dca_3desfinal
error = dca_3desfinal(ctx, ciphertext, DR_ENCRYPT);
error = dca_3desfinal(ctx, ciphertext, DR_ENCRYPT | DR_TRIPLE);
error = dca_3desfinal(ctx, plaintext, DR_DECRYPT);
error = dca_3desfinal(ctx, plaintext, DR_DECRYPT | DR_TRIPLE);
int dca_3desfinal(crypto_ctx_t *, crypto_data_t *, int);