This function performs an AES single-block encryption or decryption operation. It performs the operation defined in the \p mode parameter (encrypt or decrypt), on the input data buffer defined in the \p input parameter. mbedtls_aes_init(), and either mbedtls_aes_setkey_enc() or mbedtls_aes_setkey_dec() must be called before the first call to this API with the same context.