: Buffer(payload_length + sizeof(struct HeaderStruct), allow_realloc), auth_tag_length_(auth_tag_length)
{
header_ = reinterpret_cast<struct HeaderStruct*>(buf_);
payload_ = buf_ + sizeof(struct HeaderStruct);
auth_tag_ = NULL;
: Buffer(payload_length + sizeof(struct HeaderStruct), allow_realloc), auth_tag_length_(auth_tag_length)
{
header_ = reinterpret_cast<struct HeaderStruct*>(buf_);
payload_ = buf_ + sizeof(struct HeaderStruct);
auth_tag_ = NULL;