5 files changed, 174 insertions, 0 deletions
diff --git a/3.1/charon.rb b/3.1/charon.rb
new file mode 100755
index 0000000..75619b8
--- /dev/null
+++ b/3.1/charon.rb
@@ -0,0 +1,61 @@
+#!/usr/bin/env ruby
+
+require 'openssl'
+require 'securerandom'
+require 'sinatra'
+
+Users = {
+  "Athena" => "Passw0rd!"
+}
+
+Services = {
+  "_TGS" => "eiqu@a5ahs8mooqu9Eng",
+  "Mail" => "{FvM<kgG}VpHxKJO;6Zo"
+}
+
+def encrypt(obj, key)
+  cipher = OpenSSL::Cipher::AES.new(256, :CBC).encrypt
+  cipher.key = Digest::SHA2.digest(key)
+  s = cipher.update(obj) + cipher.final
+  s.unpack('H*')[0].upcase
+end
+
+def decrypt(obj, key)
+  ticket = [obj].pack("H*").unpack("C*").pack("c*")
+  cipher = OpenSSL::Cipher::AES.new(256, :CBC).decrypt
+  cipher.key = Digest::SHA2.digest(key)
+  p = cipher.update(ticket) + cipher.final
+  p.split(?\0)
+end
+
+def ticket(username, ws_address, service)
+  encrypt([username, ws_address, service].join(?\0), Services[service])
+end
+
+def noleak(msg, ul, ws)
+  puts "Error: #{msg}, returning nonsense to avoid leakage."
+  ticket(SecureRandom.alphanumeric(ul), ws, SecureRandom.alphanumeric(rand(24) + 8))
+end
+
+post '/login' do
+  request.body.rewind
+  data = JSON.parse(request.body.read)
+  next "Invalid request\n" unless data.keys == %w(username)
+  un = data["username"]
+  ul = un.length
+  ws = request.ip
+  next noleak("Invalid username", ul, ws) unless Users.keys.include?(un)
+  tgt = ticket(un, ws, "_TGS")
+  encrypt(tgt, Users[un])
+end
+
+post '/ticket' do
+  request.body.rewind
+  data = JSON.parse(request.body.read)
+  next "Invalid request\n" unless data.keys.sort == %w(service ticket username)
+  un, ws, sn = decrypt(data["ticket"], Services["_TGS"])
+  next "Invalid ticket\n" unless sn == "_TGS"
+  next "Invalid ticket\n" unless un == data["username"]
+  next "Invalid ticket\n" unless ws == request.ip
+  ticket(un, ws, data["service"])
+end
diff --git a/3.1/get_mail.rb b/3.1/get_mail.rb
new file mode 100755
index 0000000..b212aed
--- /dev/null
+++ b/3.1/get_mail.rb
@@ -0,0 +1,24 @@
+#!/usr/bin/env ruby
+
+require 'net/http'
+require 'uri'
+require 'json'
+
+uri = URI.parse("http://localhost:4568/login")
+
+header = {'Content-Type': 'text/json'}
+
+print "Username: "; un = gets.strip
+print "Ticket: "; t = gets.strip
+
+login = {
+  "username": un,
+  "ticket": t
+}
+
+http = Net::HTTP.new(uri.host, uri.port)
+request = Net::HTTP::Post.new(uri.request_uri, header)
+request.body = login.to_json
+
+response = http.request(request)
+puts response.body
diff --git a/3.1/get_ticket.rb b/3.1/get_ticket.rb
new file mode 100755
index 0000000..d22d843
--- /dev/null
+++ b/3.1/get_ticket.rb
@@ -0,0 +1,26 @@
+#!/usr/bin/env ruby
+
+require 'net/http'
+require 'uri'
+require 'json'
+
+uri = URI.parse("http://localhost:4567/ticket")
+
+header = {'Content-Type': 'text/json'}
+
+print "Username: "; un = gets.strip
+print "Ticket: "; t = gets.strip
+print "Service: "; s = gets.strip
+
+login = {
+  "username": un,
+  "ticket": t,
+  "service": s
+}
+
+http = Net::HTTP.new(uri.host, uri.port)
+request = Net::HTTP::Post.new(uri.request_uri, header)
+request.body = login.to_json
+
+response = http.request(request)
+puts response.body
diff --git a/3.1/kinit.rb b/3.1/kinit.rb
new file mode 100755
index 0000000..0cfa220
--- /dev/null
+++ b/3.1/kinit.rb
@@ -0,0 +1,34 @@
+#!/usr/bin/env ruby
+
+require 'io/console'
+require 'json'
+require 'net/http'
+require 'openssl'
+require 'uri'
+
+uri = URI.parse("http://localhost:4567/login")
+
+header = {'Content-Type': 'text/json'}
+
+print "Username: "; un = gets.strip
+print "Password: "; pw = STDIN.noecho(&:gets).strip; puts
+
+login = {
+  "username": un
+}
+
+http = Net::HTTP.new(uri.host, uri.port)
+request = Net::HTTP::Post.new(uri.request_uri, header)
+request.body = login.to_json
+
+response = http.request(request)
+eticket = [response.body].pack("H*").unpack("C*").pack("c*")
+
+cipher = OpenSSL::Cipher::AES.new(256, :CBC).decrypt
+cipher.key = Digest::SHA2.digest(pw)
+begin
+  ticket = cipher.update(eticket) + cipher.final
+  puts ticket + ?\n
+rescue OpenSSL::Cipher::CipherError
+  puts "Invalid password?"
+end
diff --git a/3.1/mail.rb b/3.1/mail.rb
new file mode 100755
index 0000000..e7fa6ff
--- /dev/null
+++ b/3.1/mail.rb
@@ -0,0 +1,29 @@
+#!/usr/bin/env ruby
+
+require 'openssl'
+require 'securerandom'
+require 'sinatra'
+
+set :port, 4568
+
+Service = "Mail"
+ServicePassword = "{FvM<kgG}VpHxKJO;6Zo"
+
+def decrypt(ticket)
+  ticket = [ticket].pack("H*").unpack("C*").pack("c*")
+  cipher = OpenSSL::Cipher::AES.new(256, :CBC).decrypt
+  cipher.key = Digest::SHA2.digest(ServicePassword)
+  p = cipher.update(ticket) + cipher.final
+  p.split(?\0)
+end
+
+post '/login' do
+  request.body.rewind
+  data = JSON.parse(request.body.read)
+  next "Invalid request\n" unless data.keys.sort == %w(ticket username)
+  un, ws, sn = decrypt(data["ticket"])
+  next "Invalid ticket\n" unless sn == Service
+  next "Invalid ticket\n" unless un == data["username"]
+  next "Invalid ticket\n" unless ws == request.ip
+  "Login okay! You have no mail.\n"
+end