--- a/common/strhelp.c	Mon Mar 31 11:41:43 2014 +0200
+++ b/common/strhelp.c	Tue Apr 01 10:48:35 2014 +0000
@@ -7,6 +7,10 @@
 
 #include <polarssl/base64.h>
 
+#ifdef WIN32
+#include <windows.h>
+#endif
+
 /* Remarks regarding the "Flawfinder: ignore" comments in this file:
  *
  * - strlen:
@@ -182,3 +186,65 @@
     }
     return ret;
 }
+
+void
+xfree (void *p)
+{
+  if (p)
+    free (p);
+}
+
+#ifdef WIN32
+/* Adapted from GPGOL rev. e512053 */
+char *
+wchar_to_utf8 (const wchar_t *string, size_t len)
+{
+  int n, ilen;
+  char *result;
+
+  ilen = (int) len;
+  if (ilen < 0)
+    return NULL;
+
+  /* Note, that CP_UTF8 is not defined in Windows versions earlier
+     than NT.*/
+  n = WideCharToMultiByte (CP_UTF8, 0, string, ilen, NULL, 0, NULL, NULL);
+  if (n < 0)
+    return NULL;
+
+  result = xmalloc ((size_t)n+1);
+  n = WideCharToMultiByte (CP_UTF8, 0, string, ilen, result, n, NULL, NULL);
+  if (n < 0)
+    {
+      xfree (result);
+      return NULL;
+    }
+  return result;
+}
+
+/* Adapted from GPGOL rev. e512053 */
+wchar_t *
+utf8_to_wchar (const char *string, size_t len)
+{
+  int n, ilen;
+  wchar_t *result;
+
+  ilen = (int) len;
+  if (ilen < 0)
+    return NULL;
+
+  n = MultiByteToWideChar (CP_UTF8, 0, string, ilen, NULL, 0);
+  if (n < 0 || n + 1 < 0)
+    return NULL;
+
+  result = xmalloc ((size_t)(n+1) * sizeof *result);
+  n = MultiByteToWideChar (CP_UTF8, 0, string, ilen, result, n);
+  if (n < 0)
+    {
+      xfree (result);
+      return NULL;
+    }
+  result[n] = 0;
+  return result;
+}
+#endif

--- a/common/strhelp.h	Mon Mar 31 11:41:43 2014 +0200
+++ b/common/strhelp.h	Tue Apr 01 10:48:35 2014 +0000
@@ -6,6 +6,7 @@
 #endif
 
 #include <stdbool.h>
+#include <stddef.h>
 
 /**
  * @file  strhelp.h
@@ -19,6 +20,7 @@
 void *xrealloc( void *a, size_t n );
 void *xcalloc( size_t n, size_t m );
 char *xstrndup( const char *string, const size_t len );
+void xfree ( void *p );
 
 /**
  * @brief Returns the length of the given %NULL-terminated
@@ -101,6 +103,30 @@
  */
 int str_base64_decode(char **dst, size_t *dst_size, char *src,
                       size_t src_size);
+
+#ifdef WIN32
+
+/** @brief convert a utf8 string to utf16 wchar
+ *
+ * @param[in] string utf8 string. Must be at least len characters long.
+ * @param[in] len number of characters to be converted.
+ *
+ * @returns pointer to a newly allocated wchar array. NULL on error.
+ *
+ **/
+wchar_t *utf8_to_wchar (const char *string, size_t len);
+
+/** @brief convert a utf16 string to utf8
+ *
+ * @param[in] string utf16 string. Must be at least len characters long.
+ * @param[in] len number of characters to be converted.
+ *
+ * @returns pointer to a newly allocated char array. NULL on error.
+ *
+ **/
+char *wchar_to_utf8 (const wchar_t *string, size_t len);
+#endif
+
 #ifdef __cplusplus
 }
 #endif