1 files changed, 52 insertions, 0 deletions
diff --git a/libtommath/bn_s_mp_rand_jenkins.c b/libtommath/bn_s_mp_rand_jenkins.c
new file mode 100644
index 0000000..da0771c
--- /dev/null
+++ b/libtommath/bn_s_mp_rand_jenkins.c
@@ -0,0 +1,52 @@
+#include "tommath_private.h"
+#ifdef BN_S_MP_RAND_JENKINS_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
+
+/* Bob Jenkins' http://burtleburtle.net/bob/rand/smallprng.html */
+/* Chosen for speed and a good "mix" */
+typedef struct {
+   uint64_t a;
+   uint64_t b;
+   uint64_t c;
+   uint64_t d;
+} ranctx;
+
+static ranctx jenkins_x;
+
+#define rot(x,k) (((x)<<(k))|((x)>>(64-(k))))
+static uint64_t s_rand_jenkins_val(void)
+{
+   uint64_t e = jenkins_x.a - rot(jenkins_x.b, 7);
+   jenkins_x.a = jenkins_x.b ^ rot(jenkins_x.c, 13);
+   jenkins_x.b = jenkins_x.c + rot(jenkins_x.d, 37);
+   jenkins_x.c = jenkins_x.d + e;
+   jenkins_x.d = e + jenkins_x.a;
+   return jenkins_x.d;
+}
+
+void s_mp_rand_jenkins_init(uint64_t seed)
+{
+   uint64_t i;
+   jenkins_x.a = 0xf1ea5eedULL;
+   jenkins_x.b = jenkins_x.c = jenkins_x.d = seed;
+   for (i = 0uLL; i < 20uLL; ++i) {
+      (void)s_rand_jenkins_val();
+   }
+}
+
+mp_err s_mp_rand_jenkins(void *p, size_t n)
+{
+   char *q = (char *)p;
+   while (n > 0u) {
+      int i;
+      uint64_t x = s_rand_jenkins_val();
+      for (i = 0; (i < 8) && (n > 0u); ++i, --n) {
+         *q++ = (char)(x & 0xFFuLL);
+         x >>= 8;
+      }
+   }
+   return MP_OKAY;
+}
+
+#endif