*/
/*
- * Copyright (C) 2012-2016 Eric Biggers
+ * Copyright 2012-2023 Eric Biggers
*
* This file 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
#endif
#include <errno.h>
+#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
# include <sys/types.h>
# include <sys/sysctl.h>
#endif
+#ifdef HAVE_SYS_SYSCALL_H
+# include <sys/syscall.h>
+#endif
#include <unistd.h>
#include "wimlib.h"
#include "wimlib/error.h"
#include "wimlib/timestamp.h"
#include "wimlib/util.h"
-#include "wimlib/xml.h"
/*******************
* Memory allocation
return memdup(str, strlen(str) + 1);
}
-#ifdef __WIN32__
+#ifdef _WIN32
wchar_t *
wimlib_wcsdup(const wchar_t *str)
{
wimlib_malloc_func = malloc_func ? malloc_func : malloc;
wimlib_free_func = free_func ? free_func : free;
wimlib_realloc_func = realloc_func ? realloc_func : realloc;
-
- xml_set_memory_allocator(wimlib_malloc_func, wimlib_free_func,
- wimlib_realloc_func);
return 0;
}
}
#endif
-static bool seeded = false;
+/**************************
+ * Random number generation
+ **************************/
-static void
-seed_random(void)
+#ifndef _WIN32
+/*
+ * Generate @n cryptographically secure random bytes (thread-safe)
+ *
+ * This is the UNIX version. It uses the Linux getrandom() system call if
+ * available; otherwise, it falls back to reading from /dev/urandom.
+ */
+void
+get_random_bytes(void *p, size_t n)
{
- srand(now_as_wim_timestamp());
- seeded = true;
+ if (n == 0)
+ return;
+#ifdef __NR_getrandom
+ static bool getrandom_unavailable;
+
+ if (getrandom_unavailable)
+ goto try_dev_urandom;
+ do {
+ int res = syscall(__NR_getrandom, p, n, 0);
+ if (unlikely(res < 0)) {
+ if (errno == ENOSYS) {
+ getrandom_unavailable = true;
+ goto try_dev_urandom;
+ }
+ if (errno == EINTR)
+ continue;
+ ERROR_WITH_ERRNO("getrandom() failed");
+ wimlib_assert(0);
+ res = 0;
+ }
+ p += res;
+ n -= res;
+ } while (n != 0);
+ return;
+
+try_dev_urandom:
+ ;
+#endif /* __NR_getrandom */
+ int fd = open("/dev/urandom", O_RDONLY);
+ if (fd < 0) {
+ ERROR_WITH_ERRNO("Unable to open /dev/urandom");
+ wimlib_assert(0);
+ }
+ do {
+ int res = read(fd, p, min(n, INT_MAX));
+ if (unlikely(res < 0)) {
+ if (errno == EINTR)
+ continue;
+ ERROR_WITH_ERRNO("Error reading from /dev/urandom");
+ wimlib_assert(0);
+ res = 0;
+ }
+ p += res;
+ n -= res;
+ } while (n != 0);
+ close(fd);
}
+#endif /* !_WIN32 */
-/* Fills @n characters pointed to by @p with random alphanumeric characters. */
+/*
+ * Generate @n cryptographically secure random alphanumeric characters
+ * (thread-safe)
+ *
+ * This is implemented on top of get_random_bytes(). For efficiency the calls
+ * to get_random_bytes() are batched.
+ */
void
-randomize_char_array_with_alnum(tchar *p, size_t n)
+get_random_alnum_chars(tchar *p, size_t n)
{
- if (!seeded)
- seed_random();
- while (n--) {
- int r = rand() % 62;
- if (r < 26)
- *p++ = r + 'a';
- else if (r < 52)
- *p++ = r - 26 + 'A';
+ u32 r[64];
+ int r_idx = 0;
+ int r_end = 0;
+
+ for (; n != 0; p++, n--) {
+ tchar x;
+
+ if (r_idx >= r_end) {
+ r_idx = 0;
+ r_end = min(n, ARRAY_LEN(r));
+ get_random_bytes(r, r_end * sizeof(r[0]));
+ }
+
+ STATIC_ASSERT(sizeof(r[0]) == sizeof(u32));
+ while (unlikely(r[r_idx] >= UINT32_MAX - (UINT32_MAX % 62)))
+ get_random_bytes(&r[r_idx], sizeof(r[0]));
+
+ x = r[r_idx++] % 62;
+
+ if (x < 26)
+ *p = 'a' + x;
+ else if (x < 52)
+ *p = 'A' + x - 26;
else
- *p++ = r - 52 + '0';
+ *p = '0' + x - 52;
}
}
-/* Fills @n bytes pointer to by @p with random numbers. */
-void
-randomize_byte_array(u8 *p, size_t n)
-{
- if (!seeded)
- seed_random();
- while (n--)
- *p++ = rand();
-}
+/************************
+ * System information
+ ************************/
-#ifndef __WIN32__
+#ifndef _WIN32
unsigned
get_available_cpus(void)
{
}
return n;
}
-#endif /* !__WIN32__ */
+#endif /* !_WIN32 */
-#ifndef __WIN32__
+#ifndef _WIN32
u64
get_available_memory(void)
{
WARNING("Failed to determine available memory; assuming 1 GiB");
return (u64)1 << 30;
}
-#endif /* !__WIN32__ */
+#endif /* !_WIN32 */