First commit, Vystem v0.1

Blastproof/keygen/randombytes.c

@@ -0,0 +1,43 @@
+/*
+This code was taken from the SPHINCS reference implementation and is public domain.
+*/
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "randombytes.h"
+
+static int fd = -1;
+
+void randombytes(unsigned char *x, unsigned long long xlen)
+{
+    unsigned long long i;
+
+    if (fd == -1) {
+        for (;;) {
+            fd = open("/dev/urandom", O_RDONLY);
+            if (fd != -1) {
+                break;
+            }
+            sleep(1);
+        }
+    }
+
+    while (xlen > 0) {
+        if (xlen < 1048576) {
+            i = xlen;
+        }
+        else {
+            i = 1048576;
+        }
+
+        i = (unsigned long long)read(fd, x, i);
+        if (i < 1) {
+            sleep(1);
+            continue;
+        }
+
+        x += i;
+        xlen -= i;
+    }
+}