| /* 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 |
