Thanks for your answer !

I guess then that the following lines (based on the default script) would work to implement all of Michael's example ?

Lasse

if (uri=~mydomain.com) {

if (method=="REGISTER") {

# Uncomment this if you want to use digest authentication if (!www_authorize("mydomain.com", "subscriber")) { www_challenge("mydomain.com", "1"); break; };

save("location"); break; };

# For authenticating requests with methods other than REGISTER if (search("(f|From).*mydomain.com")) { if (!proxy_authorize("mydomain.com", "subscriber")) { proxy_challenge("mydomain.com", "1"); break; }; }; # native SIP destinations are handled using our USRLOC DB if (!lookup("location")) { sl_send_reply("404", "Not Found"); break; }; } else { # For authenticating requests to other domains, any method if (search("(f|From).*mydomain.com")) { if (!proxy_authorize("mydomain.com", "subscriber")) { proxy_challenge("mydomain.com", "1"); break; }; }; }; # forward to current uri now if (!t_relay()) { sl_reply_error(); };

On Tuesday 04 March 2003 19.05, Jiri Kuthan wrote:

At 12:11 AM 3/3/2003, Lasse Jansson wrote:

...

Hi Michael,

This is exactly what I would like to achieve.

I understand the meaning of your pseudo code below, but alas I have not enough knowledge and skills to transform your pseudo code below into a working script.

Could you please provide a real example ?

You may want to look at the default script and add the "if (to me)" condition. The "if (to me)" condition can be implemented with 0_8_10 as a brute regexp search: if (search("(From|f).*mydomain.com"))

The upcoming release will have specific support to address this issues.

-Jiri

...

Lasse

Michael_Graff@isc.org wrote:

...

Nils Ohlmeier nils@ohlmeier.de writes:

...

A proxy can challenge Invites and Byes, but should not do this with external Invites to your local user. Otherwise your your user wouldn't be reachable from outside.

I implemented something much like this:

if (to me): if register

            www_authorize or fail if not a valid register

            done

    if claiming to be "From" one of the domains I accept
    registrations for

            proxy_authorize

            done

if not to me (I'm relaying for a local phone to an external address)

    proxy_authorize (once again, based on from address)

    done

--Michael

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Thanks,

One last question: I guess that if I want my server to offer <forwarding of requests to other domains> only to authorized users in my domain I should restrict the last part more, as follows:

# For requests to other domains if (!proxy_authorize("mydomain.com", "subscriber")) { proxy_challenge("mydomain.com", "1"); break; };

(i.e. I can skip the (search("(f|From).*mydomain.com")) condition in this case)

Lasse

On Wednesday 05 March 2003 02.08, Jiri Kuthan wrote:

At 10:43 PM 3/4/2003, Lasse Jansson wrote:

...

Thanks for your answer !

I guess then that the following lines (based on the default script) would work to implement all of Michael's example ?

Lasse

   if (uri=~mydomain.com) {

perhaps better (uri=~"[@:]mydomain.com"). Everything else seems reasonable to me.

-Jiri

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Serusers mailing list serusers@lists.iptel.org http://lists.iptel.org/mailman/listinfo/serusers

OK, I see what you mean. I think the policy you recommend will do just fine in order to stop the most obvious types of abuse of a sip server. (If you want more paranoid "firewalling" you need to know sip really well, and there is always a risk that you stop legal cases).

Thanks for yor advice. The following script should do the trick then, huh ?

Lasse

# REQUESTS DIRECTED TO MY DOMAIN if (uri=~"[@:]mydomain.com") {

# Challenge registrations if (method=="REGISTER") { if (!www_authorize("mydomain.com", "subscriber")) { www_challenge("mydomain.com", "1"); break; }; save("location"); break; };

# Challenge any other request where the sender has my domain in From if (search("(f|From).*mydomain.com")) { if (!proxy_authorize("mydomain.com", "subscriber")) { proxy_challenge("mydomain.com", "1"); break; }; }; # native SIP destinations are handled using our USRLOC DB if (!lookup("location")) { sl_send_reply("404", "Not Found"); break; };

# REQUESTS DIRECTED TO OTHER DOMAINS } else {

# Challenge any request where the sender has my domain in From if (search("(f|From).*mydomain.com")) { if (!proxy_authorize("mydomain.com", "subscriber")) { proxy_challenge("mydomain.com", "1"); break; };

# Drop INVITE requests where the sender does not have my domain in From } else { if (method=="INVITE") { sl_send_reply("403", "Forbidden"); break; }; }; }; # forward to current uri now if (!t_relay()) { sl_reply_error(); };

On Wednesday 05 March 2003 23.05, Jiri Kuthan wrote:

Lasse,

I see two limitations:

• if you only challenge INVITEs to outside domain, people out of your domain can call people in your domain and claim shamelessly your domain name in From, which is then sort of rubberstamped by the proxy; so I

think you can combine challenging based on From along with "anti-spam" policy "drop invites which have my domain neither in From nor in r-uri" - if you apply such policies to other requests than BYE, you will run into troubles, better be permissive about non-INVITEs. See

http://www.ietf.org/mail-archive/working-groups/sipping/current/msg04002.ht ml

-Jiri

At 10:10 PM 3/5/2003, Lasse Jansson wrote:

...

Thanks,

One last question: I guess that if I want my server to offer <forwarding of requests to other domains> only to authorized users in my domain I should restrict the last part more, as follows:

# For requests to other domains if (!proxy_authorize("mydomain.com", "subscriber")) { proxy_challenge("mydomain.com", "1"); break; };

(i.e. I can skip the (search("(f|From).*mydomain.com")) condition in this case)

Lasse

On Wednesday 05 March 2003 02.08, Jiri Kuthan wrote:

...

At 10:43 PM 3/4/2003, Lasse Jansson wrote:

...

Thanks for your answer !

I guess then that the following lines (based on the default script) would work to implement all of Michael's example ?

Lasse

   if (uri=~mydomain.com) {

perhaps better (uri=~"[@:]mydomain.com"). Everything else seems reasonable to me.

-Jiri

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-- Jiri Kuthan http://iptel.org/~jiri/

---

Serusers mailing list serusers@lists.iptel.org http://lists.iptel.org/mailman/listinfo/serusers

Hello,

On 16-03 00:01, Lasse Jansson wrote:

Or perhaps I understand a little bit better now. I think the following script passage will work better. /Lasse P.S. To other beginners at SIP: Several clients can't handle the qop parameter correctly so it is safer to change the "1" to "0" in the challenges.

And there were (maybe still are) clients that cannot handle authentication without qop parameter correctly :-)

Jan.

OK, thanks

I've learned something from this thread. I understand the delay in your answer, and I am anyway impressed by your "mail answering throughput" !

Lasse

On Friday 28 March 2003 14.13, Jiri Kuthan wrote:

Looks reasonable to me. My apologies it has taken so long to reply -- I've been traveling too much.

-Jiri

At 12:01 AM 3/16/2003, Lasse Jansson wrote:

...

Or perhaps I understand a little bit better now. I think the following script passage will work better. /Lasse P.S. To other beginners at SIP: Several clients can't handle the qop parameter correctly so it is safer to change the "1" to "0" in the challenges.

# REQUESTS DIRECTED TO MY DOMAIN if (uri=~"[@:]mydomain.com") {

# Challenge registrations if (method=="REGISTER") { if (!www_authorize("mydomain.com", "subscriber")) { www_challenge("mydomain.com", "1"); break; }; save("location"); break; };

# Challenge INVITE request where the sender has my domain in From if (method=="INVITE") { if (search("(f|From).*mydomain.com")) { if (!proxy_authorize("mydomain.com", "subscriber")) { proxy_challenge("mydomain.com", "1"); break; }; }; }; # native SIP destinations are handled using our USRLOC DB if (!lookup("location")) { sl_send_reply("404", "Not Found"); break; };

# REQUESTS DIRECTED TO OTHER DOMAINS } else {

# Challenge any INVITE request where the sender has my domain in From if (method=="INVITE") { if (search("(f|From).*mydomain.com")) { if (!proxy_authorize("mydomain.com", "subscriber")) { proxy_challenge("mydomain.com", "1"); break; };

# Drop INVITE requests where the sender does not have my domain in From } else { sl_send_reply("403", "Forbidden"); break; }; }; }; # forward to current uri now if (!t_relay()) { sl_reply_error(); };

On Friday 07 March 2003 00.49, Lasse Jansson wrote:

...

OK, I see what you mean.

<snip>

...

...

I see two limitations:

• if you only challenge INVITEs to outside domain, people out of your domain can call people in your domain and claim shamelessly your

domain name in From, which is then sort of rubberstamped by the proxy; so I think you can combine challenging based on From along with "anti-spam" policy "drop invites which have my domain neither in From nor in r-uri" - if you apply such policies to other requests than BYE, you will run into troubles, better be permissive about non-INVITEs. See

http://www.ietf.org/mail-archive/working-groups/sipping/current/msg040 02. ht ml

-Jiri

At 10:10 PM 3/5/2003, Lasse Jansson wrote:

...

Thanks,

One last question: I guess that if I want my server to offer <forwarding of requests to other domains> only to authorized users in my domain I should restrict the last part more, as follows:

# For requests to other domains if (!proxy_authorize("mydomain.com", "subscriber")) { proxy_challenge("mydomain.com", "1"); break; };

(i.e. I can skip the (search("(f|From).*mydomain.com")) condition in this case)

Lasse

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-- Jiri Kuthan http://iptel.org/~jiri/

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