mbedtls_chacha20_free() function

The ChaCha20 context to clear. This may be \c NULL, in which case this function is a no-op. If it is not \c NULL, it must point to an initialized context.

This function encrypts or decrypts data. Since ChaCha20 is a stream cipher, the same operation is used for encrypting and decrypting data.

This function initializes the specified ChaCha20 context. It must be the first API called before using the context. It is usually followed by calls to \c mbedtls_chacha20_setkey() and \c mbedtls_chacha20_starts(), then one or more calls to to \c mbedtls_chacha20_update(), and finally to \c mbedtls_chacha20_free().

This function sets the encryption/decryption key.

This function sets the nonce and initial counter value. \warning You must never use the same nonce twice with the same key. This would void any confidentiality guarantees for the messages encrypted with the same nonce and key.