1 files changed, 49 insertions, 0 deletions
diff --git a/ckcapi.c b/ckcapi.c
index 1b6654e..9ea7815 100644
--- a/ckcapi.c
+++ b/ckcapi.c
@@ -160,6 +160,55 @@ ckcapi_return_data(CK_VOID_PTR dst, CK_ULONG_PTR dlen,
 	return CKR_OK;
 }
 
+CK_RV
+ckcapi_return_string(CK_VOID_PTR dst, CK_ULONG_PTR dlen,
+                     WCHAR* string)
+{
+	DWORD error;
+	int result;
+
+	SetLastError(0);
+
+	/* 
+	 * Sadly WideCharToMultiByte doesn't handle zero 
+	 * length strings properly. So we have to special
+	 * case this part.
+	 */
+	if(!string[0])
+		return ckcapi_return_data(dst, dlen, "\0", 1);
+
+	result = WideCharToMultiByte(CP_UTF8, 0, string, -1, 
+	                             dst, dst ? *dlen : 0, NULL, NULL);
+
+
+	/* An error result somehow */
+	if(!result)
+	{
+		error = GetLastError();
+		switch(error)
+		{
+		/* If buffer was too short, calculate good buffer length */
+		case ERROR_INSUFFICIENT_BUFFER:
+			result = WideCharToMultiByte(CP_UTF8, 0, string, -1, 
+				                         NULL, 0, NULL, NULL);
+			if(!result)
+				return CKR_GENERAL_ERROR;
+			*dlen = result;
+			return CKR_BUFFER_TOO_SMALL;
+
+		/* A strange zero length success */
+		case ERROR_SUCCESS:
+			break;
+
+		/* All other errors are not handleable */
+		default:
+			return CKR_GENERAL_ERROR;
+		}
+	}
+
+	*dlen = result;
+	return CKR_OK;
+}
 
 /* ---------------------------------------------------------------- */