diff --git a/django/core/signing.py b/django/core/signing.py index 6fc76bc..61faee2 100644 --- a/django/core/signing.py +++ b/django/core/signing.py @@ -32,6 +32,7 @@ start of the base64 JSON. There are 65 url-safe characters: the 64 used by url-safe base64 and the ':'. These functions make use of all of them. """ + from __future__ import unicode_literals import base64 @@ -43,7 +44,7 @@ from django.conf import settings from django.core.exceptions import ImproperlyConfigured from django.utils import baseconv from django.utils.crypto import constant_time_compare, salted_hmac -from django.utils.encoding import smart_bytes +from django.utils.encoding import force_str, force_text from django.utils.importlib import import_module @@ -62,12 +63,12 @@ class SignatureExpired(BadSignature): def b64_encode(s): - return base64.urlsafe_b64encode(smart_bytes(s)).decode('ascii').strip('=') + return base64.urlsafe_b64encode(s).strip(b'=') def b64_decode(s): - pad = '=' * (-len(s) % 4) - return base64.urlsafe_b64decode(smart_bytes(s + pad)).decode('ascii') + pad = b'=' * (-len(s) % 4) + return base64.urlsafe_b64decode(s + pad) def base64_hmac(salt, value, key): @@ -116,20 +117,20 @@ def dumps(obj, key=None, salt='django.core.signing', serializer=JSONSerializer, value or re-using a salt value across different parts of your application without good cause is a security risk. """ - data = serializer().dumps(obj) + data = serializer().dumps(obj).encode() # Flag for if it's been compressed or not is_compressed = False if compress: # Avoid zlib dependency unless compress is being used - compressed = zlib.compress(smart_bytes(data)) + compressed = zlib.compress(data) if len(compressed) < (len(data) - 1): data = compressed is_compressed = True base64d = b64_encode(data) if is_compressed: - base64d = '.' + base64d + base64d = b'.' + base64d return TimestampSigner(key, salt=salt).sign(base64d) @@ -137,37 +138,45 @@ def loads(s, key=None, salt='django.core.signing', serializer=JSONSerializer, ma """ Reverse of dumps(), raises BadSignature if signature fails """ - base64d = TimestampSigner(key, salt=salt).unsign(s, max_age=max_age) + # TimestampSigner.unsign always returns unicode but base64 and zlib + # compression operate on bytes, so we decode() here. + base64d = TimestampSigner(key, salt=salt).unsign(s, max_age=max_age).encode() decompress = False - if base64d[0] == '.': + if base64d[0] == b'.': # It's compressed; uncompress it first base64d = base64d[1:] decompress = True data = b64_decode(base64d) if decompress: data = zlib.decompress(data) - return serializer().loads(data) + return serializer().loads(data.decode()) class Signer(object): + def __init__(self, key=None, sep=':', salt=None): - self.sep = sep - self.key = key or settings.SECRET_KEY - self.salt = salt or ('%s.%s' % - (self.__class__.__module__, self.__class__.__name__)) + # Use of native strings in all versions of Python + self.sep = str(sep) + self.key = str(key or settings.SECRET_KEY) + self.salt = str(salt or + '%s.%s' % (self.__class__.__module__, self.__class__.__name__)) def signature(self, value): - return base64_hmac(self.salt + 'signer', value, self.key) + signature = base64_hmac(self.salt + 'signer', value, self.key) + # Convert the signature from bytes to str only on Python 3 + return force_str(signature) def sign(self, value): - return '%s%s%s' % (value, self.sep, self.signature(value)) + value = force_str(value) + return str('%s%s%s') % (value, self.sep, self.signature(value)) def unsign(self, signed_value): + signed_value = force_str(signed_value) if not self.sep in signed_value: raise BadSignature('No "%s" found in value' % self.sep) value, sig = signed_value.rsplit(self.sep, 1) if constant_time_compare(sig, self.signature(value)): - return value + return force_text(value) raise BadSignature('Signature "%s" does not match' % sig) @@ -177,8 +186,9 @@ class TimestampSigner(Signer): return baseconv.base62.encode(int(time.time())) def sign(self, value): - value = '%s%s%s' % (value, self.sep, self.timestamp()) - return '%s%s%s' % (value, self.sep, self.signature(value)) + value = force_str(value) + value = str('%s%s%s') % (value, self.sep, self.timestamp()) + return super(TimestampSigner, self).sign(value) def unsign(self, value, max_age=None): result = super(TimestampSigner, self).unsign(value) diff --git a/tests/regressiontests/signing/tests.py b/tests/regressiontests/signing/tests.py index 7145ec8..05c8b3d 100644 --- a/tests/regressiontests/signing/tests.py +++ b/tests/regressiontests/signing/tests.py @@ -4,8 +4,8 @@ import time from django.core import signing from django.test import TestCase +from django.utils.encoding import force_str from django.utils import six -from django.utils.encoding import force_text class TestSigner(TestCase): @@ -22,7 +22,7 @@ class TestSigner(TestCase): self.assertEqual( signer.signature(s), signing.base64_hmac(signer.salt + 'signer', s, - 'predictable-secret') + 'predictable-secret').decode() ) self.assertNotEqual(signer.signature(s), signer2.signature(s)) @@ -32,7 +32,8 @@ class TestSigner(TestCase): self.assertEqual( signer.signature('hello'), signing.base64_hmac('extra-salt' + 'signer', - 'hello', 'predictable-secret')) + 'hello', 'predictable-secret').decode() + ) self.assertNotEqual( signing.Signer('predictable-secret', salt='one').signature('hello'), signing.Signer('predictable-secret', salt='two').signature('hello')) @@ -40,17 +41,20 @@ class TestSigner(TestCase): def test_sign_unsign(self): "sign/unsign should be reversible" signer = signing.Signer('predictable-secret') - examples = ( + examples = [ 'q;wjmbk;wkmb', '3098247529087', '3098247:529:087:', 'jkw osanteuh ,rcuh nthu aou oauh ,ud du', '\u2019', - ) + ] + if not six.PY3: + examples.append(b'a byte string') for example in examples: - self.assertNotEqual( - force_text(example), force_text(signer.sign(example))) - self.assertEqual(example, signer.unsign(signer.sign(example))) + signed = signer.sign(example) + self.assertIsInstance(signed, str) + self.assertNotEqual(force_str(example), signed) + self.assertEqual(example, signer.unsign(signed)) def unsign_detects_tampering(self): "unsign should raise an exception if the value has been tampered with"