What is the type of `peer` for `DTLSv1_listen`?

Question

I'm trying to implement a DTLS server following https://gist.github.com/Jxck/b211a12423622fe304d2370b1f1d30d5, but i'm running into trouble at DTLSv1_listen. I'm using OpenSSL 1.1.1c, and the peer arg from DTLSv1_listen appears to have type of BIO_ADDR *. I'm confused as to how to use it, as the documentation isn't really helpful. The tutorial just passes in a sockaddr * (or was it sockaddr_in6?) to peer. Would that work? If not, how can I convert a BIO_ADDR * to a sockaddr *?

Answer 1

Create a new BIO_ADDR object using BIO_ADDR_new. So something like this:

    BIO_ADDR *addr = BIO_ADDR_new();
    int ret;

    if (addr == NULL)
        goto err;

    ret = DTLSv1_listen(ssl, addr);

    /* Handle the result of DTLSv1_listen */


    BIO_ADDR_free(addr);

You can examine the contents of the BIO_ADDR using the various getter functions available. See the BIO_ADDR documentation here:

https://www.openssl.org/docs/man1.1.1/man3/BIO_ADDR.html