Before configuring DefaultShell, ensure the following prerequisites are met

• OpenSSH installation path is in system PATH.
  • If not already present, amend system PATH and restart sshd service.

Follow these steps:

• On the server side, configure the default ssh shell in the windows registry.
  • Computer\HKEY_LOCAL_MACHINE\SOFTWARE\OpenSSH\DefaultShell - full path of the shell executable
  • Computer\HKEY_LOCAL_MACHINE\SOFTWARE\OpenSSH\DefaultShellCommandOption (optional) - switch that the configured default shell requires to execute a command, immediately exit and return to the calling process. By default this is -c.
  • Computer\HKEY_LOCAL_MACHINE\SOFTWARE\OpenSSH\DefaultShellEscapeArguments (optional) - flag that allow you to skip escaping the arguments of default shell. By default this is 0. This option is only applicable to shells other than powershell, bash, cygwin, cmd, and ssh-shellhost.exe.

Examples:

• Powershell cmdlets to set powershell bash as default shell

 New-ItemProperty -Path "HKLM:\SOFTWARE\OpenSSH" -Name DefaultShell -Value "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -PropertyType String -Force
 New-ItemProperty -Path "HKLM:\SOFTWARE\OpenSSH" -Name DefaultShellCommandOption -Value "/c" -PropertyType String -Force

• Powershell cmdlets to set custom default shell and skip escaping of argument

 New-ItemProperty -Path "HKLM:\SOFTWARE\OpenSSH" -Name DefaultShell -Value "C:\temp\GetCommandLine.exe" -PropertyType String -Force
 New-ItemProperty -Path "HKLM:\SOFTWARE\OpenSSH" -Name DefaultShellCommandOption -Value "/c" -PropertyType String -Force
 New-ItemProperty -Path "HKLM:\SOFTWARE\OpenSSH" -Name DefaultShellEscapeArguments -Value 1 -PropertyType DWORD -Force

• If you are configuring the powershell.exe/cmd.exe/WSL-bash.exe as default ssh shell, your registry should look like this.