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Bug 1840772

Summary: ssh(d)_config manual page do not lists Supported KexAlgorithms and MACs values
Product: Red Hat Enterprise Linux 6 Reporter: Andrea Perotti <aperotti>
Component: opensshAssignee: Jakub Jelen <jjelen>
Status: CLOSED WONTFIX QA Contact: BaseOS QE Security Team <qe-baseos-security>
Severity: low Docs Contact:
Priority: low    
Version: 6.10CC: ssorce
Target Milestone: rcKeywords: Triaged
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of:
: 1841028 (view as bug list) Environment:
Last Closed: 2020-06-27 07:54:22 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 1841028    
Attachments:
Description Flags
Man changes proposal
none
man ssh_config.5 changes
none
man sshd_config.5 changes none

Description Andrea Perotti 2020-05-27 15:22:06 UTC
Description of problem:

In the man pages for ssh_config and sshd_config, for the parameters:

KexAlgorithms 
MACs

are only reported the default values, but not all the supported one, like what has been done in RHEL7.

On RHEL6, openssh lack the -Q feature that allow to list the supported features, so an up to date man page is very important for customer trying to do hardening of their ssh setup.


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

openssh-server-5.3p1-124.el6_10.x86_64
openssh-clients-5.3p1-124.el6_10.x86_64


How reproducible:
Always

Steps to Reproduce:
1. man ssh_config (or) man sshd_config

Actual results:
1. no info about all the supported KEX and MAC


Expected results:
Finding the complete list of the supported KEX and MAC on RHEL6.

Comment 2 Andrea Perotti 2020-05-27 16:48:41 UTC
As confirmed by the Maintainer, rhel6 openssh support the following:

kexAlgorithms:

diffie-hellman-group1-sha1
diffie-hellman-group14-sha1
diffie-hellman-group-exchange-sha1
diffie-hellman-group-exchange-sha256
ecdh-sha2-nistp256
ecdh-sha2-nistp384
ecdh-sha2-nistp521


MACs:

hmac-sha1
hmac-sha1-96
hmac-sha2-256
hmac-sha2-512
hmac-md5
hmac-md5-96
hmac-ripemd160
hmac-ripemd160
umac-64

Comment 3 Andrea Perotti 2020-05-27 17:45:05 UTC
Created attachment 1692775 [details]
Man changes proposal

Comment 4 Andrea Perotti 2020-05-27 21:45:35 UTC
Created attachment 1692874 [details]
man ssh_config.5 changes

Comment 5 Andrea Perotti 2020-05-27 21:46:00 UTC
Created attachment 1692875 [details]
man sshd_config.5 changes

Comment 7 Jakub Jelen 2020-05-28 07:26:33 UTC
The proposed changes to man pages look good to me. But it is very unlikely we would be doing the openssh errata for this in RHEL 6 so if there is a chance to get it fixed through manual page override, it would be preferable (though not sure what the process is here).

Comment 8 Simo Sorce 2020-05-28 12:42:28 UTC
Andrea,
would a knowledge base article be sufficient for the customer.
We really have no latitude to fix non-critical bugs in RHEL-6.

If a KB is sufficient, please close this bug and state that, if not I will need to ask you to escalate via Program Management.