Bug 1456853

Summary: ssh -Q and -G list host key types that are not allowed in FIPS mode
Product: Red Hat Enterprise Linux 7 Reporter: Hubert Kario <hkario>
Component: opensshAssignee: Jakub Jelen <jjelen>
Status: CLOSED ERRATA QA Contact: Stefan Dordevic <sdordevi>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 7.4CC: nmavrogi, sdordevi
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: openssh-7.4p1-15.el7 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2018-04-10 18:19:11 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Hubert Kario 2017-05-30 13:59:20 UTC
Description of problem:
When the system is put in fips mode, `ssh -Q key` and `ssh -G example.com | grep key` list algorithms that use the DSS authentication method.
Because DSS in SSH can use only 1024 bit keys, that are considered too weak now, and they are not supported, but are still listed by the above commands

Version-Release number of selected component (if applicable):
openssh-7.4p1-11.el7.x86_64

How reproducible:
always

Steps to Reproduce:
1. ssh -Q key | grep dss
2. ssh -G example.com | grep dss
3.

Actual results:
ssh-dss
ssh-dss-cert-v01@openssh.com

hostkeyalgorithms (...),ssh-rsa,ssh-dss
hostbasedkeytypes (...),ssh-rsa,ssh-dss
pubkeyacceptedkeytypes (...),ssh-dss


Expected results:
no dss types listed

Additional info:

Comment 1 Jakub Jelen 2017-05-31 11:09:14 UTC
We should not use ed25519 keys either in FIPS, which is also listed there. After applying the patch, the output in FIPS looks this:

# ssh -Q key
ssh-rsa
ecdsa-sha2-nistp256
ecdsa-sha2-nistp384
ecdsa-sha2-nistp521
ssh-rsa-cert-v01@openssh.com
ecdsa-sha2-nistp256-cert-v01@openssh.com
ecdsa-sha2-nistp384-cert-v01@openssh.com
ecdsa-sha2-nistp521-cert-v01@openssh.com

# ssh -G example.com | grep dss
(empty)

I have got the patch ready to fix it in 7.4 or later.

Comment 2 Jakub Jelen 2017-06-07 11:13:23 UTC
no ... we can not remove them from the output of the -Q option, because the keys are technically enabled, but just not used by default.

The -G should certainly not list them.

Comment 6 Stefan Dordevic 2017-12-04 10:23:01 UTC
*** Bug 1459249 has been marked as a duplicate of this bug. ***

Comment 9 errata-xmlrpc 2018-04-10 18:19:11 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, and where to find the updated
files, follow the link below.

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

https://access.redhat.com/errata/RHSA-2018:0980