Draw from the kernel's CPRNG.
#include <zircon/syscalls.h> void zx_cprng_draw(void* buffer, size_t buffer_size);
zx_cprng_draw() draws random bytes from the kernel CPRNG. This data should
be suitable for cryptographic applications.
Clients that require a large volume of randomness should consider using these bytes to seed a user-space random number generator for better performance.
zx_cprng_draw() triggers terminates the calling process if buffer is not
a valid userspace pointer.
There are no other error conditions. If its arguments are valid,
zx_cprng_draw() will succeed.