It's for aarch64, for x64, change path $libssl/usr/include/aarch64-linux-gnu accordingly.
The most annoying part is the old libssl dependence.

#!/bin/bash

libssl=libssl-dev_1.0.2g-1ubuntu15_arm64
wget http://launchpadlibrarian.net/348439221/$libssl.deb
dpkg -x $libssl.deb $libssl
ln -svrf $libssl/usr/include/aarch64-linux-gnu/openssl/*  $libssl/usr/include/openssl/

export OPENSSL_INCLUDE_PATH=$libssl/usr/include
export OPENSSL_LIB_PATH=$libssl/usr/lib/aarch64-linux-gnu
make -f verium/src/makefile.unix

The binary built can run without $libssl/ path.