Class: RecordOnChain::Crypto::Cryptor

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

Instance Method Summary collapse

Constructor Details

#initialize(crypto_engine) ⇒ Cryptor

Returns a new instance of Cryptor.



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# File 'lib/record_on_chain/crypto/cryptor.rb', line 8

def initialize( crypto_engine )
  @crypto_engine = crypto_engine
end

Instance Method Details

#decrypt(passwd, hex_salt, hex_encrypted_data) ⇒ Object 



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# File 'lib/record_on_chain/crypto/cryptor.rb', line 29

def decrypt( passwd, hex_salt, hex_encrypted_data )
  b_data = Utils.hex_to_bytes( hex_encrypted_data )
  b_salt = Utils.hex_to_bytes( hex_salt )
  decrypted = ""
  begin
    # At this point it is not known whether the decrypted data is correct or not.
    # You should verify decrypted data with checksum.
    decrypted = @crypto_engine.decrypt( passwd, b_salt, b_data )
  rescue OpenSSL::Cipher::CipherError
    # fail to encrypt
    return ""
  end
  # validate checksum
  secret_length = decrypted.size - CHECKSUM_LENGTH
  secret_part   = decrypted[0,secret_length]
  checksum_part = decrypted[secret_length..-1]
  checksum = calc_checksum( secret_part )
  # not match checksum
  return "" unless checksum_part == checksum
  # match checksum
  return Utils.bytes_to_hex( secret_part )
end

#encrypt(passwd, hex_salt, hex_secret) ⇒ Object 



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# File 'lib/record_on_chain/crypto/cryptor.rb', line 20

def encrypt( passwd, hex_salt, hex_secret )
  b_secret = Utils.hex_to_bytes( hex_secret )
  # add checksum to secret
  b_secret << calc_checksum( b_secret )
  b_salt   = Utils.hex_to_bytes( hex_salt )
  encrypted = @crypto_engine.encrypt( passwd, b_salt, b_secret )
  return Utils.bytes_to_hex( encrypted )
end

#generate_salt ⇒ Object 



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# File 'lib/record_on_chain/crypto/cryptor.rb', line 16

def generate_salt
  return SecureRandom.hex( SALT_LENGTH )
end

#generate_secret ⇒ Object 



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# File 'lib/record_on_chain/crypto/cryptor.rb', line 12

def generate_secret
  return SecureRandom.hex( SECRET_LENGTH )
end