1 files changed, 53 insertions, 0 deletions
diff --git a/src/reducer/validation_XY_PRIME.c b/src/reducer/validation_XY_PRIME.c
new file mode 100644
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--- /dev/null
+++ b/src/reducer/validation_XY_PRIME.c
@@ -0,0 +1,53 @@
+/*
+  This file is part of Anastasis
+  Copyright (C) 2020, 2021 Taler Systems SA
+
+  Anastasis is free software; you can redistribute it and/or modify it under the
+  terms of the GNU Lesser General Public License as published by the Free Software
+  Foundation; either version 3, or (at your option) any later version.
+
+  Anastasis is distributed in the hope that it will be useful, but WITHOUT ANY
+  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+  A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License along with
+  Anastasis; see the file COPYING.GPL.  If not, see <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file redux/validation_XY_PRIME.c
+ * @brief anastasis reducer api
+ * @author Christian Grothoff
+ * @author Dominik Meister
+ * @author Dennis Neufeld
+ */
+#include <string.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <gcrypt.h>
+
+/**
+ * Function to validate a prime number.
+ *
+ * @param pr_number prime number to validate (input)
+ * @return true if pr_number is a prime, else false
+ */
+bool
+XY_PRIME_check (const char *pr_number)
+{
+  unsigned long long n;
+  char dummy;
+  gcry_mpi_t p;
+  bool is_prime;
+
+  if (1 != sscanf (pr_number,
+                   "%llu%c",
+                   &n,
+                   &dummy))
+    return false;
+  p = gcry_mpi_set_ui (NULL,
+                       (unsigned long) n);
+  is_prime = (0 == gcry_prime_check (p,
+                                     0));
+  gcry_mpi_release (p);
+  return is_prime;
+}