aead / chacha20poly1305 Goto Github PK

I'm looking to use the XChaCha20Poly1305, but the official library for Golang doesn't supports it. I take a time looking the code and it brings me a question. I don't know if here is the right place for that, but I will ask here because I don't find a better room for that.

The crypto/subtle have a function ConstantTimeCopy, but I don't find any library using it. Only the PKCS1v15.

In the ChaCha20Poly1305, in this line have a simple copy, copying the key. If the ConstantTimeCopy is used will have some benefit? If not, where should the ConstantTimeCopy be used?

This makes it not work with io.Copy

https://github.com/aead/chacha20poly1305/blob/master/writer.go#L106