* LocalIdentity:: writeTo( array ) and readFrom (array )

lib/ed25519/keypair.c

@@ -14,3 +14,10 @@ void ed25519_create_keypair(unsigned char *public_key, unsigned char *private_ke
     ge_scalarmult_base(&A, private_key);
     ge_p3_tobytes(public_key, &A);
 }
+
+void ed25519_derive_pub(unsigned char *public_key, const unsigned char *private_key) {
+    ge_p3 A;
+
+    ge_scalarmult_base(&A, private_key);
+    ge_p3_tobytes(public_key, &A);
+}