diff options
Diffstat (limited to 'util/nvmutil/lib/num.c')
| -rw-r--r-- | util/nvmutil/lib/num.c | 349 |
1 files changed, 0 insertions, 349 deletions
diff --git a/util/nvmutil/lib/num.c b/util/nvmutil/lib/num.c deleted file mode 100644 index bbb5a83e..00000000 --- a/util/nvmutil/lib/num.c +++ /dev/null @@ -1,349 +0,0 @@ -/* SPDX-License-Identifier: MIT - * Copyright (c) 2026 Leah Rowe <leah@libreboot.org> - * - * Numerical functions. - */ - -#ifdef __OpenBSD__ -#include <sys/param.h> -#endif -#include <sys/types.h> -#if defined(FALLBACK_RAND_1989) && \ - (FALLBACK_RAND_1989) > 0 -#include <sys/time.h> -#endif - -#include <errno.h> -#if !((defined(__OpenBSD__) && (OpenBSD) >= 201) || \ - defined(__FreeBSD__) || \ - defined(__NetBSD__) || defined(__APPLE__)) -#include <fcntl.h> /* if not arc4random: /dev/urandom */ -#endif -#include <limits.h> -#include <stddef.h> -#include <string.h> -#if defined(FALLBACK_RAND_1989) && \ - (FALLBACK_RAND_1989) > 0 -#include <time.h> -#endif -#include <unistd.h> - -#include "../include/common.h" - -unsigned short -hextonum(char ch_s) -{ - unsigned char ch; - - ch = (unsigned char)ch_s; - - if ((unsigned int)(ch - '0') <= 9) - return ch - '0'; - - ch |= 0x20; - - if ((unsigned int)(ch - 'a') <= 5) - return ch - 'a' + 10; - - if (ch == '?' || ch == 'x') - return (unsigned short)rlong() & 0xf; - - return 16; /* invalid character */ -} - -/* Random numbers - */ - -unsigned long -rlong(void) -{ -#if !(defined(FALLBACK_RAND_1989) && \ - ((FALLBACK_RAND_1989) > 0)) -#if (defined(__OpenBSD__) && (OpenBSD) >= 201) || \ - defined(__FreeBSD__) || \ - defined(__NetBSD__) || defined(__APPLE__) - - unsigned long rval; - arc4random_buf(&rval, sizeof(unsigned long)); - - return rval; -#else - static int fd = -1; - static long nr = -1; - static unsigned long off = 0; -#if defined (BUFSIZ) - static char rbuf[BUFSIZ]; -#else -#ifndef PORTABLE - static char rbuf[4096]; -#elif ((PORTABLE) > 0) - static char rbuf[256]; /* scarce memory on old systems */ -#else - static char rbuf[4096]; /* typical 32-bit BUFSIZ */ -#endif -#endif - unsigned long rval; - long new_nr; - - int retries = 0; - int max_retries = 100; - -#if defined(__linux__) -#if defined(HAVE_GETRANDOM) || \ - defined(HAVE_GETRANDOM_SYSCALL) - - /* linux getrandom() - * - * we *can* use arc4random on - * modern linux, but not on - * every libc. better use the - * official linux function - * - * similar benefits to arc4random - * e.g. works in chroot, blocks - * until it has enough entropy, - * and works even when /dev/urandom - * is available (doesn't use it); - * it's generally more reliable - */ - - if (fallback_rand_getrandom(&rval, sizeof(rval)) == 0) - return rval; - - /* - * now fall back to urandom if getrandom failed: - */ -#endif -#endif - - /* reading from urandom is inherently - * unreliable on old systems, even if - * newer systems make it more reliable - * - * modern linux/bsd make it safe, but - * we have to assume that someone is - * compiling this on linux from 1999 - * - * this logic therefore applies various - * tricks to mitigate possible os bugs - */ - -retry_urandom_read: - - if (++retries > max_retries) - goto rlong_next; - - if (nr < 0 || nr < (long)sizeof(unsigned long)) { - - if (fd < 0) { - - fd = open("/dev/urandom", - O_RDONLY | O_BINARY | O_NOFOLLOW | - O_CLOEXEC); - -#ifdef USE_OLD_DEV_RANDOM -#if (USE_OLD_DEV_RANDOM) > 0 - /* WARNING: - * /dev/random may block - * forever and does **NOT** - * guarantee better entropy - * on old systems - * - * only use it if needed - */ - - if (fd < 0) - fd = open("/dev/random", - O_RDONLY | O_BINARY | O_NOFOLLOW | - O_CLOEXEC); -#endif -#endif - - if (fd < 0) - goto retry_urandom_read; - - retries = 0; - } - - new_nr = rw_file_exact(fd, (unsigned char *)rbuf, - sizeof(rbuf), 0, IO_READ, LOOP_EAGAIN, - LOOP_EINTR, MAX_ZERO_RW_RETRY, OFF_ERR); - - if (new_nr < 0 || new_nr < (long)sizeof(rbuf)) - goto retry_urandom_read; - - /* only reset buffer after successful refill */ - nr = new_nr; - off = 0; - - /* to mitigate file descriptor - * injection, we do not re-use - * the same descriptor each time - */ - (void) close_on_eintr(fd); - fd = -1; - } - - fd = -1; - retries = 0; - - memcpy(&rval, rbuf + off, sizeof(unsigned long)); - - nr -= (long)sizeof(unsigned long); - off += sizeof(unsigned long); - - return rval; - -rlong_next: - - fd = -1; - off = 0; - nr = -1; - - err(EIO, "Can't read from /dev/[ua]random"); - return 0; - -#endif -#else /* FALLBACK_RAND_1989 */ - /* your computer is from a museum - */ - unsigned long mix = 0; - int nr; - - /* 100 times, for entropy - */ - for (nr = 0; nr < 100; nr++) - mix ^= fallback_rand_1989(); - - /* 101 times ;) - */ - return fallback_rand_1989(); -#endif -} - -#if !(defined(FALLBACK_RAND_1989) && \ - ((FALLBACK_RAND_1989) > 0)) -#if defined(__linux__) -#if defined(HAVE_GETRANDOM) || \ - defined(HAVE_GETRANDOM_SYSCALL) -int -fallback_rand_getrandom(void *buf, unsigned long len) -{ - unsigned long off = 0; - long rval = -1; - - if (!len) - return -1; - - if (buf == NULL) - return -1; - -#if defined(HAVE_GETRANDOM) || \ - defined(HAVE_GETRANDOM_SYSCALL) - - while (off < len) { - -#if defined(HAVE_GETRANDOM) - rval = (long)getrandom((char *)buf + off, len - off, 0); -#elif defined(HAVE_GETRANDOM_SYSCALL) - rval = (long)syscall(SYS_getrandom, - (char *)buf + off, len - off, 0); -#endif - - if (rval < 0) { - if (errno == EINTR) - continue; - - return -1; /* unsupported by kernel */ - } - - off += (unsigned long)rval; - } - - return 0; - -#else - (void)buf; - (void)len; - - return -1; -#endif -} -#endif -#endif -#else -/* nobody should use this - * (not crypto-safe) - */ -unsigned long -fallback_rand_1989(void) -{ - static unsigned long mix = 0; - static unsigned long counter = 0; - - struct timeval tv; - - gettimeofday(&tv, NULL); - - mix ^= (unsigned long)tv.tv_sec - ^ (unsigned long)tv.tv_usec - ^ (unsigned long)getpid() - ^ (unsigned long)&mix - ^ counter++ - ^ entropy_jitter(); - - /* - * Stack addresses can vary between - * calls, thus increasing entropy. - */ - mix ^= (unsigned long)&mix; - mix ^= (unsigned long)&tv; - mix ^= (unsigned long)&counter; - - return mix; -} - -unsigned long -entropy_jitter(void) -{ - unsigned long mix; - - struct timeval a, b; - long mix_diff; - - int c; - - mix = 0; - - gettimeofday(&a, NULL); - - for (c = 0; c < 32; c++) { - - getpid(); - gettimeofday(&b, NULL); - - /* - * prevent negative numbers to prevent overflow, - * which would bias rand to large numbers - */ - mix_diff = (long)(b.tv_usec - a.tv_usec); - if (mix_diff < 0) - mix_diff = -mix_diff; - - mix ^= (unsigned long)(mix_diff); - - mix ^= (unsigned long)&mix; - - } - - return mix; -} -#endif - -void -check_bin(unsigned long a, const char *a_name) -{ - if (a > 1) - err(EINVAL, "%s must be 0 or 1, but is %lu", - a_name, (unsigned long)a); -} |