| """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 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 represeting 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 an |
| 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 only put fws here if it was in the source. |
| header = parser.Header([ |
| parser.HeaderLabel([ |
| parser.ValueTerminal(self.name, 'header-name'), |
| parser.ValueTerminal(':', 'header-sep')]), |
| parser.CFWSList([parser.WhiteSpaceTerminal(' ', 'fws')]), |
| 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 self._params.copy() |
| |
| |
| 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 |
| |
| |
| # 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, |
| } |
| |
| 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) |