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import io
import textwrap
import unittest
from email import message_from_string, message_from_bytes
from email.message import EmailMessage
from email.generator import Generator, BytesGenerator
from email.headerregistry import Address
from email import policy
import email.errors
from test.test_email import TestEmailBase, parameterize
@parameterize
class TestGeneratorBase:
policy = policy.default
def msgmaker(self, msg, policy=None):
policy = self.policy if policy is None else policy
return self.msgfunc(msg, policy=policy)
refold_long_expected = {
0: textwrap.dedent("""\
To: whom_it_may_concern@example.com
From: nobody_you_want_to_know@example.com
Subject: We the willing led by the unknowing are doing the
impossible for the ungrateful. We have done so much for so long with so little
we are now qualified to do anything with nothing.
None
"""),
40: textwrap.dedent("""\
To: whom_it_may_concern@example.com
From:
nobody_you_want_to_know@example.com
Subject: We the willing led by the
unknowing are doing the impossible for
the ungrateful. We have done so much
for so long with so little we are now
qualified to do anything with nothing.
None
"""),
20: textwrap.dedent("""\
To:
whom_it_may_concern@example.com
From:
nobody_you_want_to_know@example.com
Subject: We the
willing led by the
unknowing are doing
the impossible for
the ungrateful. We
have done so much
for so long with so
little we are now
qualified to do
anything with
nothing.
None
"""),
}
refold_long_expected[100] = refold_long_expected[0]
refold_all_expected = refold_long_expected.copy()
refold_all_expected[0] = (
"To: whom_it_may_concern@example.com\n"
"From: nobody_you_want_to_know@example.com\n"
"Subject: We the willing led by the unknowing are doing the "
"impossible for the ungrateful. We have done so much for "
"so long with so little we are now qualified to do anything "
"with nothing.\n"
"\n"
"None\n")
refold_all_expected[100] = (
"To: whom_it_may_concern@example.com\n"
"From: nobody_you_want_to_know@example.com\n"
"Subject: We the willing led by the unknowing are doing the "
"impossible for the ungrateful. We have\n"
" done so much for so long with so little we are now qualified "
"to do anything with nothing.\n"
"\n"
"None\n")
length_params = [n for n in refold_long_expected]
def length_as_maxheaderlen_parameter(self, n):
msg = self.msgmaker(self.typ(self.refold_long_expected[0]))
s = self.ioclass()
g = self.genclass(s, maxheaderlen=n, policy=self.policy)
g.flatten(msg)
self.assertEqual(s.getvalue(), self.typ(self.refold_long_expected[n]))
def length_as_max_line_length_policy(self, n):
msg = self.msgmaker(self.typ(self.refold_long_expected[0]))
s = self.ioclass()
g = self.genclass(s, policy=self.policy.clone(max_line_length=n))
g.flatten(msg)
self.assertEqual(s.getvalue(), self.typ(self.refold_long_expected[n]))
def length_as_maxheaderlen_parm_overrides_policy(self, n):
msg = self.msgmaker(self.typ(self.refold_long_expected[0]))
s = self.ioclass()
g = self.genclass(s, maxheaderlen=n,
policy=self.policy.clone(max_line_length=10))
g.flatten(msg)
self.assertEqual(s.getvalue(), self.typ(self.refold_long_expected[n]))
def length_as_max_line_length_with_refold_none_does_not_fold(self, n):
msg = self.msgmaker(self.typ(self.refold_long_expected[0]))
s = self.ioclass()
g = self.genclass(s, policy=self.policy.clone(refold_source='none',
max_line_length=n))
g.flatten(msg)
self.assertEqual(s.getvalue(), self.typ(self.refold_long_expected[0]))
def length_as_max_line_length_with_refold_all_folds(self, n):
msg = self.msgmaker(self.typ(self.refold_long_expected[0]))
s = self.ioclass()
g = self.genclass(s, policy=self.policy.clone(refold_source='all',
max_line_length=n))
g.flatten(msg)
self.assertEqual(s.getvalue(), self.typ(self.refold_all_expected[n]))
def test_crlf_control_via_policy(self):
source = "Subject: test\r\n\r\ntest body\r\n"
expected = source
msg = self.msgmaker(self.typ(source))
s = self.ioclass()
g = self.genclass(s, policy=policy.SMTP)
g.flatten(msg)
self.assertEqual(s.getvalue(), self.typ(expected))
def test_flatten_linesep_overrides_policy(self):
source = "Subject: test\n\ntest body\n"
expected = source
msg = self.msgmaker(self.typ(source))
s = self.ioclass()
g = self.genclass(s, policy=policy.SMTP)
g.flatten(msg, linesep='\n')
self.assertEqual(s.getvalue(), self.typ(expected))
def test_set_mangle_from_via_policy(self):
source = textwrap.dedent("""\
Subject: test that
from is mangled in the body!
From time to time I write a rhyme.
""")
variants = (
(None, True),
(policy.compat32, True),
(policy.default, False),
(policy.default.clone(mangle_from_=True), True),
)
for p, mangle in variants:
expected = source.replace('From ', '>From ') if mangle else source
with self.subTest(policy=p, mangle_from_=mangle):
msg = self.msgmaker(self.typ(source))
s = self.ioclass()
g = self.genclass(s, policy=p)
g.flatten(msg)
self.assertEqual(s.getvalue(), self.typ(expected))
def test_compat32_max_line_length_does_not_fold_when_none(self):
msg = self.msgmaker(self.typ(self.refold_long_expected[0]))
s = self.ioclass()
g = self.genclass(s, policy=policy.compat32.clone(max_line_length=None))
g.flatten(msg)
self.assertEqual(s.getvalue(), self.typ(self.refold_long_expected[0]))
def test_rfc2231_wrapping(self):
# This is pretty much just to make sure we don't have an infinite
# loop; I don't expect anyone to hit this in the field.
msg = self.msgmaker(self.typ(textwrap.dedent("""\
To: nobody
Content-Disposition: attachment;
filename="afilenamelongenoghtowraphere"
None
""")))
expected = textwrap.dedent("""\
To: nobody
Content-Disposition: attachment;
filename*0*=us-ascii''afilename;
filename*1*=longenoghtowraphere
None
""")
s = self.ioclass()
g = self.genclass(s, policy=self.policy.clone(max_line_length=33))
g.flatten(msg)
self.assertEqual(s.getvalue(), self.typ(expected))
def test_rfc2231_wrapping_switches_to_default_len_if_too_narrow(self):
# This is just to make sure we don't have an infinite loop; I don't
# expect anyone to hit this in the field, so I'm not bothering to make
# the result optimal (the encoding isn't needed).
msg = self.msgmaker(self.typ(textwrap.dedent("""\
To: nobody
Content-Disposition: attachment;
filename="afilenamelongenoghtowraphere"
None
""")))
expected = textwrap.dedent("""\
To: nobody
Content-Disposition:
attachment;
filename*0*=us-ascii''afilenamelongenoghtowraphere
None
""")
s = self.ioclass()
g = self.genclass(s, policy=self.policy.clone(max_line_length=20))
g.flatten(msg)
self.assertEqual(s.getvalue(), self.typ(expected))
def test_keep_encoded_newlines(self):
msg = self.msgmaker(self.typ(textwrap.dedent("""\
To: nobody
Subject: Bad subject=?UTF-8?Q?=0A?=Bcc: injection@example.com
None
""")))
expected = textwrap.dedent("""\
To: nobody
Subject: Bad subject=?UTF-8?Q?=0A?=Bcc: injection@example.com
None
""")
s = self.ioclass()
g = self.genclass(s, policy=self.policy.clone(max_line_length=80))
g.flatten(msg)
self.assertEqual(s.getvalue(), self.typ(expected))
def test_keep_long_encoded_newlines(self):
msg = self.msgmaker(self.typ(textwrap.dedent("""\
To: nobody
Subject: Bad subject=?UTF-8?Q?=0A?=Bcc: injection@example.com
None
""")))
expected = textwrap.dedent("""\
To: nobody
Subject: Bad subject
=?utf-8?q?=0A?=Bcc:
injection@example.com
None
""")
s = self.ioclass()
g = self.genclass(s, policy=self.policy.clone(max_line_length=30))
g.flatten(msg)
self.assertEqual(s.getvalue(), self.typ(expected))
class TestGenerator(TestGeneratorBase, TestEmailBase):
msgfunc = staticmethod(message_from_string)
genclass = Generator
ioclass = io.StringIO
typ = str
def test_verify_generated_headers(self):
"""gh-121650: by default the generator prevents header injection"""
class LiteralHeader(str):
name = 'Header'
def fold(self, **kwargs):
return self
for text in (
'Value\r\nBad Injection\r\n',
'NoNewLine'
):
with self.subTest(text=text):
message = message_from_string(
"Header: Value\r\n\r\nBody",
policy=self.policy,
)
del message['Header']
message['Header'] = LiteralHeader(text)
with self.assertRaises(email.errors.HeaderWriteError):
message.as_string()
class TestBytesGenerator(TestGeneratorBase, TestEmailBase):
msgfunc = staticmethod(message_from_bytes)
genclass = BytesGenerator
ioclass = io.BytesIO
typ = lambda self, x: x.encode('ascii')
def test_cte_type_7bit_handles_unknown_8bit(self):
source = ("Subject: Maintenant je vous présente mon "
"collègue\n\n").encode('utf-8')
expected = ('Subject: Maintenant je vous =?unknown-8bit?q?'
'pr=C3=A9sente_mon_coll=C3=A8gue?=\n\n').encode('ascii')
msg = message_from_bytes(source)
s = io.BytesIO()
g = BytesGenerator(s, policy=self.policy.clone(cte_type='7bit'))
g.flatten(msg)
self.assertEqual(s.getvalue(), expected)
def test_cte_type_7bit_transforms_8bit_cte(self):
source = textwrap.dedent("""\
From: foo@bar.com
To: Dinsdale
Subject: Nudge nudge, wink, wink
Mime-Version: 1.0
Content-Type: text/plain; charset="latin-1"
Content-Transfer-Encoding: 8bit
oh là là, know what I mean, know what I mean?
""").encode('latin1')
msg = message_from_bytes(source)
expected = textwrap.dedent("""\
From: foo@bar.com
To: Dinsdale
Subject: Nudge nudge, wink, wink
Mime-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
oh l=E0 l=E0, know what I mean, know what I mean?
""").encode('ascii')
s = io.BytesIO()
g = BytesGenerator(s, policy=self.policy.clone(cte_type='7bit',
linesep='\n'))
g.flatten(msg)
self.assertEqual(s.getvalue(), expected)
def test_smtputf8_policy(self):
msg = EmailMessage()
msg['From'] = "Páolo <főo@bar.com>"
msg['To'] = 'Dinsdale'
msg['Subject'] = 'Nudge nudge, wink, wink \u1F609'
msg.set_content("oh là là, know what I mean, know what I mean?")
expected = textwrap.dedent("""\
From: Páolo <főo@bar.com>
To: Dinsdale
Subject: Nudge nudge, wink, wink \u1F609
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
oh là là, know what I mean, know what I mean?
""").encode('utf-8').replace(b'\n', b'\r\n')
s = io.BytesIO()
g = BytesGenerator(s, policy=policy.SMTPUTF8)
g.flatten(msg)
self.assertEqual(s.getvalue(), expected)
def test_smtp_policy(self):
msg = EmailMessage()
msg["From"] = Address(addr_spec="foo@bar.com", display_name="Páolo")
msg["To"] = Address(addr_spec="bar@foo.com", display_name="Dinsdale")
msg["Subject"] = "Nudge nudge, wink, wink"
msg.set_content("oh boy, know what I mean, know what I mean?")
expected = textwrap.dedent("""\
From: =?utf-8?q?P=C3=A1olo?= <foo@bar.com>
To: Dinsdale <bar@foo.com>
Subject: Nudge nudge, wink, wink
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
oh boy, know what I mean, know what I mean?
""").encode().replace(b"\n", b"\r\n")
s = io.BytesIO()
g = BytesGenerator(s, policy=policy.SMTP)
g.flatten(msg)
self.assertEqual(s.getvalue(), expected)
if __name__ == '__main__':
unittest.main()
|
