Session.lua

random_hash

Returns a base64 encoded hash, using _- as the extra characters, as these are safe for using in a URL.

INPUT:

• size
  • Hash size, in bits

OUTPUT:

• A base64 encoded hash of at least size length
  • Comes from reading /dev/urandom

CODING EXAMPLE:

-- Set variable/Call for this library
bobo = require "session"
print(bobo.random_hash(100))

Will output a hash from /dev/urandom that is 17 char long

hash_ip_addr

Takes an ip address string and returns a HEX encoded version.

INPUT:

• String containing an ip address

OUTPUT:

• HEX encoded ip address

CODING EXAMPLE:

-- Set variable/Call for this library
bobo = require "session"
print(bobo.hash_ip_addr("192.168.10.1))

Output could be:

c0a80a01

ip_addr_from_hash

Takes a HEX encoded ip address and returns an ip address string.

INPUT:

• HEX encoded ip address

OUTPUT:

• String containing an ip address

CODING EXAMPLE:

-- Set variable/Call for this library
bobo = require "session"
print(bobo.ip_addr_from_hash("c0a80a01")

Output could be:

192.168.10.1

serialize

Takes an input variable and name and returns a string containing LUA code to generate the variable.

INPUT:

• name
  • Name of the variable / table to serialize
• value
  • Value of the variable / table to serialize
• saved
  • Used internally by recursive function to keep track of progress.

OUTPUT:

• String with the table serialized

CODING EXAMPLE:

-- Set variable/Call for this library
bobo = require "session"
t = {foo={1,2,3,4}, "one", "two", "bar", "baz"}
stuff = bobo.serialize("t",t)
print(stuff)

Output:

t = {}
t[1] = "one"
t[2] = "two"
t[3] = "bar"
t[4] = "baz"
t["foo"] = {}
t["foo"][1] = 1
t["foo"][2] = 2
t["foo"][3] = 3
t["foo"][4] = 4

save_session

Saves a serialized user session to a file.

INPUT:

• sessionpath
  • Path where session file is to be saved
• sessiontable
  • User session

OUTPUT:

• true if success, false if error

CODING EXAMPLE:

-- Set variable/Call for this library
bobo = require "session"
print(bobo.save_session("tmp", session, sessiontable)

Will print true if success or false if failed

load_session

Loads a serialized user session from a file.

INPUT:

• sessionpath
  • Path where session file is saved
• session
  • Session id

OUTPUT:

• ts
  • Timestamp when the session was saved
• sessiontable
  • User session

CODING EXAMPLE:

-- Set variable/Call for this library
bobo = require "session"
ts, sess = bobo.load_session("tmp", "OPRfhPH3rq2p8tpG978oiql8vy58tr9q3ghiUIH")

Will load the session into sess if available.

unlink_session

Deletes a saved session file.

INPUT:

• sessionpath
  • Path where session file is saved
• session
  • Session id

OUTPUT:

• nil if failed

CODING EXAMPLE:

-- Set variable/Call for this library
bobo = require "session"
result = bobo.unlink_session("tmp", "OPRfhPH3rq2p8tpG978oiql8vy58tr9q3ghiUIH")

Will delete the session if it exists.

record_event

Record an invalid login attempt by creating a zero-length file.

INPUT:

• sessionpath
  • Path where event file is to be saved
• id_u
  • First id string, typically username
• id_ip
  • Second id string, typically hashed ip address

OUTPUT:

• none

CODING EXAMPLE:

-- Set variable/Call for this library
bobo = require "session"
result = bobo.record_event("tmp", username, hash_ip_addr(ipaddr))

Will create an event file for this user and ip address.

count_events

Count how many invalid user attempts have occured for this id in the last 30 minutes.

INPUT:

• sessionpath
  • Path where event files are saved
• id_u
  • First id string, typically username
• id_ip
  • Second id string, typically hashed ip address

OUTPUT:

• blockaccess
  • True if more than 10 events.

CODING EXAMPLE:

-- Set variable/Call for this library
bobo = require "session"
print(bobo.count_events("tmp", username, hash_ip_addr(ipaddr)))

Output true if more than 10 lockevents.

expired_events

Clear the invalid user attempts and saved user sessions that are older than 30 minutes.

INPUT:

• sessionpath
  • Path where event files are saved

CODING EXAMPLE:

-- Set variable/Call for this library
bobo = require "session"
bobo.expired_events("tmp")

Deletes the events and sessions more that 30 minutes old.