text: # ===================================================================
  #
  # Copyright (c) 2015, Legrandin <helderijs@gmail.com>
  # All rights reserved.
  #
  # Redistribution and use in source and binary forms, with or without
  # modification, are permitted provided that the following conditions
  # are met:
  #
  # 1. Redistributions of source code must retain the above copyright
  #    notice, this list of conditions and the following disclaimer.
  # 2. Redistributions in binary form must reproduce the above copyright
  #    notice, this list of conditions and the following disclaimer in
  #    the documentation and/or other materials provided with the
  #    distribution.
  #
  # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  # FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  # BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  # POSSIBILITY OF SUCH DAMAGE.
  # ===================================================================
  
  import unittest
  
  from Crypto.SelfTest.st_common import list_test_cases
  from Crypto.Util.py3compat import tobytes, b, unhexlify
  from Crypto.Cipher import AES, DES3, DES
  from Crypto.Hash import SHAKE128
  
  def get_tag_random(tag, length):
      return SHAKE128.new(data=tobytes(tag)).read(length)
  
  from Crypto.SelfTest.Cipher.test_CBC import BlockChainingTests
  
  class OfbTests(BlockChainingTests):
  
      aes_mode = AES.MODE_OFB
      des3_mode = DES3.MODE_OFB
  
      # Redefine test_unaligned_data_128/64
  
      def test_unaligned_data_128(self):
          plaintexts = [ b("7777777") ] * 100
  
          cipher = AES.new(self.key_128, AES.MODE_CFB, self.iv_128, segment_size=8)
          ciphertexts = [ cipher.encrypt(x) for x in plaintexts ]
          cipher = AES.new(self.key_128, AES.MODE_CFB, self.iv_128, segment_size=8)
          self.assertEqual(b("").join(ciphertexts), cipher.encrypt(b("").join(plaintexts)))
  
          cipher = AES.new(self.key_128, AES.MODE_CFB, self.iv_128, segment_size=128)
          ciphertexts = [ cipher.encrypt(x) for x in plaintexts ]
          cipher = AES.new(self.key_128, AES.MODE_CFB, self.iv_128, segment_size=128)
          self.assertEqual(b("").join(ciphertexts), cipher.encrypt(b("").join(plaintexts)))
  
      def test_unaligned_data_64(self):
          plaintexts = [ b("7777777") ] * 100
          cipher = DES3.new(self.key_192, DES3.MODE_CFB, self.iv_64, segment_size=8)
          ciphertexts = [ cipher.encrypt(x) for x in plaintexts ]
          cipher = DES3.new(self.key_192, DES3.MODE_CFB, self.iv_64, segment_size=8)
          self.assertEqual(b("").join(ciphertexts), cipher.encrypt(b("").join(plaintexts)))
  
          cipher = DES3.new(self.key_192, DES3.MODE_CFB, self.iv_64, segment_size=64)
          ciphertexts = [ cipher.encrypt(x) for x in plaintexts ]
          cipher = DES3.new(self.key_192, DES3.MODE_CFB, self.iv_64, segment_size=64)
          self.assertEqual(b("").join(ciphertexts), cipher.encrypt(b("").join(plaintexts)))
  
  
  from Crypto.SelfTest.Cipher.test_CBC import NistBlockChainingVectors
  
  class NistOfbVectors(NistBlockChainingVectors):
      aes_mode = AES.MODE_OFB
      des_mode = DES.MODE_OFB
      des3_mode = DES3.MODE_OFB
  
  
  # Create one test method per file
  nist_aes_kat_mmt_files = (
      # KAT
      "OFBGFSbox128.rsp",
      "OFBGFSbox192.rsp",
      "OFBGFSbox256.rsp",
      "OFBKeySbox128.rsp",
      "OFBKeySbox192.rsp",
      "OFBKeySbox256.rsp",
      "OFBVarKey128.rsp",
      "OFBVarKey192.rsp",
      "OFBVarKey256.rsp",
      "OFBVarTxt128.rsp",
      "OFBVarTxt192.rsp",
      "OFBVarTxt256.rsp",
      # MMT
      "OFBMMT128.rsp",
      "OFBMMT192.rsp",
      "OFBMMT256.rsp",
      )
  nist_aes_mct_files = (
      "OFBMCT128.rsp",
      "OFBMCT192.rsp",
      "OFBMCT256.rsp",
      )
  
  for file_name in nist_aes_kat_mmt_files:
      def new_func(self, file_name=file_name):
          self._do_kat_aes_test(file_name)
      setattr(NistOfbVectors, "test_AES_" + file_name, new_func)
  
  for file_name in nist_aes_mct_files:
      def new_func(self, file_name=file_name):
          self._do_mct_aes_test(file_name)
      setattr(NistOfbVectors, "test_AES_" + file_name, new_func)
  del file_name, new_func
  
  nist_tdes_files = (
      "TOFBMMT2.rsp",    # 2TDES
      "TOFBMMT3.rsp",    # 3TDES
      "TOFBinvperm.rsp", # Single DES
      "TOFBpermop.rsp",
      "TOFBsubtab.rsp",
      "TOFBvarkey.rsp",
      "TOFBvartext.rsp",
      )
  
  for file_name in nist_tdes_files:
      def new_func(self, file_name=file_name):
          self._do_tdes_test(file_name)
      setattr(NistOfbVectors, "test_TDES_" + file_name, new_func)
  
  # END OF NIST OFB TEST VECTORS
  
  
  class SP800TestVectors(unittest.TestCase):
      """Class exercising the OFB test vectors found in Section F.4
      of NIST SP 800-3A"""
  
      def test_aes_128(self):
          plaintext =     '6bc1bee22e409f96e93d7e117393172a' +\
                          'ae2d8a571e03ac9c9eb76fac45af8e51' +\
                          '30c81c46a35ce411e5fbc1191a0a52ef' +\
                          'f69f2445df4f9b17ad2b417be66c3710'
          ciphertext =    '3b3fd92eb72dad20333449f8e83cfb4a' +\
                          '7789508d16918f03f53c52dac54ed825' +\
                          '9740051e9c5fecf64344f7a82260edcc' +\
                          '304c6528f659c77866a510d9c1d6ae5e'
          key =           '2b7e151628aed2a6abf7158809cf4f3c'
          iv =            '000102030405060708090a0b0c0d0e0f'
  
          key = unhexlify(key)
          iv = unhexlify(iv)
          plaintext = unhexlify(plaintext)
          ciphertext = unhexlify(ciphertext)
  
          cipher = AES.new(key, AES.MODE_OFB, iv)
          self.assertEqual(cipher.encrypt(plaintext), ciphertext)
          cipher = AES.new(key, AES.MODE_OFB, iv)
          self.assertEqual(cipher.decrypt(ciphertext), plaintext)
  
          cipher = AES.new(key, AES.MODE_OFB, iv)
          self.assertEqual(cipher.encrypt(plaintext[:-8]), ciphertext[:-8])
          cipher = AES.new(key, AES.MODE_OFB, iv)
          self.assertEqual(cipher.decrypt(ciphertext[:-8]), plaintext[:-8])
  
      def test_aes_192(self):
          plaintext =     '6bc1bee22e409f96e93d7e117393172a' +\
                          'ae2d8a571e03ac9c9eb76fac45af8e51' +\
                          '30c81c46a35ce411e5fbc1191a0a52ef' +\
                          'f69f2445df4f9b17ad2b417be66c3710'
          ciphertext =    'cdc80d6fddf18cab34c25909c99a4174' +\
                          'fcc28b8d4c63837c09e81700c1100401' +\
                          '8d9a9aeac0f6596f559c6d4daf59a5f2' +\
                          '6d9f200857ca6c3e9cac524bd9acc92a'
          key =           '8e73b0f7da0e6452c810f32b809079e562f8ead2522c6b7b'
          iv =            '000102030405060708090a0b0c0d0e0f'
  
          key = unhexlify(key)
          iv = unhexlify(iv)
          plaintext = unhexlify(plaintext)
          ciphertext = unhexlify(ciphertext)
  
          cipher = AES.new(key, AES.MODE_OFB, iv)
          self.assertEqual(cipher.encrypt(plaintext), ciphertext)
          cipher = AES.new(key, AES.MODE_OFB, iv)
          self.assertEqual(cipher.decrypt(ciphertext), plaintext)
  
          cipher = AES.new(key, AES.MODE_OFB, iv)
          self.assertEqual(cipher.encrypt(plaintext[:-8]), ciphertext[:-8])
          cipher = AES.new(key, AES.MODE_OFB, iv)
          self.assertEqual(cipher.decrypt(ciphertext[:-8]), plaintext[:-8])
  
      def test_aes_256(self):
          plaintext =     '6bc1bee22e409f96e93d7e117393172a' +\
                          'ae2d8a571e03ac9c9eb76fac45af8e51' +\
                          '30c81c46a35ce411e5fbc1191a0a52ef' +\
                          'f69f2445df4f9b17ad2b417be66c3710'
          ciphertext =    'dc7e84bfda79164b7ecd8486985d3860' +\
                          '4febdc6740d20b3ac88f6ad82a4fb08d' +\
                          '71ab47a086e86eedf39d1c5bba97c408' +\
                          '0126141d67f37be8538f5a8be740e484'
          key =           '603deb1015ca71be2b73aef0857d77811f352c073b6108d72d9810a30914dff4'
          iv =            '000102030405060708090a0b0c0d0e0f'
  
          key = unhexlify(key)
          iv = unhexlify(iv)
          plaintext = unhexlify(plaintext)
          ciphertext = unhexlify(ciphertext)
  
          cipher = AES.new(key, AES.MODE_OFB, iv)
          self.assertEqual(cipher.encrypt(plaintext), ciphertext)
          cipher = AES.new(key, AES.MODE_OFB, iv)
          self.assertEqual(cipher.decrypt(ciphertext), plaintext)
  
          cipher = AES.new(key, AES.MODE_OFB, iv)
          self.assertEqual(cipher.encrypt(plaintext[:-8]), ciphertext[:-8])
          cipher = AES.new(key, AES.MODE_OFB, iv)
          self.assertEqual(cipher.decrypt(ciphertext[:-8]), plaintext[:-8])
  
  
  def get_tests(config={}):
      tests = []
      tests += list_test_cases(OfbTests)
      if config.get('slow_tests'):
          tests += list_test_cases(NistOfbVectors)
      tests += list_test_cases(SP800TestVectors)
      return tests
  
  
  if __name__ == '__main__':
      suite = lambda: unittest.TestSuite(get_tests())
      unittest.main(defaultTest='suite')
  