Bug 2040770

This bug was initially created as a copy of Bug #2035049

I am copying this bug because: 
generic templates in lorax should also be updated with this change.


Description of problem:
The 'scp' utility has been using SFTP protocol by default since OpenSSH 8.7. However, the sshd configuration in Anaconda environment hasn't reflected this situation and doesn't have the SFTP transfers enabled.

This leads to the necessity to add -O option when using scp to transfer files from/to the installation environment (with the 'inst.sshd' kernel command line option), otherwise the user gets an error from scp:

...
subsystem request failed on channel 0
Connection closed

This could potentailly lead to user confusion (the scp error is not very descriptive in relation to what the root cause is), so it would be worth to fix the Anaconda's sshd configuration. Just experimentally adding the following option to /etc/ssh/sshd_config.anaconda fixed the issue for me:

Subsystem sftp internal-sftp


Version-Release number of selected component (if applicable):
lorax-templates-rhel-9.0-28.el9

How reproducible:
100%

Steps to Reproduce:
1. Boot into installation environment with 'inst.sshd' on kernel command line
2. Switch into console
3. Transfer some file connecting to the local sshd instance using scp from OpenSSH >= 8.7 (it's OK to do just a transfer to/from localhost):

touch somefile
scp somefile localhost:/tmp


Actual results:
File transfer fails with 'subsystem request failed on channel 0' error.

Expected results:
File transfer is successful.

Additional info:
A workaround is to use -O option for the scp utility to fallback to SCP protocol.