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Bug 1873581 - Rebase python-cryptography to 2.6+ for ed25519 support
Summary: Rebase python-cryptography to 2.6+ for ed25519 support
Alias: None
Product: Red Hat Enterprise Linux 8
Classification: Red Hat
Component: python-cryptography
Version: 8.2
Hardware: x86_64
OS: Linux
Target Milestone: rc
: 8.4
Assignee: Christian Heimes
QA Contact: Kaleem
: 1669539 2003742 2011720 (view as bug list)
Depends On: 1891947 1907429
Blocks: 1668318 1669539 1778939 CVE-2020-25659 1908879 2011720 2011721
TreeView+ depends on / blocked
Reported: 2020-08-28 16:40 UTC by Mauro Oddi
Modified: 2021-10-19 16:03 UTC (History)
10 users (show)

Fixed In Version: python-cryptography-3.2.1-3.el8
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Last Closed: 2021-05-18 14:52:08 UTC
Type: Feature Request
Target Upstream Version:

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Red Hat Issue Tracker FREEIPA-7052 0 None None None 2021-10-07 08:16:41 UTC

Description Mauro Oddi 2020-08-28 16:40:03 UTC
Description of problem:

The version of python3-cryptography shipped in RHEL 8.2 lacks support for twisted Edwards curves.

This creates a problem in OSP16 Nova:
 - https://bugzilla.redhat.com/show_bug.cgi?id=1669539

Version-Release number of selected component (if applicable):
RHEL 8.2

How reproducible:

Steps to Reproduce:

1. Create an ssh keypair of key type ed25519 
(undercloud) [stack@undercloud-osp16 ~]$ ssh-keygen -t ed25519
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAHHlefD0G8ir1v/oirs3DDC9mR/ZkZ8+CMVUa9YBuLK stack.local

2. Try to load ssh pubkey using cryptography library:

(undercloud) [stack@undercloud-osp16 ~]$ LC_ALL=en_US.UTF-8 python3
Python 3.6.8 (default, Oct 11 2019, 15:04:54) 
[GCC 8.3.1 20190507 (Red Hat 8.3.1-4)] on linux
Type "help", "copyright", "credits" or "license" for more information.

>>> from cryptography.hazmat import backends
>>> from cryptography.hazmat.primitives import serialization

>>> serialization.load_ssh_public_key(data='ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAHHlefD0G8ir1v/oirs3DDC9mR/ZkZ8+CMVUa9YBuLK stack.local'.encode('utf-8'), backend=backends.default_backend())

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib64/python3.6/site-packages/cryptography/hazmat/primitives/serialization.py", line 61, in load_ssh_public_key
    raise UnsupportedAlgorithm('Key type is not supported.')
cryptography.exceptions.UnsupportedAlgorithm: Key type is not supported.

Actual results:
raise UnsupportedAlgorithm('Key type is not supported.')

Expected results:
 ed25519 key type should be supported.

Additional info:
Version 2.7 or higher should be required.

Comment 2 Christian Heimes 2020-09-07 06:45:32 UTC
RHEL 8 ships PyCA cryptography 2.3, which does not support ed25519. In order to support ed25519 python-cryptography has to be rebased to 2.6 or newer. Version 2.6 contains some backwards incompatible changes [1], which I would have to revert. I can do a rebase for RHEL 8.4 earliest.

[1] https://cryptography.io/en/latest/changelog/#v2-6

Comment 3 Mauro Oddi 2020-09-07 07:59:07 UTC
Hi Christian,

Thanks for the confirmation.

Best Regards,

Comment 4 Christian Heimes 2020-09-07 08:20:51 UTC
You are welcome!

Do you need a rebase for 8.4? It would be a good idea to start the rebase process early by filing a rebase request RHBZ with a business case.

Comment 6 Christian Heimes 2020-09-07 09:54:22 UTC
I recommend to rebase to either 2.6 (ed25519 support), 2.9 (Poly1305 and fixed rfc4514_string function), or 3.0 (OpenSSH serialization format for private keys)

python-cryptography depends on python-cryptography-vectors for testing. The vector package must be updated in sync. It is an internal development package and not shipped with RHEL.

python-cryptography 2.6 has removed three deprecated features. The features can be easily re-added:
* cryptography.hazmat.primitives.asymmetric.utils.encode_rfc6979_signature() and decode_rfc6979_signature() functions. The functions were removed in 2.6. Both are simple aliases for encode_dss_signature() and decode_dss_signature() in the same name space
* cryptography.hazmat.backends.openssl.x509._Certificate.serial. The property was removed in 2.6. It's a simple alias for Certificate.serial_number

2.7 removed cryptography.hazmat.primitives.mac.MACContext

The backwards incompatible changed to rfc4514_string() in 2.9 is not an issue for RHEL. The function is not available in RHEL 8 because it was added in 2.5.

3.0 removed support for passing an Extension instance to from_issuer_subject_key_identifier(). This feature can be patched back easily, too.

Comment 23 anuja 2020-12-17 12:09:51 UTC
Using version:

Sanity check performed by executing:
bash: ipa-getcert
pytest: ipa-getcert
pytest: ipa-cert

2020-12-17T08:32:26 [ci-vm-10-0-153-197.h] |       ipa-client-4.9.0-0.5.rc3.module+el8.4.0+9124+ced20601.x86_64
2020-12-17T08:32:26 [ci-vm-10-0-153-197.h] |       ipa-client-common-4.9.0-0.5.rc3.module+el8.4.0+9124+ced20601.noarch
2020-12-17T08:32:26 [ci-vm-10-0-153-197.h] |       sssd-ipa-2.4.0-3.el8.x86_64
2020-12-17T08:32:26 [ci-vm-10-0-153-197.h] ------------------------------------------------------------------------------------------
2020-12-17T08:32:26 [ci-vm-10-0-153-197.h]  +-----------------------------------------------------------------------------------------+
2020-12-17T08:32:26 [ci-vm-10-0-153-197.h]      Test:[/ipa-server/rhel80/ipa-getcert/root]: [ Pass(242/242): 100% ] 
2020-12-17T08:32:26 [ci-vm-10-0-153-197.h]  +-----------------------------------------------------------------------------------------+

2020-12-17T08:47:47+0000 --------- generated xml file: /home/jenkins/tews/ipa-getcert/junit.xml ---------
2020-12-17T08:47:47+0000 ---- generated html file: file:///home/jenkins/tews/ipa-getcert/report.html ----
2020-12-17T08:47:47+0000 ========================== 1 passed in 323.62 seconds ==========================

2020-12-17T08:45:42+0000 ---------- generated xml file: /home/jenkins/tews/ipa-cert/junit.xml -----------
2020-12-17T08:45:42+0000 ----- generated html file: file:///home/jenkins/tews/ipa-cert/report.html ------
2020-12-17T08:45:42+0000 ========================== 3 passed in 397.12 seconds ==========================

Based on this marking bug as verified.

Comment 25 melanie witt 2021-02-19 04:07:13 UTC
*** Bug 1669539 has been marked as a duplicate of this bug. ***

Comment 27 errata-xmlrpc 2021-05-18 14:52:08 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (Moderate: python-cryptography security, bug fix, and enhancement update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.


Comment 28 Christian Heimes 2021-10-07 08:12:06 UTC
*** Bug 2011720 has been marked as a duplicate of this bug. ***

Comment 29 Florence Blanc-Renaud 2021-10-19 16:03:15 UTC
*** Bug 2003742 has been marked as a duplicate of this bug. ***

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