On Mon, Mar 30, 2020 at 12:55 AM Stefano Piletti <ste@xxxxxxxxxxxx> wrote: > > > Hello, > I'm looking for a way to make openconnect server and client connect using protocol chacha20-poly1305 which happens to be faster on my setup. > I have tried to modify the tls-priorities string in this way: > "NORMAL:%SERVER_PRECEDENCE:%COMPAT:+CHACHA20-POLY1305:-RSA:-VERS-SSL3.0:-ARCFOUR-128:-VERS-TLS1.0:-VERS-TLS1.1" > > > > but the connection still make use of AES. Assuming *server* does indeed support ChaCha20/Poly1305… the ordering of ciphersuites with GnuTLS is something I don't fully understand; maybe Nikos can weigh in here. Try this to make it allow *only* ChaCha20/Poly1305 as the AEAD algorithm: gnutls-cli --list --priority "NONE:%SERVER_PRECEDENCE:+VERS-ALL:+COMP-ALL:+KX-ALL:+MAC-ALL:+CURVE-ALL:+SIGN-ALL:+CHACHA20-POLY1305" > > > environment (server and client): > > Linux debian 10 AMD64 > > Openconnect 0.12.6 I think you mean ocserv 0.12.6. The openconnect client is important here too. The client is what actually chooses the cipher. See this recently-merged change, which will allow you to experiment with ciphersuite priority overrides from the OpenConnect CLI: https://gitlab.com/openconnect/openconnect/-/merge_requests/71 -Dan _______________________________________________ openconnect-devel mailing list openconnect-devel@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/openconnect-devel