diff -r 000000000000 -r 6474c204b198 security/nss/lib/freebl/mpi/utils/exptmod.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/security/nss/lib/freebl/mpi/utils/exptmod.c	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,50 @@
+/*
+ *  exptmod.c
+ *
+ * Command line tool to perform modular exponentiation on arbitrary
+ * precision integers.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "mpi.h"
+
+int main(int argc, char *argv[])
+{
+  mp_int  a, b, m;
+  mp_err  res;
+  char   *str;
+  int     len, rval = 0;
+
+  if(argc < 3) {
+    fprintf(stderr, "Usage: %s <a> <b> <m>\n", argv[0]);
+    return 1;
+  }
+
+  mp_init(&a); mp_init(&b); mp_init(&m);
+  mp_read_radix(&a, argv[1], 10);
+  mp_read_radix(&b, argv[2], 10);
+  mp_read_radix(&m, argv[3], 10);
+
+  if((res = mp_exptmod(&a, &b, &m, &a)) != MP_OKAY) {
+    fprintf(stderr, "%s: error: %s\n", argv[0], mp_strerror(res));
+    rval = 1;
+  } else {
+    len = mp_radix_size(&a, 10);
+    str = calloc(len, sizeof(char));
+    mp_toradix(&a, str, 10);
+
+    printf("%s\n", str);
+
+    free(str);
+  }
+
+  mp_clear(&a); mp_clear(&b); mp_clear(&m);
+
+  return rval;
+}