initial nDPId UDP crypto [WiP!]

Signed-off-by: Toni Uhlig <matzeton@googlemail.com>

scripts/gen_keypair.sh

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+printf 'usage: %s [out-pem-private-key-file] [out-pem-public-key-file]\n' "${0}"
+
+if [ -z "${1}" ]; then
+    PRIV_KEY="./nDPId-x25519-priv.pem"
+else
+    PRIV_KEY="${1}"
+fi
+
+if [ -z "${2}" ]; then
+    PUB_KEY="./nDPId-x25519-pub.pem"
+else
+    PUB_KEY="${2}"
+fi
+
+printf 'Private Key: %s\n' "${PRIV_KEY}"
+printf 'Public Key.: %s\n' "${PUB_KEY}"
+
+openssl genpkey -algorithm x25519 -out "${PRIV_KEY}"
+openssl pkey -in "${PRIV_KEY}" -outform PEM -pubout -out "${PUB_KEY}"