Update ngx_http_auth_digest_module.h

[davidecrista]

We discovered a bug with IPv6 authentication: the ngx_memcpy() in the function ngx_http_auth_digest_evasion_tracking() causes a segmentation fault because node.src_addr is defined as struct sockaddr, that is too small to contain a struct sockaddr_in6.
It must be defined as struct sockaddr_storage.

[erikdubbelboer]

Thanks for the pull request!
But I'm afraid only changing the storage type isn't enough. src_addr is passed to ngx_http_auth_digest_srcaddr_cmp as argument which now fails to compile:

../nginx-http-auth-digest/ngx_http_auth_digest_module.c: In function ‘ngx_http_auth_digest_ev_rbtree_cmp’:
../nginx-http-auth-digest/ngx_http_auth_digest_module.c:1047:9: error: passing argument 1 of ‘ngx_http_auth_digest_srcaddr_cmp’ from incompatible pointer type [-Werror]
         evright->src_addrlen);
         ^
In file included from ../nginx-http-auth-digest/ngx_http_auth_digest_module.c:13:0:
../nginx-http-auth-digest/ngx_http_auth_digest_module.h:125:12: note: expected ‘struct sockaddr *’ but argument is of type ‘struct sockaddr_storage *’
 static int ngx_http_auth_digest_srcaddr_cmp(struct sockaddr *sa1,
            ^
../nginx-http-auth-digest/ngx_http_auth_digest_module.c:1047:9: error: passing argument 3 of ‘ngx_http_auth_digest_srcaddr_cmp’ from incompatible pointer type [-Werror]
         evright->src_addrlen);
         ^
In file included from ../nginx-http-auth-digest/ngx_http_auth_digest_module.c:13:0:
../nginx-http-auth-digest/ngx_http_auth_digest_module.h:125:12: note: expected ‘struct sockaddr *’ but argument is of type ‘struct sockaddr_storage *’
 static int ngx_http_auth_digest_srcaddr_cmp(struct sockaddr *sa1,
            ^

Please fix this error.