Module: BlockIo::Helper

Defined in:
lib/block_io.rb

Class Method Summary collapse

Class Method Details

.decrypt(encrypted_data, b64_enc_key, iv = nil, cipher_type = 'AES-256-ECB') ⇒ Object

Decrypts a block of data (encrypted_data) given an encryption key



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# File 'lib/block_io.rb', line 277

def self.decrypt(encrypted_data, b64_enc_key, iv = nil, cipher_type = 'AES-256-ECB')
  
  response = nil

  begin
    aes = OpenSSL::Cipher::Cipher.new(cipher_type)
    aes.decrypt
    aes.key = Base64.strict_decode64(b64_enc_key)
    aes.iv = iv if iv != nil
    response = aes.update(Base64.strict_decode64(encrypted_data)) + aes.final
  rescue Exception => e
    # decryption failed, must be an invalid Secret PIN
    raise Exception.new('Invalid Secret PIN provided.')
  end

  return response
end

.encrypt(data, b64_enc_key, iv = nil, cipher_type = 'AES-256-ECB') ⇒ Object

Encrypts a block of data given an encryption key



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# File 'lib/block_io.rb', line 296

def self.encrypt(data, b64_enc_key, iv = nil, cipher_type = 'AES-256-ECB')
  aes = OpenSSL::Cipher::Cipher.new(cipher_type)
  aes.encrypt
  aes.key = Base64.strict_decode64(b64_enc_key)
  aes.iv = iv if iv != nil
  Base64.strict_encode64(aes.update(data) + aes.final)
end

.extractKey(encrypted_data, b64_enc_key) ⇒ Object 



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# File 'lib/block_io.rb', line 249

def self.extractKey(encrypted_data, b64_enc_key)
  # passphrase is in plain text
  # encrypted_data is in base64, as it was stored on Block.io
  # returns the private key extracted from the given encrypted data
  
  decrypted = self.decrypt(encrypted_data, b64_enc_key)
  
  return Key.from_passphrase(decrypted)
end

.pinToAesKey(secret_pin, iterations = 2048) ⇒ Object 



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# File 'lib/block_io.rb', line 266

def self.pinToAesKey(secret_pin, iterations = 2048)
  # converts the pincode string to PBKDF2
  # returns a base64 version of PBKDF2 pincode
  salt = ""
  aes_key_bin = OpenSSL::PKCS5.pbkdf2_hmac(secret_pin, salt, iterations/2, 16, OpenSSL::Digest::SHA256.new)
  aes_key_bin = OpenSSL::PKCS5.pbkdf2_hmac(aes_key_bin.unpack("H*")[0], salt, iterations/2, 32, OpenSSL::Digest::SHA256.new)
  
  return Base64.strict_encode64(aes_key_bin) # the base64 encryption key
end

.sha256(value) ⇒ Object 



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# File 'lib/block_io.rb', line 259

def self.sha256(value)
  # returns the hex of the hash of the given value
  hash = Digest::SHA2.new(256)
  hash << value
  hash.hexdigest # return hex
end