diff options
Diffstat (limited to 'lib/randutils.c')
-rw-r--r-- | lib/randutils.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/lib/randutils.c b/lib/randutils.c index 02c3d9eb0..de4279530 100644 --- a/lib/randutils.c +++ b/lib/randutils.c @@ -95,6 +95,9 @@ int random_get_fd(void) * 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; @@ -111,11 +114,14 @@ void random_get_bytes(void *buf, size_t nbytes) n -= x; cp += x; lose_counter = 0; - } else if (errno == ENOSYS) /* kernel without getrandom() */ - break; - else if (errno == EAGAIN) + + } else if (errno == ENOSYS) { /* kernel without getrandom() */ break; - else if (lose_counter++ > 16) /* entropy problem? */ + + } else if (errno == EAGAIN && lose_counter < UL_RAND_READ_ATTEMPTS) { + xusleep(UL_RAND_READ_DELAY); /* no etropy, wait and try again */ + lose_counter++; + } else break; } @@ -134,8 +140,9 @@ void random_get_bytes(void *buf, size_t nbytes) while (n > 0) { ssize_t x = read(fd, cp, n); if (x <= 0) { - if (lose_counter++ > 16) + if (lose_counter++ > UL_RAND_READ_ATTEMPTS) break; + xusleep(UL_RAND_READ_DELAY); continue; } n -= x; |