works now again

src/random.c

@@ -0,0 +1,59 @@
+#include "config.h"
+#include "ch.h"
+#include "gnuk.h"
+
+/*
+ * XXX: I have tried havege_rand, but it requires too much memory...
+ */
+
+/*
+ * Multiply-with-carry method by George Marsaglia
+ */
+static uint32_t m_w;
+static uint32_t m_z;
+
+uint32_t
+get_random (void)
+{
+  m_z = 36969 * (m_z & 65535) + (m_z >> 16);
+  m_w = 18000 * (m_w & 65535) + (m_w >> 16);
+
+  return (m_z << 16) + m_w;
+}
+
+void
+random_init (void)
+{
+  static uint8_t s = 0;
+
+ again:
+  if ((s & 1))
+    m_w = (m_w << 8) ^ hardclock ();
+  else
+    m_z = (m_z << 8) ^ hardclock ();
+
+  s++;
+  if (m_w == 0 || m_z == 0)
+    goto again;
+}
+
+uint8_t dek[16];
+uint8_t *get_data_encryption_key (void)
+{
+  uint32_t r;
+  r = get_random ();
+  memcpy (dek, &r, 4);
+  r = get_random ();
+  memcpy (dek+4, &r, 4);
+  r = get_random ();
+  memcpy (dek+8, &r, 4);
+  r = get_random ();
+  memcpy (dek+12, &r, 4);
+  return dek;
+}
+
+void
+dek_free (uint8_t *dek)
+{
+  (void)dek;
+}