import mimetypes
from email import (
charset as Charset, encoders as Encoders, generator, message_from_string,
)
from email.errors import InvalidHeaderDefect, NonASCIILocalPartDefect
from email.header import Header
from email.headerregistry import Address
from email.message import Message
from email.mime.base import MIMEBase
from email.mime.message import MIMEMessage
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.utils import formatdate, getaddresses, make_msgid, parseaddr
from io import BytesIO, StringIO
from pathlib import Path
from django.conf import settings
from django.core.mail.utils import DNS_NAME
from django.utils.encoding import force_text
# Don't BASE64-encode UTF-8 messages so that we avoid unwanted attention from
# some spam filters.
utf8_charset = Charset.Charset('utf-8')
utf8_charset.body_encoding = None # Python defaults to BASE64
utf8_charset_qp = Charset.Charset('utf-8')
utf8_charset_qp.body_encoding = Charset.QP
# Default MIME type to use on attachments (if it is not explicitly given
# and cannot be guessed).
DEFAULT_ATTACHMENT_MIME_TYPE = 'application/octet-stream'
RFC5322_EMAIL_LINE_LENGTH_LIMIT = 998
class BadHeaderError(ValueError):
pass
# Header names that contain structured address data (RFC #5322)
ADDRESS_HEADERS = {
'from',
'sender',
'reply-to',
'to',
'cc',
'bcc',
'resent-from',
'resent-sender',
'resent-to',
'resent-cc',
'resent-bcc',
}
def forbid_multi_line_headers(name, val, encoding):
"""Forbid multi-line headers to prevent header injection."""
encoding = encoding or settings.DEFAULT_CHARSET
val = str(val) # val may be lazy
if '\n' in val or '\r' in val:
raise BadHeaderError("Header values can't contain newlines (got %r for header %r)" % (val, name))
try:
val.encode('ascii')
except UnicodeEncodeError:
if name.lower() in ADDRESS_HEADERS:
val = ', '.join(sanitize_address(addr, encoding) for addr in getaddresses((val,)))
else:
val = Header(val, encoding).encode()
else:
if name.lower() == 'subject':
val = Header(val).encode()
return name, val
def split_addr(addr, encoding):
"""
Split the address into local part and domain and encode them.
When non-ascii characters are present in the local part, it must be
MIME-word encoded. The domain name must be idna-encoded if it contains
non-ascii characters.
"""
if '@' in addr:
localpart, domain = addr.split('@', 1)
# Try to get the simplest encoding - ascii if possible so that
# [email protected] doesn't become [email protected]. This
# makes unit testing a bit easier and more readable.
try:
localpart.encode('ascii')
except UnicodeEncodeError:
localpart = Header(localpart, encoding).encode()
domain = domain.encode('idna').decode('ascii')
else:
localpart = Header(addr, encoding).encode()
domain = ''
return (localpart, domain)
def sanitize_address(addr, encoding):
"""
Format a pair of (name, address) or an email address string.
"""
if not isinstance(addr, tuple):
addr = parseaddr(addr)
nm, addr = addr
localpart, domain = None, None
nm = Header(nm, encoding).encode()
try:
addr.encode('ascii')
except UnicodeEncodeError: # IDN or non-ascii in the local part
localpart, domain = split_addr(addr, encoding)
# An `email.headerregistry.Address` object is used since
# email.utils.formataddr() naively encodes the name as ascii (see #25986).
if localpart and domain:
address = Address(nm, username=localpart, domain=domain)
return str(address)
try:
address = Address(nm, addr_spec=addr)
except (InvalidHeaderDefect, NonASCIILocalPartDefect):
localpart, domain = split_addr(addr, encoding)
address = Address(nm, username=localpart, domain=domain)
return str(address)
class MIMEMixin:
def as_string(self, unixfrom=False, linesep='\n'):
"""Return the entire formatted message as a string.
Optional `unixfrom' when True, means include the Unix From_ envelope
header.
This overrides the default as_string() implementation to not mangle
lines that begin with 'From '. See bug #13433 for details.
"""
fp = StringIO()
g = generator.Generator(fp, mangle_from_=False)
g.flatten(self, unixfrom=unixfrom, linesep=linesep)
return fp.getvalue()
def as_bytes(self, unixfrom=False, linesep='\n'):
"""Return the entire formatted message as bytes.
Optional `unixfrom' when True, means include the Unix From_ envelope
header.
This overrides the default as_bytes() implementation to not mangle
lines that begin with 'From '. See bug #13433 for details.
"""
fp = BytesIO()
g = generator.BytesGenerator(fp, mangle_from_=False)
g.flatten(self, unixfrom=unixfrom, linesep=linesep)
return fp.getvalue()
class SafeMIMEMessage(MIMEMixin, MIMEMessage):
def __setitem__(self, name, val):
# message/rfc822 attachments must be ASCII
name, val = forbid_multi_line_headers(name, val, 'ascii')
MIMEMessage.__setitem__(self, name, val)
class SafeMIMEText(MIMEMixin, MIMEText):
def __init__(self, _text, _subtype='plain', _charset=None):
self.encoding = _charset
MIMEText.__init__(self, _text, _subtype=_subtype, _charset=_charset)
def __setitem__(self, name, val):
name, val = forbid_multi_line_headers(name, val, self.encoding)
MIMEText.__setitem__(self, name, val)
def set_payload(self, payload, charset=None):
if charset == 'utf-8':
has_long_lines = any(
len(l.encode()) > RFC5322_EMAIL_LINE_LENGTH_LIMIT
for l in payload.splitlines()
)
# Quoted-Printable encoding has the side effect of shortening long
# lines, if any (#22561).
charset = utf8_charset_qp if has_long_lines else utf8_charset
MIMEText.set_payload(self, payload, charset=charset)
class SafeMIMEMultipart(MIMEMixin, MIMEMultipart):
def __init__(self, _subtype='mixed', boundary=None, _subparts=None, encoding=None, **_params):
self.encoding = encoding
MIMEMultipart.__init__(self, _subtype, boundary, _subparts, **_params)
def __setitem__(self, name, val):
name, val = forbid_multi_line_headers(name, val, self.encoding)
MIMEMultipart.__setitem__(self, name, val)
class EmailMessage:
"""A container for email information."""
content_subtype = 'plain'
mixed_subtype = 'mixed'
encoding = None # None => use settings default
def __init__(self, subject='', body='', from_email=None, to=None, bcc=None,
connection=None, attachments=None, headers=None, cc=None,
reply_to=None):
"""
Initialize a single email message (which can be sent to multiple
recipients).
"""
if to:
if isinstance(to, str):
raise TypeError('"to" argument must be a list or tuple')
self.to = list(to)
else:
self.to = []
if cc:
if isinstance(cc, str):
raise TypeError('"cc" argument must be a list or tuple')
self.cc = list(cc)
else:
self.cc = []
if bcc:
if isinstance(bcc, str):
raise TypeError('"bcc" argument must be a list or tuple')
self.bcc = list(bcc)
else:
self.bcc = []
if reply_to:
if isinstance(reply_to, str):
raise TypeError('"reply_to" argument must be a list or tuple')
self.reply_to = list(reply_to)
else:
self.reply_to = []
self.from_email = from_email or settings.DEFAULT_FROM_EMAIL
self.subject = subject
self.body = body or ''
self.attachments = []
if attachments:
for attachment in attachments:
if isinstance(attachment, MIMEBase):
self.attach(attachment)
else:
self.attach(*attachment)
self.extra_headers = headers or {}
self.connection = connection
def get_connection(self, fail_silently=False):
from django.core.mail import get_connection
if not self.connection:
self.connection = get_connection(fail_silently=fail_silently)
return self.connection
def message(self):
encoding = self.encoding or settings.DEFAULT_CHARSET
msg = SafeMIMEText(self.body, self.content_subtype, encoding)
msg = self._create_message(msg)
msg['Subject'] = self.subject
msg['From'] = self.extra_headers.get('From', self.from_email)
self._set_list_header_if_not_empty(msg, 'To', self.to)
self._set_list_header_if_not_empty(msg, 'Cc', self.cc)
self._set_list_header_if_not_empty(msg, 'Reply-To', self.reply_to)
# Email header names are case-insensitive (RFC 2045), so we have to
# accommodate that when doing comparisons.
header_names = [key.lower() for key in self.extra_headers]
if 'date' not in header_names:
# formatdate() uses stdlib methods to format the date, which use
# the stdlib/OS concept of a timezone, however, Django sets the
# TZ environment variable based on the TIME_ZONE setting which
# will get picked up by formatdate().
msg['Date'] = formatdate(localtime=settings.EMAIL_USE_LOCALTIME)
if 'message-id' not in header_names:
# Use cached DNS_NAME for performance
msg['Message-ID'] = make_msgid(domain=DNS_NAME)
for name, value in self.extra_headers.items():
if name.lower() != 'from': # From is already handled
msg[name] = value
return msg
def recipients(self):
"""
Return a list of all recipients of the email (includes direct
addressees as well as Cc and Bcc entries).
"""
return [email for email in (self.to + self.cc + self.bcc) if email]
def send(self, fail_silently=False):
"""Send the email message."""
if not self.recipients():
# Don't bother creating the network connection if there's nobody to
# send to.
return 0
return self.get_connection(fail_silently).send_messages([self])
def attach(self, filename=None, content=None, mimetype=None):
"""
Attach a file with the given filename and content. The filename can
be omitted and the mimetype is guessed, if not provided.
If the first parameter is a MIMEBase subclass, insert it directly
into the resulting message attachments.
For a text/* mimetype (guessed or specified), when a bytes object is
specified as content, decode it as UTF-8. If that fails, set the
mimetype to DEFAULT_ATTACHMENT_MIME_TYPE and don't decode the content.
"""
if isinstance(filename, MIMEBase):
assert content is None
assert mimetype is None
self.attachments.append(filename)
else:
assert content is not None
mimetype = mimetype or mimetypes.guess_type(filename)[0] or DEFAULT_ATTACHMENT_MIME_TYPE
basetype, subtype = mimetype.split('/', 1)
if basetype == 'text':
if isinstance(content, bytes):
try:
content = content.decode()
except UnicodeDecodeError:
# If mimetype suggests the file is text but it's
# actually binary, read() raises a UnicodeDecodeError.
mimetype = DEFAULT_ATTACHMENT_MIME_TYPE
self.attachments.append((filename, content, mimetype))
def attach_file(self, path, mimetype=None):
"""
Attach a file from the filesystem.
Set the mimetype to DEFAULT_ATTACHMENT_MIME_TYPE if it isn't specified
and cannot be guessed.
For a text/* mimetype (guessed or specified), decode the file's content
as UTF-8. If that fails, set the mimetype to
DEFAULT_ATTACHMENT_MIME_TYPE and don't decode the content.
"""
path = Path(path)
with path.open('rb') as file:
content = file.read()
self.attach(path.name, content, mimetype)
def _create_message(self, msg):
return self._create_attachments(msg)
def _create_attachments(self, msg):
if self.attachments:
encoding = self.encoding or settings.DEFAULT_CHARSET
body_msg = msg
msg = SafeMIMEMultipart(_subtype=self.mixed_subtype, encoding=encoding)
if self.body or body_msg.is_multipart():
msg.attach(body_msg)
for attachment in self.attachments:
if isinstance(attachment, MIMEBase):
msg.attach(attachment)
else:
msg.attach(self._create_attachment(*attachment))
return msg
def _create_mime_attachment(self, content, mimetype):
"""
Convert the content, mimetype pair into a MIME attachment object.
If the mimetype is message/rfc822, content may be an
email.Message or EmailMessage object, as well as a str.
"""
basetype, subtype = mimetype.split('/', 1)
if basetype == 'text':
encoding = self.encoding or settings.DEFAULT_CHARSET
attachment = SafeMIMEText(content, subtype, encoding)
elif basetype == 'message' and subtype == 'rfc822':
# Bug #18967: per RFC2046 s5.2.1, message/rfc822 attachments
# must not be base64 encoded.
if isinstance(content, EmailMessage):
# convert content into an email.Message first
content = content.message()
elif not isinstance(content, Message):
# For compatibility with existing code, parse the message
# into an email.Message object if it is not one already.
content = message_from_string(force_text(content))
attachment = SafeMIMEMessage(content, subtype)
else:
# Encode non-text attachments with base64.
attachment = MIMEBase(basetype, subtype)
attachment.set_payload(content)
Encoders.encode_base64(attachment)
return attachment
def _create_attachment(self, filename, content, mimetype=None):
"""
Convert the filename, content, mimetype triple into a MIME attachment
object.
"""
attachment = self._create_mime_attachment(content, mimetype)
if filename:
try:
filename.encode('ascii')
except UnicodeEncodeError:
filename = ('utf-8', '', filename)
attachment.add_header('Content-Disposition', 'attachment', filename=filename)
return attachment
def _set_list_header_if_not_empty(self, msg, header, values):
"""
Set msg's header, either from self.extra_headers, if present, or from
the values argument.
"""
if values:
try:
value = self.extra_headers[header]
except KeyError:
value = ', '.join(str(v) for v in values)
msg[header] = value
class EmailMultiAlternatives(EmailMessage):
"""
A version of EmailMessage that makes it easy to send multipart/alternative
messages. For example, including text and HTML versions of the text is
made easier.
"""
alternative_subtype = 'alternative'
def __init__(self, subject='', body='', from_email=None, to=None, bcc=None,
connection=None, attachments=None, headers=None, alternatives=None,
cc=None, reply_to=None):
"""
Initialize a single email message (which can be sent to multiple
recipients).
"""
super().__init__(
subject, body, from_email, to, bcc, connection, attachments,
headers, cc, reply_to,
)
self.alternatives = alternatives or []
def attach_alternative(self, content, mimetype):
"""Attach an alternative content representation."""
assert content is not None
assert mimetype is not None
self.alternatives.append((content, mimetype))
def _create_message(self, msg):
return self._create_attachments(self._create_alternatives(msg))
def _create_alternatives(self, msg):
encoding = self.encoding or settings.DEFAULT_CHARSET
if self.alternatives:
body_msg = msg
msg = SafeMIMEMultipart(_subtype=self.alternative_subtype, encoding=encoding)
if self.body:
msg.attach(body_msg)
for alternative in self.alternatives:
msg.attach(self._create_mime_attachment(*alternative))
return msg