Module: TBK::Webpay::Encryption

Defined in:
lib/tbk/webpay/encryption.rb

Constant Summary collapse

KEY_ID =

Constants

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KEY = 
TBK.parse_key('webpay.101')
TEST_KEY = 
TBK.parse_key('webpay_test.101')
IV_PADDING = 
"\x10\xBB\xFF\xBF\x00\x00\x00\x00\x00\x00\x00\x00\xF4\xBF"

Instance Method Summary collapse

Instance Method Details

#webpay_decrypt(encripted_text) ⇒ Object 



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# File 'lib/tbk/webpay/encryption.rb', line 42

def webpay_decrypt(encripted_text)
  data = Base64.decode64(encripted_text)

  iv = data[0...16]
  encripted_key = data[16...(16 + self.key_bytes)]
  key = self.key.private_decrypt(encripted_key, OpenSSL::PKey::RSA::PKCS1_OAEP_PADDING)

  cipher = OpenSSL::Cipher.new('AES-256-CBC')
  cipher.decrypt
  cipher.key = key
  cipher.iv = iv + IV_PADDING
  decrypted_text = cipher.update(data[(16 + self.key_bytes)..-1]) + cipher.final
  signature = decrypted_text[0...(webpay_key_length)]
  text = decrypted_text[(webpay_key_length)..-1]

  unless webpay_key.verify(OpenSSL::Digest::SHA512.new, signature, text)
    raise TBK::Webpay::EncryptionError, "Invalid message signature"
  end

  {
    :body => text,
    :signature => signature.unpack('H*').first
  }
rescue TBK::Error
  raise
rescue => error
  raise TBK::Webpay::EncryptionError.new("Decryption failed",error)
end

#webpay_encrypt(text) ⇒ Object 



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# File 'lib/tbk/webpay/encryption.rb', line 23

def webpay_encrypt(text)
  signature = self.key.sign(OpenSSL::Digest::SHA512.new, text)

  key = SecureRandom.random_bytes(32)
  encripted_key = webpay_key.public_encrypt(key, OpenSSL::PKey::RSA::PKCS1_OAEP_PADDING)

  iv = SecureRandom.random_bytes(16)

  cipher = OpenSSL::Cipher.new('AES-256-CBC')
  cipher.encrypt
  cipher.key = key
  cipher.iv = iv + IV_PADDING
  encripted_text = cipher.update(signature + text) + cipher.final

  Base64.encode64( iv + encripted_key + encripted_text).strip
rescue RuntimeError => error
  raise TBK::Webpay::EncryptionError.new("Encryption failed",error)
end

#webpay_key ⇒ Object 



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# File 'lib/tbk/webpay/encryption.rb', line 15

def webpay_key
  self.production? ? KEY : TEST_KEY
end

#webpay_key_id ⇒ Object 



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# File 'lib/tbk/webpay/encryption.rb', line 11

def webpay_key_id
  KEY_ID
end

#webpay_key_length ⇒ Object 



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# File 'lib/tbk/webpay/encryption.rb', line 19

def webpay_key_length
  webpay_key.n.num_bytes
end