def test_signature_with_salt(self):
"""signature(value, salt=...) should work"""
signer = signing.BytesSigner('predictable-secret', salt='extra-salt')
self.assertEqual(
signer.signature('hello'),
signing.salted_hmac('extra-salt' + 'signer', 'hello',
'predictable-secret').finalize())
self.assertNotEqual(
signing.BytesSigner('predictable-secret',
salt='one').signature('hello'),
signing.BytesSigner('predictable-secret',
salt='two').signature('hello'))
def test_signature(self):
"""signature() method should generate a signature"""
signer = signing.BytesSigner('predictable-secret')
signer2 = signing.BytesSigner('predictable-secret2')
for s in (
b'hello',
b'3098247:529:087:',
'\u2019'.encode('utf-8'),
):
self.assertEqual(
signer.signature(s),
signing.salted_hmac(signer.salt + 'signer', s,
'predictable-secret').finalize())
self.assertNotEqual(signer.signature(s), signer2.signature(s))
def test_works_with_non_ascii_keys(self):
binary_key = b'\xe7' # Set some binary (non-ASCII key)
s = signing.BytesSigner(binary_key)
self.assertEqual(
b'foo\xb5\x8a\xc47\x19\xaeN\xdcMT\x83{PAb\r'
b'B\xf3\xd2i\xd1P\x94\xeb^\xc7(\xb4\xd3\x92'
b'\xd3\xf4', s.sign('foo'))
def test_unsign_detects_tampering(self):
"""unsign should raise an exception if the value has been tampered with"""
signer = signing.BytesSigner('predictable-secret')
value = b'Another string'
signed_value = signer.sign(value)
transforms = (
lambda s: s.upper(),
lambda s: s + b'a',
lambda s: b'a' + s[1:],
)
self.assertEqual(value, signer.unsign(signed_value))
for transform in transforms:
with self.assertRaises(signing.BadSignature):
signer.unsign(transform(signed_value))
def test_sign_unsign(self):
"""sign/unsign should be reversible"""
signer = signing.BytesSigner('predictable-secret')
examples = [
b'q;wjmbk;wkmb',
b'3098247529087',
b'3098247:529:087:',
b'jkw osanteuh ,rcuh nthu aou oauh ,ud du',
b'\u2019',
]
for example in examples:
signed = signer.sign(example)
self.assertIsInstance(signed, bytes)
self.assertNotEqual(force_str(example), signed)
self.assertEqual(example, signer.unsign(signed))