Class: HashId

Inherits:
Object
  • Object
show all
Defined in:
lib/hashid.rb

Defined Under Namespace

Classes: Error

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(salt = nil) ⇒ HashId 



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# File 'lib/hashid.rb', line 4

def initialize(salt = nil)
	@salt = salt || 'ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890'
	
	@letters = [
		'P0MVLWNTZD',
		'UE58X2VSCT',
		'43Z0Y9AQLS',
		'V5Q1P4E8L9',
		'MOIRZCWXED',
		'7NBYXCZU9R',
		'G2S90I84MC',
		'TQAMIWH4ZC',
		'POERHBYA1F',
		'XKO20UB3IL',
		'Y0NTH78VSO',
		'P4DE6VUZLK',
		'9OKN2JLQGI',
		'61UTFSN0BR',
		'R7ZAHJVGE9',
		'ADHIZ5WNUQ',
		'Z9SPX2OQI5',
		'V7YFEU4PTJ',
		'YZVFD6UXNG',
		'VH8UDLCE93',
		'W0H5GMTFZK',
		'GXE6CT2VOP',
		'QH2FLZOM9V',
		'MBGHIF78PU',
		'MHS04FY8L7',
		'E95IGRSMZ1',
		'MN8AILRB95',
		'S7JVO4EHCD',
		'GT01ZPLVUA',
		'9OKN2JLQGI',
		'DUF24AGTSN',
		'4ASPNFJ2BR',
		'OR465YEXQV',
		'DUF24AGTSN',
		'M78PCRAGKS',
		'D8LVQSKA7U'
	]
	
	@indexes = [
		[0,0],
		[0,1],
		[1,0],
		[2,0],
		[0,2],
		[1,1],
		[2,1],
		[1,2]
	]
end

Class Method Details

.generate_salt ⇒ Object 



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# File 'lib/hashid.rb', line 58

def self.generate_salt
	'ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890'.split(//).shuffle.join('')
end

Instance Method Details

#decrypt(string) ⇒ Object

Raises:



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# File 'lib/hashid.rb', line 97

def decrypt(string)

	# Require a string for the decryption process
	raise Error, 'HashID.decrypt expected a String as its argument' unless string.is_a?(String)

	# Prep the string for decryption
	string = string.upcase.gsub(/[^A-Z0-9]+/, '').split(//)
	
	# Require no less then 8 characters
	raise Error, 'A minimum of 8 characters is required for decryption' if string.length < 8
	
	begin
		# Get the indexes and index id
		indexid = @salt.index(string.pop)
		injections = @indexes[indexid]
		
		# Go ahead and locate the salts
		saltids = [string.pop]
		saltids << string.slice!(string.length - 1 - injections.last)
		saltids << string.slice!(injections.first)
		
		# Go ahead and reverse and determine the salt ids
		saltids = saltids.reverse.collect{|x|@salt.index(x)}
		
		# Get the letters cooresponding to the salts
		salts = saltids.collect{|x|@letters[x]}
		
		# Go ahead and convert the alphanumeric id back into numbers
		i=2;string=string.collect{|x|i==2?i=0:i+=1;salts[i].index(x)}.join('')
		
		# Return the integer
		return string.to_i
	rescue
		raise Error, 'The ID provided was not decryptable'
	end
end

#encrypt(string, len = 8) ⇒ Object

Raises:



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# File 'lib/hashid.rb', line 62

def encrypt(string, len = 8)

	# Require a fixnum for the encryption process
	raise Error, 'HashID.encrypt expected a Fixnum as its argument' unless string.is_a?(Fixnum)
	
	# Require a fixnum for the encryption process
	raise Error, 'HashID.encrypt must have a length of no less then 6' unless string.is_a?(Fixnum)

	# Prep the string for encryption
	string = string.to_s.rjust(len, '0')

	# Get the salt ids to use
	saltids = Array.new
	random = [*0..35].shuffle
	3.times{saltids<<random.shift}
	
	# Get the letters cooresponding to the salts
	salts = saltids.collect{|x|@letters[x]}
	
	# Go ahead and convert the numbers into the new format
	i=2;string=string.split(//).collect{|x|i==2?i=0:i+=1;salts[i][x.to_i,1]}.join('')
	
	# Turn the salt ids into their letter forms
	saltids.collect!{|x|@salt[x,1]}
	
	# Get the index id and the indexes
	indexid = [*0..7].shuffle.first
	injections = @indexes[indexid]
	
	# Inject the indexes and index id
	string.insert(injections.first, saltids[0])
	string.insert(string.length - injections.last, saltids[1])
	string << saltids[2] + @salt[indexid,1]
end