The support of a new SASL mechanism called "ecdsa-nist256p-challenge" has been added three weeks ago.
This new mechanism uses a challenge with public/private key, so no password is required to connect.

Instructions to configure and use this mechanism are in user's guide: https://weechat.org/doc/devel/user/en/#irc_sasl_authentication.

Important notes:

• GnuTLS ≥ 3.0.21 is required.
• This mechanism can only be used on servers supporting it (for example servers using atheme, like freenode).