Как правильно передавать char* в функцию?

void SFromBase64(char* target, char* source)
{
    QByteArray qs64(source);
    target = QByteArray::fromBase64(qs64).data();
}
 
std::string fFromBase64(std::string base64)
{
    QByteArray qs64(base64.c_str());
    std::string s = (const char*)QByteArray::fromBase64(qs64).data();
    return s;
}

    char sor[] = "PCFE";
    char tar[4];
    SFromBase64(tar,sor);
    std::string sd = fFromBase64("PCFE");
    ui->label->setText(tar);
    ui->label1->setText(sd);

void SFromBase64(char* &target, char* source)

strcpy(target, QByteArray::fromBase64(qs64).data());

//from c-string     
string (const char* s);
//from buffer 
string (const char* s, size_t n);

void SFromBase64(char* &target, char* source)
{
    QByteArray qs64(source);
    strcpy(target, QByteArray::fromBase64(qs64).data());
 
}

    char sor[] = "PCFE";
    char *tar = new char[6];
    SFromBase64(tar,sor);

    char sor[] = "PCFE";
    char *tar;
    SFromBase64(tar,sor);

    char sor[] = "aHR0cDovL2FtaW4tYW";
    char *tar = new char[3];
    SFromBase64(tar,sor);

void SFromBase64(char* &target, char* source)
{
    QByteArray qs64(source);
    strcpy(target, QByteArray::fromBase64(qs64).data());
}