Class: RubeePass::ProtectedDecryptor

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

Instance Method Summary collapse

Constructor Details

#initialize(key, iv) ⇒ ProtectedDecryptor

Returns a new instance of ProtectedDecryptor.



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# File 'lib/rubeepass/protected_decryptor.rb', line 25

def initialize(key, iv)
    @ciphertext = Array.new
    @iv = iv
    @key = key
end

Instance Method Details

#add_to_stream(str) ⇒ Object 



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# File 'lib/rubeepass/protected_decryptor.rb', line 4

def add_to_stream(str)
    @ciphertext.push(str)
    return (@ciphertext.length - 1)
end

#decrypt(index) ⇒ Object 



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# File 'lib/rubeepass/protected_decryptor.rb', line 9

def decrypt(index)
    return nil if (@iv.nil? || @key.nil?)
    return nil if ((index < 0) || (index >= @ciphertext.length))

    plaintext = Salsa20.new(@key, @iv).decrypt(@ciphertext.join)

    start = 0
    index.times do |i|
        start += @ciphertext[i].length
    end

    stop = start + @ciphertext[index].length

    return plaintext[start...stop]
end