1  # Reticulum License
  2  #
  3  # Copyright (c) 2016-2025 Mark Qvist
  4  #
  5  # Permission is hereby granted, free of charge, to any person obtaining a copy
  6  # of this software and associated documentation files (the "Software"), to deal
  7  # in the Software without restriction, including without limitation the rights
  8  # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  9  # copies of the Software, and to permit persons to whom the Software is
 10  # furnished to do so, subject to the following conditions:
 11  #
 12  # - The Software shall not be used in any kind of system which includes amongst
 13  #   its functions the ability to purposefully do harm to human beings.
 14  #
 15  # - The Software shall not be used, directly or indirectly, in the creation of
 16  #   an artificial intelligence, machine learning or language model training
 17  #   dataset, including but not limited to any use that contributes to the
 18  #   training or development of such a model or algorithm.
 19  #
 20  # - The above copyright notice and this permission notice shall be included in
 21  #   all copies or substantial portions of the Software.
 22  #
 23  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 24  # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 25  # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 26  # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 27  # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 28  # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 29  # SOFTWARE.
 30  
 31  import RNS.Cryptography.Provider as cp
 32  import RNS.vendor.platformutils as pu
 33  
 34  if cp.PROVIDER == cp.PROVIDER_INTERNAL:
 35      from .aes import AES128
 36      from .aes import AES256
 37      
 38  elif cp.PROVIDER == cp.PROVIDER_PYCA:
 39      from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
 40      if pu.cryptography_old_api(): from cryptography.hazmat.backends import default_backend
 41  
 42  
 43  class AES_128_CBC:
 44      @staticmethod
 45      def encrypt(plaintext, key, iv):
 46          if len(key) != 16: raise ValueError(f"Invalid key length {len(key)*8} for {self}")
 47          if cp.PROVIDER == cp.PROVIDER_INTERNAL:
 48              cipher = AES128(key)
 49              return cipher.encrypt(plaintext, iv)
 50  
 51          elif cp.PROVIDER == cp.PROVIDER_PYCA:
 52              if not pu.cryptography_old_api():
 53                  cipher = Cipher(algorithms.AES(key), modes.CBC(iv))
 54              else:
 55                  cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=default_backend())
 56  
 57              encryptor = cipher.encryptor()
 58              ciphertext = encryptor.update(plaintext) + encryptor.finalize()
 59              return ciphertext
 60  
 61      @staticmethod
 62      def decrypt(ciphertext, key, iv):
 63          if len(key) != 16: raise ValueError(f"Invalid key length {len(key)*8} for {self}")
 64          if cp.PROVIDER == cp.PROVIDER_INTERNAL:
 65              cipher = AES128(key)
 66              return cipher.decrypt(ciphertext, iv)
 67  
 68          elif cp.PROVIDER == cp.PROVIDER_PYCA:
 69              if not pu.cryptography_old_api():
 70                  cipher = Cipher(algorithms.AES(key), modes.CBC(iv))
 71              else:
 72                  cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=default_backend())
 73  
 74              decryptor = cipher.decryptor()
 75              plaintext = decryptor.update(ciphertext) + decryptor.finalize()
 76              return plaintext
 77  
 78  class AES_256_CBC:
 79      @staticmethod
 80      def encrypt(plaintext, key, iv):
 81          if len(key) != 32: raise ValueError(f"Invalid key length {len(key)*8} for {self}")
 82          if cp.PROVIDER == cp.PROVIDER_INTERNAL:
 83              cipher = AES256(key)
 84              return cipher.encrypt_cbc(plaintext, iv)
 85  
 86          elif cp.PROVIDER == cp.PROVIDER_PYCA:
 87              if not pu.cryptography_old_api():
 88                  cipher = Cipher(algorithms.AES(key), modes.CBC(iv))
 89              else:
 90                  cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=default_backend())
 91              
 92              encryptor = cipher.encryptor()
 93              ciphertext = encryptor.update(plaintext) + encryptor.finalize()
 94              return ciphertext
 95  
 96      @staticmethod
 97      def decrypt(ciphertext, key, iv):
 98          if len(key) != 32: raise ValueError(f"Invalid key length {len(key)*8} for {self}")
 99          if cp.PROVIDER == cp.PROVIDER_INTERNAL:
100              cipher = AES256(key)
101              return cipher.decrypt_cbc(ciphertext, iv)
102  
103          elif cp.PROVIDER == cp.PROVIDER_PYCA:
104              if not pu.cryptography_old_api():
105                  cipher = Cipher(algorithms.AES(key), modes.CBC(iv))
106              else:
107                  cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=default_backend())
108  
109              decryptor = cipher.decryptor()
110              plaintext = decryptor.update(ciphertext) + decryptor.finalize()
111              return plaintext