cipher Directory Reference

Files
	aes256ctr.cpp
	AES-256-CTR implementation (stateless, see aes256ctr.h).
	aes256ctr.h
	AES-256-CTR stream cipher (aes256-ctr, RFC 4344 §4) - stateless one-shot API.
	aes_block.h
	Compact table-free software AES key schedule + single-block encrypt (FIPS 197) - one source of truth.
	aes_sbox.h
	The AES forward S-box (FIPS 197 Figure 7) - one shared copy.
	chacha20.cpp
	ChaCha20 (RFC 8439) - implementation. See pc_chacha20.h.
	chacha20.h
	ChaCha20 stream cipher (D. J. Bernstein; RFC 8439).