Instead of using the internal DRBG-based RNG, use the `getrandom()` system
call where available.
Keep the existing version as fall-back for other systems that don't provide
that system call.
... and for cases where auto-detection fails or the user simply wants to
use the internal RNG a new configure-switch is provided.
Signed-off-by: Steffen Jaeckel <jaeckel-floss@eyet-services.de>
@sjaeckel integrated clang-format with formal coding style. Run his
script and commit changes.
There are pros and cons of this commit.
Mixed coding style is a "broken window". A good single style simplifies
reading and writing code.
On the other hand, this is a big change which will lead to conflicts.
* Removed dependency from internal headers in rand.h. xmpp_rand
interface can be public in the future;
* xmpp_rand functions accept xmpp_rand_t object instead of xmpp_ctx_t.
sha1.c contains symbols that overlap with libcrypto. This patch
fixes linking with libstrophe as static library.
Prefix crypto_ will help to group other crypto API in the future.
This pseudo-random number generator solves problem with
platform-independent generation of randomized nonces.
Current implementation uses weak entropy, especially when
kernel.randomize_va_space = 0. But it can be improved by
adding new sources to xmpp_rand_reseed().
New internal API introduced:
xmpp_rand_new
xmpp_rand_free
xmpp_rand
xmpp_rand_bytes
xmpp_rand_nonce
