mbedtls_chachapoly_init() function

This function initializes the specified ChaCha20-Poly1305 context. It must be the first API called before using the context. It must be followed by a call to \c mbedtls_chachapoly_setkey() before any operation can be done, and to \c mbedtls_chachapoly_free() once all operations with that context have been finished. In order to encrypt or decrypt full messages at once, for each message you should make a single call to \c mbedtls_chachapoly_crypt_and_tag() or \c mbedtls_chachapoly_auth_decrypt(). In order to encrypt messages piecewise, for each message you should make a call to \c mbedtls_chachapoly_starts(), then 0 or more calls to \c mbedtls_chachapoly_update_aad(), then 0 or more calls to \c mbedtls_chachapoly_update(), then one call to \c mbedtls_chachapoly_finish(). \warning Decryption with the piecewise API is discouraged! Always use \c mbedtls_chachapoly_auth_decrypt() when possible! If however this is not possible because the data is too large to fit in memory, you need to: - call \c mbedtls_chachapoly_starts() and (if needed) \c mbedtls_chachapoly_update_aad() as above, - call \c mbedtls_chachapoly_update() multiple times and ensure its output (the plaintext) is NOT used in any other way than placing it in temporary storage at this point, - call \c mbedtls_chachapoly_finish() to compute the authentication tag and compared it in constant time to the tag received with the ciphertext. If the tags are not equal, you must immediately discard all previous outputs of \c mbedtls_chachapoly_update(), otherwise you can now safely use the plaintext.

Found 8 other functions taking a mbedtls_chachapoly_context argument: