/ Ruby
/
method

ecdh_curves=

ecdh_curves=(p1)
public

Sets the list of “supported elliptic curves” for this context.

For a TLS client, the list is directly used in the Supported Elliptic Curves Extension. For a server, the list is used by OpenSSL to determine the set of shared curves. OpenSSL will pick the most appropriate one from it.

Note that this works differently with old OpenSSL (<= 1.0.1). Only one curve can be set, and this has no effect for TLS clients.

Example

ctx1 = OpenSSL::SSL::SSLContext.new
ctx1.ecdh_curves = "X25519:P-256:P-224"
svr = OpenSSL::SSL::SSLServer.new(tcp_svr, ctx1)
Thread.new { svr.accept }

ctx2 = OpenSSL::SSL::SSLContext.new
ctx2.ecdh_curves = "P-256"
cli = OpenSSL::SSL::SSLSocket.new(tcp_sock, ctx2)
cli.connect

p cli.tmp_key.group.curve_name
# => "prime256v1" (is an alias for NIST P-256)