mbedtls_md_init() function

This function clears the internal structure of \p ctx and frees any embedded internal structure, but does not free \p ctx itself. If you have called mbedtls_md_setup() on \p ctx, you must call mbedtls_md_free() when you are no longer using the context. Calling this function if you have previously called mbedtls_md_init() and nothing else is optional. You must not call this function if you have not called mbedtls_md_init().

This function returns the message-digest information from the given context.