Task 18.2 - echo_string/high.rb

modules/generators/challenges/misc/programming/echo_string/secgen_local/flag

@@ -0,0 +1 @@
+test successful wayyy :D

modules/generators/challenges/misc/programming/echo_string/secgen_local/high.rb

@@ -0,0 +1,76 @@
+# #####################
+# Programming Challenge
+# Echo string - Medium: Reverse a string and repeat it back to the script
+# #####################
+
+# TODO: Decide the below
+# Should the challenge types be separate scripts (medium1,medium2,medium3 etc?)
+# so the challenge type is static on the box? less difficult + more replayable
+
+$stdout.sync = true # Disable stdout caching (for challenges that can be run over the network)
+require 'securerandom'
+require 'timeout'
+
+# determine encoding format required
+encoding_formats = %w[hex_little_endian hex_big_endian binary_little_endian binary_big_endian base64 octal decimal]
+encoding_format = encoding_formats.sample
+
+case encoding_format
+  when 'hex_little_endian'
+    print_string = 'hexadecimal (little endian / LSB first)'
+    operation = ->(data) {data.unpack('h*').first}
+  when 'hex_big_endian'
+    print_string = 'hexadecimal (big endian / MSB first)'
+    operation = ->(data) {data.unpack('H*').first}
+  when 'binary_little_endian'
+    print_string = 'binary (little endian / LSB first)'
+    operation = ->(data) {data.unpack('b*').first}
+  when 'binary_big_endian'
+    print_string = 'binary (big endian / MSB first)'
+    operation = ->(data) {data.unpack('B*').first}
+  when 'base64'
+    require 'base64'
+    print_string = 'base64'
+    operation = ->(data) {Base64.strict_encode64(data)}
+  when 'octal'
+    print_string = 'octal'
+    operation = lambda {|data|
+      sum = []
+      data.each_char {|char| sum << char.ord.to_s(8).to_i}
+      sum.join
+    }
+  when 'decimal'
+    print_string = 'decimal'
+    operation = ->(data) {data.sum.to_s}
+  else
+    print_string = 'ERROR'
+    operation = ->(data) {data}
+end
+
+puts 'Prepare yourself. You need to work quickly for this challenge.'
+sleep 2
+puts "Echo the string back to me, in #{print_string}, before the script times out. Try writing a script of your own to make it easier!"
+sleep 2
+puts 'Get ready, here we go...'
+sleep 2
+# Generate random string
+string = [SecureRandom.base64(rand(20..40)), SecureRandom.hex(rand(20..40))].sample
+
+puts string
+
+begin
+  Timeout.timeout 60 do
+    response = gets.chomp
+    valid_answer = operation.call(string)
+    if response == valid_answer
+      puts File.read('flag')
+    else
+      puts 'Incorrect!'
+      puts 'We were looking for: ' + valid_answer
+      exit
+    end
+  end
+rescue Timeout::Error
+  puts 'Too slow!'
+  exit
+end

modules/generators/challenges/misc/programming/echo_string/secgen_local/medium.rb

@@ -7,8 +7,15 @@ require 'securerandom'
 require 'timeout'
 
 $stdout.sync = true  # Disable stdout caching (for challenges that can be run over the network)
-puts 'Prepare yourself. You need to work quickly for this challenge.'
 
+# Should the challenge types be separate scripts (medium1,medium2,medium3 etc?)
+# so the challenge type is static on the box? less difficult + more replayable
+# TODO: Implement other medium difficulty options:
+# in reverse [done]
+# but I only want every second character starting with index 0 e.g. [0,2,4...]
+# but I only want every second character starting with index 1 e.g. [1,3,5...]
+
+puts 'Prepare yourself. You need to work quickly for this challenge.'
 sleep 2
 puts 'Echo the string back to me, in reverse, before the script times out. Try writing a script of your own to make it easier!'
 sleep 2

modules/generators/challenges/misc/programming/echo_string/secgen_metadata.xml

@@ -19,9 +19,9 @@
 
   <default_input into="difficulty">
     <!--<value>low</value>-->
-    <value>medium</value>
+    <!--<value>medium</value>-->
     <!--TODO: implement high difficulty options -->
-    <!--<value>high</value>-->
+    <value>high</value>
   </default_input>
 
   <output_type>script</output_type>