Issue with SSH Login Using ed25519-SK Key on YubiKey Bio

When logging in via SSH using an ed25519-SK key tied to a YubiKey Bio (fingerprint authentication), the process introduces an unnecessary and persistent text input field.

Expected Behavior

1. The user initiates SSH authentication.

2. The terminal prompts: Confirm user presence for key ED25519-SK SHA256:[HASH]

3. Once the user confirms via fingerprint, the terminal responds: User presence confirmed

4. The login completes successfully.

Observed Issue

When using the same key, this time predefined in ~/.ssh/config (for convenience), the authentication flow is similar, but different:

1. Upon SSH login through the Remote-SSH extension, a text input field appears instead of the usual fingerprint prompt of SSH.

   • The presence of this field suggests something is listening, but authentication can proceed without interacting with it (except to dismiss it).

2. If the user confirms fingerprint authentication without interacting with the text field, the server successfully authenticates the session, but the input field remains open and non-functional.

3. If authentication fails or times out:

   • The system prompts for the key’s PIN.

   • After entering the PIN, it requests fingerprint authentication again.

   • The text input field remains visible and unresponsive, even after successful authentication and PIN verification.

Impact

• The lingering input field serves no function and does not close automatically, leading to confusion.

• Unless manually dismissed (e.g., by pressing Esc), it obstructs normal interaction.

Suggested Resolution

The SSH authentication flow should either:

• The SSH authentication flow should not display a text input field unless user action (e.g., PIN authentication) is required.

• Automatically dismiss the text input once authentication succeeds.

Start by reproducing the Remote-SSH login flow with an ed25519-SK key configured in ~/.ssh/config and a YubiKey Bio. Compare successful and failed or timed-out authentication, and consider the issue done when the text input is not shown unnecessarily or is dismissed after authentication completes.