PowerShell / PowerShell/Win32-OpenSSH

ssh-askpass missing with PKCS11 use

Open
#1,921 2 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
No language data
Stars
8.3k
Forks
819
PR merge metrics
No merged PRs in 30d

Description

"OpenSSH for Windows" version
8.9.1.0

Client OperatingSystem
Windows 10 Enterprise

What is failing
When leveraging certificate based authentication, I am unable to get a prompt when accessing the card. I believe this lies in the fact that there is no ssh-askpass as there is in linux. In pathnames.h line 124 I see reference to ssh-askpass with a linux pathing, but not matching line for win32.

The certificate authentication works, and agent forwarding is functional but I would like to get a prompt when accessing the card for security purposes. If I use OpenSSH with Pageant and wsl-ssh-pageant (https://github.com/benpye/wsl-ssh-pageant) I can configure it to prompt (yes/no) on card access.

Expected output
Prompt for Smart Card use, either a yes/no prompt or PIN input.

step 1
ssh-add -c -s 'C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll'
Enter passphrase for PKCS#11: ********

step2
ssh- A host.fqdn -l someuser

step 3
some sort of dialogue box with focus prompting for card use (yes/no) or PIN prompt as ssh-askpass works on Linux

Actual output
no dialogue box, forwarding of cert works. I see the private key in the slot being accessed on my yubikey by it blinking

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start at pathnames.h line 124 and trace how the Win32 build handles ssh-askpass during PKCS#11 certificate use. Reproduce the issue with the supplied ssh-add and SSH commands, then verify that card access produces a focused yes/no or PIN dialogue instead of only forwarding the certificate.

Written by the indexing model from the issue text.

Assessment

Domain
authentication, operating-systems, security
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
42/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.