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Diffstat (limited to 'stdlib/arc4random.h')
-rw-r--r-- | stdlib/arc4random.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/stdlib/arc4random.h b/stdlib/arc4random.h new file mode 100644 index 0000000000..cd39389c19 --- /dev/null +++ b/stdlib/arc4random.h @@ -0,0 +1,48 @@ +/* Arc4random definition used on TLS. + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef _CHACHA20_H +#define _CHACHA20_H + +#include <stddef.h> +#include <stdint.h> + +/* Internal ChaCha20 state. */ +#define CHACHA20_STATE_LEN 16 +#define CHACHA20_BLOCK_SIZE 64 + +/* Maximum number bytes until reseed (16 MB). */ +#define CHACHA20_RESEED_SIZE (16 * 1024 * 1024) + +/* Internal arc4random buffer, used on each feedback step so offer some + backtracking protection and to allow better used of vectorized + chacha20 implementations. */ +#define CHACHA20_BUFSIZE (8 * CHACHA20_BLOCK_SIZE) + +_Static_assert (CHACHA20_BUFSIZE >= CHACHA20_BLOCK_SIZE + CHACHA20_BLOCK_SIZE, + "CHACHA20_BUFSIZE < CHACHA20_BLOCK_SIZE + CHACHA20_BLOCK_SIZE"); + +struct arc4random_state_t +{ + uint32_t ctx[CHACHA20_STATE_LEN]; + size_t have; + size_t count; + uint8_t buf[CHACHA20_BUFSIZE]; +}; + +#endif |