):
quality_match = match.group(2)
if not quality_match:
quality: float = 1
else:
quality = max(min(float(quality_match), 1), 0)
result.append((match.group(1), quality))
return cls(result)
_TAnyCC = t.TypeVar("_TAnyCC", bound="ds._CacheControl")
_t_cc_update = t.Optional[t.Callable[[_TAnyCC], None]]
@typing.overload
def parse_cache_control_header(
value: t.Optional[str], on_update: _t_cc_update, cls: None = None
) -> "ds.RequestCacheControl":
...
@typing.overload
def parse_cache_control_header(
value: t.Optional[str], on_update: _t_cc_update, cls: t.Type[_TAnyCC]
) -> _TAnyCC:
...
def parse_cache_control_header(
value: t.Optional[str],
on_update: _t_cc_update = None,
cls: t.Optional[t.Type[_TAnyCC]] = None,
) -> _TAnyCC:
"""Parse a cache control header. The RFC differs between response and
request cache control, this method does not. It's your responsibility
to not use the wrong control statements.
.. versionadded:: 0.5
The `cls` was added. If not specified an immutable
:class:`~werkzeug.datastructures.RequestCacheControl` is returned.
:param value: a cache control header to be parsed.
:param on_update: an optional callable that is called every time a value
on the :class:`~werkzeug.datastructures.CacheControl`
object is changed.
:param cls: the class for the returned object. By default
:class:`~werkzeug.datastructures.RequestCacheControl` is used.
:return: a `cls` object.
"""
if cls is None:
cls = t.cast(t.Type[_TAnyCC], ds.RequestCacheControl)
if not value:
return cls((), on_update)
return cls(parse_dict_header(value), on_update)
_TAnyCSP = t.TypeVar("_TAnyCSP", bound="ds.ContentSecurityPolicy")
_t_csp_update = t.Optional[t.Callable[[_TAnyCSP], None]]
@typing.overload
def parse_csp_header(
value: t.Optional[str], on_update: _t_csp_update, cls: None = None
) -> "ds.ContentSecurityPolicy":
...
@typing.overload
def parse_csp_header(
value: t.Optional[str], on_update: _t_csp_update, cls: t.Type[_TAnyCSP]
) -> _TAnyCSP:
...
def parse_csp_header(
value: t.Optional[str],
on_update: _t_csp_update = None,
cls: t.Optional[t.Type[_TAnyCSP]] = None,
) -> _TAnyCSP:
"""Parse a Content Security Policy header.
.. versionadded:: 1.0.0
Support for Content Security Policy headers was added.
:param value: a csp header to be parsed.
:param on_update: an optional callable that is called every time a value
on the object is changed.
:param cls: the class for the returned object. By default
:class:`~werkzeug.datastructures.ContentSecurityPolicy` is used.
:return: a `cls` object.
"""
if cls is None:
cls = t.cast(t.Type[_TAnyCSP], ds.ContentSecurityPolicy)
if value is None:
return cls((), on_update)
items = []
for policy in value.split(";"):
policy = policy.strip()
# Ignore badly formatted policies (no space)
if " " in policy:
directive, value = policy.strip().split(" ", 1)
items.append((directive.strip(), value.strip()))
return cls(items, on_update)
def parse_set_header(
value: t.Optional[str],
on_update: t.Optional[t.Callable[["ds.HeaderSet"], None]] = None,
) -> "ds.HeaderSet":
"""Parse a set-like header and return a
:class:`~werkzeug.datastructures.HeaderSet` object:
>>> hs = parse_set_header('token, "quoted value"')
The return value is an object that treats the items case-insensitively
and keeps the order of the items:
>>> 'TOKEN' in hs
True
>>> hs.index('quoted value')
1
>>> hs
HeaderSet(['token', 'quoted value'])
To create a header from the :class:`HeaderSet` again, use the
:func:`dump_header` function.
:param value: a set header to be parsed.
:param on_update: an optional callable that is called every time a
value on the :class:`~werkzeug.datastructures.HeaderSet`
object is changed.
:return: a :class:`~werkzeug.datastructures.HeaderSet`
"""
if not value:
return ds.HeaderSet(None, on_update)
return ds.HeaderSet(parse_list_header(value), on_update)
def parse_authorization_header(
value: t.Optional[str],
) -> t.Optional["ds.Authorization"]:
"""Parse an HTTP basic/digest authorization header transmitted by the web
browser. The return value is either `None` if the header was invalid or
not given, otherwise an :class:`~werkzeug.datastructures.Authorization`
object.
:param value: the authorization header to parse.
:return: a :class:`~werkzeug.datastructures.Authorization` object or `None`.
"""
if not value:
return None
value = _wsgi_decoding_dance(value)
try:
auth_type, auth_info = value.split(None, 1)
auth_type = auth_type.lower()
except ValueError:
return None
if auth_type == "basic":
try:
username, password = base64.b64decode(auth_info).split(b":", 1)
except Exception:
return None
try:
return ds.Authorization(
"basic",
{
"username": _to_str(username, "utf-8"),
"password": _to_str(password, "utf-8"),
},
)
except UnicodeDecodeError:
return None
elif auth_type == "digest":
auth_map = parse_dict_header(auth_info)
for key in "username", "realm", "nonce", "uri", "response":
if key not in auth_map:
return None
if "qop" in auth_map:
if not auth_map.get("nc") or not auth_map.get("cnonce"):
return None
return ds.Authorization("digest", auth_map)
return None
def parse_www_authenticate_header(
value: t.Optional[str],
on_update: t.Optional[t.Callable[["ds.WWWAuthenticate"], None]] = None,
) -> "ds.WWWAuthenticate":
"""Parse an HTTP WWW-Authenticate header into a
:class:`~werkzeug.datastructures.WWWAuthenticate` object.
:param value: a WWW-Authenticate header to parse.
:param on_update: an optional callable that is called every time a value
on the :class:`~werkzeug.datastructures.WWWAuthenticate`
object is changed.
:return: a :class:`~werkzeug.datastructures.WWWAuthenticate` object.
"""
if not value:
return ds.WWWAuthenticate(on_update=on_update)
try:
auth_type, auth_info = value.split(None, 1)
auth_type = auth_type.lower()
except (ValueError, AttributeError):
return ds.WWWAuthenticate(value.strip().lower(), on_update=on_update)
return ds.WWWAuthenticate(auth_type, parse_dict_header(auth_info), on_update)
def parse_if_range_header(value: t.Optional[str]) -> "ds.IfRange":
"""Parses an if-range header which can be an etag or a date. Returns
a :class:`~werkzeug.datastructures.IfRange` object.
.. versionchanged:: 2.0
If the value represents a datetime, it is timezone-aware.
.. versionadded:: 0.7
"""
if not value:
return ds.IfRange()
date = parse_date(value)
if date is not None:
return ds.IfRange(date=date)
# drop weakness information
return ds.IfRange(unquote_etag(value)[0])
def parse_range_header(
value: t.Optional[str], make_inclusive: bool = True
) -> t.Optional["ds.Range"]:
"""Parses a range header into a :class:`~werkzeug.datastructures.Range`
object. If the header is missing or malformed `None` is returned.
`ranges` is a list of ``(start, stop)`` tuples where the ranges are
non-inclusive.
.. versionadded:: 0.7
"""
if not value or "=" not in value:
return None
ranges = []
last_end = 0
units, rng = value.split("=", 1)
units = units.strip().lower()
for item in rng.split(","):
item = item.strip()
if "-" not in item:
return None
if item.startswith("-"):
if last_end < 0:
return None
try:
begin = int(item)
except ValueError:
return None
end = None
last_end = -1
elif "-" in item:
begin_str, end_str = item.split("-", 1)
begin_str = begin_str.strip()
end_str = end_str.strip()
try:
begin = int(begin_str)
except ValueError:
return None
if begin < last_end or last_end < 0:
return None
if end_str:
try:
end = int(end_str) + 1
except ValueError:
return None
if begin >= end:
return None
else:
end = None
last_end = end if end is not None else -1
ranges.append((begin, end))
return ds.Range(units, ranges)
def parse_content_range_header(
value: t.Optional[str],
on_update: t.Optional[t.Callable[["ds.ContentRange"], None]] = None,
) -> t.Optional["ds.ContentRange"]:
"""Parses a range header into a
:class:`~werkzeug.datastructures.ContentRange` object or `None` if
parsing is not possible.
.. versionadded:: 0.7
:param value: a content range header to be parsed.
:param on_update: an optional callable that is called every time a value
on the :class:`~werkzeug.datastructures.ContentRange`
object is changed.
"""
if value is None:
return None
try:
units, rangedef = (value or "").strip().split(None, 1)
except ValueError:
return None
if "/" not in rangedef:
return None
rng, length_str = rangedef.split("/", 1)
if length_str == "*":
length = None
else:
try:
length = int(length_str)
except ValueError:
return None
if rng == "*":
if not is_byte_range_valid(None, None, length):
return None
return ds.ContentRange(units, None, None, length, on_update=on_update)
elif "-" not in rng:
return None
start_str, stop_str = rng.split("-", 1)
try:
start = int(start_str)
stop = int(stop_str) + 1
except ValueError:
return None
if is_byte_range_valid(start, stop, length):
return ds.ContentRange(units, start, stop, length, on_update=on_update)
return None
def quote_etag(etag: str, weak: bool = False) -> str:
"""Quote an etag.
:param etag: the etag to quote.
:param weak: set to `True` to tag it "weak".
"""
if '"' in etag:
raise ValueError("invalid etag")
etag = f'"{etag}"'
if weak:
etag = f"W/{etag}"
return etag
def unquote_etag(
etag: t.Optional[str],
) -> t.Union[t.Tuple[str, bool], t.Tuple[None, None]]:
"""Unquote a single etag:
>>> unquote_etag('W/"bar"')
('bar', True)
>>> unquote_etag('"bar"')
('bar', False)
:param etag: the etag identifier to unquote.
:return: a ``(etag, weak)`` tuple.
"""
if not etag:
return None, None
etag = etag.strip()
weak = False
if etag.startswith(("W/", "w/")):
weak = True
etag = etag[2:]
if etag[:1] == etag[-1:] == '"':
etag = etag[1:-1]
return etag, weak
def parse_etags(value: t.Optional[str]) -> "ds.ETags":
"""Parse an etag header.
:param value: the tag header to parse
:return: an :class:`~werkzeug.datastructures.ETags` object.
"""
if not value:
return ds.ETags()
strong = []
weak = []
end = len(value)
pos = 0
while pos < end:
match = _etag_re.match(value, pos)
if match is None:
break
is_weak, quoted, raw = match.groups()
if raw == "*":
return ds.ETags(star_tag=True)
elif quoted:
raw = quoted
if is_weak:
weak.append(raw)
else:
strong.append(raw)
pos = match.end()
return ds.ETags(strong, weak)
def generate_etag(data: bytes) -> str:
"""Generate an etag for some data.
.. versionchanged:: 2.0
Use SHA-1. MD5 may not be available in some environments.
"""
return sha1(data).hexdigest()
def parse_date(value: t.Optional[str]) -> t.Optional[datetime]:
"""Parse an :rfc:`2822` date into a timezone-aware
:class:`datetime.datetime` object, or ``None`` if parsing fails.
This is a wrapper for :func:`email.utils.parsedate_to_datetime`. It
returns ``None`` if parsing fails instead of raising an exception,
and always returns a timezone-aware datetime object. If the string
doesn't have timezone information, it is assumed to be UTC.
:param value: A string with a supported date format.
.. versionchanged:: 2.0
Return a timezone-aware datetime object. Use
``email.utils.parsedate_to_datetime``.
"""
if value is None:
return None
try:
dt = email.utils.parsedate_to_datetime(value)
except (TypeError, ValueError):
return None
if dt.tzinfo is None:
return dt.replace(tzinfo=timezone.utc)
return dt
def http_date(
timestamp: t.Optional[t.Union[datetime, date, int, float, struct_time]] = None
) -> str:
"""Format a datetime object or timestamp into an :rfc:`2822` date
string.
This is a wrapper for :func:`email.utils.format_datetime`. It
assumes naive datetime objects are in UTC instead of raising an
exception.
:param timestamp: The datetime or timestamp to format. Defaults to
the current time.
.. versionchanged:: 2.0
Use ``email.utils.format_datetime``. Accept ``date`` objects.
"""
if isinstance(timestamp, date):
if not isinstance(timestamp, datetime):
# Assume plain date is midnight UTC.
timestamp = datetime.combine(timestamp, time(), tzinfo=timezone.utc)
else:
# Ensure datetime is timezone-aware.
timestamp = _dt_as_utc(timestamp)
return email.utils.format_datetime(timestamp, usegmt=True)
if isinstance(timestamp, struct_time):
timestamp = mktime(timestamp)
return email.utils.formatdate(timestamp, usegmt=True)
def parse_age(value: t.Optional[str] = None) -> t.Optional[timedelta]:
"""Parses a base-10 integer count of seconds into a timedelta.
If parsing fails, the return value is `None`.
:param value: a string consisting of an integer represented in base-10
:return: a :class:`datetime.timedelta` object or `None`.
"""
if not value:
return None
try:
seconds = int(value)
except ValueError:
return None
if seconds < 0:
return None
try:
return timedelta(seconds=seconds)
except OverflowError:
return None
def dump_age(age: t.Optional[t.Union[timedelta, int]] = None) -> t.Optional[str]:
"""Formats the duration as a base-10 integer.
:param age: should be an integer number of seconds,
a :class:`datetime.timedelta` object, or,
if the age is unknown, `None` (default).
"""
if age is None:
return None
if isinstance(age, timedelta):
age = int(age.total_seconds())
else:
age = int(age)
if age < 0:
raise ValueError("age cannot be negative")
return str(age)
def is_resource_modified(
environ: "WSGIEnvironment",
etag: t.Optional[str] = None,
data: t.Optional[bytes] = None,
last_modified: t.Optional[t.Union[datetime, str]] = None,
ignore_if_range: bool = True,
) -> bool:
"""Convenience method for conditional requests.
:param environ: the WSGI environment of the request to be checked.
:param etag: the etag for the response for comparison.
:param data: or alternatively the data of the response to automatically
generate an etag using :func:`generate_etag`.
:param last_modified: an optional date of the last modification.
:param ignore_if_range: If `False`, `If-Range` header will be taken into
account.
:return: `True` if the resource was modified, otherwise `False`.
.. versionchanged:: 2.0
SHA-1 is used to generate an etag value for the data. MD5 may
not be available in some environments.
.. versionchanged:: 1.0.0
The check is run for methods other than ``GET`` and ``HEAD``.
"""
return _sansio_http.is_resource_modified(
http_range=environ.get("HTTP_RANGE"),
http_if_range=environ.get("HTTP_IF_RANGE"),
http_if_modified_since=environ.get("HTTP_IF_MODIFIED_SINCE"),
http_if_none_match=environ.get("HTTP_IF_NONE_MATCH"),
http_if_match=environ.get("HTTP_IF_MATCH"),
etag=etag,
data=data,
last_modified=last_modified,
ignore_if_range=ignore_if_range,
)
def remove_entity_headers(
headers: t.Union["ds.Headers", t.List[t.Tuple[str, str]]],
allowed: t.Iterable[str] = ("expires", "content-location"),
) -> None:
"""Remove all entity headers from a list or :class:`Headers` object. This
operation works in-place. `Expires` and `Content-Location` headers are
by default not removed. The reason for this is :rfc:`2616` section
10.3.5 which specifies some entity headers that should be sent.
.. versionchanged:: 0.5
added `allowed` parameter.
:param headers: a list or :class:`Headers` object.
:param allowed: a list of headers that should still be allowed even though
they are entity headers.
"""
allowed = {x.lower() for x in allowed}
headers[:] = [
(key, value)
for key, value in headers
if not is_entity_header(key) or key.lower() in allowed
]
def remove_hop_by_hop_headers(
headers: t.Union["ds.Headers", t.List[t.Tuple[str, str]]]
) -> None:
"""Remove all HTTP/1.1 "Hop-by-Hop" headers from a list or
:class:`Headers` object. This operation works in-place.
.. versionadded:: 0.5
:param headers: a list or :class:`Headers` object.
"""
headers[:] = [
(key, value) for key, value in headers if not is_hop_by_hop_header(key)
]
def is_entity_header(header: str) -> bool:
"""Check if a header is an entity header.
.. versionadded:: 0.5
:param header: the header to test.
:return: `True` if it's an entity header, `False` otherwise.
"""
return header.lower() in _entity_headers
def is_hop_by_hop_header(header: str) -> bool:
"""Check if a header is an HTTP/1.1 "Hop-by-Hop" header.
.. versionadded:: 0.5
:param header: the header to test.
:return: `True` if it's an HTTP/1.1 "Hop-by-Hop" header, `False` otherwise.
"""
return header.lower() in _hop_by_hop_headers
def parse_cookie(
header: t.Union["WSGIEnvironment", str, bytes, None],
charset: str = "utf-8",
errors: str = "replace",
cls: t.Optional[t.Type["ds.MultiDict"]] = None,
) -> "ds.MultiDict[str, str]":
"""Parse a cookie from a string or WSGI environ.
The same key can be provided multiple times, the values are stored
in-order. The default :class:`MultiDict` will have the first value
first, and all values can be retrieved with
:meth:`MultiDict.getlist`.
:param header: The cookie header as a string, or a WSGI environ dict
with a ``HTTP_COOKIE`` key.
:param charset: The charset for the cookie values.
:param errors: The error behavior for the charset decoding.
:param cls: A dict-like class to store the parsed cookies in.
Defaults to :class:`MultiDict`.
.. versionchanged:: 1.0.0
Returns a :class:`MultiDict` instead of a
``TypeConversionDict``.
.. versionchanged:: 0.5
Returns a :class:`TypeConversionDict` instead of a regular dict.
The ``cls`` parameter was added.
"""
if isinstance(header, dict):
cookie = header.get("HTTP_COOKIE", "")
elif header is None:
cookie = ""
else:
cookie = header
return _sansio_http.parse_cookie(
cookie=cookie, charset=charset, errors=errors, cls=cls
)
def dump_cookie(
key: str,
value: t.Union[bytes, str] = "",
max_age: t.Optional[t.Union[timedelta, int]] = None,
expires: t.Optional[t.Union[str, datetime, int, float]] = None,
path: t.Optional[str] = "/",
domain: t.Optional[str] = None,
secure: bool = False,
httponly: bool = False,
charset: str = "utf-8",
sync_expires: bool = True,
max_size: int = 4093,
samesite: t.Optional[str] = None,
) -> str:
"""Create a Set-Cookie header without the ``Set-Cookie`` prefix.
The return value is usually restricted to ascii as the vast majority
of values are properly escaped, but that is no guarantee. It's
tunneled through latin1 as required by :pep:`3333`.
The return value is not ASCII safe if the key contains unicode
characters. This is technically against the specification but
happens in the wild. It's strongly recommended to not use
non-ASCII values for the keys.
:param max_age: should be a number of seconds, or `None` (default) if
the cookie should last only as long as the client's
browser session. Additionally `timedelta` objects
are accepted, too.
:param expires: should be a `datetime` object or unix timestamp.
:param path: limits the cookie to a given path, per default it will
span the whole domain.
:param domain: Use this if you want to set a cross-domain cookie. For
example, ``domain=".example.com"`` will set a cookie
that is readable by the domain ``www.example.com``,
``foo.example.com`` etc. Otherwise, a cookie will only
be readable by the domain that set it.
:param secure: The cookie will only be available via HTTPS
:param httponly: disallow JavaScript to access the cookie. This is an
extension to the cookie standard and probably not
supported by all browsers.
:param charset: the encoding for string values.
:param sync_expires: automatically set expires if max_age is defined
but expires not.
:param max_size: Warn if the final header value exceeds this size. The
default, 4093, should be safely `supported by most browsers
<cookie_>`_. Set to 0 to disable this check.
:param samesite: Limits the scope of the cookie such that it will
only be attached to requests if those requests are same-site.
.. _`cookie`: http://browsercookielimits.squawky.net/
.. versionchanged:: 1.0.0
The string ``'None'`` is accepted for ``samesite``.
"""
key = _to_bytes(key, charset)
value = _to_bytes(value, charset)
if path is not None:
from .urls import iri_to_uri
path = iri_to_uri(path, charset)
domain = _make_cookie_domain(domain)
if isinstance(max_age, timedelta):
max_age = int(max_age.total_seconds())
if expires is not None:
if not isinstance(expires, str):
expires = http_date(expires)
elif max_age is not None and sync_expires:
expires = http_date(datetime.now(tz=timezone.utc).timestamp() + max_age)
if samesite is not None:
samesite = samesite.title()
if samesite not in {"Strict", "Lax", "None"}:
raise ValueError("SameSite must be 'Strict', 'Lax', or 'None'.")
buf = [key + b"=" + _cookie_quote(value)]
# XXX: In theory all of these parameters that are not marked with `None`
# should be quoted. Because stdlib did not quote it before I did not
# want to introduce quoting there now.
for k, v, q in (
(b"Domain", domain, True),
(b"Expires", expires, False),
(b"Max-Age", max_age, False),
(b"Secure", secure, None),
(b"HttpOnly", httponly, None),
(b"Path", path, False),
(b"SameSite", samesite, False),
):
if q is None:
if v:
buf.append(k)
continue
if v is None:
continue
tmp = bytearray(k)
if not isinstance(v, (bytes, bytearray)):
v = _to_bytes(str(v), charset)
if q:
v = _cookie_quote(v)
tmp += b"=" + v
buf.append(bytes(tmp))
# The return value will be an incorrectly encoded latin1 header for
# consistency with the headers object.
rv = b"; ".join(buf)
rv = rv.decode("latin1")
# Warn if the final value of the cookie is larger than the limit. If the
# cookie is too large, then it may be silently ignored by the browser,
# which can be quite hard to debug.
cookie_size = len(rv)
if max_size and cookie_size > max_size:
value_size = len(value)
warnings.warn(
f"The {key.decode(charset)!r} cookie is too large: the value was"
f" {value_size} bytes but the"
f" header required {cookie_size - value_size} extra bytes. The final size"
f" was {cookie_size} bytes but the limit is {max_size} bytes. Browsers may"
f" silently ignore cookies larger than this.",
stacklevel=2,
)
return rv
def is_byte_range_valid(
start: t.Optional[int], stop: t.Optional[int], length: t.Optional[int]
) -> bool:
"""Checks if a given byte content range is valid for the given length.
.. versionadded:: 0.7
"""
if (start is None) != (stop is None):
return False
elif start is None:
return length is None or length >= 0
elif length is None:
return 0 <= start < stop # type: ignore
elif start >= stop: # type: ignore
return False
return 0 <= start < length
# circular dependencies
from . import datastructures as ds
from .sansio import http as _sansio_http
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