1 files changed, 115 insertions, 0 deletions
diff --git a/mozilla/security/nss/lib/freebl/mpi/utils/fact.c b/mozilla/security/nss/lib/freebl/mpi/utils/fact.c
new file mode 100644
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--- /dev/null
+++ b/mozilla/security/nss/lib/freebl/mpi/utils/fact.c
@@ -0,0 +1,115 @@
+/*
+ * fact.c
+ *
+ * Compute factorial of input integer
+ *
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is the MPI Arbitrary Precision Integer Arithmetic library.
+ *
+ * The Initial Developer of the Original Code is
+ * Michael J. Fromberger.
+ * Portions created by the Initial Developer are Copyright (C) 1998
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+/* $Id: fact.c,v 1.3 2004/04/27 23:04:37 gerv%gerv.net Exp $ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "mpi.h"
+
+mp_err mp_fact(mp_int *a, mp_int *b);
+
+int main(int argc, char *argv[])
+{
+  mp_int  a;
+  mp_err  res;
+
+  if(argc < 2) {
+    fprintf(stderr, "Usage: %s <number>\n", argv[0]);
+    return 1;
+  }
+
+  mp_init(&a);
+  mp_read_radix(&a, argv[1], 10);
+
+  if((res = mp_fact(&a, &a)) != MP_OKAY) {
+    fprintf(stderr, "%s: error: %s\n", argv[0],
+	    mp_strerror(res));
+    mp_clear(&a);
+    return 1;
+  }
+
+  {
+    char  *buf;
+    int    len;
+
+    len = mp_radix_size(&a, 10);
+    buf = malloc(len);
+    mp_todecimal(&a, buf);
+
+    puts(buf);
+
+    free(buf);
+  }
+
+  mp_clear(&a);
+  return 0;
+}
+
+mp_err mp_fact(mp_int *a, mp_int *b)
+{
+  mp_int    ix, s;
+  mp_err    res = MP_OKAY;
+
+  if(mp_cmp_z(a) < 0)
+    return MP_UNDEF;
+
+  mp_init(&s);
+  mp_add_d(&s, 1, &s);   /* s = 1  */
+  mp_init(&ix);
+  mp_add_d(&ix, 1, &ix); /* ix = 1 */
+
+  for(/*  */; mp_cmp(&ix, a) <= 0; mp_add_d(&ix, 1, &ix)) {
+    if((res = mp_mul(&s, &ix, &s)) != MP_OKAY)
+      break;
+  }
+
+  mp_clear(&ix);
+
+  /* Copy out results if we got them */
+  if(res == MP_OKAY)
+    mp_copy(&s, b);
+
+  mp_clear(&s);
+
+  return res;
+}