Chapter 7. SER - Adding Authentication and MySQL
What this ser.cfg does:
Adds authentication of IP phones by using credentials stored in
MySQL
Contact information is stored persistently in MySQL
Now that you have tested a basic SIP environment, we need to add more
functionality. This section we talk about authentication.
In normal circumstances, we must restrict the use of the SIP server to
those telephones (i.e., users) that we want. Authentication is about
ensuring only those telephones that we have given a password to are allowed
to use our sip services.
To support authentication, we need a way to store information that
does not get lost when we stop the sip server. We need a database and the
most popular is MySQL as it comes with all Linux configurations. Support is
provided for other databases, such as PostgreSQL, but in this Quick Start
guide we focus on MySQL.
To add support for MySQL you need to go back to the source code and
modify a few parameters. In Chapter 11 - Supporting MySQL describes how to do this
and re-install the binaries. Once you have updated your SER environment you
need to modify your ser.cfg file as described below.
Listed below is the SIP proxy configuration to which builds upon
subject matter covered in the Hello World section.
debug=3
fork=no
log_stderror=yes
listen=192.0.2.13 # INSERT YOUR IP ADDRESS HERE
port=5060
children=4
dns=no
rev_dns=no
fifo="/tmp/ser_fifo"
fifo_db_url="mysql://ser:heslo@localhost/ser"
loadmodule "/usr/local/lib/ser/modules/mysql.so"
loadmodule "/usr/local/lib/ser/modules/sl.so"
loadmodule "/usr/local/lib/ser/modules/tm.so"
loadmodule "/usr/local/lib/ser/modules/rr.so"
loadmodule "/usr/local/lib/ser/modules/maxfwd.so"
loadmodule "/usr/local/lib/ser/modules/usrloc.so"
loadmodule "/usr/local/lib/ser/modules/registrar.so"
loadmodule "/usr/local/lib/ser/modules/auth.so"
loadmodule "/usr/local/lib/ser/modules/auth_db.so"
loadmodule "/usr/local/lib/ser/modules/uri_db.so"
modparam("auth_db|uri_db|usrloc", "db_url", "mysql://ser:heslo@localhost/ser")
modparam("auth_db", "calculate_ha1", 1)
modparam("auth_db", "password_column", "password")
modparam("usrloc", "db_mode", 2)
modparam("rr", "enable_full_lr", 1)
route {
# -----------------------------------------------------------------
# Sanity Check Section
# -----------------------------------------------------------------
if (!mf_process_maxfwd_header("10")) {
sl_send_reply("483", "Too Many Hops");
break;
};
if (msg:len > max_len) {
sl_send_reply("513", "Message Overflow");
break;
};
# -----------------------------------------------------------------
# Record Route Section
# -----------------------------------------------------------------
if (method!="REGISTER") {
record_route();
};
# -----------------------------------------------------------------
# Loose Route Section
# -----------------------------------------------------------------
if (loose_route()) {
route(1);
break;
};
# -----------------------------------------------------------------
# Call Type Processing Section
# -----------------------------------------------------------------
if (uri!=myself) {
route(1);
break;
};
if (method=="ACK") {
route(1);
break;
} if (method=="INVITE") { 
route(3);(11)
break;
} else if (method=="REGISTER") {
route(2);
break;
};
lookup("aliases");
if (uri!=myself) {
route(1);
break;
};
if (!lookup("location")) {
sl_send_reply("404", "User Not Found");
break;
};
route(1);
}
route[1] {
# -----------------------------------------------------------------
# Default Message Handler
# -----------------------------------------------------------------
if (!t_relay()) {
sl_reply_error();
};
}
route[2] {
# -----------------------------------------------------------------
# REGISTER Message Handler
# ----------------------------------------------------------------
sl_send_reply("100", "Trying");(12)
if (!www_authorize("","subscriber")) { (13)
www_challenge("","0");(14)
break;(15)
};
if (!check_to()) { (16)
sl_send_reply("401", "Unauthorized");(17)
break;
};
consume_credentials();(18)
if (!save("location")) { (19)
sl_reply_error();
};
}
(20)route[3] {
# -----------------------------------------------------------------
# INVITE Message Handler
# -----------------------------------------------------------------
if (!proxy_authorize("","subscriber")) { (21)
proxy_challenge("","0");(22)
break;
} else if (!check_from()) { (23)
sl_send_reply("403", "Use From=ID");(24)
break;
};
consume_credentials();(25)
(26)lookup("aliases");
if (uri!=myself) {
route(1);
break;
};
(27)if (!lookup("location")) {
sl_send_reply("404", "User Not Found");
break;
};
route(1);(28)
}
