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Security & Passwords by @ryancnelson

otp-challenger

Challenge users to prove identity with one-time passwords or a YubiKey press

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Source Code

OTP Identity Challenge Skill

Challenge users for fresh two-factor authentication before sensitive actions.

When to Use

Require OTP verification before:

  • Deploy commands (kubectl apply, terraform apply)
  • Financial operations (transfers, payment approvals)
  • Data access (PII exports, customer data)
  • Admin operations (user modifications, permission changes)

Scripts

verify.sh

Verify a user's OTP code and record verification state.

./verify.sh <user_id> <code>

Parameters:

  • user_id - Identifier for the user (e.g., email, username)
  • code - Either 6-digit TOTP or 44-character YubiKey OTP

Exit codes:

  • 0 - Verification successful
  • 1 - Invalid code or rate limited
  • 2 - Configuration error (missing secret, invalid format)

Output on success:

โœ… OTP verified for <user_id> (valid for 24 hours)
โœ… YubiKey verified for <user_id> (valid for 24 hours)

Output on failure:

โŒ Invalid OTP code
โŒ Too many attempts. Try again in X minutes.
โŒ Invalid code format. Expected 6-digit TOTP or 44-character YubiKey OTP.

check-status.sh

Check if a user's verification is still valid.

./check-status.sh <user_id>

Exit codes:

  • 0 - User has valid (non-expired) verification
  • 1 - User not verified or verification expired

Output:

โœ… Valid for 23 more hours
โš ๏ธ Expired 2 hours ago
โŒ Never verified

generate-secret.sh

Generate a new TOTP secret with QR code (requires qrencode to be installed).

./generate-secret.sh <account_name>

Usage Pattern

#!/bin/bash
source ../otp/verify.sh

if ! verify_otp "$USER_ID" "$OTP_CODE"; then
  echo "๐Ÿ”’ This action requires OTP verification"
  exit 1
fi

# Proceed with sensitive action

Configuration

Required for TOTP:

  • OTP_SECRET - Base32 TOTP secret

Required for YubiKey:

  • YUBIKEY_CLIENT_ID - Yubico API client ID
  • YUBIKEY_SECRET_KEY - Yubico API secret key (base64)

Optional:

  • OTP_INTERVAL_HOURS - Verification expiry (default: 24)
  • OTP_MAX_FAILURES - Failed attempts before rate limiting (default: 3)
  • OTP_STATE_FILE - State file path (default: memory/otp-state.json)

Configuration can be set via environment variables or in ~/.openclaw/config.yaml:

security:
  otp:
    secret: "BASE32_SECRET"
  yubikey:
    clientId: "12345"
    secretKey: "base64secret"

Code Format Detection

The script auto-detects code type:

  • 6 digits (123456) โ†’ TOTP validation
  • 44 ModHex characters (cccccc...) โ†’ YubiKey validation

ModHex alphabet: cbdefghijklnrtuv

State File

Verification state stored in memory/otp-state.json. Contains only timestamps, no secrets.

Human Documentation

See README.md for:

  • Installation instructions
  • Setup guides (TOTP and YubiKey)
  • Security considerations
  • Troubleshooting
  • Examples