Source Code for Module pike.digest

  1  # 
  2  # Copyright (c) 2013, EMC Corporation 
  3  # All rights reserved. 
  4  # 
  5  # Redistribution and use in source and binary forms, with or without 
  6  # modification, are permitted provided that the following conditions are met: 
  7  # 
  8  # 1. Redistributions of source code must retain the above copyright notice, 
  9  # this list of conditions and the following disclaimer. 
 10  # 2. Redistributions in binary form must reproduce the above copyright notice, 
 11  # this list of conditions and the following disclaimer in the documentation 
 12  # and/or other materials provided with the distribution. 
 13  # 
 14  # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 15  # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 16  # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 17  # ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 
 18  # LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 19  # CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 20  # SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 21  # INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 22  # CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 23  # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 24  # POSSIBILITY OF SUCH DAMAGE. 
 25  # 
 26  # Module Name: 
 27  # 
 28  #        digest.py 
 29  # 
 30  # Abstract: 
 31  # 
 32  #        Message digest and key derivation (for SMB2/3) 
 33  # 
 34  # Authors: Brian Koropoff (brian.koropoff@emc.com) 
 35  # 
 36   
 37  import Cryptodome.Hash.HMAC as HMAC 
 38  import Cryptodome.Hash.SHA256 as SHA256 
 39  import Cryptodome.Hash.SHA512 as SHA512 
 40  import Cryptodome.Cipher.AES as AES 
 41  import array 
 42  import core 
 43   
 44 -def sha256_hmac(key,message): 
 45      return array.array('B', 
 46          HMAC.new( 
 47              key.tostring(), 
 48              message.tostring(), 
 49              SHA256).digest()) 
 50   
 51 -def aes128_cmac(key,message): 
 52      aes = AES.new(key.tostring(), mode=AES.MODE_ECB) 
 53   
 54      def shiftleft(data): 
 55          cin = 0 
 56          cout = 0 
 57          for i in reversed(xrange(0,len(data))): 
 58              cout = (data[i] & 0x80) >> 7 
 59              data[i] = ((data[i] << 1) | cin) & 0xFF 
 60              cin = cout 
 61   
 62          return cout 
 63   
 64      def xor(data1, data2): 
 65          for i in xrange(0, len(data1)): 
 66              data1[i] ^= data2[i] 
 67   
 68      def subkeys(key): 
 69          zero = array.array('B', [0]*16) 
 70          rb = array.array('B', [0]*15 + [0x87]) 
 71   
 72          key1 = array.array('B', aes.encrypt(zero.tostring())) 
 73   
 74          if shiftleft(key1): 
 75              xor(key1, rb) 
 76   
 77          key2 = array.array('B', key1) 
 78   
 79          if shiftleft(key2): 
 80              xor(key2, rb) 
 81   
 82          return (key1, key2) 
 83   
 84      message = array.array('B', message) 
 85      mac = array.array('B', [0]*16) 
 86      scratch = array.array('B', [0]*16) 
 87      n = (len(message) + 16 - 1) / 16 
 88      rem = len(message) % 16 
 89      last_complete = n != 0 and rem == 0 
 90      i = 0 
 91   
 92      if (n == 0): 
 93          n = 1 
 94   
 95      subkey1, subkey2 = subkeys(array.array('B',key)) 
 96   
 97      for i in xrange(0, n - 1): 
 98          xor(mac, message[i*16:i*16+16]) 
 99          mac = array.array('B',aes.encrypt(mac.tostring())) 
100   
101      if last_complete: 
102          scratch[0:16] = message[-16:] 
103          xor(scratch, subkey1) 
104      else: 
105          scratch[0:rem] = message[-rem:] 
106          scratch[rem] = 0x80 
107          xor(scratch, subkey2) 
108   
109      xor(mac, scratch) 
110      mac = array.array('B',aes.encrypt(mac.tostring())) 
111   
112      return mac 
113   
114 -def smb3_sha512(message): 
115      return array.array('B', 
116              SHA512.new(message.tostring()).digest()) 
117   
118 -def derive_key(key, label, context): 
119      message = array.array('B') 
120      cur = core.Cursor(message, 0) 
121   
122      cur.encode_uint32be(1) 
123      cur.encode_bytes(label) 
124      cur.encode_uint8be(0) 
125      cur.encode_uint8be(0) 
126      cur.encode_bytes(context) 
127      cur.encode_uint32be(len(key)*8) 
128   
129      return sha256_hmac(key, message) 
130