Class: DBus::DBusCookieSHA1

Inherits:
Authenticator show all
Defined in:
lib/dbus/auth.rb

Overview

Authentication class using SHA1 crypto algorithm

Class for ‘CookieSHA1’ type authentication. Implements the AUTH DBUS_COOKIE_SHA1 mechanism.

Instance Method Summary collapse

Instance Method Details

#authenticate ⇒ Object

the autenticate method (called in stage one of authentification)



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# File 'lib/dbus/auth.rb', line 53

def authenticate
  require 'etc'
  #number of retries we have for auth
  @retries = 1
  return "#{hex_encode(Etc.getlogin)}" #server expects it to be binary
end

#data(hexdata) ⇒ Object

handles the interesting crypto stuff, check the rbus-project for more info: rbus.rubyforge.org/



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# File 'lib/dbus/auth.rb', line 66

def data(hexdata)
  require 'digest/sha1'
  data = hex_decode(hexdata)
  # name of cookie file, id of cookie in file, servers random challenge  
  context, id, s_challenge = data.split(' ')
  # Random client challenge        
  c_challenge = Array.new(s_challenge.bytesize/2).map{|obj|obj=rand(255).to_s}.join
  # Search cookie file for id
  path = File.join(ENV['HOME'], '.dbus-keyrings', context)
  DBus.logger.debug "path: #{path.inspect}"
  File.foreach(path) do |line|
    if line.index(id) == 0
      # Right line of file, read cookie
      cookie = line.split(' ')[2].chomp
      DBus.logger.debug "cookie: #{cookie.inspect}"
      # Concatenate and encrypt
      to_encrypt = [s_challenge, c_challenge, cookie].join(':')
      sha = Digest::SHA1.hexdigest(to_encrypt)
      #the almighty tcp server wants everything hex encoded
      hex_response = hex_encode("#{c_challenge} #{sha}")
      # Return response
      response = [:AuthOk, hex_response]
      return response
    end
  end
  #a little rescue magic
  unless @retries <= 0
    puts "ERROR: Could not auth, will now exit." 
    puts "ERROR: Unable to locate cookie, retry in 1 second."
    @retries -= 1
    sleep 1
    data(hexdata)
  end
end

#hex_decode(encoded) ⇒ Object

decode hex to plain



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# File 'lib/dbus/auth.rb', line 108

def hex_decode(encoded)
  encoded.scan(/[[:xdigit:]]{2}/).map{|h|h.hex.chr}.join
end

#hex_encode(plain) ⇒ Object

encode plain to hex



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# File 'lib/dbus/auth.rb', line 102

def hex_encode(plain)
  return nil if plain.nil?
  plain.to_s.unpack('H*')[0]
end

#name ⇒ Object

returns the modules name



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# File 'lib/dbus/auth.rb', line 61

def name
  return 'DBUS_COOKIE_SHA1'
end