Clean up and modernize librandom.

 Correct random number generation has historically been
suprisingly painful to achieve. There was no standard,
every system behaved in a subtly different way, and there
were a few userland initiatives to get decent randomness,
all incompatible of course.
 The situation is a bit better now, we're heading towards
some standardization. The arc4random() series of functions
is a good API, and available on a lot of systems -
unfortunately not Linux, but on Linux the new getrandom()
makes using /dev/random obsolete.

 So I removed the old crap in librandom, dropped EGD support,
dropped dynamic backend selection, made a single API series
(random_* instead of goodrandom_* and badrandom_*), added
an arc4random backend and a getrandom backend, and defaulted
to /dev/urandom backed up by SURF in the worst case. This
should be much smaller and logical. However, it's a major
API break, so the skarnet.org stack will be changed to
adapt.

1 files changed, 22 insertions, 0 deletions

diff --git a/src/sysdeps/trygetrandom.c b/src/sysdeps/trygetrandom.c
new file mode 100644
index 0000000..67a623d
--- /dev/null
+++ b/src/sysdeps/trygetrandom.c
@@ -0,0 +1,22 @@
+/* ISC license. */
+
+#undef _POSIX_C_SOURCE
+#undef _XOPEN_SOURCE
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <sys/types.h>
+#include <sys/syscall.h>
+
+static int getrandom (void *buf, size_t buflen, unsigned int flags)
+{
+  return syscall(SYS_getrandom, buf, buflen, flags) ;
+}
+
+int main (void)
+{
+  char buf[4] ;
+  return getrandom(buf, 4, 0) ;
+}