diff options
Diffstat (limited to 'lib/util/arc4random_buf.c')
-rw-r--r-- | lib/util/arc4random_buf.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/lib/util/arc4random_buf.c b/lib/util/arc4random_buf.c new file mode 100644 index 0000000..c0fbe70 --- /dev/null +++ b/lib/util/arc4random_buf.c @@ -0,0 +1,70 @@ +/* + * SPDX-License-Identifier: ISC + * + * Copyright (c) 2020 Todd C. Miller <Todd.Miller@sudo.ws> + * + * Permission to use, copy, modify, and 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. + */ + +/* + * This is an open source non-commercial project. Dear PVS-Studio, please check it. + * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com + */ + +#include <config.h> + +#ifndef HAVE_ARC4RANDOM_BUF + +#include <stdlib.h> +#if defined(HAVE_STDINT_H) +# include <stdint.h> +#elif defined(HAVE_INTTYPES_H) +# include <inttypes.h> +#endif + +#include <sudo_compat.h> +#include <sudo_rand.h> + +#define minimum(a, b) ((a) < (b) ? (a) : (b)) + +/* + * Call arc4random() repeatedly to fill buf with n bytes of random data. + */ +void +sudo_arc4random_buf(void *buf, size_t n) +{ + char *cp = buf; + + while (n != 0) { + size_t m = minimum(n, 4); + uint32_t val = arc4random(); + + switch (m) { + case 4: + *cp++ = (val >> 24) & 0xff; + FALLTHROUGH; + case 3: + *cp++ = (val >> 16) & 0xff; + FALLTHROUGH; + case 2: + *cp++ = (val >> 8) & 0xff; + FALLTHROUGH; + case 1: + *cp++ = val & 0xff; + break; + } + n -= m; + } +} + +#endif /* HAVE_ARC4RANDOM_BUF */ |