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