SilcUInt32 silc_utf8_encode(const unsigned char *bin, SilcUInt32 bin_len,
                                SilcStringEncoding bin_encoding,
                                unsigned char *utf8, SilcUInt32 utf8_size);

    Encodes the string `bin' of which encoding is `bin_encoding' to the
    UTF-8 encoding into the buffer `utf8' which is of size of `utf8_size'.
    Returns the length of the UTF-8 encoded string, or zero (0) on error.
    By default `bin_encoding' is ASCII, and the caller needs to know the
    encoding of the input string if it is anything else.