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| author | Jason A. Donenfeld <Jason@zx2c4.com> | 2017-06-12 16:32:59 +0200 |
|---|---|---|
| committer | Jason A. Donenfeld <Jason@zx2c4.com> | 2017-06-12 17:02:12 +0200 |
| commit | 0d0681304d9a91970ea06ffce9bf98cc5e2db811 (patch) | |
| tree | b0f3498957cf088cab2512bf42efa7f15bc4f12d /src/compat | |
| parent | 46825dc7ccdf06ad83b106a2dd9d44873f3cc805 (diff) | |
random: wait for random bytes when generating nonces and ephemerals
We can let userspace configure wireguard interfaces before the RNG is
fully initialized, since what we mostly care about is having good
randomness for ephemerals and xchacha nonces. By deferring the wait to
actually asking for the randomness, we give a lot more opportunity for
gathering entropy. This won't cover entropy for hash table secrets or
cookie secrets (which rotate anyway), but those have far less
catastrophic failure modes, so ensuring good randomness for elliptic
curve points and nonces should be sufficient.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'src/compat')
| -rw-r--r-- | src/compat/compat.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/src/compat/compat.h b/src/compat/compat.h index 68d62b9..6c1bfa3 100644 --- a/src/compat/compat.h +++ b/src/compat/compat.h @@ -265,6 +265,16 @@ static inline int wait_for_random_bytes(void) return 0; } #endif +#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 13, 0) +static inline int get_random_bytes_wait(void *buf, int nbytes) +{ + int ret = wait_for_random_bytes(); + if (unlikely(ret)) + return ret; + get_random_bytes(buf, nbytes); + return 0; +} +#endif /* https://lkml.org/lkml/2015/6/12/415 */ #include <linux/netdevice.h> |