TLS_MGM module

Admin Guide

Overview

This module is a management module for TLS certificates and parameters. It provides an interface for all the modules that use the TLS protocol. It also exports pseudo variables with certificate and TLS parameters.

Usage

This module is used to provision TLS certificates and parameters for all the modules that use TLS transport (like proto_tls or proto_wss). The module supports multiple virtual domains that can be assigned to different listeners (servers) or new connections (clients). Each TLS module that uses this management module should assign itself to one or more domains.

The module allows the definition of the TLS domains both via module parameters (script level) and via an SQL table.

A script example which details this module’s usage can be found in tls example.

TLS domains

The wording ‘TLS domain’ means that this TLS connection will have different parameters than another TLS connection (from another TLS domain). Thus, TLS domains are not directly related to different SIP domains, although they are often used in conjunction. Depending on the direction of the TLS handshake, a TLS domain is called ‘client domain’ (=outgoing TLS connection) or ‘server domain’ (= incoming TLS connection).

If you run several SIP domains you can specify some parameters for each of them separately (regardless if you have only one or multiple socket=tls:ip:port entries in the config file).

For example, TLS domains can be used in virtual hosting scenarios with TLS. OpenSIPS offers SIP service for multiple domains, e.g. atlanta.com and biloxi.com. Altough both domains will be hosted on a single SIP proxy, the SIP proxy needs 2 certificates: One for atlanta.com and one for biloxi.com. For incoming TLS connections, the SIP proxy has to present the respective certificate during the TLS handshake. As the SIP proxy does not have a received SIP message yet (this is done after the TLS handshake), the SIP proxy can not retrieve the target domain from SIP (which would have been usually retrieved from the domain in the request URI). Thus, distinction for these domains must be done by using multiple listening sockets or by having clients that send the Servername TLS extension(SNI) in the handshake process.

For outgoing TLS connections, the TLS domain is chosen based on the destination socket of the underlying outgoing TCP connection and/or by taking a decision at script level via an AVP. For example, you can inspect headers like RURI or From and match the domain in the SIP header with filters that you have set up for the TLS domains.

Note

Except tls_handshake_timeout and tls_send_timeout all TLS parameters can be set per TLS domain.

Defining TLS domains

TLS domains can be defined in two ways:

• by setting the server_domain or client_domain module parameters
• by provisioning in DB

For the domains defined in the DB, the certificate, private key, list of trusted CAs and Diffie-Hellman parameters are provisioned as BLOB values while for script defined domains you must provide path to files.

You can define domains both in the DB and script at the same time.

For any TLS domain (defined through script or DB) if not specified otherwise, the default settings are:

• method - SSLv23
• verify_cert - 1
• require_cert - 1
• certificate - CFG_DIR/tls/cert.pem
• private_key - CFG_DIR/tls/ckey.pem
• crl_check_all - 0
• crl_dir - none
• ca_list - none
• ca_dir - /etc/pki/CA/
• cipher_list - the OpenSSL default ciphers
• dh_params - none
• ec_curve - none

Dependencies of external libraries

OpenSIPS TLS v1.0 support requires the following packages:

• openssl or libssl >= 0.9.6
• openssl-dev or libssl-dev

OpenSIPS TLS v1.1/1.2 support requires the following packages:

• openssl or libssl >= 1.0.1e
• openssl-dev or libssl-dev

Exported Functions

is_peer_verified

Returns 1 if the message is received via TLS and the peer was verified during TLS connection handshake, otherwise it returns -1

This function can be used from REQUEST_ROUTE.

is_peer_verified usage

...
if (is_peer_verified()) {
        xlog("L_INFO","request from verified TLS peer\n");
} else {
        xlog("L_INFO","request not verified\n");
}
...

Exported MI Functions

tls_list

List all domains information.

tls_reload

Reloads the TLS domains information from the database. The previous DB defined domains are discarded but the script defined domains are preserved.

Exported Parameters

All these parameters can be used from the opensips.cfg file, to configure the behavior of OpenSIPS-TLS.

listen=interface

Not specific to TLS. Allows to specify the protocol (udp, tcp, tls), the IP address and the port where the listening server will be.

Set listen variable

...
socket= tls:1.2.3.4:5061
...

tls_method ([domain]string)

Sets the TLS protocol. The domain part represents the name of the TLS domain. The supported TLS methods are:

• TLSv1_3 - means OpenSIPS will accept only TLSv1.3 connections. This version is only available starting with OpenSSL 1.1.1 version.
• TLSv1_2 - means OpenSIPS will accept only TLSv1.2 connections (rfc3261 conformant).
• TLSv1 - means OpenSIPS will accept only TLSv1 connections (rfc3261 conformant).
• SSLv23 - means OpenSIPS will accept any of the above methods, but the initial SSL hello must be v2 (in the initial hello all the supported protocols are advertised enabling switching to a higher and more secure version). The initial v2 hello means it will not accept connections from SSLv3 or TLSv1 only clients.

If you are using an OpenSSL library newer than 1.1.0, you can also specify a range of accepted TLS versions as [VLOW]-[VHIGH]. If VLOW is not specified it will use the minimum supported protocol version and if VHIGH is not specified it will use the maximum supported protocol version. This means that using a range where both the low and high values are missing, will accept all the supported methods, but unlike SSLv23 will not require the initial hello to be SSLv2.

Default value is SSLv23.

Danger

For extended compatibility with older system, best use SSLv23.

If you want RFC3261 conformance and all your clients support TLSv1 (or you are planning to use encrypted “tunnels” only between different OpenSIPS proxies) use TLSv1. If you want to support older clients use SSLv23 (in fact most of the applications with SSL support use the SSLv23 method).

Set tls_method variable

...
modparam("tls_mgm", "tls_method", "[dom]TLSv1")
...

Set tls_method range variable

...
modparam("tls_mgm", "tls_method", "[dom]TLSv1-TLSv1_3")  # between v1 and v1.3
modparam("tls_mgm", "tls_method", "[dom]TLSv1-")         # v1 or higher
modparam("tls_mgm", "tls_method", "[dom]-TLSv1_2")       # up to v1.2
modparam("tls_mgm", "tls_method", "[dom]-")              # all supported
...

certificate (domain

Public certificate file for OpenSIPS. It will be used as server-side certificate for incoming TLS connections, and as a client-side certificate for outgoing TLS connections. The domain part represents the name of the TLS domain.

Default value is “CFG_DIR/tls/cert.pem”.

Set certificate variable

...
modparam("tls_mgm", "certificate", "[dom]/mycerts/certs/opensips_server_cert.pem")
...

private_key (domain

Private key of the above certificate. I must be kept in a safe place with tight permissions! The domain part represents the name of the TLS omain.

Default value is “CFG_DIR/tls/ckey.pem”.

Set private_key variable

...
modparam("tls_mgm", "private_key", "[dom]/mycerts/private/prik.pem")
...

ca_list (domain

List of trusted CAs. The file contains the certificates accepted, one after the other. It MUST be a file, not a folder. The domain part represents the name of the TLS domain.

Default value is "".

Set ca_list variable

...
modparam("tls_mgm", "ca_list", "[dom]/mycerts/certs/ca_list.pem")
...

ca_dir (domain

Directory storing trusted CAs. The certificates in the directory must be in hashed form, as described in the openssl documentation for the Hashed Directory Method. The domain part represents the name of the TLS domain.

Default value is “/etc/pki/CA/”.

Set ca_dir variable

...
modparam("tls_mgm", "ca_dir", "[dom]/mycerts/certs")
...

crl_dir (domain

Directory storing certificate revocation lists (CRLs). The domain part represents the name of the TLS domain.

If this parameter is not set, no CRLs will be used.

Set crl_dir variable

...
modparam("tls_mgm", "crl_dir", "[dom]/mycerts/crls")
...

crl_check_all (domain

Setting this parameter with a non-zero integer value enables CRL checking for the entire certificate chain.

By default, only the leaf certificate in the certificate chain is checked.

Set crl_check_all variable

...
modparam("tls_mgm", "crl_check_all", "[dom]1")
...

ciphers_list (domain

You can specify the list of algorithms for authentication and encryption that you allow. The domain part represents the name of the TLS domain. To obtain a list of ciphers and then choose, use the openssl application:

• openssl ciphers ‘ALL:eNULL:!LOW:!EXPORT’

Danger

Do not use the NULL algorithms (no encryption) … only for testing!!!

It defaults to the OpenSSL default ciphers.

Set ciphers_list variable

...
modparam("tls_mgm", "ciphers_list", "[dom]NULL")
...

dh_params (domain

You can specify a file which contains Diffie-Hellman parameters as a PEM-file. This is needed if you would like to specify ciphers including Diffie-Hellman mode. The domain part represents the name of the TLS domain.

It defaults to not set a dh param file.

Set dh_params variable

...
modparam("tls_mgm", "dh_params", "[dom]/etc/pki/CA/dh1024.pem")
...

ec_curve (domain

You can specify an elliptic curve which should be used for ciphers which demand an elliptic curve. The domain part represents the name of the TLS domain.

It’s usable only if TLS v1.1/1.2 support was compiled. A list of curves which can be used you can get by

openssl ecparam -list_curves

It defaults to not set a elliptic curve.

verify_cert (domain

Activates SSL_VERIFY_PEER in the ssl_context. For a detailed explanation, check the openssl documentation.

The domain part represents the name of the TLS domain.

Default value is 1.

Set verify_cert variable

...
modparam("tls_mgm", "verify_cert", "[dom]0")
...

require_cert (domain

Activates SSL_VERIFY_FAIL_IF_NO_PEER_CERT in the ssl_context. For a detailed explanation, check the openssl documentation. This parameter only makes sense for server domains and if the verify cert parameter is also set.

The domain part represents the name of the TLS domain.

Default value is 1.

Set require_cert variable

...
modparam("tls_mgm", "require_cert", "[dom]0")
...

client_tls_domain_avp (string)

Name of the AVP used for enforcing the selection of a specific TLS client domain. Setting this AVP to the name of a TLS client domain will result in using that specific domain regardless of the standard matching mechanism.

Note

If there is already an existing TLS connection to the remote target, it will be reused and setting this AVP has no effect.

No default value.

Set client_tls_domain_avp variable

...
modparam("tls_mgm", "client_tls_domain_avp", "tls_match_dom")
...

client_sip_domain_avp (string)

Name of the AVP that sets the SIP domain used in the TLS client domain matching process.

Note

If there is already an existing TLS connection to the remote target, it will be reused and setting this AVP has no effect.

For the AVP usage example, refer to domains param.

No default value.

Set client_sip_domain_avp variable

...
modparam("tls_mgm", "client_sip_domain_avp", "sip_match_dom")
...

db_url (string)

The database url. It cannot be NULL.

You cannot use the “tls_domain=dom_name” URL parameter for a TLS connection to the database for the tls_mgm module itself.

Usage of db_url block

modparam("tls_mgm", "db_url", "mysql://root:admin@localhost/opensips")

db_table (string)

Sets the database table name.

Default value is “tls_mgm”.

Usage of db_table block

modparam("tls_mgm", "db_table", "tls_mgm")

domain_col (string)

Sets the name for the TLS domain column.

Default value is “domain”.

Usage of domain_col block

modparam("tls_mgm", "domain_col", "tls_domain")

match_ip_address_col (string)

Sets the IP address matching column name.

Default value is “match_ip_address”.

Usage of match_ip_address_col block

modparam("tls_mgm", "match_ip_address_col", "addr")

match_sip_domain_col (string)

Sets the SIP domain matching column name.

Default value is “match_sip_domain”.

Usage of match_sip_domain_col block

modparam("tls_mgm", "match_sip_domain_col", "addr")

tls_method_col (string)

Sets the method column name.

Default value is “method”.

Usage of tls_method_col block

modparam("tls_mgm", "tls_method_col", "method")

verify_cert_col (string)

Sets the verrify certificate column name.

Default value is “verify_cert”.

Usage of vertify_cert_col block

modparam("tls_mgm", "verify_cert_col", "verify_cert")

require_cert_col (string)

Sets the require certificate column name.

Default value is “require_cert”.

Usage of require_cert_col block

modparam("tls_mgm", "require_cert_col", "req")

certificate_col (string)

Sets the certificate column name.

Default value is “certificate”.

Usage of certificate_col block

modparam("tls_mgm", "certificate_col", "certificate")

private_key_col (string)

Sets the private key column name.

Default value is “private_key”.

Usage of private_key_col block

modparam("tls_mgm", "private_key_col", "pk")

crl_check_all_col (string)

Sets the crl_check_all column name.

Default value is “crl_check_all”.

Usage of crl_check_all block

modparam("tls_mgm", "crl_check_all_col", "crl_check")

crl_dir_col (string)

Sets the crl directory column name.

Default value is “crl_dir”.

Usage of crl_dir_col block

modparam("tls_mgm", "crl_dir_col", "crl_dir")

ca_list_col (string)

Sets the CA list column name.

Default value is “ca_list”.

Usage of ca_list_col block

modparam("tls_mgm", "ca_list_col", "ca_list")

ca_dir_col (string)

Sets the CA directory column name.

Default value is “ca_dir”.

Usage of ca_dir_col block

modparam("tls_mgm", "ca_dir_col", "ca_dir")

cipher_list_col (string)

Sets the cipher list column name.

Default value is “cipher_list”.

Usage of cipher_list_col block

modparam("tls_mgm", "cipher_list_col", "cipher_list")

dh_params_col (string)

Sets the Diffie-Hellmann parameters column name.

Default value is “dh_params”.

Usage of dh_params_col block

modparam("tls_mgm", "dh_params_col", "dh_parms")

ec_curve_col (string)

Sets the ec_curve column name.

Default value is “ec_curve”.

Usage of ec_curve_col block

modparam("tls_mgm", "ec_curve_col", "ec_curve")

match_ip_address (string)

The IP addresses and ports used to match a TLS connection with a virtual TLS domain. For TLS server domains, these values will be mathced against the socket on which the connection is received. For TLS client domains, the values will be compared with the destination socket of the connection.

The parameter accepts a list of values, and the special value ”*” means: match any address.

Default value is "" (match any address).*

Set match_ip_address variable

...
modparam("tls_mgm", "match_ip_address", "[dom1]10.0.0.10:5061, 10.0.0.11:5061")
...

match_sip_domain (string)

The SIP domains used to match a TLS connection with a virtual TLS domain. For TLS server domains, these values will be matched against the hostname provided in the TLS Servername extension(SNI). For TLS client domains, the values will be compared with the value of the client sip domain avp AVP.

The parameter accepts a list of FQDNs or the special values:

• * - match any sip domain( including no SNI provided, in case of TLS server domains);
• none - match the TLS domain when there is no SNI provided (make sense only for TLS server domains). Note that if a SNI is provided, but does not match any other SIP domain filter, the connection will be rejected.

The FQDNs can be specified as with Unix shell-style wildcards. If there are multiple potential matches, the most specific domain will be selected(eg. a request for “foo.bar.com” is matched with the domain specified with “foo.bar.com” versus the one with “*.bar.com”).

Default value is ”*” (match any sip domain).

Set match_sip_domain variable

...
modparam("tls_mgm", "match_sip_domain", "[dom1]foo.com, bar.com, *.baz.com")
modparam("tls_mgm", "match_sip_domain", "[default_dom]*")
...

server_domain, client_domain (string)

You can define virtual TLS domains through these parameters.

The value of these parameters represents the virtual tls domain’s name which is only used for identification.

Usage of tls_client_domain and tls_server_domain block

...
socket=tls:10.0.0.10:5061
...
# set the TLS client domain AVP
modparam("tls_mgm", "client_sip_domain_avp", "tls_sip_dom")
...

# 'atlanta' server domain
modparam("tls_mgm", "server_domain", "dom1")
modparam("tls_mgm", "match_ip_address", "[dom1]10.0.0.10:5061")
modparam("tls_mgm", "match_sip_domain", "[dom1]atlanta.com")

modparam("tls_mgm", "certificate", "[dom1]/certs/atlanta.com/cert.pem")
modparam("tls_mgm", "private_key", "[dom1]/certs/atlanta.com/privkey.pem")
modparam("tls_mgm", "ca_list", "[dom1]/certs/wellknownCAs")
modparam("tls_mgm", "tls_method", "[dom1]tlsv1")
modparam("tls_mgm", "verify_cert", "[dom1]1")
modparam("tls_mgm", "require_cert", "[dom1]1")

#'biloxi' server domain
modparam("tls_mgm", "server_domain", "dom2")
modparam("tls_mgm", "match_ip_address", "[dom2]10.0.0.10:5061")
modparam("tls_mgm", "match_sip_domain", "[dom2]biloxi.com")

modparam("tls_mgm", "certificate", "[dom2]/certs/biloxi.com/cert.pem")
modparam("tls_mgm", "private_key", "[dom2]/certs/biloxi.com/privkey.pem")
modparam("tls_mgm", "ca_list", "[dom2]/certs/wellknownCAs")
modparam("tls_mgm", "tls_method", "[dom2]tlsv1")
modparam("tls_mgm", "verify_cert", "[dom2]1")
modparam("tls_mgm", "require_cert", "[dom2]1")

# generic TLS server domain, if the client does not provide SNI
modparam("tls_mgm", "server_domain", "dom3")
modparam("tls_mgm", "match_ip_address", "[dom3]10.0.0.10:5061")
modparam("tls_mgm", "match_sip_domain", "[dom3]none")

modparam("tls_mgm", "certificate", "[dom3]/certs/generic/cert.pem")
modparam("tls_mgm", "private_key", "[dom3]/certs/generic/privkey.pem")
modparam("tls_mgm", "ca_list", "[dom3]/certs/wellknownCAs")
modparam("tls_mgm", "tls_method", "[dom3]tlsv1")
modparam("tls_mgm", "verify_cert", "[dom3]1")
modparam("tls_mgm", "require_cert", "[dom3]1")

# 'atlanta' client domain
modparam("tls_mgm", "client_domain", "dom4")
modparam("tls_mgm", "match_ip_address", "[dom4]*")
modparam("tls_mgm", "match_sip_domain", "[dom4]atlanta.com")


modparam("tls_mgm", "certificate", "[dom4]/certs/atlanta.com/cert.pem")
modparam("tls_mgm", "private_key", "[dom4]/certs/atlanta.com/privkey.pem")
modparam("tls_mgm", "ca_list", "[dom4]/certs/wellknownCAs")
modparam("tls_mgm", "tls_method", "[dom4]tlsv1")
modparam("tls_mgm", "verify_cert", "[dom4]1")
modparam("tls_mgm", "require_cert", "[dom4]1")

# 'biloxi' client domain
modparam("tls_mgm", "client_domain", "dom5")
modparam("tls_mgm", "match_ip_address", "[dom5]*")
modparam("tls_mgm", "match_sip_domain", "[dom5]biloxi.com")

modparam("tls_mgm", "certificate", "[dom5]/certs/biloxi.com/cert.pem")
modparam("tls_mgm", "private_key", "[dom5]/certs/biloxi.com/privkey.pem")
modparam("tls_mgm", "ca_list", "[dom5]/certs/wellknownCAs")
modparam("tls_mgm", "tls_method", "[dom5]tlsv1")
modparam("tls_mgm", "verify_cert", "[dom5]1")
modparam("tls_mgm", "require_cert", "[dom5]1")

# TLS client domain for GW provider
modparam("tls_mgm", "client_domain", "dom6")
modparam("tls_mgm", "match_ip_address", "[dom6]1.2.3.4:6677")
modparam("tls_mgm", "match_sip_domain", "[dom6]*")

modparam("tls_mgm", "certificate", "[dom6]/certs/gw/cert.pem")
modparam("tls_mgm", "private_key", "[dom6]/certs/gw/privkey.pem")
modparam("tls_mgm", "ca_list", "[dom6]/certs/wellknownCAs")
modparam("tls_mgm", "tls_method", "[dom6]tlsv1")
modparam("tls_mgm", "verify_cert", "[dom6]0")

...
route{
...
    # we match the TLS client domain using the SIP domain in the RURI
    $avp(tls_sip_dom) = $rd;
    t_relay();
    exit;
...
    # calls to the PSTN GW, will match the correct TLS domain by IP
    t_relay("tls:1.2.3.4:6677");
    exit;
...

Variables

This module exports the follong variables:

Some variables are available for both, the peer’S certificate and the local certificate. Further, some parameters can be read from the “Subject” field or the “Issuer” field.

$tls_version

$tls_version - the TLS/SSL version which is used on the TLS connection from which the message was received. String type.

$tls_description

$tls_description - the TLS/SSL description of the TLS connection from which the message was received. String type.

$tls_cipher_info

$tls_cipher_info - the TLS/SSL cipher which is used on the TLS connection from which the message was received. String type.

$tls_cipher_bits

$tls_cipher_bits - the number of cipher bits which are used on the TLS connection from which the message was received. String and Integer type.

$tls_[peer|my]_version

$tls_[peer|my]_version - the version of the certificate. String type.

$tls_[peer|my]_serial

$tls_[peer|my]_serial - the serial number of the certificate. String and Integer type.

$tls_[peer|my]_[subject|issuer]

$tls_[peer|my]_[subject|issuer] - ASCII dump of the fields in the issuer/subject section of the certificate. String type.

Example of $tls_[peer|my]_[subject|issuer]

/C=AT/ST=Vienna/L=Vienna/O=enum.at/CN=enum.at

$tls_[peer|my]_[subject|issuer]_cn

$tls_[peer|my]_[subject|issuer]_cn - commonName in the issuer/subject section of the certificate. String type.

$tls_[peer|my]_[subject|issuer]_locality

$tls_[peer|my]_[subject|issuer]_locality - localityName in the issuer/subject section of the certificate. String type.

$tls_[peer|my]_[subject|issuer]_country

$tls_[peer|my]_[subject|issuer]_country - countryName in the issuer/subject section of the certificate. String type.

$tls_[peer|my]_[subject|issuer]_state

$tls_[peer|my]_[subject|issuer]_state - stateOrProvinceName in the issuer/subject section of the certificate. String type.

$tls_[peer|my]_[subject|issuer]_organization

$tls_[peer|my]_[subject|issuer]_organization - organizationName in the issuer/subject section of the certificate. String type.

$tls_[peer|my]_[subject|issuer]_unit

$tls_[peer|my]_[subject|issuer]_unit - organizationalUnitName in the issuer/subject section of the certificate. String type.

$tls_[peer|my]_san_email

$tls_[peer|my]_san_email - email address in the “subject alternative name” extension. String type.

$tls_[peer|my]_san_hostname

$tls_[peer|my]_san_hostname - hostname (DNS) in the “subject alternative name” extension. String type.

$tls_[peer|my]_san_uri

$tls_[peer|my]_san_uri - URI in the “subject alternative name” extension. String type.

$tls_[peer|my]_san_ip

$tls_[peer|my]_san_ip - ip address in the “subject alternative name” extension. String type.

$tls_peer_verified

$tls_peer_verified - Returns 1 if the peer’s certificate was successful verified. Otherwise it returns 0. String and Integer type.

$tls_peer_revoked

$tls_peer_revoked - Returns 1 if the peer’s certificate was revoked. Otherwise it returns 0. String and Integer type.

$tls_peer_expired

$tls_peer_expired - Returns 1 if the peer’s certificate is expired. Otherwise it returns 0. String and Integer type.

$tls_peer_selfsigned

$tls_peer_selfsigned - Returns 1 if the peer’s certificate is selfsigned. Otherwise it returns 0. String and Integer type.

$tls_peer_notBefore

$tls_peer_notBefore - Returns the notBefore validity date of the peer’s certificate. String type.

$tls_peer_notAfter

$tls_peer_notAfter - Returns the notAfter validity date of the peer’s certificate. String type.

OpenSIPS with TLS - script example

Caution

The TLS support is based on TCP, and for allowing OpenSIPS to use TCP, it must be started in multi-process mode. So, there is a must to have the “fork” parameter set to “yes”:

Note

Since the TLS engine is quite memory consuming, increase the used memory by the run time parameter “-m” (see OpenSIPS -h for more details).

• fork = yes

Script with TLS support

  # ----------- global configuration parameters ------------------------
  log_level=3
  log_stderror=no

  check_via=no
  dns=no
  rev_dns=no
  socket=udp:your_serv_IP:5060
  socket=tls:your_serv_IP:5061
  udp_workers=4

  # ------------------ module loading ----------------------------------

  loadmodule "proto_tls.so"
  loadmodule "proto_udp.so"

  #TLS specific settings
  loadmodule "tls_mgm.so"

  modparam("tls_mgm", "certificate", "/path/opensipsX_cert.pem")
  modparam("tls_mgm", "private_key", "/path/privkey.pem")
  modparam("tls_mgm", "ca_list", "/path/calist.pem")
  modparam("tls_mgm", "ca_list", "/path/calist.pem")
  modparam("tls_mgm", "require_cert", "1")
  modparam("tls_mgm", "verify_cert", "1")

  alias=_DNS_ALIAS_


  loadmodule "sl.so"
  loadmodule "rr.so"
  loadmodule "maxfwd.so"
  loadmodule "mysql.so"
  loadmodule "usrloc.so"
  loadmodule "registrar.so"
  loadmodule "tm.so"
  loadmodule "auth.so"
  loadmodule "auth_db.so"
  loadmodule "textops.so"
  loadmodule "sipmsgops.so"
  loadmodule "signaling.so"
  loadmodule "uri_db.so"

  # ----------------- setting module-specific parameters ---------------

  # -- auth_db params --
  modparam("auth_db", "db_url", "sql_url")
  modparam("auth_db", "password_column", "password")
  modparam("auth_db", "calculate_ha1", 1)

  # -- registrar params --
  # no multiple registrations
  modparam("registrar", "append_branches", 0)

  # -------------------------  request routing logic -------------------

  # main routing logic

  route{

  # initial sanity checks
  if (!mf_process_maxfwd_header("10")) {
      send_reply("483","Too Many Hops");
      exit;
  };

  # if somene claims to belong to our domain in From,
  # challenge him (skip REGISTERs -- we will chalenge them later)
  if (is_myself("$fd")) {
      setflag(1);
      if ( is_method("INVITE|SUBSCRIBE|MESSAGE")
      && !(is_myself("$si")) ) {
          if  (!(proxy_authorize( "domA.net", "subscriber" ))) {
              proxy_challenge("domA.net","0"/*no-qop*/);
              exit;
          };
          if ($au!=$fU) {
              xlog("FROM hdr Cheating attempt in INVITE\n");
              send_reply("403",
                  "That is ugly -- use From=id next time (OB)");
              exit;
          };
      }; # non-REGISTER from other domain
  } else if ( is_method("INVITE") && !is_myself("$rd") ) {
      send_reply("403", "No relaying");
      exit;
  };

  /* ********   do record-route and loose-route ******* */
  if (!is_method("REGISTER"))
      record_route();

  if (loose_route()) {
      append_hf("P-hint: rr-enforced\r\n");
      t_relay();
      exit;
  };

  /* ******* check for requests targeted out of our domain ******* */
  if ( !is_myself("$rd") ) {
      append_hf("P-hint: OUTBOUND\r\n");
      if ($rd=="domB.net") {
          t_relay("tls:domB.net:5061");
      } else if ($rd=="domC.net") {
          t_relay("tls:domC.net:5061");
      } else {
          t_relay();
      };
      exit;
  };

  /* ******* divert to other domain according to prefixes ******* */
  if (!is_method("REGISTER")) {
      if ( $ru=~"sip:201") {
          strip(3);
          $rd = "domB.net";
          t_relay("tls:domB.net:5061");
          exit;
      } else if ( $ru=~"sip:202" ) {
          strip(3);
          $rd = "domC.net";
          t_relay("tls:domC.net:5061");
          exit;
      };
  };

  /* ************ requests for our domain ********** */
  if (is_method("REGISTER")) {
      if (!www_authorize( "domA.net", "subscriber" )) {
          # challenge if none or invalid credentials
          www_challenge( "domA.net" /* realm */,
              "0" /* no qop -- some phones can't deal with it */);
          exit;
      };
      if ($au!=$tU) {
          xlog("TO hdr Cheating attempt\n");
          send_reply("403", "That is ugly -- use To=id in REGISTERs");
          exit;
      };
      # it is an authenticated request, update Contact database now
      if (!save("location")) {
          sl_reply_error();
      };
      exit;
  };

  # native SIP destinations are handled using USRLOC DB
  if (!lookup("location")) {
      # handle user which was not found
      send_reply("404", "Not Found");
      exit;
  };

  # remove all present Alert-info headers
  remove_hf("Alert-Info");

  if (is_method("INVITE") && ($rP=="TLS" || isflagset(1))) {
      append_hf("Alert-info: 1\r\n");                     # cisco 7960
      append_hf("Alert-info: Bellcore-dr4\r\n");          # cisco ATA
      append_hf("Alert-info: http://foo.bar/x.wav\r\n");  # snom
  };

  # do forwarding
  if (!t_relay()) {
      sl_reply_error();
  };

  #end of script
  }

Debug TLS connections

If you want to debug TLS connections, put the following log statements into your OpenSIPS.cfg. This will dump all available TLS pseudo variables.

Example of TLS logging

xlog("L_INFO","================= start TLS pseudo variables ===============\n");
xlog("L_INFO","$$tls_version                   = '$tls_version'\n");
xlog("L_INFO","$$tls_description               = '$tls_description'\n");
xlog("L_INFO","$$tls_cipher_info               = '$tls_cipher_info'\n");
xlog("L_INFO","$$tls_cipher_bits               = '$tls_cipher_bits'\n");
xlog("L_INFO","$$tls_peer_subject              = '$tls_peer_subject'\n");
xlog("L_INFO","$$tls_peer_issuer               = '$tls_peer_issuer'\n");
xlog("L_INFO","$$tls_my_subject                = '$tls_my_subject'\n");
xlog("L_INFO","$$tls_my_issuer                 = '$tls_my_issuer'\n");
xlog("L_INFO","$$tls_peer_version              = '$tls_peer_version'\n");
xlog("L_INFO","$$tls_my_version                = '$tls_my_version'\n");
xlog("L_INFO","$$tls_peer_serial               = '$tls_peer_serial'\n");
xlog("L_INFO","$$tls_my_serial                 = '$tls_my_serial'\n");
xlog("L_INFO","$$tls_peer_subject_cn           = '$tls_peer_subject_cn'\n");
xlog("L_INFO","$$tls_peer_issuer_cn            = '$tls_peer_issuer_cn'\n");
xlog("L_INFO","$$tls_my_subject_cn             = '$tls_my_subject_cn'\n");
xlog("L_INFO","$$tls_my_issuer_cn              = '$tls_my_issuer_cn'\n");
xlog("L_INFO","$$tls_peer_subject_locality     = '$tls_peer_subject_locality'\n");
xlog("L_INFO","$$tls_peer_issuer_locality      = '$tls_peer_issuer_locality'\n");
xlog("L_INFO","$$tls_my_subject_locality       = '$tls_my_subject_locality'\n");
xlog("L_INFO","$$tls_my_issuer_locality        = '$tls_my_issuer_locality'\n");
xlog("L_INFO","$$tls_peer_subject_country      = '$tls_peer_subject_country'\n");
xlog("L_INFO","$$tls_peer_issuer_country       = '$tls_peer_issuer_country'\n");
xlog("L_INFO","$$tls_my_subject_country        = '$tls_my_subject_country'\n");
xlog("L_INFO","$$tls_my_issuer_country         = '$tls_my_issuer_country'\n");
xlog("L_INFO","$$tls_peer_subject_state        = '$tls_peer_subject_state'\n");
xlog("L_INFO","$$tls_peer_issuer_state         = '$tls_peer_issuer_state'\n");
xlog("L_INFO","$$tls_my_subject_state          = '$tls_my_subject_state'\n");
xlog("L_INFO","$$tls_my_issuer_state           = '$tls_my_issuer_state'\n");
xlog("L_INFO","$$tls_peer_subject_organization = '$tls_peer_subject_organization'\n");
xlog("L_INFO","$$tls_peer_issuer_organization  = '$tls_peer_issuer_organization'\n");
xlog("L_INFO","$$tls_my_subject_organization   = '$tls_my_subject_organization'\n");
xlog("L_INFO","$$tls_my_issuer_organization    = '$tls_my_issuer_organization'\n");
xlog("L_INFO","$$tls_peer_subject_unit         = '$tls_peer_subject_unit'\n");
xlog("L_INFO","$$tls_peer_issuer_unit          = '$tls_peer_issuer_unit'\n");
xlog("L_INFO","$$tls_my_subject_unit           = '$tls_my_subject_unit'\n");
xlog("L_INFO","$$tls_my_issuer_unit            = '$tls_my_issuer_unit'\n");
xlog("L_INFO","$$tls_peer_san_email            = '$tls_peer_san_email'\n");
xlog("L_INFO","$$tls_my_san_email              = '$tls_my_san_email'\n");
xlog("L_INFO","$$tls_peer_san_hostname         = '$tls_peer_san_hostname'\n");
xlog("L_INFO","$$tls_my_san_hostname           = '$tls_my_san_hostname'\n");
xlog("L_INFO","$$tls_peer_san_uri              = '$tls_peer_san_uri'\n");
xlog("L_INFO","$$tls_my_san_uri                = '$tls_my_san_uri'\n");
xlog("L_INFO","$$tls_peer_san_ip               = '$tls_peer_san_ip'\n");
xlog("L_INFO","$$tls_my_san_ip                 = '$tls_my_san_ip'\n");
xlog("L_INFO","$$tls_peer_verified             = '$tls_peer_verified'\n");
xlog("L_INFO","$$tls_peer_revoked              = '$tls_peer_revoked'\n");
xlog("L_INFO","$$tls_peer_expired              = '$tls_peer_expired'\n");
xlog("L_INFO","$$tls_peer_selfsigned           = '$tls_peer_selfsigned'\n");
xlog("L_INFO","$$tls_peer_notBefore            = '$tls_peer_notBefore'\n");
xlog("L_INFO","$$tls_peer_notAfter             = '$tls_peer_notAfter'\n");
xlog("L_INFO","================= end TLS pseudo variables ===============\n");

Developer Guide

API Functions

find_server_domain

struct tls_domain *find_server_domain(struct ip_addr *ip, unsigned short port);

Find a TLS server domain with given ip and port (local listening socket).

find_client_domain

struct tls_domain *find_client_domain(struct ip_addr *ip, unsigned short port);

Find TLS client domain.

get_handshake_timeout

int get_handshake_timeout(void);

Returns the handshanke timeout.

get_send_timeout

int get_send_timeout(void);

Returns the send timeout.

TLS_CONFIG

It contains configuration variables for OpenSIPS’s TLS (timeouts, file paths, etc).

TLS_INIT

Initialization related functions and parameters.

ssl context

extern SSL_CTX *default_client_ctx;

The ssl context is a member of the TLS domain strcuture. Thus, every TLS domain, default and virtual - servers and clients, have its own SSL context.

pre_init_tls

int init_tls(void);

Called once to pre_initialize the tls subsystem, from the main(). Called before parsing the configuration file.

init_tls

int init_tls(void);

Called once to initialize the tls subsystem, from the main(). Called after parsing the configuration file.

destroy_tls

void destroy_tls(void);

Called once, just before cleanup.

tls_init

int tls_init(struct socket_info *c);

Called once for each tls socket created, from main.c

os_malloc, os_realloc, os_free

Wrapper functions around the shm_* functions. OpenSSL uses non-shared memory to create its objects, thus it would not work in OpenSIPS. By creating these wrappers and configuring OpenSSL to use them instead of its default memory functions, we have all OpenSSL objects in shared memory, ready to use.

TLS_DOMAIN

tls_domains

extern struct tls_domain *tls_default_server_domain;

The default TLS server domain.

extern struct tls_domain *tls_default_client_domain;

The default TLS client domain.

extern struct tls_domain *tls_server_domains;

List with defined server domains.

extern struct tls_domain *tls_client_domains;

List with defined client domains.

tls_find_server_domain

struct tls_domain *tls_find_server_domain(struct ip_addr *ip, unsigned short port);

Find a TLS server domain with given ip and port (local listening socket).

tls_find_client_domain

struct tls_domain *tls_find_client_domain(struct ip_addr *ip, unsigned short port);

Find TLS client domain.

tls_find_client_domain_addr

struct tls_domain *tls_find_client_domain_addr(struct ip_addr *ip, unsigned short port);

Find TLS client domain with given ip and port (socket of the remote destination).

tls_find_client_domain_name

struct tls_domain *tls_find_client_name(str name);

Find TLS client domain with given name.

tls_new__domain

struct tls_domain *tls_new_domain(int type);

Creates new TLS: allocate memory, set the type and initialize members

tls_new_server_domain

int tls_new_server_domain(struct ip_addr *ip, unsigned short port);

Creates and adds to the list of TLS server domains a new domain.

tls_new_client_domain

int tls_new_client_domain(struct ip_addr *ip, unsigned short port);

Creates and adds to the list of TLS client domains a new socket based domain.

tls_new_client_domain_name

int tls_new_client_domain_name(char *s, int len);

Creates and adds to the list of TLS client domains a new name based domain.

tls_free_domains

void tls_free_domains(void);

Cleans up the entire domain lists.

Contributors

By Commit Statistics

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

#	Name	DevScore	Commits	Lines++	Lines—
1.	Vlad Patrascu (@rvlad-patrascu)	124	44	3951	2727
2.	Razvan Crainea (@razvancrainea)	84	54	1824	800
3.	Eseanu Marius Cristian (@eseanucristian)	73	11	6365	466
4.	Liviu Chircu (@liviuchircu)	26	20	181	236
5.	Stefan Darius (@dariusstefan)	26	5	1889	264
6.	Bogdan-Andrei Iancu (@bogdan-iancu)	25	13	336	505
7.	Dan Pascu (@danpascu)	17	13	93	179
8.	Ionut Ionita (@ionutrazvanionita)	17	9	398	184
9.	Ionel Cerghit (@ionel-cerghit)	8	1	504	119
10.	Alexey Vasilyev (@vasilevalex)	4	2	36	22

All remaining contributors: Maksym Sobolyev (@sobomax), Callum Guy (@spacetourist), Aleksei Vasilev, Fabian Gast (@fgast), Peter Lemenkov (@lemenkov), Ovidiu Sas (@ovidiusas).

(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)	Sep 2015 - Jun 2026
3.	Vlad Patrascu (@rvlad-patrascu)	Apr 2017 - Nov 2021
4.	Liviu Chircu (@liviuchircu)	Oct 2015 - Jul 2021
5.	Aleksei Vasilev	Apr 2021 - Apr 2021
6.	Maksym Sobolyev (@sobomax)	Mar 2016 - Sep 2020
7.	Bogdan-Andrei Iancu (@bogdan-iancu)	Mar 2016 - Apr 2020
8.	Dan Pascu (@danpascu)	Jun 2019 - Feb 2020
9.	Fabian Gast (@fgast)	Jan 2020 - Jan 2020
10.	Alexey Vasilyev (@vasilevalex)	Nov 2018 - May 2019

All remaining contributors: Callum Guy (@spacetourist), Peter Lemenkov (@lemenkov), Ovidiu Sas (@ovidiusas), Ionut Ionita (@ionutrazvanionita), Ionel Cerghit (@ionel-cerghit), Eseanu Marius Cristian (@eseanucristian).

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

Documentation

Contributors

Last edited by: Razvan Crainea (@razvancrainea), Liviu Chircu (@liviuchircu), Bogdan-Andrei Iancu (@bogdan-iancu), Dan Pascu (@danpascu), Vlad Patrascu (@rvlad-patrascu), Callum Guy (@spacetourist), Peter Lemenkov (@lemenkov), Eseanu Marius Cristian (@eseanucristian).

License

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