Binary package “strongswan-plugin-gmp” in ubuntu trusty

strongSwan plugin for libgmp based crypto

 The strongSwan VPN suite uses the native IPsec stack in the standard
 Linux kernel. It supports both the IKEv1 and IKEv2 protocols.
 .
 This package provides the crypto backend based on libgmp, which provides a
 RSA/DH plugin for strongSwan.