char_set = " ABCDEFGHIJKLMNOPQRSTUVWXYZ ▁ abcdefghijklmnopqrstuvwxyz0123456789 + / "
char * base64Decoder ( char encoded [ ] , int len_str ) { char * decoded_string ; decoded_string = ( char * ) malloc ( sizeof ( char ) * SIZE ) ; int i , j , k = 0 ;