module angel.utils.cryptography.cryptography;

// Internal imports
import angel.utils.logging;
import angel.utils.cryptography.curve25519;
// External imports
import std.stdio;
import std.random;
import std.format;

class Cryptography {
    public {
        struct KeyPair {
            ubyte[32] clientSecretKey;
            ubyte[32] sharedSecret;
        }
    }

    public static KeyPair derive_25519(ubyte[] pk) {
        ubyte[32] sk; // generate client secret key
        for (int i = 0; i < 32; ++i) {
            sk[i] = cast(ubyte)(uniform(0, 256));
        }

        Logger.log(LogLevel.Debug, "Generated client sk");

        ubyte[32] ss = curve25519_scalarmult(sk, pk); // derive shared secret out of pk and sk

        Logger.log(LogLevel.Debug, format("Derived shared secret: %s", ss));

        return KeyPair(sk, ss);
    }
}