UAC module

Admin Guide

Overview

UAC (User Agent Client) module provides some basic UAC functionalities like FROM header manipulation (anonymization) or client authentication.

Known limitations in this version:

authentication does not support qop auth-int, just qop auth;
CSeq not increased during authentication - the response may be rejected.

Dependencies

OpenSIPS Modules

The following modules must be loaded before this module:

TM - Transaction Module
RR - Record-Route Module, but only if restore mode for FROM URI is set to “auto”.

External Libraries or Applications

The following libraries or applications must be installed before running OpenSIPS with this module loaded:

None

Exported Parameters

rr_store_param (string)

Name of Record-Route header parameter that will be used to store (encoded) the original FROM URI.

This parameter is optional, it’s default value being “vsf”.

...
modparam("uac","rr_store_param","my_param")
...

from_restore_mode (string)

There are 3 mode of restoring the original FROM URI:

“none” - no information about original URI is stored; restoretion is not possible.
“manual” - all following replies will be restored, but not also the sequential requests - this must be manually updated based on original URI.
“auto” - all sequential requests and replies will be automatically updated based on stored original URI.

This parameter is optional, it’s default value being “auto”.

...
modparam("uac","from_restore_mode","auto")
...

from_passwd (string)

String password to be used to encrypt the RR storing paramter. If empty, no encryption will be used.

Default value of this parameter is empty.

...
modparam("uac","from_passwd","my_secret_passwd")
...

credential (string)

Contains a multiple definition of credentials used to perform authentication.

This parameter is required if UAC authentication is used.

...
modparam("uac","credential","username:domain:password")
...

auth_realm_avp (string)

The definition of an AVP that might contain the realm to be used to perform authentication.

If you define it, you also need to define “auth_username_avp” (auth username avp id) and “auth_username_avp” (auth password avp id).

...
modparam("uac","auth_realm_avp","$avp(i:10)")
...

auth_username_avp (string)

The definition of an AVP that might contain the username to be used to perform authentication.

If you define it, you also need to define “auth_realm_avp” (auth realm avp id) and “auth_username_avp” (auth password avp id).

...
modparam("uac","auth_username_avp","$avp(i:11)")
...

auth_password_avp (string)

The definition of an AVP that might contain the password to be used to perform authentication.

If you define it, you also need to define “auth_password_avp” (auth password avp id) and “auth_username_avp” (auth password avp id).

...
modparam("uac","auth_password_avp","$avp(i:12)")
...

Exported Functions

uac_replace_from(display,uri)

Replace in FROM header the display name and the URI part.

display and URI parameters can include pseudo-variables.

This function can be used from REQUEST_ROUTE, BRANCH_ROUTE and FAILURE_ROUTE.

...
# replace both display and uri
uac_replace_from("$avp(s:display)","$avp(s:uri)");
# replace only display and do not touch uri
uac_replace_from("batman","");
# remove display and replace uri
uac_replace_from("","sip:robin@gotham.org");
# remove display and do not touch uri
uac_replace_from("","");
...

uac_replace_from(uri)

Replace in FROM header the URI part without altering the display name.

URI parameter can include pseudo-variables.

This function can be used from REQUEST_ROUTE.

...
uac_replace_from("sip:batman@gotham.org");
...

uac_restore_from()

This function will check if the FROM URI was modified and will use the information stored in header parameter to restore the original FROM URI value.

This function can be used from REQUEST_ROUTE.

...
uac_restore_from();
...

uac_auth()

This function can be called only from failure route and will build the authentication response header and insert it into the request without sending anything.

This function can be used from FAILURE_ROUTE.

...
uac_auth();
...

Contributors

By Commit Statistics

Top contributors by DevScore⁽¹⁾, authored commits⁽²⁾ and lines added/removed⁽³⁾

#	Name	DevScore	Commits	Lines++	Lines—
1.	Bogdan-Andrei Iancu (@bogdan-iancu)	83	45	3260	548
2.	Daniel-Constantin Mierla (@miconda)	14	11	119	73
3.	Stefan Darius (@dariusstefan)	10	4	362	63
4.	Andreas Heise	7	3	105	129
5.	Elena-Ramona Modroiu	4	2	85	44
6.	Henning Westerholt (@henningw)	4	2	9	9
7.	Razvan Crainea (@razvancrainea)	3	1	2	2
8.	Dan Pascu (@danpascu)	3	1	2	2
9.	Konstantin Bokarius	3	1	2	5
10.	Sergio Gutierrez	3	1	1	1

All remaining contributors: Jesus Rodrigues, Edson Gellert Schubert.

(1) DevScore = author_commits + author_lines_added / (project_lines_added / project_commits) + author_lines_deleted / (project_lines_deleted / project_commits)

(2) including any documentation-related commits, excluding merge commits

(3) ignoring whitespace edits, renamed files and auto-generated files

By Commit Activity

#	Name	Commit Activity
1.	Stefan Darius (@dariusstefan)	Jun 2026 - Jul 2026
2.	Razvan Crainea (@razvancrainea)	Jun 2026 - Jun 2026
3.	Bogdan-Andrei Iancu (@bogdan-iancu)	Jun 2005 - Jul 2010
4.	Sergio Gutierrez	Nov 2008 - Nov 2008
5.	Dan Pascu (@danpascu)	Nov 2008 - Nov 2008
6.	Daniel-Constantin Mierla (@miconda)	Nov 2006 - Mar 2008
7.	Konstantin Bokarius	Mar 2008 - Mar 2008
8.	Edson Gellert Schubert	Feb 2008 - Feb 2008
9.	Henning Westerholt (@henningw)	Aug 2007 - Dec 2007
10.	Jesus Rodrigues	Dec 2007 - Dec 2007

All remaining contributors: Andreas Heise, Elena-Ramona Modroiu.

(1) including any documentation-related commits, excluding merge commits

Documentation

Contributors

Last edited by: Razvan Crainea (@razvancrainea), Bogdan-Andrei Iancu (@bogdan-iancu), Daniel-Constantin Mierla (@miconda), Konstantin Bokarius, Edson Gellert Schubert, Jesus Rodrigues, Elena-Ramona Modroiu.

License

All documentation files (i.e. .md extension) are licensed under the Creative Common License 4.0