As specified in the documentation for IO::Socket::SSL:

my $socket = IO::Socket::SSL->new (
  PeerAddr => 'some.server.com',
  PeerPort => 443,
  SSL_cipher_list => 'ECDH+AES128:ECDH+AESGCM:ECDH+AES256:DH+AES:DH+AE
+SGCM:DH+AES256:RSA+AES:RSA+AESGCM:!aNULL:!RC4:!MD5:!DSS:!3DES:!SSLv3'
+,
  # ... more options here
);
[download]