Read and write CD key in lowercase

code/qcommon/common.c

@@ -2485,6 +2485,8 @@ void Com_ReadCDKey( const char *filename ) {
 	FS_Read( buffer, 16, f );
 	FS_FCloseFile( f );
 
+	Q_strlwr(buffer);
+
 	if (CL_CDKeyValidate(buffer, NULL)) {
 		Q_strncpyz( cl_cdkey, buffer, 17 );
 	} else {
@@ -2555,6 +2557,8 @@ static void Com_WriteCDKey( const char *filename, const char *ikey ) {
 		goto out;
 	}
 
+	Q_strlwr(key);
+
 	FS_Write( key, 16, f );
 
 	FS_Printf( f, "\n// generated by " PRODUCT_NAME ", do not modify\r\n" );