diff options
| author | John Denker <jsd@av8n.com> | 2013-10-16 16:52:59 -0700 |
|---|---|---|
| committer | John Denker <jsd@av8n.com> | 2013-10-18 05:33:22 -0700 |
| commit | 30e2b629cc9df4c76f63b56afb35ec9f7cc3f1ce (patch) | |
| tree | c74e00fe24591e179fd3ed13d65f43480d89d897 | |
| parent | 3c7f459211c744e91e02d7a73c3deffe76f41987 (diff) | |
smarter about calculating /total/ entropy
| -rw-r--r-- | drivers/char/random.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 4a2487c..b423214 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -201,6 +201,15 @@ * amount of stored entropy, measured in bits. This includes entropy * stored in both the input pool and the blocking pool. + * Exported interfaces ---- ioctl + * =============================== + *** FIXME + + **?? There may be older programs out there that write to + /dev/random and then do ioctl(RNDADDTOENTCNT...); this + is guaranteed to fail insidiously, since writing + to /dev/random does nothing to the input pool. + * Ensuring unpredictability at system startup * ============================================ * @@ -1497,8 +1506,10 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg) case RNDGETENTCNT: /* inherently racy, no point locking */ if (put_user(input_pool.entropy_count +#ifdef OVERCOMPLICATED + devrand_pool.entropy_count - + prng_pool.entropy_count, p)) +#endif + , p)) return -EFAULT; return 0; case RNDADDTOENTCNT: @@ -1636,7 +1647,7 @@ static int sum_entropy_count(struct ctl_table *table, int write, #ifdef OVERCOMPLICATED + devrand_pool.entropy_count #endif - + prng_pool.entropy_count; + ; return proc_dointvec(table, write, buffer, lenp, ppos); } |