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Diffstat (limited to 'utils/lib/randutils.c')
| -rw-r--r-- | utils/lib/randutils.c | 238 |
1 files changed, 0 insertions, 238 deletions
diff --git a/utils/lib/randutils.c b/utils/lib/randutils.c deleted file mode 100644 index bd2a8f6..0000000 --- a/utils/lib/randutils.c +++ /dev/null @@ -1,238 +0,0 @@ -/* - * SPDX-License-Identifier: BSD-3-Clause - * - * General purpose random utilities. Based on libuuid code. - * - * This code is free software; you can redistribute it and/or modify it under - * the terms of the Modified BSD License. The complete text of the license is - * available in the Documentation/licenses/COPYING.BSD-3-Clause file. - */ -#include <stdio.h> -#include <unistd.h> -#include <fcntl.h> -#include <stdlib.h> -#include <string.h> -#include <sys/time.h> - -#include <sys/syscall.h> - -#include "c.h" -#include "randutils.h" -#include "nls.h" - -#ifdef HAVE_TLS -#define THREAD_LOCAL static __thread -#else -#define THREAD_LOCAL static -#endif - -#ifdef HAVE_GETRANDOM -# include <sys/random.h> -#elif defined (__linux__) -# if !defined(SYS_getrandom) && defined(__NR_getrandom) - /* usable kernel-headers, but old glibc-headers */ -# define SYS_getrandom __NR_getrandom -# endif -#endif - -#if !defined(HAVE_GETRANDOM) && defined(SYS_getrandom) -/* libc without function, but we have syscal */ -#define GRND_NONBLOCK 0x01 -#define GRND_RANDOM 0x02 -static int getrandom(void *buf, size_t buflen, unsigned int flags) -{ - return (syscall(SYS_getrandom, buf, buflen, flags)); -} -# define HAVE_GETRANDOM -#endif - -#if defined(__linux__) && defined(__NR_gettid) && defined(HAVE_JRAND48) -#define DO_JRAND_MIX -THREAD_LOCAL unsigned short ul_jrand_seed[3]; -#endif - -int rand_get_number(int low_n, int high_n) -{ - return rand() % (high_n - low_n + 1) + low_n; -} - -static void crank_random(void) -{ - int i; - struct timeval tv; - unsigned int n_pid, n_uid; - - gettimeofday(&tv, NULL); - n_pid = getpid(); - n_uid = getuid(); - srand((n_pid << 16) ^ n_uid ^ tv.tv_sec ^ tv.tv_usec); - -#ifdef DO_JRAND_MIX - ul_jrand_seed[0] = getpid() ^ (tv.tv_sec & 0xFFFF); - ul_jrand_seed[1] = getppid() ^ (tv.tv_usec & 0xFFFF); - ul_jrand_seed[2] = (tv.tv_sec ^ tv.tv_usec) >> 16; -#endif - /* Crank the random number generator a few times */ - gettimeofday(&tv, NULL); - for (i = (tv.tv_sec ^ tv.tv_usec) & 0x1F; i > 0; i--) - rand(); -} - -int random_get_fd(void) -{ - int i, fd; - - fd = open("/dev/urandom", O_RDONLY | O_CLOEXEC); - if (fd == -1) - fd = open("/dev/random", O_RDONLY | O_NONBLOCK | O_CLOEXEC); - if (fd >= 0) { - i = fcntl(fd, F_GETFD); - if (i >= 0) - fcntl(fd, F_SETFD, i | FD_CLOEXEC); - } - crank_random(); - return fd; -} - -/* - * Generate a stream of random nbytes into buf. - * Use /dev/urandom if possible, and if not, - * use glibc pseudo-random functions. - */ -#define UL_RAND_READ_ATTEMPTS 8 -#define UL_RAND_READ_DELAY 125000 /* microseconds */ - -void random_get_bytes(void *buf, size_t nbytes) -{ - unsigned char *cp = (unsigned char *)buf; - size_t i, n = nbytes; - int lose_counter = 0; - -#ifdef HAVE_GETRANDOM - while (n > 0) { - int x; - - errno = 0; - x = getrandom(cp, n, GRND_NONBLOCK); - if (x > 0) { /* success */ - n -= x; - cp += x; - lose_counter = 0; - - } else if (errno == ENOSYS) { /* kernel without getrandom() */ - break; - - } else if (errno == EAGAIN && lose_counter < UL_RAND_READ_ATTEMPTS) { - xusleep(UL_RAND_READ_DELAY); /* no entropy, wait and try again */ - lose_counter++; - } else - break; - } - - if (errno == ENOSYS) -#endif - /* - * We've been built against headers that support getrandom, but the - * running kernel does not. Fallback to reading from /dev/{u,}random - * as before - */ - { - int fd = random_get_fd(); - - lose_counter = 0; - if (fd >= 0) { - while (n > 0) { - ssize_t x = read(fd, cp, n); - if (x <= 0) { - if (lose_counter++ > UL_RAND_READ_ATTEMPTS) - break; - xusleep(UL_RAND_READ_DELAY); - continue; - } - n -= x; - cp += x; - lose_counter = 0; - } - - close(fd); - } - } - /* - * We do this all the time, but this is the only source of - * randomness if /dev/random/urandom is out to lunch. - */ - crank_random(); - for (cp = buf, i = 0; i < nbytes; i++) - *cp++ ^= (rand() >> 7) & 0xFF; - -#ifdef DO_JRAND_MIX - { - unsigned short tmp_seed[3]; - - memcpy(tmp_seed, ul_jrand_seed, sizeof(tmp_seed)); - ul_jrand_seed[2] = ul_jrand_seed[2] ^ syscall(__NR_gettid); - for (cp = buf, i = 0; i < nbytes; i++) - *cp++ ^= (jrand48(tmp_seed) >> 7) & 0xFF; - memcpy(ul_jrand_seed, tmp_seed, - sizeof(ul_jrand_seed)-sizeof(unsigned short)); - } -#endif -} - - -/* - * Tell source of randomness. - */ -const char *random_tell_source(void) -{ -#ifdef HAVE_GETRANDOM - return _("getrandom() function"); -#else - size_t i; - static const char *random_sources[] = { - "/dev/urandom", - "/dev/random" - }; - - for (i = 0; i < ARRAY_SIZE(random_sources); i++) { - if (!access(random_sources[i], R_OK)) - return random_sources[i]; - } -#endif - return _("libc pseudo-random functions"); -} - -#ifdef TEST_PROGRAM_RANDUTILS -#include <inttypes.h> - -int main(int argc, char *argv[]) -{ - size_t i, n; - int64_t *vp, v; - char *buf; - size_t bufsz; - - n = argc == 1 ? 16 : atoi(argv[1]); - - printf("Multiple random calls:\n"); - for (i = 0; i < n; i++) { - random_get_bytes(&v, sizeof(v)); - printf("#%02zu: %25"PRIu64"\n", i, v); - } - - - printf("One random call:\n"); - bufsz = n * sizeof(*vp); - buf = malloc(bufsz); - if (!buf) - err(EXIT_FAILURE, "failed to allocate buffer"); - - random_get_bytes(buf, bufsz); - for (i = 0; i < n; i++) { - vp = (int64_t *) (buf + (i * sizeof(*vp))); - printf("#%02zu: %25"PRIu64"\n", i, *vp); - } - - return EXIT_SUCCESS; -} -#endif /* TEST_PROGRAM_RANDUTILS */ |