def _parse_rfc_forwarded(self):
"""Parse RFC 7239 "Forwarded" header.
Returns:
list: addresses derived from "for" parameters.
"""
addr = []
for forwarded in self.env["HTTP_FORWARDED"].split(","):
for param in forwarded.split(";"):
# PERF(kgriffs): Partition() is faster than split().
key, _, val = param.strip().partition("=")
if not val:
# NOTE(kgriffs): The '=' separator was not found or
# it was, but the value was missing.
continue
if key.lower() != "for":
# We only want "for" params
continue
host, _ = parse_host(unquote_string(val))
addr.append(host)
return addr
def _parse_rfc_forwarded(self):
"""Parse RFC 7239 "Forwarded" header.
Returns:
list: addresses derived from "for" parameters.
"""
addr = []
for forwarded in self.env['HTTP_FORWARDED'].split(','):
for param in forwarded.split(';'):
# PERF(kgriffs): Partition() is faster than split().
key, _, val = param.strip().partition('=')
if not val:
# NOTE(kgriffs): The '=' separator was not found or
# it was, but the value was missing.
continue
if key.lower() != 'for':
# We only want "for" params
continue
host, _ = parse_host(unquote_string(val))
addr.append(host)
return addr
def _parse_rfc_forwarded(self):
"""Parse RFC 7239 "Forwarded" header.
Returns:
list: addresses derived from "for" parameters.
"""
addr = []
for forwarded in self.env['HTTP_FORWARDED'].split(','):
for param in forwarded.split(';'):
param = param.strip().split('=', 1)
if len(param) == 1:
continue
key, val = param
if key.lower() != 'for':
# we only want for params
continue
host, _ = parse_host(unquote_string(val))
addr.append(host)
return addr
def test_unquote_string(self):
assert uri.unquote_string('v') == 'v'
assert uri.unquote_string('not-quoted') == 'not-quoted'
assert uri.unquote_string('partial-quoted"') == 'partial-quoted"'
assert uri.unquote_string('"partial-quoted') == '"partial-quoted'
assert uri.unquote_string('"partial-quoted"') == 'partial-quoted'
def _parse_forwarded_header(forwarded):
"""Parse the value of a Forwarded header.
Makes an effort to parse Forwarded headers as specified by RFC 7239:
- It checks that every value has valid syntax in general as specified
in section 4: either a 'token' or a 'quoted-string'.
- It un-escapes found escape sequences.
- It does NOT validate 'by' and 'for' contents as specified in section
6.
- It does NOT validate 'host' contents (Host ABNF).
- It does NOT validate 'proto' contents for valid URI scheme names.
Arguments:
forwarded (str): Value of a Forwarded header
Returns:
list: Sequence of Forwarded instances, representing each forwarded-element
in the header, in the same order as they appeared in the header.
"""
elements = []
pos = 0
end = len(forwarded)
need_separator = False
parsed_element = None
while 0 <= pos < end:
match = _FORWARDED_PAIR_RE.match(forwarded, pos)
if match is not None: # got a valid forwarded-pair
if need_separator:
# bad syntax here, skip to next comma
pos = forwarded.find(',', pos)
else:
pos += len(match.group(0))
need_separator = True
name, value = match.groups()
# NOTE(kgriffs): According to RFC 7239, parameter
# names are case-insensitive.
name = name.lower()
if value[0] == '"':
value = unquote_string(value)
# NOTE(kgriffs): If this is the first pair we've encountered
# for this forwarded-element, initialize a new object.
if not parsed_element:
parsed_element = Forwarded()
if name == 'by':
parsed_element.dest = value
elif name == 'for':
parsed_element.src = value
elif name == 'host':
parsed_element.host = value
elif name == 'proto':
# NOTE(kgriffs): RFC 7239 only requires that
# the "proto" value conform to the Host ABNF
# described in RFC 7230. The Host ABNF, in turn,
# does not require that the scheme be in any
# particular case, so we normalize it here to be
# consistent with the WSGI spec that *does*
# require the value of 'wsgi.url_scheme' to be
# either 'http' or 'https' (case-sensitive).
parsed_element.scheme = value.lower()
elif forwarded[pos] == ',': # next forwarded-element
need_separator = False
pos += 1
# NOTE(kgriffs): It's possible that we arrive here without a
# parsed element if the header is malformed.
if parsed_element:
elements.append(parsed_element)
parsed_element = None
elif forwarded[pos] == ';': # next forwarded-pair
need_separator = False
pos += 1
elif forwarded[pos] in ' \t':
# Allow whitespace even between forwarded-pairs, though
# RFC 7239 doesn't. This simplifies code and is in line
# with Postel's law.
pos += 1
else:
# bad syntax here, skip to next comma
pos = forwarded.find(',', pos)
# NOTE(kgriffs): Add the last forwarded-element, if any
if parsed_element:
elements.append(parsed_element)
return elements
def test_unquote_string(self):
assert uri.unquote_string('v') == 'v'
assert uri.unquote_string('not-quoted') == 'not-quoted'
assert uri.unquote_string('partial-quoted"') == 'partial-quoted"'
assert uri.unquote_string('"partial-quoted') == '"partial-quoted'
assert uri.unquote_string('"partial-quoted"') == 'partial-quoted'
def _parse_forwarded_header(forwarded):
"""Parses the value of a Forwarded header.
Makes an effort to parse Forwarded headers as specified by RFC 7239:
- It checks that every value has valid syntax in general as specified
in section 4: either a 'token' or a 'quoted-string'.
- It un-escapes found escape sequences.
- It does NOT validate 'by' and 'for' contents as specified in section
6.
- It does NOT validate 'host' contents (Host ABNF).
- It does NOT validate 'proto' contents for valid URI scheme names.
Arguments:
forwarded (str): Value of a Forwarded header
Returns:
list: Sequence of Forwarded instances, representing each forwarded-element
in the header, in the same order as they appeared in the header.
"""
elements = []
pos = 0
end = len(forwarded)
need_separator = False
parsed_element = None
while 0 <= pos < end:
match = _FORWARDED_PAIR_RE.match(forwarded, pos)
if match is not None: # got a valid forwarded-pair
if need_separator:
# bad syntax here, skip to next comma
pos = forwarded.find(',', pos)
else:
pos += len(match.group(0))
need_separator = True
name, value = match.groups()
# NOTE(kgriffs): According to RFC 7239, parameter
# names are case-insensitive.
name = name.lower()
if value[0] == '"':
value = unquote_string(value)
# NOTE(kgriffs): If this is the first pair we've encountered
# for this forwarded-element, initialize a new object.
if not parsed_element:
parsed_element = Forwarded()
if name == 'by':
parsed_element.dest = value
elif name == 'for':
parsed_element.src = value
elif name == 'host':
parsed_element.host = value
elif name == 'proto':
# NOTE(kgriffs): RFC 7239 only requires that
# the "proto" value conform to the Host ABNF
# described in RFC 7230. The Host ABNF, in turn,
# does not require that the scheme be in any
# particular case, so we normalize it here to be
# consistent with the WSGI spec that *does*
# require the value of 'wsgi.url_scheme' to be
# either 'http' or 'https' (case-sensitive).
parsed_element.scheme = value.lower()
elif forwarded[pos] == ',': # next forwarded-element
need_separator = False
pos += 1
# NOTE(kgriffs): It's possible that we arrive here without a
# parsed element if the header is malformed.
if parsed_element:
elements.append(parsed_element)
parsed_element = None
elif forwarded[pos] == ';': # next forwarded-pair
need_separator = False
pos += 1
elif forwarded[pos] in ' \t':
# Allow whitespace even between forwarded-pairs, though
# RFC 7239 doesn't. This simplifies code and is in line
# with Postel's law.
pos += 1
else:
# bad syntax here, skip to next comma
pos = forwarded.find(',', pos)
# NOTE(kgriffs): Add the last forwarded-element, if any
if parsed_element:
elements.append(parsed_element)
return elements
