Replace backspace code on client side from 0x7F by 0x08 #715
Conversation
Some proprietary SSH servers use default code for backpace as 0x08 (^H) if ssh client does not provide option ERASE option. Putty has option to specify code of backspace but OpenSSH hasn't. One solution is to replace 0x7F (^?) by 0x08(^H) on client side.
|
/AzurePipelines run |
|
Azure Pipelines successfully started running 1 pipeline(s). |
There was a problem hiding this comment.
Thank you for the contribution, @kor44!
Could you elaborate on which proprietary SSH servers demonstrate this behavior?
This creates a slight change in behavior, as it erases the entire word, as opposed to erasing per character.
i.e. if I type "this is a test" within the ssh session, then I hit the backspace key 7 times, the entire line is erased.
Currently, hitting the backspace key 7 times would only erase " a test"
Therefore, I'd like to see if this could be made optional.
Also, I suggest creating a working branch off of latestw_all, as it's hard to build/test an outdated branch.
|
I have synced my branch but it's very strange that not used latest from the beginning. I made tests with different OpenSSH server versions (OpenSSH_8.4, OpenSSH_8.0 linux) type "this is a test" and backspace works as expected (delete single symbol) even when set console locate as UTF-8 |
|
@kor44, ah ok - I tested with the latest Win32-OpenSSH (version 9.5) as the server & client (with the proposed change). My primary concern is the behavior on the latest versions for Windows/Linux. |
|
Should I make some actions to merge this pull request? |
No, the PR needs to be approved before it can be merged. I'm still concerned about the behavior change with the latest OpenSSH server versions (9.5 for Windows, and 9.7 for Linux (as of today))
Please test with the latest OpenSSH server versions mentioned above. |
I have only access to Linux (OpenSSH_9.6p1, OpenSSL 3.2.1 30 Jan 2024) |
PR Summary
Replace backspace code from Control-? to Control-H
PR Context
Some proprietary SSH servers use Control-H (ASCII code 8) as default code for backpace if ssh client does not provide ERASE option. OpenSSH does not support to set this option as Putty. I have modified input processing on client side to replace Control-? (ASCII code 127) by Control-H (ASCII code 8).
There is pull request Handle backspace (Control+?) in no-pty session which add support processing Control-? on server side of OpenSSH