374 lines
13 KiB
Python
374 lines
13 KiB
Python
from __future__ import annotations
|
|
|
|
import re
|
|
|
|
from typing import Any, Dict, Iterable, List, Optional, Set, Tuple, Union
|
|
from urllib.parse import unquote
|
|
|
|
from sanic.exceptions import InvalidHeader
|
|
from sanic.helpers import STATUS_CODES
|
|
|
|
|
|
# TODO:
|
|
# - the Options object should be a typed object to allow for less casting
|
|
# across the application (in request.py for example)
|
|
HeaderIterable = Iterable[Tuple[str, Any]] # Values convertible to str
|
|
HeaderBytesIterable = Iterable[Tuple[bytes, bytes]]
|
|
Options = Dict[str, Union[int, str]] # key=value fields in various headers
|
|
OptionsIterable = Iterable[Tuple[str, str]] # May contain duplicate keys
|
|
|
|
_token, _quoted = r"([\w!#$%&'*+\-.^_`|~]+)", r'"([^"]*)"'
|
|
_param = re.compile(rf";\s*{_token}=(?:{_token}|{_quoted})", re.ASCII)
|
|
_firefox_quote_escape = re.compile(r'\\"(?!; |\s*$)')
|
|
_ipv6 = "(?:[0-9A-Fa-f]{0,4}:){2,7}[0-9A-Fa-f]{0,4}"
|
|
_ipv6_re = re.compile(_ipv6)
|
|
_host_re = re.compile(
|
|
r"((?:\[" + _ipv6 + r"\])|[a-zA-Z0-9.\-]{1,253})(?::(\d{1,5}))?"
|
|
)
|
|
|
|
# RFC's quoted-pair escapes are mostly ignored by browsers. Chrome, Firefox and
|
|
# curl all have different escaping, that we try to handle as well as possible,
|
|
# even though no client escapes in a way that would allow perfect handling.
|
|
|
|
# For more information, consult ../tests/test_requests.py
|
|
|
|
|
|
def parse_arg_as_accept(f):
|
|
def func(self, other, *args, **kwargs):
|
|
if not isinstance(other, MediaType) and other:
|
|
other = MediaType._parse(other)
|
|
return f(self, other, *args, **kwargs)
|
|
|
|
return func
|
|
|
|
|
|
class MediaType:
|
|
"""A media type, as used in the Accept header."""
|
|
def __init__(
|
|
self,
|
|
type_: str,
|
|
subtype: str,
|
|
**params: str,
|
|
):
|
|
self.type_ = type_
|
|
self.subtype = subtype
|
|
self.q = float(params.get("q", "1.0"))
|
|
self.params = params
|
|
self.mime = f"{type_}/{subtype}"
|
|
|
|
def __repr__(self):
|
|
return self.mime + "".join(f";{k}={v}" for k, v in self.params.items())
|
|
|
|
def __eq__(self, other):
|
|
"""Check for mime (str or MediaType) identical type/subtype."""
|
|
if isinstance(other, str):
|
|
return self.mime == other
|
|
if isinstance(other, MediaType):
|
|
return self.mime == other.mime
|
|
return NotImplemented
|
|
|
|
def match(
|
|
self,
|
|
mime: str,
|
|
allow_type_wildcard=True,
|
|
allow_subtype_wildcard=True,
|
|
) -> Optional[MediaType]:
|
|
"""Check if this media type matches the given mime type/subtype.
|
|
|
|
Wildcards are supported both ways on both type and subtype.
|
|
|
|
Note: Use the `==` operator instead to check for literal matches
|
|
without expanding wildcards.
|
|
|
|
@param media_type: A type/subtype string to match.
|
|
@return `self` if the media types are compatible, else `None`
|
|
"""
|
|
mt = MediaType._parse(mime)
|
|
return self if (
|
|
# Subtype match
|
|
(self.subtype in (mt.subtype, "*") or mt.subtype == "*")
|
|
# Type match
|
|
and (self.type_ in (mt.type_, "*") or mt.type_ == "*")
|
|
# Allow disabling wildcards (backwards compatibility with tests)
|
|
and (allow_type_wildcard or self.type_ != "*" and mt.type_ != "*")
|
|
and (allow_subtype_wildcard or self.subtype != "*" and mt.subtype != "*")
|
|
) else None
|
|
|
|
@property
|
|
def has_wildcard(self) -> bool:
|
|
"""Return True if this media type has a wildcard in it."""
|
|
return "*" in (self.subtype, self.type_)
|
|
|
|
@property
|
|
def is_wildcard(self) -> bool:
|
|
"""Return True if this is the wildcard `*/*`"""
|
|
return self.type_ == "*" and self.subtype == "*"
|
|
|
|
@classmethod
|
|
def _parse(cls, mime_with_params: str) -> MediaType:
|
|
mtype = mime_with_params.strip()
|
|
|
|
media, *raw_params = mtype.split(";")
|
|
type_, subtype = media.split("/", 1)
|
|
if not type_ or not subtype:
|
|
raise ValueError(f"Invalid media type: {mtype}")
|
|
|
|
params = dict(
|
|
[
|
|
(key.strip(), value.strip())
|
|
for key, value in (param.split("=", 1) for param in raw_params)
|
|
]
|
|
)
|
|
|
|
return cls(type_.lstrip(), subtype.rstrip(), **params)
|
|
|
|
|
|
class Matched(str):
|
|
"""A matching result of a MIME string against a MediaType."""
|
|
def __new__(cls, mime: str, m: Optional[MediaType]):
|
|
return super().__new__(cls, mime)
|
|
|
|
def __init__(self, mime: str, m: Optional[MediaType]):
|
|
self.m = m
|
|
|
|
def __repr__(self):
|
|
return f"<{self} matched {self.m}>" if self else "<no match>"
|
|
|
|
|
|
class AcceptList(list):
|
|
"""A list of media types, as used in the Accept header.
|
|
|
|
The Accept header entries are listed in order of preference, starting
|
|
with the most preferred. This class is a list of `MediaType` objects,
|
|
that encapsulate also the q value or any other parameters.
|
|
|
|
Two separate methods are provided for searching the list:
|
|
- 'match' for finding the most preferred match (wildcards supported)
|
|
- operator 'in' for checking explicit matches (wildcards as literals)
|
|
"""
|
|
|
|
def match(self, *mimes: str) -> Matched:
|
|
"""Find a media type accepted by the client.
|
|
|
|
This method can be used to find which of the media types requested by
|
|
the client is most preferred against the ones given as arguments.
|
|
|
|
The ordering of preference is set by:
|
|
1. The q values on the Accept header, and those being equal,
|
|
2. The order of the arguments (first is most preferred), and
|
|
3. The first matching entry on the Accept header.
|
|
|
|
Wildcards are matched both ways. A match is usually found, as the
|
|
Accept headers typically include `*/*`, in particular if the header
|
|
is missing, is not manually set, or if the client is a browser.
|
|
|
|
Note: the returned object behaves as a string of the mime argument
|
|
that matched, and is empty/falsy if no match was found. The matched
|
|
header entry `MediaType` or `None` is available as the `m` attribute.
|
|
|
|
@param mimes: Any MIME types to search for in order of preference.
|
|
@return A match object with the mime string and the MediaType object.
|
|
"""
|
|
l = sorted([
|
|
(-acc.q, i, j, mime, acc) # Sort by -q, i, j
|
|
for j, acc in enumerate(self)
|
|
for i, mime in enumerate(mimes)
|
|
if acc.match(mime)
|
|
])
|
|
return Matched(*(l[0][3:] if l else ("", None)))
|
|
|
|
|
|
def parse_accept(accept: str) -> AcceptList:
|
|
"""Parse an Accept header and order the acceptable media types in
|
|
accorsing to RFC 7231, s. 5.3.2
|
|
https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.2
|
|
"""
|
|
if not accept:
|
|
return AcceptList()
|
|
try:
|
|
a = [MediaType._parse(mtype) for mtype in accept.split(",")]
|
|
return AcceptList(sorted(a, key=lambda mtype: -mtype.q))
|
|
except ValueError:
|
|
raise InvalidHeader(f"Invalid header value in Accept: {accept}")
|
|
|
|
|
|
|
|
def parse_content_header(value: str) -> Tuple[str, Options]:
|
|
"""Parse content-type and content-disposition header values.
|
|
|
|
E.g. 'form-data; name=upload; filename=\"file.txt\"' to
|
|
('form-data', {'name': 'upload', 'filename': 'file.txt'})
|
|
|
|
Mostly identical to cgi.parse_header and werkzeug.parse_options_header
|
|
but runs faster and handles special characters better. Unescapes quotes.
|
|
"""
|
|
value = _firefox_quote_escape.sub("%22", value)
|
|
pos = value.find(";")
|
|
if pos == -1:
|
|
options: Dict[str, Union[int, str]] = {}
|
|
else:
|
|
options = {
|
|
m.group(1).lower(): m.group(2) or m.group(3).replace("%22", '"')
|
|
for m in _param.finditer(value[pos:])
|
|
}
|
|
value = value[:pos]
|
|
return value.strip().lower(), options
|
|
|
|
|
|
# https://tools.ietf.org/html/rfc7230#section-3.2.6 and
|
|
# https://tools.ietf.org/html/rfc7239#section-4
|
|
# This regex is for *reversed* strings because that works much faster for
|
|
# right-to-left matching than the other way around. Be wary that all things are
|
|
# a bit backwards! _rparam matches forwarded pairs alike ";key=value"
|
|
_rparam = re.compile(f"(?:{_token}|{_quoted})={_token}\\s*($|[;,])", re.ASCII)
|
|
|
|
|
|
def parse_forwarded(headers, config) -> Optional[Options]:
|
|
"""Parse RFC 7239 Forwarded headers.
|
|
The value of `by` or `secret` must match `config.FORWARDED_SECRET`
|
|
:return: dict with keys and values, or None if nothing matched
|
|
"""
|
|
header = headers.getall("forwarded", None)
|
|
secret = config.FORWARDED_SECRET
|
|
if header is None or not secret:
|
|
return None
|
|
header = ",".join(header) # Join multiple header lines
|
|
if secret not in header:
|
|
return None
|
|
# Loop over <separator><key>=<value> elements from right to left
|
|
sep = pos = None
|
|
options: List[Tuple[str, str]] = []
|
|
found = False
|
|
for m in _rparam.finditer(header[::-1]):
|
|
# Start of new element? (on parser skips and non-semicolon right sep)
|
|
if m.start() != pos or sep != ";":
|
|
# Was the previous element (from right) what we wanted?
|
|
if found:
|
|
break
|
|
# Clear values and parse as new element
|
|
del options[:]
|
|
pos = m.end()
|
|
val_token, val_quoted, key, sep = m.groups()
|
|
key = key.lower()[::-1]
|
|
val = (val_token or val_quoted.replace('"\\', '"'))[::-1]
|
|
options.append((key, val))
|
|
if key in ("secret", "by") and val == secret:
|
|
found = True
|
|
# Check if we would return on next round, to avoid useless parse
|
|
if found and sep != ";":
|
|
break
|
|
# If secret was found, return the matching options in left-to-right order
|
|
return fwd_normalize(reversed(options)) if found else None
|
|
|
|
|
|
def parse_xforwarded(headers, config) -> Optional[Options]:
|
|
"""Parse traditional proxy headers."""
|
|
real_ip_header = config.REAL_IP_HEADER
|
|
proxies_count = config.PROXIES_COUNT
|
|
addr = real_ip_header and headers.getone(real_ip_header, None)
|
|
if not addr and proxies_count:
|
|
assert proxies_count > 0
|
|
try:
|
|
# Combine, split and filter multiple headers' entries
|
|
forwarded_for = headers.getall(config.FORWARDED_FOR_HEADER)
|
|
proxies = [
|
|
p
|
|
for p in (
|
|
p.strip() for h in forwarded_for for p in h.split(",")
|
|
)
|
|
if p
|
|
]
|
|
addr = proxies[-proxies_count]
|
|
except (KeyError, IndexError):
|
|
pass
|
|
# No processing of other headers if no address is found
|
|
if not addr:
|
|
return None
|
|
|
|
def options():
|
|
yield "for", addr
|
|
for key, header in (
|
|
("proto", "x-scheme"),
|
|
("proto", "x-forwarded-proto"), # Overrides X-Scheme if present
|
|
("host", "x-forwarded-host"),
|
|
("port", "x-forwarded-port"),
|
|
("path", "x-forwarded-path"),
|
|
):
|
|
yield key, headers.getone(header, None)
|
|
|
|
return fwd_normalize(options())
|
|
|
|
|
|
def fwd_normalize(fwd: OptionsIterable) -> Options:
|
|
"""Normalize and convert values extracted from forwarded headers."""
|
|
ret: Dict[str, Union[int, str]] = {}
|
|
for key, val in fwd:
|
|
if val is not None:
|
|
try:
|
|
if key in ("by", "for"):
|
|
ret[key] = fwd_normalize_address(val)
|
|
elif key in ("host", "proto"):
|
|
ret[key] = val.lower()
|
|
elif key == "port":
|
|
ret[key] = int(val)
|
|
elif key == "path":
|
|
ret[key] = unquote(val)
|
|
else:
|
|
ret[key] = val
|
|
except ValueError:
|
|
pass
|
|
return ret
|
|
|
|
|
|
def fwd_normalize_address(addr: str) -> str:
|
|
"""Normalize address fields of proxy headers."""
|
|
if addr == "unknown":
|
|
raise ValueError() # omit unknown value identifiers
|
|
if addr.startswith("_"):
|
|
return addr # do not lower-case obfuscated strings
|
|
if _ipv6_re.fullmatch(addr):
|
|
addr = f"[{addr}]" # bracket IPv6
|
|
return addr.lower()
|
|
|
|
|
|
def parse_host(host: str) -> Tuple[Optional[str], Optional[int]]:
|
|
"""Split host:port into hostname and port.
|
|
:return: None in place of missing elements
|
|
"""
|
|
m = _host_re.fullmatch(host)
|
|
if not m:
|
|
return None, None
|
|
host, port = m.groups()
|
|
return host.lower(), int(port) if port is not None else None
|
|
|
|
|
|
_HTTP1_STATUSLINES = [
|
|
b"HTTP/1.1 %d %b\r\n" % (status, STATUS_CODES.get(status, b"UNKNOWN"))
|
|
for status in range(1000)
|
|
]
|
|
|
|
|
|
def format_http1_response(status: int, headers: HeaderBytesIterable) -> bytes:
|
|
"""Format a HTTP/1.1 response header."""
|
|
# Note: benchmarks show that here bytes concat is faster than bytearray,
|
|
# b"".join() or %-formatting. %timeit any changes you make.
|
|
ret = _HTTP1_STATUSLINES[status]
|
|
for h in headers:
|
|
ret += b"%b: %b\r\n" % h
|
|
ret += b"\r\n"
|
|
return ret
|
|
|
|
|
|
def parse_credentials(
|
|
header: Optional[str],
|
|
prefixes: Union[List, Tuple, Set] = None,
|
|
) -> Tuple[Optional[str], Optional[str]]:
|
|
"""Parses any header with the aim to retrieve any credentials from it."""
|
|
if not prefixes or not isinstance(prefixes, (list, tuple, set)):
|
|
prefixes = ("Basic", "Bearer", "Token")
|
|
if header is not None:
|
|
for prefix in prefixes:
|
|
if prefix in header:
|
|
return prefix, header.partition(prefix)[-1].strip()
|
|
return None, header
|