--sigalgs

Set specific signature algorithms to use during SSL session establishment according to RFC 5246, 7.4.1.4.1.

An algorithm can use either a signature algorithm and a hash algorithm pair separated by a + (e.g. ECDSA+SHA224), or its TLS 1.3 signature scheme name (e.g. ed25519).

Multiple algorithms can be provided by separating them with : (e.g. DSA+SHA256:rsa_pss_pss_sha256). The parameter is available as -sigalgs in the OpenSSL s_client and s_server utilities.

--sigalgs allows a OpenSSL powered curl to make SSL-connections with exactly the signature algorithms requested by the client, avoiding nontransparent client/server negotiations.

If this option is set, the default signature algorithm list built into OpenSSL are ignored.