Two Methods for filling the contact field

Method 1:

    osip_message_t* answer=NULL;

    eXosip_message_build_answer(je->tid,200,&answer);

// Add the contact field

    osip_contact_t* contact;

    osip_message_get_contact(je->request,0,&contact);

    char* pContact=NULL;

Osip_contact_to_str (contact, & pcontact); // note that there is a dynamic memory allocation, passing the second-level pointer address

    osip_message_set_contact(answer,pContact);

/*/Dynamic memory for important Deleted fields

    osip_free(pContact);

Method 2:

    osip_message_t* answer=NULL;
    eXosip_message_build_answer(je->tid,200,&answer);
// Add the contact field
    osip_contact_t* contact;
    osip_message_get_contact(je->request,0,&contact);
     char* pContact=(char*)osip_malloc(70);
    sprintf(pContact,"<sip:%s@%s:%s>",contact->url->username,contact->url->host,contact->url->port);
    osip_message_set_contact(answer,pContact);
    osip_free(pContact);
However, the above two methods have obvious Memory leakage !!!