TLS_MGM module
     __________________________________________________________

   Table of Contents

   1. Admin Guide

        1.1. Overview
        1.2. Usage
        1.3. TLS domains
        1.4. Defining TLS domains
        1.5. Dependencies of external libraries
        1.6. Exported Functions

              1.6.1. is_peer_verified

        1.7. Exported MI Functions

              1.7.1. tls_list
              1.7.2. tls_reload

        1.8. OpenSIPS Exported parameters

              1.8.1. listen=interface
              1.8.2. tls_method ([domain]string)
              1.8.3. certificate ([domain](string)
              1.8.4. private_key ([domain](string)
              1.8.5. ca_list ([domain](string)
              1.8.6. ca_dir ([domain](string)
              1.8.7. crl_dir ([domain](string)
              1.8.8. crl_check_all ([domain](string)
              1.8.9. ciphers_list ([domain](string)
              1.8.10. dh_params ([domain](string)
              1.8.11. ec_curve ([domain](string)
              1.8.12. verify_cert ([domain](string)
              1.8.13. require_cert ([domain](string)
              1.8.14. client_tls_domain_avp (string)
              1.8.15. client_sip_domain_avp (string)
              1.8.16. db_url (string)
              1.8.17. db_table (string)
              1.8.18. domain_col (string)
              1.8.19. match_ip_address_col (string)
              1.8.20. match_sip_domain_col (string)
              1.8.21. tls_method_col (string)
              1.8.22. verify_cert_col (string)
              1.8.23. require_cert_col (string)
              1.8.24. certificate_col (string)
              1.8.25. private_key_col (string)
              1.8.26. crl_check_all_col (string)
              1.8.27. crl_dir_col (string)
              1.8.28. ca_list_col (string)
              1.8.29. ca_dir_col (string)
              1.8.30. cipher_list_col (string)
              1.8.31. dh_params_col (string)
              1.8.32. ec_curve_col (string)
              1.8.33. match_ip_address (string)
              1.8.34. match_sip_domain (string)
              1.8.35. server_domain, client_domain (string)

        1.9. Variables

              1.9.1. $tls_version
              1.9.2. $tls_description
              1.9.3. $tls_cipher_info
              1.9.4. $tls_cipher_bits
              1.9.5. $tls_[peer|my]_version
              1.9.6. $tls_[peer|my]_serial
              1.9.7. $tls_[peer|my]_[subject|issuer]
              1.9.8. $tls_[peer|my]_[subject|issuer]_cn
              1.9.9. $tls_[peer|my]_[subject|issuer]_locality
              1.9.10. $tls_[peer|my]_[subject|issuer]_country
              1.9.11. $tls_[peer|my]_[subject|issuer]_state
              1.9.12. $tls_[peer|my]_[subject|issuer]_organization
              1.9.13. $tls_[peer|my]_[subject|issuer]_unit
              1.9.14. $tls_[peer|my]_san_email
              1.9.15. $tls_[peer|my]_san_hostname
              1.9.16. $tls_[peer|my]_san_uri
              1.9.17. $tls_[peer|my]_san_ip
              1.9.18. $tls_peer_verified
              1.9.19. $tls_peer_revoked
              1.9.20. $tls_peer_expired
              1.9.21. $tls_peer_selfsigned
              1.9.22. $tls_peer_notBefore
              1.9.23. $tls_peer_notAfter

        1.10. OpenSIPS with TLS - script example
        1.11. Debug TLS connections

   2. Developer Guide

        2.1. API Functions

              2.1.1. find_server_domain
              2.1.2. find_client_domain
              2.1.3. get_handshake_timeout
              2.1.4. get_send_timeout

        2.2. TLS_CONFIG
        2.3. TLS_INIT

              2.3.1. ssl context
              2.3.2. pre_init_tls
              2.3.3. init_tls
              2.3.4. destroy_tls
              2.3.5. tls_init
              2.3.6. os_malloc, os_realloc, os_free

        2.4. TLS_DOMAIN

              2.4.1. tls_domains
              2.4.2. tls_find_server_domain
              2.4.3. tls_find_client_domain
              2.4.4. tls_find_client_domain_addr
              2.4.5. tls_find_client_domain_name
              2.4.6. tls_new__domain
              2.4.7. tls_new_server_domain
              2.4.8. tls_new_client_domain
              2.4.9. tls_new_client_domain_name
              2.4.10. tls_free_domains

   3. Contributors

        3.1. By Commit Statistics
        3.2. By Commit Activity

   4. Documentation

        4.1. Contributors

   List of Tables

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

   3.2. Most recently active contributors^(1) to this module

   List of Examples

   1.1. is_peer_verified usage
   1.2. Set listen variable
   1.3. Set tls_method variable
   1.4. Set tls_method range variable
   1.5. Set certificate variable
   1.6. Set private_key variable
   1.7. Set ca_list variable
   1.8. Set ca_dir variable
   1.9. Set crl_dir variable
   1.10. Set crl_check_all variable
   1.11. Set ciphers_list variable
   1.12. Set dh_params variable
   1.13. Set verify_cert variable
   1.14. Set require_cert variable
   1.15. Set client_tls_domain_avp variable
   1.16. Set client_sip_domain_avp variable
   1.17. Usage of db_url block
   1.18. Usage of db_table block
   1.19. Usage of domain_col block
   1.20. Usage of match_ip_address_col block
   1.21. Usage of match_sip_domain_col block
   1.22. Usage of tls_method_col block
   1.23. Usage of vertify_cert_col block
   1.24. Usage of require_cert_col block
   1.25. Usage of certificate_col block
   1.26. Usage of private_key_col block
   1.27. Usage of crl_check_all block
   1.28. Usage of crl_dir_col block
   1.29. Usage of ca_list_col block
   1.30. Usage of ca_dir_col block
   1.31. Usage of cipher_list_col block
   1.32. Usage of dh_params_col block
   1.33. Usage of ec_curve_col block
   1.34. Set match_ip_address variable
   1.35. Set match_sip_domain variable
   1.36. Usage of tls_client_domain and tls_server_domain block
   1.37. Example of $tls_[peer|my]_[subject|issuer]
   1.38. Script with TLS support
   1.39. Example of TLS logging

Chapter 1. Admin Guide

1.1. 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.

1.2. 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 Section 1.10, “OpenSIPS with TLS - script example”.

1.3. 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.

1.4. 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

1.5. 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

1.6. Exported Functions

1.6.1.  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.

   Example 1.1. 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");
}
...

1.7. Exported MI Functions

1.7.1.  tls_list

   List all domains information.

1.7.2.  tls_reload

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

1.8. OpenSIPS Exported parameters

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

1.8.1. 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.

   Example 1.2. Set listen variable
...
socket= tls:1.2.3.4:5061
...

1.8.2. 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.

Warning

   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).

   Example 1.3. Set tls_method variable
...
modparam("tls_mgm", "tls_method", "[dom]TLSv1")
...

   Example 1.4. Set tls_method range variable
...
modparam("tls_mgm", "tls_method", "[dom]TLSv1-TLSv1_3")  # between v1 an
d 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
...

1.8.3. certificate ([domain](string)

   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".

   Example 1.5. Set certificate variable
...
modparam("tls_mgm", "certificate", "[dom]/mycerts/certs/opensips_server_
cert.pem")
...

1.8.4. private_key ([domain](string)

   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".

   Example 1.6. Set private_key variable
...
modparam("tls_mgm", "private_key", "[dom]/mycerts/private/prik.pem")
...

1.8.5. ca_list ([domain](string)

   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 "".

   Example 1.7. Set ca_list variable
...
modparam("tls_mgm", "ca_list", "[dom]/mycerts/certs/ca_list.pem")
...

1.8.6. ca_dir ([domain](string)

   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/".

   Example 1.8. Set ca_dir variable
...
modparam("tls_mgm", "ca_dir", "[dom]/mycerts/certs")
...

1.8.7. crl_dir ([domain](string)

   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.

   Example 1.9. Set crl_dir variable
...
modparam("tls_mgm", "crl_dir", "[dom]/mycerts/crls")
...

1.8.8. crl_check_all ([domain](string)

   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.

   Example 1.10. Set crl_check_all variable
...
modparam("tls_mgm", "crl_check_all", "[dom]1")
...

1.8.9. ciphers_list ([domain](string)

   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'

Warning

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

   It defaults to the OpenSSL default ciphers.

   Example 1.11. Set ciphers_list variable
...
modparam("tls_mgm", "ciphers_list", "[dom]NULL")
...

1.8.10. dh_params ([domain](string)

   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.

   Example 1.12. Set dh_params variable
...
modparam("tls_mgm", "dh_params", "[dom]/etc/pki/CA/dh1024.pem")
...

1.8.11. ec_curve ([domain](string)

   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.

1.8.12. verify_cert ([domain](string)

   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.

   Example 1.13. Set verify_cert variable
...
modparam("tls_mgm", "verify_cert", "[dom]0")
...

1.8.13. require_cert ([domain](string)

   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.

   Example 1.14. Set require_cert variable
...
modparam("tls_mgm", "require_cert", "[dom]0")
...

1.8.14. 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.

   Example 1.15. Set client_tls_domain_avp variable
...
modparam("tls_mgm", "client_tls_domain_avp", "tls_match_dom")
...

1.8.15. 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 Section 1.8.35,
   “server_domain, client_domain (string)”.

   No default value.

   Example 1.16. Set client_sip_domain_avp variable
...
modparam("tls_mgm", "client_sip_domain_avp", "sip_match_dom")
...

1.8.16. 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.

   Example 1.17. Usage of db_url block
modparam("tls_mgm", "db_url", "mysql://root:admin@localhost/opensips")

1.8.17.  db_table (string)

   Sets the database table name.

   Default value is "tls_mgm".

   Example 1.18. Usage of db_table block
modparam("tls_mgm", "db_table", "tls_mgm")

1.8.18.  domain_col (string)

   Sets the name for the TLS domain column.

   Default value is "domain".

   Example 1.19. Usage of domain_col block
modparam("tls_mgm", "domain_col", "tls_domain")

1.8.19.  match_ip_address_col (string)

   Sets the IP address matching column name.

   Default value is "match_ip_address".

   Example 1.20. Usage of match_ip_address_col block
modparam("tls_mgm", "match_ip_address_col", "addr")

1.8.20.  match_sip_domain_col (string)

   Sets the SIP domain matching column name.

   Default value is "match_sip_domain".

   Example 1.21. Usage of match_sip_domain_col block
modparam("tls_mgm", "match_sip_domain_col", "addr")

1.8.21.  tls_method_col (string)

   Sets the method column name.

   Default value is "method".

   Example 1.22. Usage of tls_method_col block
modparam("tls_mgm", "tls_method_col", "method")

1.8.22.  verify_cert_col (string)

   Sets the verrify certificate column name.

   Default value is "verify_cert".

   Example 1.23. Usage of vertify_cert_col block
modparam("tls_mgm", "verify_cert_col", "verify_cert")

1.8.23.  require_cert_col (string)

   Sets the require certificate column name.

   Default value is "require_cert".

   Example 1.24. Usage of require_cert_col block
modparam("tls_mgm", "require_cert_col", "req")

1.8.24.  certificate_col (string)

   Sets the certificate column name.

   Default value is "certificate".

   Example 1.25. Usage of certificate_col block
modparam("tls_mgm", "certificate_col", "certificate")

1.8.25.  private_key_col (string)

   Sets the private key column name.

   Default value is "private_key".

   Example 1.26. Usage of private_key_col block
modparam("tls_mgm", "private_key_col", "pk")

1.8.26.  crl_check_all_col (string)

   Sets the crl_check_all column name.

   Default value is "crl_check_all".

   Example 1.27. Usage of crl_check_all block
modparam("tls_mgm", "crl_check_all_col", "crl_check")

1.8.27.  crl_dir_col (string)

   Sets the crl directory column name.

   Default value is "crl_dir".

   Example 1.28. Usage of crl_dir_col block
modparam("tls_mgm", "crl_dir_col", "crl_dir")

1.8.28.  ca_list_col (string)

   Sets the CA list column name.

   Default value is "ca_list".

   Example 1.29. Usage of ca_list_col block
modparam("tls_mgm", "ca_list_col", "ca_list")

1.8.29.  ca_dir_col (string)

   Sets the CA directory column name.

   Default value is "ca_dir".

   Example 1.30. Usage of ca_dir_col block
modparam("tls_mgm", "ca_dir_col", "ca_dir")

1.8.30.  cipher_list_col (string)

   Sets the cipher list column name.

   Default value is "cipher_list".

   Example 1.31. Usage of cipher_list_col block
modparam("tls_mgm", "cipher_list_col", "cipher_list")

1.8.31.  dh_params_col (string)

   Sets the Diffie-Hellmann parameters column name.

   Default value is "dh_params".

   Example 1.32. Usage of dh_params_col block
modparam("tls_mgm", "dh_params_col", "dh_parms")

1.8.32.  ec_curve_col (string)

   Sets the ec_curve column name.

   Default value is "ec_curve".

   Example 1.33. Usage of ec_curve_col block
modparam("tls_mgm", "ec_curve_col", "ec_curve")

1.8.33. 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).

   Example 1.34. Set match_ip_address variable
...
modparam("tls_mgm", "match_ip_address", "[dom1]10.0.0.10:5061, 10.0.0.11
:5061")
...

1.8.34. 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).

   Example 1.35. Set match_sip_domain variable
...
modparam("tls_mgm", "match_sip_domain", "[dom1]foo.com, bar.com, *.baz.c
om")
modparam("tls_mgm", "match_sip_domain", "[default_dom]*")
...

1.8.35. 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.

   Example 1.36. 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;
...

1.9. 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.

1.9.1. $tls_version

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

1.9.2. $tls_description

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

1.9.3. $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.

1.9.4. $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.

1.9.5. $tls_[peer|my]_version

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

1.9.6. $tls_[peer|my]_serial

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

1.9.7. $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 1.37. Example of $tls_[peer|my]_[subject|issuer]
/C=AT/ST=Vienna/L=Vienna/O=enum.at/CN=enum.at

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

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

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

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

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

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

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

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

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

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

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

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

1.9.14. $tls_[peer|my]_san_email

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

1.9.15. $tls_[peer|my]_san_hostname

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

1.9.16. $tls_[peer|my]_san_uri

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

1.9.17. $tls_[peer|my]_san_ip

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

1.9.18. $tls_peer_verified

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

1.9.19. $tls_peer_revoked

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

1.9.20. $tls_peer_expired

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

1.9.21. $tls_peer_selfsigned

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

1.9.22. $tls_peer_notBefore

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

1.9.23. $tls_peer_notAfter

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

1.10. OpenSIPS with TLS - script example

   IMPORTANT: 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

   Example 1.38. 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
  }

1.11. 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 1.39. 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","$$tls_peer_subject_locality     = '$tls_peer_subject_loca
lity'\n");
xlog("L_INFO","$$tls_peer_issuer_locality      = '$tls_peer_issuer_local
ity'\n");
xlog("L_INFO","$$tls_my_subject_locality       = '$tls_my_subject_locali
ty'\n");
xlog("L_INFO","$$tls_my_issuer_locality        = '$tls_my_issuer_localit
y'\n");
xlog("L_INFO","$$tls_peer_subject_country      = '$tls_peer_subject_coun
try'\n");
xlog("L_INFO","$$tls_peer_issuer_country       = '$tls_peer_issuer_count
ry'\n");
xlog("L_INFO","$$tls_my_subject_country        = '$tls_my_subject_countr
y'\n");
xlog("L_INFO","$$tls_my_issuer_country         = '$tls_my_issuer_country
'\n");
xlog("L_INFO","$$tls_peer_subject_state        = '$tls_peer_subject_stat
e'\n");
xlog("L_INFO","$$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","$$tls_peer_subject_organization = '$tls_peer_subject_orga
nization'\n");
xlog("L_INFO","$$tls_peer_issuer_organization  = '$tls_peer_issuer_organ
ization'\n");
xlog("L_INFO","$$tls_my_subject_organization   = '$tls_my_subject_organi
zation'\n");
xlog("L_INFO","$$tls_my_issuer_organization    = '$tls_my_issuer_organiz
ation'\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");

Chapter 2. Developer Guide

2.1. API Functions

2.1.1. 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).

2.1.2. find_client_domain

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

   Find TLS client domain.

2.1.3. get_handshake_timeout

   int get_handshake_timeout(void);

   Returns the handshanke timeout.

2.1.4. get_send_timeout

   int get_send_timeout(void);

   Returns the send timeout.

2.2. TLS_CONFIG

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

2.3. TLS_INIT

   Initialization related functions and parameters.

2.3.1. 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.

2.3.2. pre_init_tls

   int init_tls(void);

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

2.3.3. init_tls

   int init_tls(void);

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

2.3.4. destroy_tls

   void destroy_tls(void);

   Called once, just before cleanup.

2.3.5. tls_init

   int tls_init(struct socket_info *c);

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

2.3.6. 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.

2.4. TLS_DOMAIN

2.4.1. 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.

2.4.2. 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).

2.4.3. tls_find_client_domain

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

   Find TLS client domain.

2.4.4. 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).

2.4.5. tls_find_client_domain_name

   struct tls_domain *tls_find_client_name(str name);

   Find TLS client domain with given name.

2.4.6. tls_new__domain

   struct tls_domain *tls_new_domain(int type);

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

2.4.7. 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.

2.4.8. 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.

2.4.9. 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.

2.4.10. tls_free_domains

   void tls_free_domains(void);

   Cleans up the entire domain lists.

Chapter 3. Contributors

3.1. By Commit Statistics

   Table 3.1. Top contributors by DevScore^(1), authored
   commits^(2) and lines added/removed^(3)
     Name DevScore Commits Lines ++ Lines --
   1. Vlad Patrascu (@rvlad-patrascu) 100 33 3305 2412
   2. Razvan Crainea (@razvancrainea) 72 51 1166 658
   3. Eseanu Marius Cristian (@eseanucristian) 52 11 4268 321
   4. Liviu Chircu (@liviuchircu) 24 18 152 230
   5. Bogdan-Andrei Iancu (@bogdan-iancu) 24 13 291 460
   6. Dan Pascu (@danpascu) 17 13 90 176
   7. Ionut Ionita (@ionutrazvanionita) 16 9 383 169
   8. Ionel Cerghit (@ionel-cerghit) 8 1 494 109
   9. Alexey Vasilyev (@vasilevalex) 4 2 33 19
   10. Callum Guy (@spacetourist) 3 1 33 8

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

   (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. Regarding imported patches/code, we do our best
   to count the work on behalf of the proper owner, as per the
   "fix_authors" and "mod_renames" arrays in
   opensips/doc/build-contrib.sh. If you identify any
   patches/commits which do not get properly attributed to you,
   please submit a pull request which extends "fix_authors" and/or
   "mod_renames".

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

3.2. By Commit Activity

   Table 3.2. Most recently active contributors^(1) to this module
                      Name                   Commit Activity
   1.  Vlad Patrascu (@rvlad-patrascu)     Apr 2017 - May 2020
   2.  Liviu Chircu (@liviuchircu)         Oct 2015 - May 2020
   3.  Bogdan-Andrei Iancu (@bogdan-iancu) Mar 2016 - Apr 2020
   4.  Dan Pascu (@danpascu)               Jun 2019 - Feb 2020
   5.  Razvan Crainea (@razvancrainea)     Sep 2015 - Feb 2020
   6.  Fabian Gast (@fgast)                Jan 2020 - Jan 2020
   7.  Alexey Vasilyev (@vasilevalex)      Nov 2018 - May 2019
   8.  Callum Guy (@spacetourist)          Jun 2018 - Jun 2018
   9.  Peter Lemenkov (@lemenkov)          Jun 2018 - Jun 2018
   10. Ovidiu Sas (@ovidiusas)             Jun 2017 - Jun 2017

   All remaining contributors: Ionut Ionita (@ionutrazvanionita),
   Ionel Cerghit (@ionel-cerghit), Maksym Sobolyev (@sobomax),
   Eseanu Marius Cristian (@eseanucristian).

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

Chapter 4. Documentation

4.1. Contributors

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

   Documentation Copyrights:

   Copyright © 2015 www.opensips-solutions.com

   Copyright © 2013 Secusmart GmbH

   Copyright © 2006 enum.at

   Copyright © 2005 Cesc Santasusana

   Copyright © 2005 Voice Sistem SRL
