How do I enable chacha/poly in openssl1.1.0

Question

I was looking to enable chacha/poly algorithm in the openssl 1.1.0 version. I googled alot but couldn't get the resolution. please help me if any one knows

Answer 1

How do I enable chacha/poly in openssl1.1.0

ChaCha20/Poly1305 is enabled by default in OpenSSL 1.1.0. With all other things being equal, you will use it if its a common cipher and its selected by the client or server.

If you are not seeing ChaCha20/Poly1305 as the cipher suite, then check the server. It probably lacks support for curve25519 or the cipher suite. You should still see the cipher suite advertised in the ClientHello.

A disappointing thing about ChaCha and Poly1305 is they are only available as a unit via EVP_chacha20_poly1305 . You cannot use just ChaCha or just Poly1305. (And ChaCha is TLS's ChaCha, and not Bernstein's ChaCha).

Also see How to use Poly1305 with EVP interfaces? on the OpenSSL Users mailing list.