1 files changed, 55 insertions, 0 deletions
diff --git a/security/nss/lib/freebl/mpi/utils/exptmod.c b/security/nss/lib/freebl/mpi/utils/exptmod.c
new file mode 100644
index 000000000..3ac9078f4
--- /dev/null
+++ b/security/nss/lib/freebl/mpi/utils/exptmod.c
@@ -0,0 +1,55 @@
+/*
+ *  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;
+}