603 lines
20 KiB
Python
603 lines
20 KiB
Python
"""Representing and manipulating email headers via custom objects.
|
|
|
|
This module provides an implementation of the HeaderRegistry API.
|
|
The implementation is designed to flexibly follow RFC5322 rules.
|
|
|
|
Eventually HeaderRegistry will be a public API, but it isn't yet,
|
|
and will probably change some before that happens.
|
|
|
|
"""
|
|
from types import MappingProxyType
|
|
|
|
from email import utils
|
|
from email import errors
|
|
from email import _header_value_parser as parser
|
|
|
|
class Address:
|
|
|
|
def __init__(self, display_name='', username='', domain='', addr_spec=None):
|
|
"""Create an object representing a full email address.
|
|
|
|
An address can have a 'display_name', a 'username', and a 'domain'. In
|
|
addition to specifying the username and domain separately, they may be
|
|
specified together by using the addr_spec keyword *instead of* the
|
|
username and domain keywords. If an addr_spec string is specified it
|
|
must be properly quoted according to RFC 5322 rules; an error will be
|
|
raised if it is not.
|
|
|
|
An Address object has display_name, username, domain, and addr_spec
|
|
attributes, all of which are read-only. The addr_spec and the string
|
|
value of the object are both quoted according to RFC5322 rules, but
|
|
without any Content Transfer Encoding.
|
|
|
|
"""
|
|
# This clause with its potential 'raise' may only happen when an
|
|
# application program creates an Address object using an addr_spec
|
|
# keyword. The email library code itself must always supply username
|
|
# and domain.
|
|
if addr_spec is not None:
|
|
if username or domain:
|
|
raise TypeError("addrspec specified when username and/or "
|
|
"domain also specified")
|
|
a_s, rest = parser.get_addr_spec(addr_spec)
|
|
if rest:
|
|
raise ValueError("Invalid addr_spec; only '{}' "
|
|
"could be parsed from '{}'".format(
|
|
a_s, addr_spec))
|
|
if a_s.all_defects:
|
|
raise a_s.all_defects[0]
|
|
username = a_s.local_part
|
|
domain = a_s.domain
|
|
self._display_name = display_name
|
|
self._username = username
|
|
self._domain = domain
|
|
|
|
@property
|
|
def display_name(self):
|
|
return self._display_name
|
|
|
|
@property
|
|
def username(self):
|
|
return self._username
|
|
|
|
@property
|
|
def domain(self):
|
|
return self._domain
|
|
|
|
@property
|
|
def addr_spec(self):
|
|
"""The addr_spec (username@domain) portion of the address, quoted
|
|
according to RFC 5322 rules, but with no Content Transfer Encoding.
|
|
"""
|
|
nameset = set(self.username)
|
|
if len(nameset) > len(nameset-parser.DOT_ATOM_ENDS):
|
|
lp = parser.quote_string(self.username)
|
|
else:
|
|
lp = self.username
|
|
if self.domain:
|
|
return lp + '@' + self.domain
|
|
if not lp:
|
|
return '<>'
|
|
return lp
|
|
|
|
def __repr__(self):
|
|
return "{}(display_name={!r}, username={!r}, domain={!r})".format(
|
|
self.__class__.__name__,
|
|
self.display_name, self.username, self.domain)
|
|
|
|
def __str__(self):
|
|
nameset = set(self.display_name)
|
|
if len(nameset) > len(nameset-parser.SPECIALS):
|
|
disp = parser.quote_string(self.display_name)
|
|
else:
|
|
disp = self.display_name
|
|
if disp:
|
|
addr_spec = '' if self.addr_spec=='<>' else self.addr_spec
|
|
return "{} <{}>".format(disp, addr_spec)
|
|
return self.addr_spec
|
|
|
|
def __eq__(self, other):
|
|
if type(other) != type(self):
|
|
return False
|
|
return (self.display_name == other.display_name and
|
|
self.username == other.username and
|
|
self.domain == other.domain)
|
|
|
|
|
|
class Group:
|
|
|
|
def __init__(self, display_name=None, addresses=None):
|
|
"""Create an object representing an address group.
|
|
|
|
An address group consists of a display_name followed by colon and a
|
|
list of addresses (see Address) terminated by a semi-colon. The Group
|
|
is created by specifying a display_name and a possibly empty list of
|
|
Address objects. A Group can also be used to represent a single
|
|
address that is not in a group, which is convenient when manipulating
|
|
lists that are a combination of Groups and individual Addresses. In
|
|
this case the display_name should be set to None. In particular, the
|
|
string representation of a Group whose display_name is None is the same
|
|
as the Address object, if there is one and only one Address object in
|
|
the addresses list.
|
|
|
|
"""
|
|
self._display_name = display_name
|
|
self._addresses = tuple(addresses) if addresses else tuple()
|
|
|
|
@property
|
|
def display_name(self):
|
|
return self._display_name
|
|
|
|
@property
|
|
def addresses(self):
|
|
return self._addresses
|
|
|
|
def __repr__(self):
|
|
return "{}(display_name={!r}, addresses={!r}".format(
|
|
self.__class__.__name__,
|
|
self.display_name, self.addresses)
|
|
|
|
def __str__(self):
|
|
if self.display_name is None and len(self.addresses)==1:
|
|
return str(self.addresses[0])
|
|
disp = self.display_name
|
|
if disp is not None:
|
|
nameset = set(disp)
|
|
if len(nameset) > len(nameset-parser.SPECIALS):
|
|
disp = parser.quote_string(disp)
|
|
adrstr = ", ".join(str(x) for x in self.addresses)
|
|
adrstr = ' ' + adrstr if adrstr else adrstr
|
|
return "{}:{};".format(disp, adrstr)
|
|
|
|
def __eq__(self, other):
|
|
if type(other) != type(self):
|
|
return False
|
|
return (self.display_name == other.display_name and
|
|
self.addresses == other.addresses)
|
|
|
|
|
|
# Header Classes #
|
|
|
|
class BaseHeader(str):
|
|
|
|
"""Base class for message headers.
|
|
|
|
Implements generic behavior and provides tools for subclasses.
|
|
|
|
A subclass must define a classmethod named 'parse' that takes an unfolded
|
|
value string and a dictionary as its arguments. The dictionary will
|
|
contain one key, 'defects', initialized to an empty list. After the call
|
|
the dictionary must contain two additional keys: parse_tree, set to the
|
|
parse tree obtained from parsing the header, and 'decoded', set to the
|
|
string value of the idealized representation of the data from the value.
|
|
(That is, encoded words are decoded, and values that have canonical
|
|
representations are so represented.)
|
|
|
|
The defects key is intended to collect parsing defects, which the message
|
|
parser will subsequently dispose of as appropriate. The parser should not,
|
|
insofar as practical, raise any errors. Defects should be added to the
|
|
list instead. The standard header parsers register defects for RFC
|
|
compliance issues, for obsolete RFC syntax, and for unrecoverable parsing
|
|
errors.
|
|
|
|
The parse method may add additional keys to the dictionary. In this case
|
|
the subclass must define an 'init' method, which will be passed the
|
|
dictionary as its keyword arguments. The method should use (usually by
|
|
setting them as the value of similarly named attributes) and remove all the
|
|
extra keys added by its parse method, and then use super to call its parent
|
|
class with the remaining arguments and keywords.
|
|
|
|
The subclass should also make sure that a 'max_count' attribute is defined
|
|
that is either None or 1. XXX: need to better define this API.
|
|
|
|
"""
|
|
|
|
def __new__(cls, name, value):
|
|
kwds = {'defects': []}
|
|
cls.parse(value, kwds)
|
|
if utils._has_surrogates(kwds['decoded']):
|
|
kwds['decoded'] = utils._sanitize(kwds['decoded'])
|
|
self = str.__new__(cls, kwds['decoded'])
|
|
del kwds['decoded']
|
|
self.init(name, **kwds)
|
|
return self
|
|
|
|
def init(self, name, *, parse_tree, defects):
|
|
self._name = name
|
|
self._parse_tree = parse_tree
|
|
self._defects = defects
|
|
|
|
@property
|
|
def name(self):
|
|
return self._name
|
|
|
|
@property
|
|
def defects(self):
|
|
return tuple(self._defects)
|
|
|
|
def __reduce__(self):
|
|
return (
|
|
_reconstruct_header,
|
|
(
|
|
self.__class__.__name__,
|
|
self.__class__.__bases__,
|
|
str(self),
|
|
),
|
|
self.__dict__)
|
|
|
|
@classmethod
|
|
def _reconstruct(cls, value):
|
|
return str.__new__(cls, value)
|
|
|
|
def fold(self, *, policy):
|
|
"""Fold header according to policy.
|
|
|
|
The parsed representation of the header is folded according to
|
|
RFC5322 rules, as modified by the policy. If the parse tree
|
|
contains surrogateescaped bytes, the bytes are CTE encoded using
|
|
the charset 'unknown-8bit".
|
|
|
|
Any non-ASCII characters in the parse tree are CTE encoded using
|
|
charset utf-8. XXX: make this a policy setting.
|
|
|
|
The returned value is an ASCII-only string possibly containing linesep
|
|
characters, and ending with a linesep character. The string includes
|
|
the header name and the ': ' separator.
|
|
|
|
"""
|
|
# At some point we need to put fws here iif it was in the source.
|
|
header = parser.Header([
|
|
parser.HeaderLabel([
|
|
parser.ValueTerminal(self.name, 'header-name'),
|
|
parser.ValueTerminal(':', 'header-sep')]),
|
|
])
|
|
if self._parse_tree:
|
|
header.append(
|
|
parser.CFWSList([parser.WhiteSpaceTerminal(' ', 'fws')]))
|
|
header.append(self._parse_tree)
|
|
return header.fold(policy=policy)
|
|
|
|
|
|
def _reconstruct_header(cls_name, bases, value):
|
|
return type(cls_name, bases, {})._reconstruct(value)
|
|
|
|
|
|
class UnstructuredHeader:
|
|
|
|
max_count = None
|
|
value_parser = staticmethod(parser.get_unstructured)
|
|
|
|
@classmethod
|
|
def parse(cls, value, kwds):
|
|
kwds['parse_tree'] = cls.value_parser(value)
|
|
kwds['decoded'] = str(kwds['parse_tree'])
|
|
|
|
|
|
class UniqueUnstructuredHeader(UnstructuredHeader):
|
|
|
|
max_count = 1
|
|
|
|
|
|
class DateHeader:
|
|
|
|
"""Header whose value consists of a single timestamp.
|
|
|
|
Provides an additional attribute, datetime, which is either an aware
|
|
datetime using a timezone, or a naive datetime if the timezone
|
|
in the input string is -0000. Also accepts a datetime as input.
|
|
The 'value' attribute is the normalized form of the timestamp,
|
|
which means it is the output of format_datetime on the datetime.
|
|
"""
|
|
|
|
max_count = None
|
|
|
|
# This is used only for folding, not for creating 'decoded'.
|
|
value_parser = staticmethod(parser.get_unstructured)
|
|
|
|
@classmethod
|
|
def parse(cls, value, kwds):
|
|
if not value:
|
|
kwds['defects'].append(errors.HeaderMissingRequiredValue())
|
|
kwds['datetime'] = None
|
|
kwds['decoded'] = ''
|
|
kwds['parse_tree'] = parser.TokenList()
|
|
return
|
|
if isinstance(value, str):
|
|
value = utils.parsedate_to_datetime(value)
|
|
kwds['datetime'] = value
|
|
kwds['decoded'] = utils.format_datetime(kwds['datetime'])
|
|
kwds['parse_tree'] = cls.value_parser(kwds['decoded'])
|
|
|
|
def init(self, *args, **kw):
|
|
self._datetime = kw.pop('datetime')
|
|
super().init(*args, **kw)
|
|
|
|
@property
|
|
def datetime(self):
|
|
return self._datetime
|
|
|
|
|
|
class UniqueDateHeader(DateHeader):
|
|
|
|
max_count = 1
|
|
|
|
|
|
class AddressHeader:
|
|
|
|
max_count = None
|
|
|
|
@staticmethod
|
|
def value_parser(value):
|
|
address_list, value = parser.get_address_list(value)
|
|
assert not value, 'this should not happen'
|
|
return address_list
|
|
|
|
@classmethod
|
|
def parse(cls, value, kwds):
|
|
if isinstance(value, str):
|
|
# We are translating here from the RFC language (address/mailbox)
|
|
# to our API language (group/address).
|
|
kwds['parse_tree'] = address_list = cls.value_parser(value)
|
|
groups = []
|
|
for addr in address_list.addresses:
|
|
groups.append(Group(addr.display_name,
|
|
[Address(mb.display_name or '',
|
|
mb.local_part or '',
|
|
mb.domain or '')
|
|
for mb in addr.all_mailboxes]))
|
|
defects = list(address_list.all_defects)
|
|
else:
|
|
# Assume it is Address/Group stuff
|
|
if not hasattr(value, '__iter__'):
|
|
value = [value]
|
|
groups = [Group(None, [item]) if not hasattr(item, 'addresses')
|
|
else item
|
|
for item in value]
|
|
defects = []
|
|
kwds['groups'] = groups
|
|
kwds['defects'] = defects
|
|
kwds['decoded'] = ', '.join([str(item) for item in groups])
|
|
if 'parse_tree' not in kwds:
|
|
kwds['parse_tree'] = cls.value_parser(kwds['decoded'])
|
|
|
|
def init(self, *args, **kw):
|
|
self._groups = tuple(kw.pop('groups'))
|
|
self._addresses = None
|
|
super().init(*args, **kw)
|
|
|
|
@property
|
|
def groups(self):
|
|
return self._groups
|
|
|
|
@property
|
|
def addresses(self):
|
|
if self._addresses is None:
|
|
self._addresses = tuple(address for group in self._groups
|
|
for address in group.addresses)
|
|
return self._addresses
|
|
|
|
|
|
class UniqueAddressHeader(AddressHeader):
|
|
|
|
max_count = 1
|
|
|
|
|
|
class SingleAddressHeader(AddressHeader):
|
|
|
|
@property
|
|
def address(self):
|
|
if len(self.addresses)!=1:
|
|
raise ValueError(("value of single address header {} is not "
|
|
"a single address").format(self.name))
|
|
return self.addresses[0]
|
|
|
|
|
|
class UniqueSingleAddressHeader(SingleAddressHeader):
|
|
|
|
max_count = 1
|
|
|
|
|
|
class MIMEVersionHeader:
|
|
|
|
max_count = 1
|
|
|
|
value_parser = staticmethod(parser.parse_mime_version)
|
|
|
|
@classmethod
|
|
def parse(cls, value, kwds):
|
|
kwds['parse_tree'] = parse_tree = cls.value_parser(value)
|
|
kwds['decoded'] = str(parse_tree)
|
|
kwds['defects'].extend(parse_tree.all_defects)
|
|
kwds['major'] = None if parse_tree.minor is None else parse_tree.major
|
|
kwds['minor'] = parse_tree.minor
|
|
if parse_tree.minor is not None:
|
|
kwds['version'] = '{}.{}'.format(kwds['major'], kwds['minor'])
|
|
else:
|
|
kwds['version'] = None
|
|
|
|
def init(self, *args, **kw):
|
|
self._version = kw.pop('version')
|
|
self._major = kw.pop('major')
|
|
self._minor = kw.pop('minor')
|
|
super().init(*args, **kw)
|
|
|
|
@property
|
|
def major(self):
|
|
return self._major
|
|
|
|
@property
|
|
def minor(self):
|
|
return self._minor
|
|
|
|
@property
|
|
def version(self):
|
|
return self._version
|
|
|
|
|
|
class ParameterizedMIMEHeader:
|
|
|
|
# Mixin that handles the params dict. Must be subclassed and
|
|
# a property value_parser for the specific header provided.
|
|
|
|
max_count = 1
|
|
|
|
@classmethod
|
|
def parse(cls, value, kwds):
|
|
kwds['parse_tree'] = parse_tree = cls.value_parser(value)
|
|
kwds['decoded'] = str(parse_tree)
|
|
kwds['defects'].extend(parse_tree.all_defects)
|
|
if parse_tree.params is None:
|
|
kwds['params'] = {}
|
|
else:
|
|
# The MIME RFCs specify that parameter ordering is arbitrary.
|
|
kwds['params'] = {utils._sanitize(name).lower():
|
|
utils._sanitize(value)
|
|
for name, value in parse_tree.params}
|
|
|
|
def init(self, *args, **kw):
|
|
self._params = kw.pop('params')
|
|
super().init(*args, **kw)
|
|
|
|
@property
|
|
def params(self):
|
|
return MappingProxyType(self._params)
|
|
|
|
|
|
class ContentTypeHeader(ParameterizedMIMEHeader):
|
|
|
|
value_parser = staticmethod(parser.parse_content_type_header)
|
|
|
|
def init(self, *args, **kw):
|
|
super().init(*args, **kw)
|
|
self._maintype = utils._sanitize(self._parse_tree.maintype)
|
|
self._subtype = utils._sanitize(self._parse_tree.subtype)
|
|
|
|
@property
|
|
def maintype(self):
|
|
return self._maintype
|
|
|
|
@property
|
|
def subtype(self):
|
|
return self._subtype
|
|
|
|
@property
|
|
def content_type(self):
|
|
return self.maintype + '/' + self.subtype
|
|
|
|
|
|
class ContentDispositionHeader(ParameterizedMIMEHeader):
|
|
|
|
value_parser = staticmethod(parser.parse_content_disposition_header)
|
|
|
|
def init(self, *args, **kw):
|
|
super().init(*args, **kw)
|
|
cd = self._parse_tree.content_disposition
|
|
self._content_disposition = cd if cd is None else utils._sanitize(cd)
|
|
|
|
@property
|
|
def content_disposition(self):
|
|
return self._content_disposition
|
|
|
|
|
|
class ContentTransferEncodingHeader:
|
|
|
|
max_count = 1
|
|
|
|
value_parser = staticmethod(parser.parse_content_transfer_encoding_header)
|
|
|
|
@classmethod
|
|
def parse(cls, value, kwds):
|
|
kwds['parse_tree'] = parse_tree = cls.value_parser(value)
|
|
kwds['decoded'] = str(parse_tree)
|
|
kwds['defects'].extend(parse_tree.all_defects)
|
|
|
|
def init(self, *args, **kw):
|
|
super().init(*args, **kw)
|
|
self._cte = utils._sanitize(self._parse_tree.cte)
|
|
|
|
@property
|
|
def cte(self):
|
|
return self._cte
|
|
|
|
|
|
class MessageIDHeader:
|
|
|
|
max_count = 1
|
|
value_parser = staticmethod(parser.parse_message_id)
|
|
|
|
@classmethod
|
|
def parse(cls, value, kwds):
|
|
kwds['parse_tree'] = parse_tree = cls.value_parser(value)
|
|
kwds['decoded'] = str(parse_tree)
|
|
kwds['defects'].extend(parse_tree.all_defects)
|
|
|
|
|
|
# The header factory #
|
|
|
|
_default_header_map = {
|
|
'subject': UniqueUnstructuredHeader,
|
|
'date': UniqueDateHeader,
|
|
'resent-date': DateHeader,
|
|
'orig-date': UniqueDateHeader,
|
|
'sender': UniqueSingleAddressHeader,
|
|
'resent-sender': SingleAddressHeader,
|
|
'to': UniqueAddressHeader,
|
|
'resent-to': AddressHeader,
|
|
'cc': UniqueAddressHeader,
|
|
'resent-cc': AddressHeader,
|
|
'bcc': UniqueAddressHeader,
|
|
'resent-bcc': AddressHeader,
|
|
'from': UniqueAddressHeader,
|
|
'resent-from': AddressHeader,
|
|
'reply-to': UniqueAddressHeader,
|
|
'mime-version': MIMEVersionHeader,
|
|
'content-type': ContentTypeHeader,
|
|
'content-disposition': ContentDispositionHeader,
|
|
'content-transfer-encoding': ContentTransferEncodingHeader,
|
|
'message-id': MessageIDHeader,
|
|
}
|
|
|
|
class HeaderRegistry:
|
|
|
|
"""A header_factory and header registry."""
|
|
|
|
def __init__(self, base_class=BaseHeader, default_class=UnstructuredHeader,
|
|
use_default_map=True):
|
|
"""Create a header_factory that works with the Policy API.
|
|
|
|
base_class is the class that will be the last class in the created
|
|
header class's __bases__ list. default_class is the class that will be
|
|
used if "name" (see __call__) does not appear in the registry.
|
|
use_default_map controls whether or not the default mapping of names to
|
|
specialized classes is copied in to the registry when the factory is
|
|
created. The default is True.
|
|
|
|
"""
|
|
self.registry = {}
|
|
self.base_class = base_class
|
|
self.default_class = default_class
|
|
if use_default_map:
|
|
self.registry.update(_default_header_map)
|
|
|
|
def map_to_type(self, name, cls):
|
|
"""Register cls as the specialized class for handling "name" headers.
|
|
|
|
"""
|
|
self.registry[name.lower()] = cls
|
|
|
|
def __getitem__(self, name):
|
|
cls = self.registry.get(name.lower(), self.default_class)
|
|
return type('_'+cls.__name__, (cls, self.base_class), {})
|
|
|
|
def __call__(self, name, value):
|
|
"""Create a header instance for header 'name' from 'value'.
|
|
|
|
Creates a header instance by creating a specialized class for parsing
|
|
and representing the specified header by combining the factory
|
|
base_class with a specialized class from the registry or the
|
|
default_class, and passing the name and value to the constructed
|
|
class's constructor.
|
|
|
|
"""
|
|
return self[name](name, value)
|