Module: EncryptDecrypt

Defined in:

lib/accu-encrypt.rb

Overview

The primary module which packages the classes and global methods to be used for encryption.

Defined Under Namespace

Classes: EncryptedClient, EncryptedServer

Class Method Summary

• .decrypt(secret, plainText, *args) ⇒ Object

  Decrypts based on a continuing password offset algorithm.

• .decrypt_file(filename, pass, *args) ⇒ Object

  Decrypts a file.

• .encrypt(secret, source, *args) ⇒ Object

  Encrypts based on a continuing password offset algorithm.

• .encrypt_file(filename, pass, *args) ⇒ Object

  Encrypts a file.

• .get_mode ⇒ Object

  Returns current encryption mode.

• .get_password(prompt = "Password: ") ⇒ Object

  Reads a password using the highline gem.

• .interactive ⇒ Object

  Chooses either interactive mode based on operating system.

• .interactive_help ⇒ Object

  Returns interactive help in a string.

• .interactive_terminal ⇒ Object

  Opens an interactive terminal session.

• .interactive_windows ⇒ Object

  Opens an interactive session with the WindowTerminal library.

• .set_mode(arg) ⇒ Object

  Set current encryption mode.

• .windows(manager) ⇒ Object

  Declares the default windows on a manager object.

Class Method Details

.decrypt(secret, plainText, *args) ⇒ Object

Decrypts based on a continuing password offset algorithm.

# File 'lib/accu-encrypt.rb', line 367

def self.decrypt(secret,plainText,*args)
	currentKey = secret.clone
	output = ""
	plainText.each_byte { |plain|
		secondbyte = currentKey[0].ord
		out = plain - secondbyte
		while out < 0 do
			out = out + 255
		end
		output[output.length] = out.chr
		currentKey[currentKey.length] = out.chr
		currentKey.slice! 0
	}
	if args[0] == :continuing then
		return secret,output,currentKey
	elsif args[0] == :double then
		return self.decrypt(secret,output)
	else
		return secret,output
	end
end

.decrypt_file(filename, pass, *args) ⇒ Object

Decrypts a file.

# File 'lib/accu-encrypt.rb', line 410

def self.decrypt_file(filename,pass,*args)
	if File.exists? filename then
		if args[0] != :double then
			file = File.open filename
			pass,output = *self.decrypt(pass,file.read)
			file.close
			File.delete filename
			File.open(filename,"w") do |filer|
				filer << output
			end
		else
			self.decrypt_file(filename,pass)
			self.decrypt_file(filename,pass)
		end
	else
		puts "ERROR"
	end
end

.encrypt(secret, source, *args) ⇒ Object

Encrypts based on a continuing password offset algorithm.

# File 'lib/accu-encrypt.rb', line 343

def self.encrypt(secret,source,*args)
	currentKey = secret.clone
	output = ""
	source.each_byte { |orig|
		secondbyte = currentKey[0].ord
		out = orig + secondbyte
		while out > 255 do
			out = out - 255
		end
		output[output.length] = out.chr
		currentKey[currentKey.length] = orig.chr
		currentKey.slice! 0
	}
	if args[0] == :continuing then
		return secret,output,currentKey
	elsif args[0] == :double then
		return self.encrypt(secret,output)
	else
		return secret,output
	end
end

.encrypt_file(filename, pass, *args) ⇒ Object

Encrypts a file.

# File 'lib/accu-encrypt.rb', line 390

def self.encrypt_file(filename,pass,*args)
	if File.exists? filename then
		if args[0] != :double then
			file = File.open filename
			pass,output = *self.encrypt(pass,file.read)
			file.close
			File.delete filename
			File.open(filename,"w") do |filer|
				filer << output
			end
		else
			self.encrypt_file(filename,pass)
			self.encrypt_file(filename,pass)
		end
	else
		puts "ERROR"
	end
end

.get_mode ⇒ Object

Returns current encryption mode.

# File 'lib/accu-encrypt.rb', line 811

def self.get_mode()
	@@mode.dup
end

.get_password(prompt = "Password: ") ⇒ Object

Reads a password using the highline gem.

# File 'lib/accu-encrypt.rb', line 824

def self.get_password(prompt="Password: ")
	ask(prompt) {|q| q.echo = false}
end

.interactive ⇒ Object

Chooses either interactive mode based on operating system.

# File 'lib/accu-encrypt.rb', line 801

def self.interactive()
	if defined? WindowTerminal and WindowTerminal.os == :linux then
		self.interactive_windows
	else
		self.interactive_terminal
	end
end

.interactive_help ⇒ Object

Returns interactive help in a string.

# File 'lib/accu-encrypt.rb', line 337

def self.interactive_help()
	"---------\nThis program encrypts and decrypts files by offsetting the binary representation of the current character by the binary representation of the first character in an ongoing password.  The ongoing password is made up of the password appended to the beginning of the original plaintext.  Thus, the pattern is theoretically unpredictable as it is impossible to exactly where the original password starts and the obviously unpredictable plaintext encryption begins.  However, this algorithm's security is heavily correlated to the length and complexity of the opening password.  A complex but memorable password is recommended for secure encryption.\n---------\n"
end

.interactive_terminal ⇒ Object

Opens an interactive terminal session.

# File 'lib/accu-encrypt.rb', line 430

def self.interactive_terminal()
	print "Welcome to interactive encode/decode.  "
	selection = ""
	@@mode = :normal
	verbose = true
	while selection != "q" do
		puts "What would you like to do? |E D I M N Q|"
		selection = gets.downcase
		selection.slice!(-1)
		if selection == "e" then
			file = ""
			ready = false
			while not ready do
				file = FileLibrary.select_file
				if verbose then
					puts "---------\nWARNING!!!!!\n---------\nEncoding a file could un-retrievably destroy the contents of this file.  Are you sure you would like to use this file? |Y N Q|"
					selection2 = gets.downcase
					selection2.slice!(-1)
					while (selection2 != "y" and selection2 != "n" and selection2 != "q") do
						puts "Incorrect choice: |" + selection2 + "|\nAre you sure you would like to use this file? |Y N Q|"
						selection2 = gets.downcase
						selection2.slice!(-1)
					end
					if selection2 == "q" then
						ready = true
						file = ""
					elsif selection2 == "y" then
						ready = true
					end
				else
					ready = true
				end
			end
			if File.exists? file then
				password = EncryptDecrypt.get_password
				if verbose then
					puts "Finally, are you sure you would like to encrypt this file using this password? |Y N|"
					selection2 = gets.downcase
					selection2.slice!(-1)
					if selection2 == "y" then
						self.encrypt_file(file,password,@@mode)
						puts "Successfully encrypted file."
					end
				else
					self.encrypt_file(file,password,@@mode)
					puts "Successfully encrypted file."
				end
			end
		elsif selection == "d" then
			file = ""
			ready = false
			while not ready do
				file = FileLibrary.select_file
				if verbose then
					puts "---------\nWARNING!!!!!\n---------\nDecoding a file which has not been encrypted will destroy the contents.\nDecoding a file with the incorrect password will likely also destroy the file.\n---------\nAre you sure you would like to use this file? |Y N Q|"
					selection2 = gets.downcase
					selection2.slice!(-1)
					while (selection2 != "y" and selection2 != "n" and selection2 != "q") do
						puts "Incorrect choice: |" + selection2 + "|\nAre you sure you would like to use this file? |Y N Q|"
						selection2 = gets.downcase
						selection2.slice!(-1)
					end
					if selection2 == "q" then
						ready = true
						file = ""
					elsif selection2 == "y" then
						ready = true
					end
				else
					ready = true
				end
			end
			if File.exists? file then
				password = EncryptDecrypt.get_password
				if verbose then
					puts "Finally, are you sure you would like to decrypt this file using this password? |Y N|"
					selection2 = gets.downcase
					selection2.slice!(-1)
					if selection2 == "y" then
						self.decrypt_file(file,password,@@mode)
						puts "Successfully decrypted file."
					end
				else
					self.decrypt_file(file,password,@@mode)
					puts "Successfully decrypted file."
				end
			end
		elsif selection == "i" then
			puts EncryptDecrypt.interactive_help
		elsif selection == "m" then
			puts  "Select mode: Double - D Normal - N Verbose - V Unverbose - U"
			selection2 = ""
			selection2 = gets.downcase
			selection2.slice!(-1)
			while (selection2 != "d" and selection2 != "n" and selection2 != "v" and selection2 != "u") do
				puts "Invalid: |" + selection2 + "|"
				selection2 = gets.downcase
				selection2.slice!(-1)
			end
			if selection2 == "d" then
				@@mode = :double
			elsif selection2 == "v" then
				verbose = true
			elsif selection2 == "u" then
				verbose = false
			else
				@@mode = :normal
			end
		elsif selection == "n" then
			puts "Port number: "
			selection2 = ""
			selection2 = gets.downcase
			selection2.slice!(-1)
			while (selection2.to_i == 0 or selection2.to_i == nil) do
				puts "Invalid: |" + selection2 + "|"
				selection2 = gets.downcase
				selection2.slice!(-1)
			end
			port = selection2.to_i
			puts "Would you like to open a client or a server? |C S|"
			selection2 = ""
			selection2 = gets.downcase
			selection2.slice!(-1)
			while (selection2 != "c" and selection2 != "s") do
				puts "Invalid: |" + selection2 + "|"
				selection2 = gets.downcase
				selection2.slice!(-1)
			end
			if selection2 == "c" then
				puts "IP: "
				ip = ""
				ip = gets.downcase
				ip.slice!(-1)
				begin
					server = TCPSocket.open( ip, port )
					EncryptedClient.new( server )
					server.close
				rescue
					puts "ERROR\nConnection probably refused."
				end
			else
				server = TCPServer.open port
				EncryptedServer.new( server.accept )
				server.close
			end
			puts "Returning to normal encryption tasks."
		elsif selection != "q" then
			puts "Incorrect selection: |" + selection + "|"
		end
	end
end

.interactive_windows ⇒ Object

Opens an interactive session with the WindowTerminal library.

# File 'lib/accu-encrypt.rb', line 600

def self.interactive_windows()
	raise "WindowTerminal library missing" if not defined? WindowTerminal
	manager = WindowTerminal::WindowManager.new
	text = self.windows(manager)
	selection = ""
	@@mode = :normal
	verbose = true
	while selection != "q" do
		text.set_text "What would you like to do? |E D I M N Q|"
		manager.show(1)
		manager.render()
		selection = WindowTerminal.getchr().downcase
		if selection == "e" then
			file = ""
			ready = false
			while not ready do
				file = FileLibrary.select_file_with_windows(manager)
				manager.show
				if verbose then
					text.set_text "---------\nWARNING!!!!!\n---------\nEncoding a file could un-retrievably destroy the contents of this file.  Are you sure you would like to use this file? |Y N Q|"
					manager.render()
					selection2 = WindowTerminal.getchr().downcase
					while (selection2 != "y" and selection2 != "n" and selection2 != "q") do
						text.set_text "Incorrect choice: |" + selection2 + "|\nAre you sure you would like to use this file? |Y N Q|"
						manager.render()
						selection2 = WindowTerminal.getchr().downcase
					end
					if selection2 == "q" then
						ready = true
						file = ""
					elsif selection2 == "y" then
						ready = true
					end
				else
					ready = true
				end
			end
			if File.exists? file then
				text.set_text "Password: "
				total = 0
				manager.render()
				password = WindowTerminal.getchrs{ |char,full|
					if char.ord != 127 then 
						text.set_text(text.text + "*")
						total += 1
					elsif total > 0 then
						text.set_text(text.text[0..(text.text.length-1)])
						total -= 1
					end
					manager.render()
				}
				
				if verbose then
					text.set_text "Finally, are you sure you would like to encrypt this file using this password? |Y N|"
					manager.render()
					selection2 = WindowTerminal.getchr().downcase
					if selection2 == "y" then
						self.encrypt_file(file,password,@@mode)
						text.set_text "Successfully encrypted file."
						manager.render()
					end
				else
					self.encrypt_file(file,password,@@mode)
					text.set_text "Successfully encrypted file."
					manager.render()
				end
				WindowTerminal.getchr()
			end
		elsif selection == "d" then
			file = ""
			ready = false
			while not ready do
				file = FileLibrary.select_file_with_windows(manager)
				manager.show
				if verbose then
					text.set_text "---------\nWARNING!!!!!\n---------\nDecoding a file which has not been encrypted will destroy the contents.\nDecoding a file with the incorrect password will likely also destroy the file.\n---------\nAre you sure you would like to use this file? |Y N Q|"
					manager.render()
					selection2 = WindowTerminal.getchr().downcase
					while (selection2 != "y" and selection2 != "n" and selection2 != "q") do
						text.set_text "Incorrect choice: |" + selection2 + "|\nAre you sure you would like to use this file? |Y N Q|"
						manager.render()
						selection2 = WindowTerminal.getchr().downcase
					end
					if selection2 == "q" then
						ready = true
						file = ""
					elsif selection2 == "y" then
						ready = true
					end
				else
					ready = true
				end
			end
			if File.exists? file then
				text.set_text "Password: "
				total = 0
				manager.render()
				password = WindowTerminal.getchrs{ |char,full|
					if char.ord != 127 then 
						text.set_text(text.text + "*")
						total += 1
					elsif total > 0 then
						text.set_text(text.text[0..(text.text.length-1)])
						total -= 1
					end
					manager.render()
				}
				
				if verbose then
					text.set_text "Finally, are you sure you would like to decrypt this file using this password? |Y N|"
					manager.render()
					selection2 = WindowTerminal.getchr().downcase
					if selection2 == "y" then
						self.decrypt_file(file,password,@@mode)
						text.set_text "Successfully decrypted file."
						manager.render()
					end
				else
					self.decrypt_file(file,password,@@mode)
					text.set_text "Successfully decrypted file."
					manager.render()
				end
				WindowTerminal.getchr()
			end
		elsif selection == "i" then
			manager.show(2)
			manager.render()
			WindowTerminal.getchr()
			manager.show(1)
			manager.render()
		elsif selection == "m" then
			text.set_text "Select mode: Double - D Normal - N Verbose - V Unverbose - U"
			manager.render()
			selection2 = ""
			selection2 = WindowTerminal.getchr().downcase
			while (selection2 != "d" and selection2 != "n" and selection2 != "v" and selection2 != "u") do
				text.set_text "Invalid: |" + selection2 + "|"
				manager.render()
				selection2 = WindowTerminal.getchr().downcase
			end
			if selection2 == "d" then
				@@mode = :double
			elsif selection2 == "v" then
				verbose = true
			elsif selection2 == "u" then
				verbose = false
			else
				@@mode = :normal
			end
		elsif selection == "n" then
			if WindowTerminal.os == :linux then
				print `clear`
			end
			puts "Dropping to command line for network communications.\n\n"
			puts "Port number: "
			selection2 = ""
			selection2 = gets.downcase
			selection2.slice!(-1)
			while (selection2.to_i == 0 or selection2.to_i == nil) do
				puts "Invalid: |" + selection2 + "|"
				selection2 = gets.downcase
				selection2.slice!(-1)
			end
			port = selection2.to_i
			puts "Would you like to open a client or a server? |C S|"
			selection2 = ""
			selection2 = gets.downcase
			selection2.slice!(-1)
			while (selection2 != "c" and selection2 != "s") do
				puts "Invalid: |" + selection2 + "|"
				selection2 = gets.downcase
				selection2.slice!(-1)
			end
			if selection2 == "c" then
				puts "IP: "
				ip = ""
				ip = gets.downcase
				ip.slice!(-1)
				begin
					server = TCPSocket.open( ip, port )
					EncryptedClient.new( server )
					server.close
				rescue
					puts "ERROR\nConnection probably refused."
				end
			else
				server = TCPServer.open port
				EncryptedServer.new( server.accept )
				server.close
			end
			puts "Returning to normal encryption tasks."
		elsif selection != "q" then
			text.set_text "Incorrect selection: |" + selection + "|"
			manager.render()
			WindowTerminal.getchr()
		end
	end
end

.set_mode(arg) ⇒ Object

Set current encryption mode.

# File 'lib/accu-encrypt.rb', line 817

def self.set_mode(arg)
	if arg then
		@@mode = arg
	end
end

.windows(manager) ⇒ Object

Declares the default windows on a manager object.

# File 'lib/accu-encrypt.rb', line 583

def self.windows(manager)
	#--
	# Page 1 - Simple window.
	page1_win1 = WindowTerminal::Templates.simple()[0]
	page1_win1.set_name "Lobby"
	manager.new_page(page1_win1)
	# Page 2 - Help
	page2_win1 = WindowTerminal::Window.new(WindowTerminal::Orientation.new,"Help")
	page2_text1 = WindowTerminal::ColoredWrappedText.new(WindowTerminal::Orientation.new,self.interactive_help.gsub(/-/,""),6)
	page2_win1.add_objects(page2_text1)
	manager.new_page(page2_win1)
	return page1_win1.objects[2]
	#++
end