ngtcp2_crypto_read_write_crypto_data
====================================

Synopsis
--------

*#include <ngtcp2/ngtcp2_crypto.h>*

.. function:: int ngtcp2_crypto_read_write_crypto_data(ngtcp2_conn *conn, ngtcp2_encryption_level encryption_level, const uint8_t *data, size_t datalen)

    
    `ngtcp2_crypto_read_write_crypto_data` reads CRYPTO data *data* of
    length *datalen* in an encryption level *encryption_level*, and may
    feed outgoing CRYPTO data to *conn*.  This function can drive
    handshake.  This function can be also used after handshake
    completes.  It is allowed to call this function with *datalen* ==
    0.  In this case, no additional read operation is done.
    
    This function returns 0 if it succeeds, or a negative error code.
    The generic error code is -1 if a specific error code is not
    suitable.  The error codes less than -10000 are specific to
    underlying TLS implementation.  For quictls, the error codes are
    defined in *ngtcp2_crypto_quictls.h*.