From 7e669bcf6b6336ec429da949bcb4aa456971dba2 Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Fri, 30 Jul 2021 10:38:27 +0200
Subject: folding history in preparation of GNU Anastasis v0.0.0 release

---
 src/reducer/validation_DE_SVN.c | 98 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 src/reducer/validation_DE_SVN.c

(limited to 'src/reducer/validation_DE_SVN.c')

diff --git a/src/reducer/validation_DE_SVN.c b/src/reducer/validation_DE_SVN.c
new file mode 100644
index 0000000..bfc406d
--- /dev/null
+++ b/src/reducer/validation_DE_SVN.c
@@ -0,0 +1,98 @@
+/*
+  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_DE_SVN.c
+ * @brief
+ * @author Christian Grothoff
+ * @author Dominik Meister
+ * @author Dennis Neufeld
+ */
+#include <string.h>
+#include <stdbool.h>
+
+/**
+ * Sum up all digits in @a v and return the result.
+ */
+static unsigned int
+q (unsigned int v)
+{
+  unsigned int r = 0;
+
+  while (0 != v)
+  {
+    r += v % 10;
+    v = v / 10;
+  }
+  return r;
+}
+
+
+/**
+ * Function to validate a German Social Security number.
+ *
+ * See https://www.financescout24.de/wissen/ratgeber/sozialversicherungsnummer
+ * and https://de.wikipedia.org/wiki/Versicherungsnummer
+ * for the structure!
+ *
+ * @param avh_number ahv number to validate (input)
+ * @return true if validation passed, else false
+ */
+bool
+DE_SVN_check (const char *ssn_number)
+{
+  static const unsigned int factors[] = {
+    2, 1, 2, 5, 7, 1, 2, 1, 2, 1, 2, 1
+  };
+  unsigned int sum = 0;
+
+  if (strlen (ssn_number) != 12)
+    return false;
+  for (unsigned int i = 0; i<8; i++)
+  {
+    unsigned char c = (unsigned char) ssn_number[i];
+
+    if ( ('0' > c) || ('9' < c) )
+      return false;
+    sum += q ((c - '0') * factors[i]);
+  }
+  {
+    unsigned char c = (unsigned char) ssn_number[8];
+    unsigned int v = (c - 'A' + 1);
+
+    if ( ('A' > c) || ('Z' < c) )
+      return false;
+    sum += q ((v / 10) * factors[8]);
+    sum += q ((v % 10) * factors[9]);
+  }
+  for (unsigned int i = 9; i<11; i++)
+  {
+    unsigned char c = ssn_number[i];
+
+    if ( ('0' > c) || ('9' < c) )
+      return false;
+    sum += q ((c - '0') * factors[i + 1]);
+  }
+  if (ssn_number[11] != '0' + (sum % 10))
+    return false;
+  {
+    unsigned int month = (ssn_number[4] - '0') * 10 + (ssn_number[5] - '0');
+
+    if ( (0 == month) ||
+         (12 < month) )
+      return false;
+  }
+  return true;
+}
-- 
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