1--- 2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3SPDX-License-Identifier: curl 4Long: curves 5Arg: <list> 6Help: (EC) TLS key exchange algorithms to request 7Protocols: TLS 8Added: 7.73.0 9Category: tls 10Multi: single 11See-also: 12 - ciphers 13Example: 14 - --curves X25519 $URL 15--- 16 17# `--curves` 18 19Set specific curves to use during SSL session establishment according to RFC 208422, 5.1. Multiple algorithms can be provided by separating them with `:` 21(e.g. `X25519:P-521`). The parameter is available identically in the OpenSSL 22`s_client` and `s_server` utilities. 23 24--curves allows a OpenSSL powered curl to make SSL-connections with exactly 25the (EC) curve requested by the client, avoiding nontransparent client/server 26negotiations. 27 28If this option is set, the default curves list built into OpenSSL are ignored. 29
