/* Copyright (c) 2014, Google Inc. * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #ifndef OPENSSL_HEADER_CHACHA_H #define OPENSSL_HEADER_CHACHA_H #include <openssl/base.h> #if defined(__cplusplus) extern "C" { #endif // ChaCha20. // // ChaCha20 is a stream cipher. See https://tools.ietf.org/html/rfc8439. // CRYPTO_chacha_20 encrypts |in_len| bytes from |in| with the given key and // nonce and writes the result to |out|. If |in| and |out| alias, they must be // equal. The initial block counter is specified by |counter|. // // This function implements a 32-bit block counter as in RFC 8439. On overflow, // the counter wraps. Reusing a key, nonce, and block counter combination is not // secure, so wrapping is usually a bug in the caller. While it is possible to // wrap without reuse with a large initial block counter, this is not // recommended and may not be portable to other ChaCha20 implementations. OPENSSL_EXPORT void CRYPTO_chacha_20(uint8_t *out, const uint8_t *in, size_t in_len, const uint8_t key[32], const uint8_t nonce[12], uint32_t counter); #if defined(__cplusplus) } // extern C #endif #endif // OPENSSL_HEADER_CHACHA_H