encrypt_to_decrypt
encrypt_to_decrypt(&dctx->encrypt_expkey[DES_EXPKEY_WORDS / 2], &k2[0]);
encrypt_to_decrypt(&dctx->decrypt_expkey[0], &k3[0]);
encrypt_to_decrypt(&dctx->decrypt_expkey[(DES_EXPKEY_WORDS / 2) * 2],
encrypt_to_decrypt(&dctx->decrypt_expkey[0], &dctx->encrypt_expkey[0]);