---

name: otp-challenger version: 1.0.3 description: Enable agents and skills to challenge users for fresh two-factor authentication proof (TOTP or YubiKey) before executing sensitive actions. Use this for identity verification in approval workflows - deploy commands, financial operations, data access, admin operations, and change control. metadata: {"openclaw": {"emoji": "🔐", "homepage": "https://github.com/ryancnelson/otp-challenger", "requires": {"bins": ["jq", "python3", "curl", "openssl", "base64"], "anyBins": ["oathtool", "node"]}, "envVars": {"required": [], "conditionallyRequired": [{"name": "OTP_SECRET", "condition": "TOTP mode", "description": "Base32 TOTP secret (16-128 chars)"}, {"name": "YUBIKEY_CLIENT_ID", "condition": "YubiKey mode", "description": "Yubico API client ID"}, {"name": "YUBIKEY_SECRET_KEY", "condition": "YubiKey mode", "description": "Yubico API secret key (base64)"}], "optional": [{"name": "OTP_INTERVAL_HOURS", "default": "24", "description": "Verification validity period"}, {"name": "OTP_MAX_FAILURES", "default": "3", "description": "Failed attempts before rate limiting"}, {"name": "OTP_FAILURE_HOOK", "description": "Script to execute on verification failures (privileged - runs arbitrary commands)"}]}, "privilegedFeatures": ["OTP_FAILURE_HOOK can execute arbitrary shell commands on failure events"], "install": [{"id": "jq", "kind": "brew", "formula": "jq", "bins": ["jq"], "label": "Install jq via Homebrew", "os": ["darwin", "linux"]}, {"id": "python3", "kind": "brew", "formula": "python3", "bins": ["python3"], "label": "Install Python 3 via Homebrew", "os": ["darwin", "linux"]}, {"id": "oathtool", "kind": "brew", "formula": "oath-toolkit", "bins": ["oathtool"], "label": "Install OATH Toolkit via Homebrew", "os": ["darwin", "linux"]}]}}

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:

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

Output on failure:

❌ Invalid OTP code
❌ Too many attempts. Try again in X minutes.
❌ 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:

✅ Valid for 23 more hours
⚠️ Expired 2 hours ago
❌ 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 "🔒 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) → TOTP validation
• 44 ModHex characters (cccccc...) → 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