test.c

  errf("opening");                                                                                  
  FILE *f = fopen("test", "rb");
  fread(ctx->udp_buf + SHADOWVPN_PACKET_OFFSET, 1, 1024, f);

  if (-1 == crypto_decrypt(ctx->tun_buf, ctx->udp_buf, 1000)) {
    errf("failure");
  } else {
    errf("success");
  }

test.swift

        SVCrypto.setPassword("BLANKWONDER")
        let c = NSData(contentsOfFile: NSBundle.mainBundle().pathForResource("test", ofType: "bin")!)
        print(SVCrypto.decrypt(c))