= Login Service = May First/People Link provides a web-based API for verifying login credentials called "login-service". It is designed to allow applications to verify that a given username and password is valid. It takes as input a username, password, and application id, and responds with either a 1 (indicating invalid) or a 0 indicating a valid username and password. == Server side == The server is running a python twisted web application, available via git: git://git.mayfirst.org/mfpl/login-service. It is currently installed on hay.mayfirst.org in /usr/local/share/login-service, listens on port 8080, requires tls, and is configured to use the members.mayfirst.org key and certificate. The application is managed by runit (via /etc/sv/login-service), so it should restart when the system restarts. The application runs as the login-service unix user. It also has access to it's own mysql username and password (configured via files in /etc/sv/login-service/env) that grant it the privilege of logging into the MySQL server on hay and of executing the `get_salt` and `valid_hash` MySQL procedures that enable it to verify a username and password witout having access to the table of usernames and passwords. One environment variable set via the file /etc/sv/login-service/env/LS_APP_IDS contains a space separated list of randomly generated strings that act as an application id. The idea is that each application that we configure to use the service will share a secret that is stored in this file. The shared secret helps prevent dictionary attacks against the service. == Client side == Writing a client to interface with the login service is relatively easy. Here are a few examples: {{{ }}} {{{ #!/bin/bash user="$1" pass="$2" app_id="$3" out=$(curl "https://members.mayfirst.org:8080/check?user=$user&password=$pass&app_id=$3") [ "$out" = "0" ] && exit 0 exit 1 }}}