stuff from the official site does not compile on debian buster, since it uses OpenSSL 0.9.
main changes are in commits 04dd437c15ad46eff10afbdf2de414d4dc91948b and e3df127638a0b99f0d7e1f166a32596f2e4145ac
mkdir build
cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
make -j $(nproc)
make install
# or into a directory
make install DESTDIR=shrewvpn
# or automated
./install-debian.sh
# ./install-arch.sh
sudo cp /usr/local/etc/iked.conf.sample /usr/local/etc/iked.conf
sudo iked
ii : created ike socket 0.0.0.0:500
ii : created natt socket 0.0.0.0:4500
## : IKE Daemon, ver 2.2.1
## : Copyright 2013 Shrew Soft Inc.
## : This product linked OpenSSL 1.1.1g 21 Apr 2020
ikec --help
ii : ## : VPN Connect, ver 2.2.1
## : Copyright 2013 Shrew Soft Inc.
## : press the <h> key for help
!! : invalid parameters specified ...
>> : ikec -r "name" [ -u <user> ][ -p <pass> ][ -a ]
-r site configuration path
-u connection user name
-p connection user password
-a auto connect