def command_MQ(cmdObj):
""" Generate a MAC (MAB) for a large message. """
""" Command Pattern:
request: Message header + 'MQ' + Message Block Number + TAK + IV + Message Length + Message Block + End message delimiter + Message Trailer
response: Message header + 'MR' + Error code + MAB + End Message delimiter + Message Trailer
"""
TAK = decryptKeyUnderLMK('TAK', unhexlify(cmdObj.TAK.value),
cmdObj.TAK.scheme)
if (cmdObj.MessageBlockNumber.value == '0'): # The only block.
mac = calcMAC(TAK, cmdObj.MessageBlock.value, "\0\0\0\0\0\0\0\0")
elif (cmdObj.MessageBlockNumber.value == '1'): # The first block.
mac = calcMAC(TAK, cmdObj.MessageBlock.value, "\0\0\0\0\0\0\0\0")
elif (cmdObj.MessageBlockNumber.value == '2'): # A middle block.
mac = calcMAC(TAK, cmdObj.MessageBlock.value,
unhexlify(cmdObj.IV.value))
elif (cmdObj.MessageBlockNumber.value == '3'): # The last block.
mac = calcMAC(TAK, cmdObj.MessageBlock.value,
unhexlify(cmdObj.IV.value))
else:
raise ValueError('invalid message block number [' +
cmdObj.MessageBlockNumber.value + ']')
respObj = CommandObj()
respObj.ResponseCode = DataVariable('00')
respObj.MAB = DataVariable(string.upper(hexlify(mac)))
return respObj
def command_MS(cmdObj):
""" To generate a MAB for a large message using either a TAK or a ZAK. If the
key is single length use ANSI X9.9 MAC generation or if the key is double
length use ANSI X9.19 MAC generation. """
""" Command Pattern:
request: Message header + 'MS' + Message Block Number + Key Type + Key Length + Message Length + Key + IV + Message Length + Message Block + End message delimiter + Message Trailer
response: Message header + 'MT' + Error code + MAB + End Message delimiter + Message Trailer
"""
if cmdObj.KeyType.value == '0':
KeyType = 'TAK'
elif cmdObj.KeyType.value == '1':
KeyType = 'ZAK'
else:
raise ValueError('invalid key type [' + cmdObj.KeyType.value + ']')
KEY = decryptKeyUnderLMK(KeyType, unhexlify(cmdObj.Key.value),
cmdObj.Key.scheme)
if cmdObj.KeyLength.value == '0':
keyLength = 8
elif cmdObj.KeyLength.value == '1':
keyLength = 16
else:
raise ValueError('invalid key length [' + cmdObj.KeyLength.value + ']')
if len(KEY) != keyLength:
raise ValueError('key length error')
if cmdObj.MessageType.value == '0':
messageBlock = cmdObj.MessageBlock.value
elif cmdObj.MessageType.value == '1':
messageBlock = unhexlify(cmdObj.MessageBlock.value)
else:
raise ValueError('invalid message type [' + cmdObj.MessageType.value +
']')
if (cmdObj.MessageBlockNumber.value == '0'): # The only block.
mac = calcMAC(KEY, messageBlock, "\0\0\0\0\0\0\0\0")
elif (cmdObj.MessageBlockNumber.value == '1'): # The first block.
mac = calcMAC(KEY, messageBlock, "\0\0\0\0\0\0\0\0")
elif (cmdObj.MessageBlockNumber.value == '2'): # A middle block.
mac = calcMAC(KEY, messageBlock, unhexlify(cmdObj.IV.value))
elif (cmdObj.MessageBlockNumber.value == '3'): # The last block.
mac = calcMAC(KEY, messageBlock, unhexlify(cmdObj.IV.value))
else:
raise ValueError('invalid message block number [' +
cmdObj.MessageBlockNumber.value + ']')
respObj = CommandObj()
respObj.ResponseCode = DataVariable('00')
respObj.MAB = DataVariable(string.upper(hexlify(mac)))
return respObj
