/gdata/tlslite/utils/cipherfactory.py

  1"""Factory functions for symmetric cryptography."""
  2
  3import os
  4
  5import Python_AES
  6import Python_RC4
  7
  8import cryptomath
  9
 10tripleDESPresent = False
 11
 12if cryptomath.m2cryptoLoaded:
 13    import OpenSSL_AES
 14    import OpenSSL_RC4
 15    import OpenSSL_TripleDES
 16    tripleDESPresent = True
 17
 18if cryptomath.cryptlibpyLoaded:
 19    import Cryptlib_AES
 20    import Cryptlib_RC4
 21    import Cryptlib_TripleDES
 22    tripleDESPresent = True
 23
 24if cryptomath.pycryptoLoaded:
 25    import PyCrypto_AES
 26    import PyCrypto_RC4
 27    import PyCrypto_TripleDES
 28    tripleDESPresent = True
 29
 30# **************************************************************************
 31# Factory Functions for AES
 32# **************************************************************************
 33
 34def createAES(key, IV, implList=None):
 35    """Create a new AES object.
 36
 37    @type key: str
 38    @param key: A 16, 24, or 32 byte string.
 39
 40    @type IV: str
 41    @param IV: A 16 byte string
 42
 43    @rtype: L{tlslite.utils.AES}
 44    @return: An AES object.
 45    """
 46    if implList == None:
 47        implList = ["cryptlib", "openssl", "pycrypto", "python"]
 48
 49    for impl in implList:
 50        if impl == "cryptlib" and cryptomath.cryptlibpyLoaded:
 51            return Cryptlib_AES.new(key, 2, IV)
 52        elif impl == "openssl" and cryptomath.m2cryptoLoaded:
 53            return OpenSSL_AES.new(key, 2, IV)
 54        elif impl == "pycrypto" and cryptomath.pycryptoLoaded:
 55            return PyCrypto_AES.new(key, 2, IV)
 56        elif impl == "python":
 57            return Python_AES.new(key, 2, IV)
 58    raise NotImplementedError()
 59
 60def createRC4(key, IV, implList=None):
 61    """Create a new RC4 object.
 62
 63    @type key: str
 64    @param key: A 16 to 32 byte string.
 65
 66    @type IV: object
 67    @param IV: Ignored, whatever it is.
 68
 69    @rtype: L{tlslite.utils.RC4}
 70    @return: An RC4 object.
 71    """
 72    if implList == None:
 73        implList = ["cryptlib", "openssl", "pycrypto", "python"]
 74
 75    if len(IV) != 0:
 76        raise AssertionError()
 77    for impl in implList:
 78        if impl == "cryptlib" and cryptomath.cryptlibpyLoaded:
 79            return Cryptlib_RC4.new(key)
 80        elif impl == "openssl" and cryptomath.m2cryptoLoaded:
 81            return OpenSSL_RC4.new(key)
 82        elif impl == "pycrypto" and cryptomath.pycryptoLoaded:
 83            return PyCrypto_RC4.new(key)
 84        elif impl == "python":
 85            return Python_RC4.new(key)
 86    raise NotImplementedError()
 87
 88#Create a new TripleDES instance
 89def createTripleDES(key, IV, implList=None):
 90    """Create a new 3DES object.
 91
 92    @type key: str
 93    @param key: A 24 byte string.
 94
 95    @type IV: str
 96    @param IV: An 8 byte string
 97
 98    @rtype: L{tlslite.utils.TripleDES}
 99    @return: A 3DES object.
100    """
101    if implList == None:
102        implList = ["cryptlib", "openssl", "pycrypto"]
103
104    for impl in implList:
105        if impl == "cryptlib" and cryptomath.cryptlibpyLoaded:
106           return Cryptlib_TripleDES.new(key, 2, IV)
107        elif impl == "openssl" and cryptomath.m2cryptoLoaded:
108            return OpenSSL_TripleDES.new(key, 2, IV)
109        elif impl == "pycrypto" and cryptomath.pycryptoLoaded:
110            return PyCrypto_TripleDES.new(key, 2, IV)
111    raise NotImplementedError()