Fixed #18967 -- Don't base64-encode message/rfc822 attachments. (f9d1d5dc) · Commits · Dom Sekotill / django

django/core/mail/message.py

+41 −3

Original line number	Diff line number	Diff line
		@@ -4,11 +4,13 @@ import mimetypes
		import os
		import random
		import time
		from email import charset as Charset, encoders as Encoders
		from email import charset as Charset, encoders as Encoders, message_from_string
		from email.generator import Generator
		from email.message import Message
		from email.mime.text import MIMEText
		from email.mime.multipart import MIMEMultipart
		from email.mime.base import MIMEBase
		from email.mime.message import MIMEMessage
		from email.header import Header
		from email.utils import formatdate, getaddresses, formataddr, parseaddr

		@@ -118,6 +120,27 @@ def sanitize_address(addr, encoding):
		return formataddr((nm, addr))


		class SafeMIMEMessage(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)

		def as_string(self, unixfrom=False):
		"""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 = six.StringIO()
		g = Generator(fp, mangle_from_=False)
		g.flatten(self, unixfrom=unixfrom)
		return fp.getvalue()


		class SafeMIMEText(MIMEText):

		def __init__(self, text, subtype, charset):
		@@ -292,11 +315,26 @@ class EmailMessage(object):
		def _create_mime_attachment(self, content, mimetype):
		"""
		Converts 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 a email.Message object if it is not one already.
		content = message_from_string(content)

		attachment = SafeMIMEMessage(content, subtype)
		else:
		# Encode non-text attachments with base64.
		attachment = MIMEBase(basetype, subtype)

docs/topics/email.txt

+12 −2

Original line number	Diff line number	Diff line
		@@ -319,6 +319,18 @@ The class has the following methods:

		message.attach('design.png', img_data, 'image/png')

		.. versionchanged:: 1.7

		If you specify a ``mimetype`` of ``message/rfc822``, it will also accept
		:class:`django.core.mail.EmailMessage` and :py:class:`email.message.Message`.

		In addition, ``message/rfc822`` attachments will no longer be
		base64-encoded in violation of :rfc:`2046#section-5.2.1`, which can cause
		issues with displaying the attachments in `Evolution`__ and `Thunderbird`__.

		__ https://bugzilla.gnome.org/show_bug.cgi?id=651197
		__ https://bugzilla.mozilla.org/show_bug.cgi?id=333880

		* ``attach_file()`` creates a new attachment using a file from your
		filesystem. Call it with the path of the file to attach and, optionally,
		the MIME type to use for the attachment. If the MIME type is omitted, it
		@@ -326,8 +338,6 @@ The class has the following methods:

		message.attach_file('/images/weather_map.png')

		.. _DEFAULT_FROM_EMAIL: ../settings/#default-from-email

		Sending alternative content types
		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

tests/mail/tests.py

+33 −0

Original line number	Diff line number	Diff line
		@@ -331,6 +331,39 @@ class MailTests(TestCase):
		self.assertFalse(str('Content-Transfer-Encoding: quoted-printable') in s)
		self.assertTrue(str('Content-Transfer-Encoding: 8bit') in s)

		def test_dont_base64_encode_message_rfc822(self):
		# Ticket #18967
		# Shouldn't use base64 encoding for a child EmailMessage attachment.
		# Create a child message first
		child_msg = EmailMessage('Child Subject', 'Some body of child message', 'bounce@example.com', ['to@example.com'], headers={'From': 'from@example.com'})
		child_s = child_msg.message().as_string()

		# Now create a parent
		parent_msg = EmailMessage('Parent Subject', 'Some parent body', 'bounce@example.com', ['to@example.com'], headers={'From': 'from@example.com'})

		# Attach to parent as a string
		parent_msg.attach(content=child_s, mimetype='message/rfc822')
		parent_s = parent_msg.message().as_string()

		# Verify that the child message header is not base64 encoded
		self.assertTrue(str('Child Subject') in parent_s)

		# Feature test: try attaching email.Message object directly to the mail.
		parent_msg = EmailMessage('Parent Subject', 'Some parent body', 'bounce@example.com', ['to@example.com'], headers={'From': 'from@example.com'})
		parent_msg.attach(content=child_msg.message(), mimetype='message/rfc822')
		parent_s = parent_msg.message().as_string()

		# Verify that the child message header is not base64 encoded
		self.assertTrue(str('Child Subject') in parent_s)

		# Feature test: try attaching Django's EmailMessage object directly to the mail.
		parent_msg = EmailMessage('Parent Subject', 'Some parent body', 'bounce@example.com', ['to@example.com'], headers={'From': 'from@example.com'})
		parent_msg.attach(content=child_msg, mimetype='message/rfc822')
		parent_s = parent_msg.message().as_string()

		# Verify that the child message header is not base64 encoded
		self.assertTrue(str('Child Subject') in parent_s)


		class BaseEmailBackendTests(object):
		email_backend = None