diff options
Diffstat (limited to 'util')
| -rw-r--r-- | util/libreboot-utils/lib/mkhtemp.c | 29 |
1 files changed, 14 insertions, 15 deletions
diff --git a/util/libreboot-utils/lib/mkhtemp.c b/util/libreboot-utils/lib/mkhtemp.c index 0c93fe7e..a669e208 100644 --- a/util/libreboot-utils/lib/mkhtemp.c +++ b/util/libreboot-utils/lib/mkhtemp.c @@ -879,33 +879,32 @@ err: int mkhtemp_fill_random(char *p, size_t xc) { - static char ch[] = + static const char ch[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; - size_t chx = 0; - size_t r; + unsigned char scratch[64]; - /* clamp rand to prevent modulo bias - */ - size_t limit = ((size_t)-1) - (((size_t)-1) % (sizeof(ch) - 1)); - int saved_errno = errno; + size_t off = 0; + size_t i; + + /* clamp rand to prevent modulo bias */ + size_t limit = 256 - (256 % (sizeof(ch) - 1)); if (if_err(p == NULL, EFAULT)) return -1; - for (chx = 0; chx < xc; chx++) { - retry_rand: - rset(&r, sizeof(r)); - if (r >= limit) - goto retry_rand; + rset(scratch, sizeof(scratch)); - p[chx] = ch[r % (sizeof(ch) - 1)]; + for (i = 0; i < sizeof(scratch) && off < xc; i++) { + if (scratch[i] < limit) + p[off++] = ch[scratch[i] % (sizeof(ch) - 1)]; } - errno = saved_errno; - return 0; + if (off < xc) + goto retry_rand; + return 0; } /* WARNING: **ONCE** per file. |