Class: RTunnel::Crypto::Hasher

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

Overview

A cryptographically secure hasher. Instances will hash the data

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(key = nil) ⇒ Hasher

Returns a new instance of Hasher.



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# File 'lib/rtunnel/crypto.rb', line 82

def initialize(key = nil)
  @key = key || RTunnel::Crypto::Hasher.random_key
  @cipher = OpenSSL::Cipher::Cipher.new 'aes-128-cbc'
  @cipher.encrypt
  iokey = StringIO.new @key
  @cipher.key = iokey.read_varstring
  @cipher.iv = iokey.read_varstring
end

Instance Attribute Details

#key ⇒ Object (readonly)

Returns the value of attribute key.



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# File 'lib/rtunnel/crypto.rb', line 80

def key
  @key
end

Class Method Details

.random_key ⇒ Object

Produces a random key for the hasher.



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# File 'lib/rtunnel/crypto.rb', line 99

def self.random_key
  cipher = OpenSSL::Cipher::Cipher.new 'aes-128-cbc'
  iokey = StringIO.new
  iokey.write_varstring cipher.random_key
  iokey.write_varstring cipher.random_iv
  iokey.string
end

Instance Method Details

#hash(data) ⇒ Object

Creates a hash for the given data. Warning: this method is not idempotent. The intent is that the same hash can be produced by another hasher that is initialized with the same key and has been fed the same data.



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# File 'lib/rtunnel/crypto.rb', line 94

def hash(data)
  @cipher.update Digest::SHA2.digest(data)
end