char *silc_sstrdup(SilcStack stack, const char *str);

    Duplicates the string indicated by `str' and returns the duplicated
    string.  This function allocates unaligned memory.  Returns NULL
    on error.

    Be careful with this function:  do not free the returned pointer
    explicitly and do not save the returned pointer to a permanent
    location.

    If `stack' is NULL this function calls silc_strdup.