Why use selector/token pair for password reset?

[Luisparf]

First of all, great library!

I'm building an application and I must document the database. So, I would like to know: why use a selector/token pair instead of just 1 token?

thanks a lot!

[ocram]

Thanks!

It’s split into two parts to protect against timing attacks. But it’s really just one pair with one meaning.

Actually, the two parts could even be joined together and be represented as just one piece for a developer using this library, and only be split again internally by this library.