Yubico Forum

I am interested in writing a mainframe validation server to enhance application security. I can't seem to find a good spec for decrypting a OTP for verification. The verification would be written in a combination of SQL, RPG and API's that perform encryption/decryption. Where can i find the methods for decryption of the OTP? I understand the first 12 bytes for use in registering the user assigned a key. It's the rest of the deconstruction I am looking for assistance in. Would rather implement a YUBIKEY than say, the GOOGLE authenticator. Thanks!

thanks Tom, I had seen those items but was still lacking the origination of generating a key i could match against. Short of the first bytes that identify a key i dont see how i can create one that is a match of hashes. not that that is the only way of verification