Can you identify this algorithm?
First: Analyzing code is off-topic on this site, don't expect much.

To the question: "Never write your own crypto" is a statement, that is all too often disregarded. Without digging deep, it looks like some self-made (and totally insecure) algorithm: The key is not used at all, therefore it is basically a streamcipher (one symbol at a time) with a deterministic keystream.

Recommendation: Do not use this, and don't use their crypto implementations in the future. Not every error is as easy to detect as this one. And in crypto you can do lots of things wrong.