Single sign-on and auth-check-sso triggers

Example   Interaction between client-side and server-side scripts

An auth-check-sso trigger fires whenever users run p4 login. The system administrator might add the following line to the trigger table to specify the script to run on the server:

sample13  auth-check-sso  auth  "serverside.sh %user%"

and each end user sets the following environment variable on their client:

export P4LOGINSSO=/usr/local/bin/clientside.sh %serverAddress%

When the user attempts to log on, the P4LOGINSSO script runs on the user’s workstation:

##!/bin/bash
# clientside.sh - a client-side authentication script
#
# if we use %serverAddress% in the command-line like this:
#    p4 -E P4LOGINSSO=clientside.sh %serverAddress%
# then this script receives the serverAddress as $1, and the user
# can use it for multiple connections to different Helix Servers.
#
# In this example, we simulate a client-side authentication process
# based on whether the user is connecting to the same Helix Server
# as is already configured in his or her environment.
# (We also output debugging information to a local file.)

input_saddr=$1

env_saddr=`p4 info | grep "Server address" | awk '{printf "%s", $3}'`

if test "$input_saddr" == "$env_saddr"
  then
    # User is connected to the server specified by P4PORT - pass
    echo "sso pass"; echo pass "$input_saddr" >> debug.txt; exit 0
  else
    # User is attempting to connect to another server - fail
    echo "no pass"; echo fail "$input_saddr" >> debug.txt; exit 1
fi

If the user is connected to the same Helix Core Server as specified by P4PORT (that is, if the server address passed from the server to this script matches the server that appears in the output of a plain p4 info command), client-side authentication succeeds. If the user is connected to another Helix Core Server (for example, by running p4 -p host:port login against a different Helix Core Server), client-side authentication fails.

The server-side script is as follows:

#!/bin/bash
#
# serverside.sh - a server-side authentication script
#

if test $# -eq 0
  then
    echo "No user name passed in.";
    exit 1;
fi

read msg </dev/stdin

if test "$msg" == ""
  then
    echo "1, no stdin"
    exit 1
fi

if test "$msg" == "sso pass"
  then
    exit 0
  else
    exit 1
fi

In a more realistic example, the end user’s P4LOGINSSO script points to a clientside.sh script that contacts an authentication service to obtain a token of some sort. The client-side script then passes this token to Helix Core Server’s trigger script, and serverside.sh uses the single-signon service to validate the token.

In this example, clientside.sh merely checks whether the user is using the same connection as specified by P4PORT, and the output of clientside.sh is trivially checked for the string "sso pass"; if the string is present, the user is permitted to log on.