Edit File: cookies.py
#### # Copyright 2000 by Timothy O'Malley <timo@alum.mit.edu> # # All Rights Reserved # # Permission to use, copy, modify, and distribute this software # and its documentation for any purpose and without fee is hereby # granted, provided that the above copyright notice appear in all # copies and that both that copyright notice and this permission # notice appear in supporting documentation, and that the name of # Timothy O'Malley not be used in advertising or publicity # pertaining to distribution of the software without specific, written # prior permission. # # Timothy O'Malley DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS # SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY # AND FITNESS, IN NO EVENT SHALL Timothy O'Malley BE LIABLE FOR # ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, # WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS # ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR # PERFORMANCE OF THIS SOFTWARE. # #### # # Id: Cookie.py,v 2.29 2000/08/23 05:28:49 timo Exp # by Timothy O'Malley <timo@alum.mit.edu> # # Cookie.py is a Python module for the handling of HTTP # cookies as a Python dictionary. See RFC 2109 for more # information on cookies. # # The original idea to treat Cookies as a dictionary came from # Dave Mitchell (davem@magnet.com) in 1995, when he released the # first version of nscookie.py. # #### r""" Here's a sample session to show how to use this module. At the moment, this is the only documentation. The Basics ---------- Importing is easy... >>> from http import cookies Most of the time you start by creating a cookie. >>> C = cookies.SimpleCookie() Once you've created your Cookie, you can add values just as if it were a dictionary. >>> C = cookies.SimpleCookie() >>> C["fig"] = "newton" >>> C["sugar"] = "wafer" >>> C.output() 'Set-Cookie: fig=newton\r\nSet-Cookie: sugar=wafer' Notice that the printable representation of a Cookie is the appropriate format for a Set-Cookie: header. This is the default behavior. You can change the header and printed attributes by using the .output() function >>> C = cookies.SimpleCookie() >>> C["rocky"] = "road" >>> C["rocky"]["path"] = "/cookie" >>> print(C.output(header="Cookie:")) Cookie: rocky=road; Path=/cookie >>> print(C.output(attrs=[], header="Cookie:")) Cookie: rocky=road The load() method of a Cookie extracts cookies from a string. In a CGI script, you would use this method to extract the cookies from the HTTP_COOKIE environment variable. >>> C = cookies.SimpleCookie() >>> C.load("chips=ahoy; vienna=finger") >>> C.output() 'Set-Cookie: chips=ahoy\r\nSet-Cookie: vienna=finger' The load() method is darn-tootin smart about identifying cookies within a string. Escaped quotation marks, nested semicolons, and other such trickeries do not confuse it. >>> C = cookies.SimpleCookie() >>> C.load('keebler="E=everybody; L=\\"Loves\\"; fudge=\\012;";') >>> print(C) Set-Cookie: keebler="E=everybody; L=\"Loves\"; fudge=\012;" Each element of the Cookie also supports all of the RFC 2109 Cookie attributes. Here's an example which sets the Path attribute. >>> C = cookies.SimpleCookie() >>> C["oreo"] = "doublestuff" >>> C["oreo"]["path"] = "/" >>> print(C) Set-Cookie: oreo=doublestuff; Path=/ Each dictionary element has a 'value' attribute, which gives you back the value associated with the key. >>> C = cookies.SimpleCookie() >>> C["twix"] = "none for you" >>> C["twix"].value 'none for you' The SimpleCookie expects that all values should be standard strings. Just to be sure, SimpleCookie invokes the str() builtin to convert the value to a string, when the values are set dictionary-style. >>> C = cookies.SimpleCookie() >>> C["number"] = 7 >>> C["string"] = "seven" >>> C["number"].value '7' >>> C["string"].value 'seven' >>> C.output() 'Set-Cookie: number=7\r\nSet-Cookie: string=seven' Finis. """ # # Import our required modules # import re import string __all__ = ["CookieError", "BaseCookie", "SimpleCookie"] _nulljoin = ''.join _semispacejoin = '; '.join _spacejoin = ' '.join def _warn_deprecated_setter(setter): import warnings msg = ('The .%s setter is deprecated. The attribute will be read-only in ' 'future releases. Please use the set() method instead.' % setter) warnings.warn(msg, DeprecationWarning, stacklevel=3) # # Define an exception visible to External modules # class CookieError(Exception): pass # These quoting routines conform to the RFC2109 specification, which in # turn references the character definitions from RFC2068. They provide # a two-way quoting algorithm. Any non-text character is translated # into a 4 character sequence: a forward-slash followed by the # three-digit octal equivalent of the character. Any '\' or '"' is # quoted with a preceding '\' slash. # Because of the way browsers really handle cookies (as opposed to what # the RFC says) we also encode "," and ";". # # These are taken from RFC2068 and RFC2109. # _LegalChars is the list of chars which don't require "'s # _Translator hash-table for fast quoting # _LegalChars = string.ascii_letters + string.digits + "!#$%&'*+-.^_`|~:" _UnescapedChars = _LegalChars + ' ()/<=>?@[]{}' _Translator = {n: '\\%03o' % n for n in set(range(256)) - set(map(ord, _UnescapedChars))} _Translator.update({ ord('"'): '\\"', ord('\\'): '\\\\', }) _is_legal_key = re.compile('[%s]+' % re.escape(_LegalChars)).fullmatch def _quote(str): r"""Quote a string for use in a cookie header. If the string does not need to be double-quoted, then just return the string. Otherwise, surround the string in doublequotes and quote (with a \) special characters. """ if str is None or _is_legal_key(str): return str else: return '"' + str.translate(_Translator) + '"' _OctalPatt = re.compile(r"\\[0-3][0-7][0-7]") _QuotePatt = re.compile(r"[\\].") def _unquote(str): # 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 # \" --> " # i = 0 n = len(str) res = [] while 0 <= i < n: o_match = _OctalPatt.search(str, i) q_match = _QuotePatt.search(str, i) if not o_match and not q_match: # Neither matched res.append(str[i:]) break # else: j = k = -1 if o_match: j = o_match.start(0) if q_match: k = q_match.start(0) if q_match and (not o_match or k < j): # QuotePatt matched res.append(str[i:k]) res.append(str[k+1]) i = k + 2 else: # OctalPatt matched res.append(str[i:j]) res.append(chr(int(str[j+1:j+4], 8))) i = j + 4 return _nulljoin(res) # The _getdate() routine is used to set the expiration time in the cookie's HTTP # header. By default, _getdate() returns the current time in the appropriate # "expires" format for a Set-Cookie header. The one optional argument is an # offset from now, in seconds. For example, an offset of -3600 means "one hour # ago". The offset may be a floating point number. # _weekdayname = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'] _monthname = [None, 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'] def _getdate(future=0, weekdayname=_weekdayname, monthname=_monthname): from time import gmtime, time now = time() year, month, day, hh, mm, ss, wd, y, z = gmtime(now + future) return "%s, %02d %3s %4d %02d:%02d:%02d GMT" % \ (weekdayname[wd], day, monthname[month], year, hh, mm, ss) class Morsel(dict): """A class to hold ONE (key, value) pair. In a cookie, each such pair may have several attributes, so this class is used to keep the attributes associated with the appropriate key,value pair. This class also includes a coded_value attribute, which is used to hold the network representation of the value. This is most useful when Python objects are pickled for network transit. """ # RFC 2109 lists these attributes as reserved: # path comment domain # max-age secure version # # For historical reasons, these attributes are also reserved: # expires # # This is an extension from Microsoft: # httponly # # This dictionary provides a mapping from the lowercase # variant on the left to the appropriate traditional # formatting on the right. _reserved = { "expires" : "expires", "path" : "Path", "comment" : "Comment", "domain" : "Domain", "max-age" : "Max-Age", "secure" : "Secure", "httponly" : "HttpOnly", "version" : "Version", } _flags = {'secure', 'httponly'} def __init__(self): # Set defaults self._key = self._value = self._coded_value = None # Set default attributes for key in self._reserved: dict.__setitem__(self, key, "") @property def key(self): return self._key @key.setter def key(self, key): _warn_deprecated_setter('key') self._key = key @property def value(self): return self._value @value.setter def value(self, value): _warn_deprecated_setter('value') self._value = value @property def coded_value(self): return self._coded_value @coded_value.setter def coded_value(self, coded_value): _warn_deprecated_setter('coded_value') self._coded_value = coded_value def __setitem__(self, K, V): K = K.lower() if not K in self._reserved: raise CookieError("Invalid attribute %r" % (K,)) dict.__setitem__(self, K, V) def setdefault(self, key, val=None): key = key.lower() if key not in self._reserved: raise CookieError("Invalid attribute %r" % (key,)) return dict.setdefault(self, key, val) def __eq__(self, morsel): if not isinstance(morsel, Morsel): return NotImplemented return (dict.__eq__(self, morsel) and self._value == morsel._value and self._key == morsel._key and self._coded_value == morsel._coded_value) __ne__ = object.__ne__ def copy(self): morsel = Morsel() dict.update(morsel, self) morsel.__dict__.update(self.__dict__) return morsel def update(self, values): data = {} for key, val in dict(values).items(): key = key.lower() if key not in self._reserved: raise CookieError("Invalid attribute %r" % (key,)) data[key] = val dict.update(self, data) def isReservedKey(self, K): return K.lower() in self._reserved def set(self, key, val, coded_val, LegalChars=_LegalChars): if LegalChars != _LegalChars: import warnings warnings.warn( 'LegalChars parameter is deprecated, ignored and will ' 'be removed in future versions.', DeprecationWarning, stacklevel=2) if key.lower() in self._reserved: raise CookieError('Attempt to set a reserved key %r' % (key,)) if not _is_legal_key(key): raise CookieError('Illegal key %r' % (key,)) # It's a good key, so save it. self._key = key self._value = val self._coded_value = coded_val def __getstate__(self): return { 'key': self._key, 'value': self._value, 'coded_value': self._coded_value, } def __setstate__(self, state): self._key = state['key'] self._value = state['value'] self._coded_value = state['coded_value'] def output(self, attrs=None, header="Set-Cookie:"): return "%s %s" % (header, self.OutputString(attrs)) __str__ = output def __repr__(self): return '<%s: %s>' % (self.__class__.__name__, self.OutputString()) def js_output(self, attrs=None): # Print javascript return """ <script type="text/javascript"> <!-- begin hiding document.cookie = \"%s\"; // end hiding --> </script> """ % (self.OutputString(attrs).replace('"', r'\"')) def OutputString(self, attrs=None): # Build up our result # result = [] append = result.append # First, the key=value pair append("%s=%s" % (self.key, self.coded_value)) # Now add any defined attributes if attrs is None: attrs = self._reserved items = sorted(self.items()) for key, value in items: if value == "": continue if key not in attrs: continue if key == "expires" and isinstance(value, int): append("%s=%s" % (self._reserved[key], _getdate(value))) elif key == "max-age" and isinstance(value, int): append("%s=%d" % (self._reserved[key], value)) elif key == "comment" and isinstance(value, str): append("%s=%s" % (self._reserved[key], _quote(value))) elif key in self._flags: if value: append(str(self._reserved[key])) else: append("%s=%s" % (self._reserved[key], value)) # Return the result return _semispacejoin(result) # # Pattern for finding cookie # # This used to be strict parsing based on the RFC2109 and RFC2068 # specifications. I have since discovered that MSIE 3.0x doesn't # follow the character rules outlined in those specs. As a # result, the parsing rules here are less strict. # _LegalKeyChars = r"\w\d!#%&'~_`><@,:/\$\*\+\-\.\^\|\)\(\?\}\{\=" _LegalValueChars = _LegalKeyChars + r'\[\]' _CookiePattern = re.compile(r""" \s* # Optional whitespace at start of cookie (?P<key> # Start of group 'key' [""" + _LegalKeyChars + r"""]+? # Any word of at least one letter ) # End of group 'key' ( # Optional group: there may not be a value. \s*=\s* # Equal Sign (?P<val> # Start of group 'val' "(?:[^\\"]|\\.)*" # Any doublequoted string | # or \w{3},\s[\w\d\s-]{9,11}\s[\d:]{8}\sGMT # Special case for "expires" attr | # or [""" + _LegalValueChars + r"""]* # Any word or empty string ) # End of group 'val' )? # End of optional value group \s* # Any number of spaces. (\s+|;|$) # Ending either at space, semicolon, or EOS. """, re.ASCII | re.VERBOSE) # re.ASCII may be removed if safe. # At long last, here is the cookie class. Using this class is almost just like # using a dictionary. See this module's docstring for example usage. # class BaseCookie(dict): """A container class for a set of Morsels.""" def value_decode(self, val): """real_value, coded_value = value_decode(STRING) Called prior to setting a cookie's value from the network representation. The VALUE is the value read from HTTP header. Override this function to modify the behavior of cookies. """ return val, val def value_encode(self, val): """real_value, coded_value = value_encode(VALUE) Called prior to setting a cookie's value from the dictionary representation. The VALUE is the value being assigned. Override this function to modify the behavior of cookies. """ strval = str(val) return strval, strval def __init__(self, input=None): if input: self.load(input) def __set(self, key, real_value, coded_value): """Private method for setting a cookie's value""" M = self.get(key, Morsel()) M.set(key, real_value, coded_value) dict.__setitem__(self, key, M) def __setitem__(self, key, value): """Dictionary style assignment.""" if isinstance(value, Morsel): # allow assignment of constructed Morsels (e.g. for pickling) dict.__setitem__(self, key, value) else: rval, cval = self.value_encode(value) self.__set(key, rval, cval) def output(self, attrs=None, header="Set-Cookie:", sep="\015\012"): """Return a string suitable for HTTP.""" result = [] items = sorted(self.items()) for key, value in items: result.append(value.output(attrs, header)) return sep.join(result) __str__ = output def __repr__(self): l = [] items = sorted(self.items()) for key, value in items: l.append('%s=%s' % (key, repr(value.value))) return '<%s: %s>' % (self.__class__.__name__, _spacejoin(l)) def js_output(self, attrs=None): """Return a string suitable for JavaScript.""" result = [] items = sorted(self.items()) for key, value in items: result.append(value.js_output(attrs)) return _nulljoin(result) def load(self, rawdata): """Load cookies from a string (presumably HTTP_COOKIE) or from a dictionary. Loading cookies from a dictionary 'd' is equivalent to calling: map(Cookie.__setitem__, d.keys(), d.values()) """ if isinstance(rawdata, str): self.__parse_string(rawdata) else: # self.update() wouldn't call our custom __setitem__ for key, value in rawdata.items(): self[key] = value return def __parse_string(self, str, patt=_CookiePattern): i = 0 # Our starting point n = len(str) # Length of string parsed_items = [] # Parsed (type, key, value) triples morsel_seen = False # A key=value pair was previously encountered TYPE_ATTRIBUTE = 1 TYPE_KEYVALUE = 2 # We first parse the whole cookie string and reject it if it's # syntactically invalid (this helps avoid some classes of injection # attacks). while 0 <= i < n: # Start looking for a cookie match = patt.match(str, i) if not match: # No more cookies break key, value = match.group("key"), match.group("val") i = match.end(0) if key[0] == "$": if not morsel_seen: # We ignore attributes which pertain to the cookie # mechanism as a whole, such as "$Version". # See RFC 2965. (Does anyone care?) continue parsed_items.append((TYPE_ATTRIBUTE, key[1:], value)) elif key.lower() in Morsel._reserved: if not morsel_seen: # Invalid cookie string return if value is None: if key.lower() in Morsel._flags: parsed_items.append((TYPE_ATTRIBUTE, key, True)) else: # Invalid cookie string return else: parsed_items.append((TYPE_ATTRIBUTE, key, _unquote(value))) elif value is not None: parsed_items.append((TYPE_KEYVALUE, key, self.value_decode(value))) morsel_seen = True else: # Invalid cookie string return # The cookie string is valid, apply it. M = None # current morsel for tp, key, value in parsed_items: if tp == TYPE_ATTRIBUTE: assert M is not None M[key] = value else: assert tp == TYPE_KEYVALUE rval, cval = value self.__set(key, rval, cval) M = self[key] class SimpleCookie(BaseCookie): """ SimpleCookie supports strings as cookie values. When setting the value using the dictionary assignment notation, SimpleCookie calls the builtin str() to convert the value to a string. Values received from HTTP are kept as strings. """ def value_decode(self, val): return _unquote(val), val def value_encode(self, val): strval = str(val) return strval, _quote(strval)
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