1 files changed, 64 insertions, 0 deletions
diff --git a/src/asc2bin.cc b/src/asc2bin.cc
new file mode 100644
index 0000000..65efc31
--- /dev/null
+++ b/src/asc2bin.cc
@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set et sw=2 ts=2: */
+/***************************************************************************
+ *            asc2bin.cc
+ *
+ *  Thu Sep  5 11:12:50 CEST 2013
+ *  Copyright 2013 Bent Bisballe Nyeng
+ *  deva@aasimon.org
+ ****************************************************************************/
+
+/*
+ *  This file is part of lrtp.
+ *
+ * lrtp 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 2.1 of the License, or (at your option) any later version.
+ *
+ * lrtp 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with lrtp; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include "asc2bin.h"
+
+static int asc2nibble(unsigned char c)
+{
+	if(c >= '0' && c <= '9') return c - '0';
+	if(c >= 'a' && c <= 'f') return c - 'a' + 0xa;
+	if(c >= 'A' && c <= 'F') return c - 'A' + 0xa;
+	return -1;
+}
+
+ssize_t asc2bin(char *raw, size_t rawsz, const char *hex, size_t hexlen)
+{
+  if(hexlen % 2 != 0) return -1;
+  if(rawsz < hexlen / 2) return -1;
+
+  unsigned char val;
+  int nibble;
+  size_t size = 0;
+
+  while(size < hexlen / 2) {
+    nibble = asc2nibble(hex[0]);
+    if(nibble == -1) return -1;
+    val = (nibble << 4);
+
+    nibble = asc2nibble(hex[1]);
+    if(nibble == -1) return -1;
+    val |= (nibble & 0xff);
+
+    *raw = val;
+    raw++;
+    size++;
+
+    hex += 2;
+  }
+
+  return (ssize_t)size;
+}