Skip to content

Extend --static-challenge to support concat mode like OpenVPN #428

@VtoRman

Description

@VtoRman

OpenVPN 2.x recently added support for extending the --static-challenge option with a third argument (scrv1 or concat) to specify whether the password and response should be concatenated or use the SCRV1 protocol (default: scrv1).

This allows simpler handling of password+response in some server-side scripts/plugins that expect plain concatenation instead of the SCRV1-formatted string.

OpenVPN3 currently supports --static-challenge with only two arguments (challenge text and echo flag), but lacks this third argument for format selection.

OpenVPN/openvpn@6f6a0f3
https://gerrit.openvpn.net/c/openvpn/+/665
https://patchwork.openvpn.net/project/openvpn2/patch/20240719131407.75746-1-frank@lichtenheld.com/#6530
OpenVPN/openvpn-gui#663

Example Usage

--static-challenge "Enter OTP:" 0 concat

This would prompt for the challenge response without echo and concatenate it directly with the password.

Why Needed

  • Compatibility with servers expecting concatenation behavior.
  • Parity with upstream OpenVPN features for easier migration.

Metadata

Metadata

Assignees

No one assigned

    Projects

    No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions