forked from pool/python-rsa
Accepting request 352100 from home:rjschwei:branches:devel:languages:python
- Fix CVE 2016-1494 (bsc#960680) - Add patch cve_2016-1494.diff OBS-URL: https://build.opensuse.org/request/show/352100 OBS-URL: https://build.opensuse.org/package/show/devel:languages:python/python-rsa?expand=0&rev=18
This commit is contained in:
Git OBS Bridge
parent
bf2a54df7b
commit
c45d4d1a46
103
cve_2016-1494.diff
Normal file
103
cve_2016-1494.diff
Normal file
@ -0,0 +1,103 @@
|
||||
# HG changeset patch
|
||||
# User Filippo Valsorda <hi@filippo.io>
|
||||
# Date 1450226563 0
|
||||
# Node ID 0cbcc529926afd61c6df4f50cfc29971beafd2c2
|
||||
# Parent 2baab06c8b867b01ec82b02118d4872a931a0437
|
||||
Fix BB'06 attack in verify() by switching from parsing to comparison
|
||||
|
||||
diff --git a/rsa/pkcs1.py b/rsa/pkcs1.py
|
||||
--- a/rsa/pkcs1.py
|
||||
+++ b/rsa/pkcs1.py
|
||||
@@ -22,10 +22,10 @@
|
||||
At least 8 bytes of random padding is used when encrypting a message. This makes
|
||||
these methods much more secure than the ones in the ``rsa`` module.
|
||||
|
||||
-WARNING: this module leaks information when decryption or verification fails.
|
||||
-The exceptions that are raised contain the Python traceback information, which
|
||||
-can be used to deduce where in the process the failure occurred. DO NOT PASS
|
||||
-SUCH INFORMATION to your users.
|
||||
+WARNING: this module leaks information when decryption fails. The exceptions
|
||||
+that are raised contain the Python traceback information, which can be used to
|
||||
+deduce where in the process the failure occurred. DO NOT PASS SUCH INFORMATION
|
||||
+to your users.
|
||||
'''
|
||||
|
||||
import hashlib
|
||||
@@ -288,37 +288,23 @@
|
||||
:param pub_key: the :py:class:`rsa.PublicKey` of the person signing the message.
|
||||
:raise VerificationError: when the signature doesn't match the message.
|
||||
|
||||
- .. warning::
|
||||
-
|
||||
- Never display the stack trace of a
|
||||
- :py:class:`rsa.pkcs1.VerificationError` exception. It shows where in
|
||||
- the code the exception occurred, and thus leaks information about the
|
||||
- key. It's only a tiny bit of information, but every bit makes cracking
|
||||
- the keys easier.
|
||||
-
|
||||
'''
|
||||
|
||||
- blocksize = common.byte_size(pub_key.n)
|
||||
+ keylength = common.byte_size(pub_key.n)
|
||||
encrypted = transform.bytes2int(signature)
|
||||
decrypted = core.decrypt_int(encrypted, pub_key.e, pub_key.n)
|
||||
- clearsig = transform.int2bytes(decrypted, blocksize)
|
||||
-
|
||||
- # If we can't find the signature marker, verification failed.
|
||||
- if clearsig[0:2] != b('\x00\x01'):
|
||||
- raise VerificationError('Verification failed')
|
||||
+ clearsig = transform.int2bytes(decrypted, keylength)
|
||||
|
||||
- # Find the 00 separator between the padding and the payload
|
||||
- try:
|
||||
- sep_idx = clearsig.index(b('\x00'), 2)
|
||||
- except ValueError:
|
||||
- raise VerificationError('Verification failed')
|
||||
-
|
||||
- # Get the hash and the hash method
|
||||
- (method_name, signature_hash) = _find_method_hash(clearsig[sep_idx+1:])
|
||||
+ # Get the hash method
|
||||
+ method_name = _find_method_hash(clearsig)
|
||||
message_hash = _hash(message, method_name)
|
||||
|
||||
- # Compare the real hash to the hash in the signature
|
||||
- if message_hash != signature_hash:
|
||||
+ # Reconstruct the expected padded hash
|
||||
+ cleartext = HASH_ASN1[method_name] + message_hash
|
||||
+ expected = _pad_for_signing(cleartext, keylength)
|
||||
+
|
||||
+ # Compare with the signed one
|
||||
+ if expected != clearsig:
|
||||
raise VerificationError('Verification failed')
|
||||
|
||||
return True
|
||||
@@ -351,24 +337,20 @@
|
||||
return hasher.digest()
|
||||
|
||||
|
||||
-def _find_method_hash(method_hash):
|
||||
- '''Finds the hash method and the hash itself.
|
||||
+def _find_method_hash(clearsig):
|
||||
+ '''Finds the hash method.
|
||||
|
||||
- :param method_hash: ASN1 code for the hash method concatenated with the
|
||||
- hash itself.
|
||||
+ :param clearsig: full padded ASN1 and hash.
|
||||
|
||||
- :return: tuple (method, hash) where ``method`` is the used hash method, and
|
||||
- ``hash`` is the hash itself.
|
||||
+ :return: the used hash method.
|
||||
|
||||
:raise VerificationFailed: when the hash method cannot be found
|
||||
|
||||
'''
|
||||
|
||||
for (hashname, asn1code) in HASH_ASN1.items():
|
||||
- if not method_hash.startswith(asn1code):
|
||||
- continue
|
||||
-
|
||||
- return (hashname, method_hash[len(asn1code):])
|
||||
+ if asn1code in clearsig:
|
||||
+ return hashname
|
||||
|
||||
raise VerificationError('Verification failed')
|
||||
@ -1,3 +1,9 @@
|
||||
-------------------------------------------------------------------
|
||||
Tue Jan 5 18:39:56 UTC 2016 - rjschwei@suse.com
|
||||
|
||||
- Fix CVE 2016-1494 (bsc#960680)
|
||||
- Add patch cve_2016-1494.diff
|
||||
|
||||
-------------------------------------------------------------------
|
||||
Tue Dec 1 15:02:09 UTC 2015 - rjschwei@suse.com
|
||||
|
||||
|
||||
@ -1,7 +1,7 @@
|
||||
#
|
||||
# spec file for package python-rsa
|
||||
#
|
||||
# Copyright (c) 2015 SUSE LINUX GmbH, Nuernberg, Germany.
|
||||
# Copyright (c) 2016 SUSE LINUX GmbH, Nuernberg, Germany.
|
||||
#
|
||||
# All modifications and additions to the file contributed by third parties
|
||||
# remain the property of their copyright owners, unless otherwise agreed
|
||||
@ -24,6 +24,7 @@ Summary: Pure-Python RSA Implementation
|
||||
License: Apache-2.0
|
||||
Group: Development/Languages/Python
|
||||
Source: http://pypi.python.org/packages/source/r/rsa/rsa-%{version}.tar.gz
|
||||
Patch0: cve_2016-1494.diff
|
||||
BuildRoot: %{_tmppath}/%{name}-%{version}-build
|
||||
BuildRequires: python-devel
|
||||
BuildRequires: python-pyasn1
|
||||
@ -55,6 +56,7 @@ sed -i "s/pyrsa-sign/pyrsa-sign-%{py_ver}/" setup.py
|
||||
sed -i "s/pyrsa-verify/pyrsa-verify-%{py_ver}/" setup.py
|
||||
sed -i "s/pyrsa-encrypt-bigfile =/pyrsa-encrypt-bigfile-%{py_ver} =/" setup.py
|
||||
sed -i "s/pyrsa-decrypt-bigfile =/pyrsa-decrypt-bigfile-%{py_ver} =/" setup.py
|
||||
%patch0 -p1
|
||||
|
||||
%build
|
||||
python setup.py build
|
||||
|
||||
Loading…
Reference in New Issue
Block a user