Starting with version 4.6, wolfCrypt includes full implementations of the XChaCha stream cipher and the XChaCha20-Poly1305 AEAD. This new AEAD supports messages with 64 bit size and immense 192 bit nonces, removing all practical limitations on size and number of messages within a cryptographic session or context. It is ideal for applications such as VPN transports, particularly when a high degree of portability is paramount.
wolfCrypt can process fully authenticated sequences of AEAD messages using a simple one-shot API, via wc_XChaCha20Poly1305_Encrypt() and wc_XChaCha20Poly1305_Decrypt(), or wc_XChaCha20Poly1305_Init() can be called directly to set up the underlying cipher for incremental processing by the existing ChaCha20 and Poly1305 interfaces.
If you have any questions or run into any issues, contact us at facts@wolfssl.com, or call us at +1 425 245 8247.