Welcome to Yubico tech community.

I've written a rubygem that decodes, decrypts, and parses Yubikey OTPs.

Install it by running

The source is available at http://github.com/titanous/yubikey

The gem wraps the C library for ModHex decoding, AES decryption, and CRC verification.

Let me know if you have questions.

I went to https://upgrade.yubico.com/getapikey/ and generated a secret key. This key looks like AES because it ends with an = sign.

I tried this key when calling Yubikey::OTP.new(otp, key) and I get the following error.

Yubikey::OTP::InvalidKeyError: Key must be 32 hex characters

I then went to http://demo.yubico.com/php-yubico/Modhex_Calculator.php and tried a bunch of different combinations but the results are the same.

HELP!

Hello,

That code looks to be for decrypting OTPs, not verifying them. If you look at https://github.com/titanous/yubikey there is an example for verifying OTP with Yubikey::OTP::Verify

/klas