cis-kuldeep/PyBitmessage-2021-04-27
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Finished timing attack mitigation

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This commit is contained in:
Jonathan Warren 2013-02-06 16:17:49 -05:00
parent b3383bec02
commit 9b32261053
2 changed files with 317 additions and 292 deletions
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544
bitmessagemain.py
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@ -5,7 +5,7 @@
#Right now, PyBitmessage only support connecting to stream 1. It doesn't yet contain logic to expand into further streams. #Right now, PyBitmessage only support connecting to stream 1. It doesn't yet contain logic to expand into further streams.
softwareVersion = '0.2.1' softwareVersion = '0.2.2'
verbose = 2 verbose = 2
maximumAgeOfAnObjectThatIAmWillingToAccept = 216000 #Equals two days and 12 hours. maximumAgeOfAnObjectThatIAmWillingToAccept = 216000 #Equals two days and 12 hours.
lengthOfTimeToLeaveObjectsInInventory = 237600 #Equals two days and 18 hours. This should be longer than maximumAgeOfAnObjectThatIAmWillingToAccept so that we don't process messages twice. lengthOfTimeToLeaveObjectsInInventory = 237600 #Equals two days and 18 hours. This should be longer than maximumAgeOfAnObjectThatIAmWillingToAccept so that we don't process messages twice.
@ -321,8 +321,8 @@ class receiveDataThread(QThread):
#The time we've last seen this node is obviously right now since we just received valid data from it. So update the knownNodes list so that other peers can be made aware of its existance. #The time we've last seen this node is obviously right now since we just received valid data from it. So update the knownNodes list so that other peers can be made aware of its existance.
if self.initiatedConnection: #The remote port is only something we should share with others if it is the remote node's incoming port (rather than some random operating-system-assigned outgoing port). if self.initiatedConnection: #The remote port is only something we should share with others if it is the remote node's incoming port (rather than some random operating-system-assigned outgoing port).
knownNodes[self.streamNumber][self.HOST] = (self.PORT,int(time.time())) knownNodes[self.streamNumber][self.HOST] = (self.PORT,int(time.time()))
if self.payloadLength <= 180000000: #If the size of the message is greater than 180MB, ignore it. (I get memory errors when processing messages much larger than this though it is concievable that this value will have to be lowered if some systems are less tolarant of large messages.)
remoteCommand = self.data[4:16] remoteCommand = self.data[4:16]
if verbose >= 2:
printLock.acquire() printLock.acquire()
print 'remoteCommand ', remoteCommand, 'from', self.HOST print 'remoteCommand ', remoteCommand, 'from', self.HOST
printLock.release() printLock.release()
@ -484,7 +484,7 @@ class receiveDataThread(QThread):
#We have received a broadcast message #We have received a broadcast message
def recbroadcast(self): def recbroadcast(self):
messageProcessingStartTime = time.time() self.messageProcessingStartTime = time.time()
#First we must check to make sure the proof of work is sufficient. #First we must check to make sure the proof of work is sufficient.
if not self.isProofOfWorkSufficient(): if not self.isProofOfWorkSufficient():
print 'Proof of work in broadcast message insufficient.' print 'Proof of work in broadcast message insufficient.'
@ -500,22 +500,48 @@ class receiveDataThread(QThread):
print 'The payload length of this broadcast packet is unreasonably low. Someone is probably trying funny business. Ignoring message.' print 'The payload length of this broadcast packet is unreasonably low. Someone is probably trying funny business. Ignoring message.'
return return
inventoryLock.acquire() inventoryLock.acquire()
inventoryHash = calculateInventoryHash(self.data[24:self.payloadLength+24]) self.inventoryHash = calculateInventoryHash(self.data[24:self.payloadLength+24])
if inventoryHash in inventory: if self.inventoryHash in inventory:
print 'We have already received this broadcast object. Ignoring.' print 'We have already received this broadcast object. Ignoring.'
inventoryLock.release() inventoryLock.release()
return return
elif isInSqlInventory(inventoryHash): elif isInSqlInventory(self.inventoryHash):
print 'We have already received this broadcast object (it is stored on disk in the SQL inventory). Ignoring it.' print 'We have already received this broadcast object (it is stored on disk in the SQL inventory). Ignoring it.'
inventoryLock.release() inventoryLock.release()
return return
#It is valid so far. Let's let our peers know about it. #It is valid so far. Let's let our peers know about it.
objectType = 'broadcast' objectType = 'broadcast'
inventory[inventoryHash] = (objectType, self.streamNumber, self.data[24:self.payloadLength+24], embeddedTime) inventory[self.inventoryHash] = (objectType, self.streamNumber, self.data[24:self.payloadLength+24], embeddedTime)
inventoryLock.release() inventoryLock.release()
self.broadcastinv(inventoryHash) self.broadcastinv(self.inventoryHash)
self.emit(SIGNAL("incrementNumberOfBroadcastsProcessed()")) self.emit(SIGNAL("incrementNumberOfBroadcastsProcessed()"))
self.processbroadcast()#When this function returns, we will have either successfully processed this broadcast because we are interested in it, ignored it because we aren't interested in it, or found problem with the broadcast that warranted ignoring it.
# Let us now set lengthOfTimeWeShouldUseToProcessThisMessage. If we haven't used the specified amount of time, we shall sleep. These values are mostly the same values used for msg messages although broadcast messages are processed faster.
if self.payloadLength > 100000000: #Size is greater than 100 megabytes
lengthOfTimeWeShouldUseToProcessThisMessage = 100 #seconds.
elif self.payloadLength > 10000000: #Between 100 and 10 megabytes
lengthOfTimeWeShouldUseToProcessThisMessage = 20 #seconds.
elif self.payloadLength > 1000000: #Between 10 and 1 megabyte
lengthOfTimeWeShouldUseToProcessThisMessage = 3 #seconds.
else: #Less than 1 megabyte
lengthOfTimeWeShouldUseToProcessThisMessage = .1 #seconds.
sleepTime = lengthOfTimeWeShouldUseToProcessThisMessage - (time.time()- self.messageProcessingStartTime)
if sleepTime > 0:
printLock.acquire()
print 'Timing attack mitigation: Sleeping for', sleepTime ,'seconds.'
printLock.release()
time.sleep(sleepTime)
printLock.acquire()
print 'Total message processing time:', time.time()- self.messageProcessingStartTime, 'seconds.'
printLock.release()
#A broadcast message has a valid time and POW and requires processing. The recbroadcast function calls this one.
def processbroadcast(self):
readPosition = 36 readPosition = 36
broadcastVersion, broadcastVersionLength = decodeVarint(self.data[readPosition:readPosition+9]) broadcastVersion, broadcastVersionLength = decodeVarint(self.data[readPosition:readPosition+9])
if broadcastVersion <> 1: if broadcastVersion <> 1:
@ -542,16 +568,7 @@ class receiveDataThread(QThread):
if sendersHash not in broadcastSendersForWhichImWatching: if sendersHash not in broadcastSendersForWhichImWatching:
#Display timing data #Display timing data
printLock.acquire() printLock.acquire()
print 'Time spent deciding that we are not interested in this broadcast:', time.time()- messageProcessingStartTime print 'Time spent deciding that we are not interested in this broadcast:', time.time()- self.messageProcessingStartTime
printLock.release()
sleepTime = 0.1- (time.time()- messageProcessingStartTime)
if sleepTime > 0:
printLock.acquire()
print 'Timing attack mitigation: Sleeping for', sleepTime ,'seconds.'
printLock.release()
time.sleep(sleepTime)
printLock.acquire()
print 'Total broadcast processing time:', time.time()- messageProcessingStartTime, 'seconds.'
printLock.release() printLock.release()
return return
#At this point, this message claims to be from sendersHash and we are interested in it. We still have to hash the public key to make sure it is truly the key that matches the hash, and also check the signiture. #At this point, this message claims to be from sendersHash and we are interested in it. We still have to hash the public key to make sure it is truly the key that matches the hash, and also check the signiture.
@ -605,25 +622,16 @@ class receiveDataThread(QThread):
toAddress = '[Broadcast subscribers]' toAddress = '[Broadcast subscribers]'
if messageEncodingType <> 0: if messageEncodingType <> 0:
sqlLock.acquire() sqlLock.acquire()
t = (inventoryHash,toAddress,fromAddress,subject,int(time.time()),body,'inbox') t = (self.inventoryHash,toAddress,fromAddress,subject,int(time.time()),body,'inbox')
sqlSubmitQueue.put('''INSERT INTO inbox VALUES (?,?,?,?,?,?,?)''') sqlSubmitQueue.put('''INSERT INTO inbox VALUES (?,?,?,?,?,?,?)''')
sqlSubmitQueue.put(t) sqlSubmitQueue.put(t)
sqlReturnQueue.get() sqlReturnQueue.get()
sqlLock.release() sqlLock.release()
self.emit(SIGNAL("displayNewMessage(PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject)"),inventoryHash,toAddress,fromAddress,subject,body) self.emit(SIGNAL("displayNewMessage(PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject)"),self.inventoryHash,toAddress,fromAddress,subject,body)
#Display timing data #Display timing data
printLock.acquire() printLock.acquire()
print 'Time spent processing this interesting broadcast:', time.time()- messageProcessingStartTime print 'Time spent processing this interesting broadcast:', time.time()- self.messageProcessingStartTime
printLock.release()
sleepTime = 0.1- (time.time()- messageProcessingStartTime)
if sleepTime > 0:
printLock.acquire()
print 'Timing attack mitigation: Sleeping for', sleepTime ,'seconds.'
printLock.release()
time.sleep(sleepTime)
printLock.acquire()
print 'Total broadcast processing time:', time.time()- messageProcessingStartTime, 'seconds.'
printLock.release() printLock.release()
elif sendersAddressVersion == 1: elif sendersAddressVersion == 1:
@ -699,21 +707,22 @@ class receiveDataThread(QThread):
toAddress = '[Broadcast subscribers]' toAddress = '[Broadcast subscribers]'
if messageEncodingType <> 0: if messageEncodingType <> 0:
sqlLock.acquire() sqlLock.acquire()
t = (inventoryHash,toAddress,fromAddress,subject,int(time.time()),body,'inbox') t = (self.inventoryHash,toAddress,fromAddress,subject,int(time.time()),body,'inbox')
sqlSubmitQueue.put('''INSERT INTO inbox VALUES (?,?,?,?,?,?,?)''') sqlSubmitQueue.put('''INSERT INTO inbox VALUES (?,?,?,?,?,?,?)''')
sqlSubmitQueue.put(t) sqlSubmitQueue.put(t)
sqlReturnQueue.get() sqlReturnQueue.get()
sqlLock.release() sqlLock.release()
self.emit(SIGNAL("displayNewMessage(PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject)"),inventoryHash,toAddress,fromAddress,subject,body) self.emit(SIGNAL("displayNewMessage(PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject)"),self.inventoryHash,toAddress,fromAddress,subject,body)
#We have received a msg message. #We have received a msg message.
def recmsg(self): def recmsg(self):
self.messageProcessingStartTime = time.time()
#First we must check to make sure the proof of work is sufficient. #First we must check to make sure the proof of work is sufficient.
messageProcessingStartTime = time.time()
if not self.isProofOfWorkSufficient(): if not self.isProofOfWorkSufficient():
print 'Proof of work in msg message insufficient.' print 'Proof of work in msg message insufficient.'
return return
initialDecryptionSuccessful = False
readPosition = 32 readPosition = 32
embeddedTime, = unpack('>I',self.data[readPosition:readPosition+4]) embeddedTime, = unpack('>I',self.data[readPosition:readPosition+4])
if embeddedTime > int(time.time())+10800: if embeddedTime > int(time.time())+10800:
@ -728,247 +737,46 @@ class receiveDataThread(QThread):
print 'The stream number encoded in this msg (' + str(streamNumberAsClaimedByMsg) + ') message does not match the stream number on which it was received. Ignoring it.' print 'The stream number encoded in this msg (' + str(streamNumberAsClaimedByMsg) + ') message does not match the stream number on which it was received. Ignoring it.'
return return
readPosition += streamNumberAsClaimedByMsgLength readPosition += streamNumberAsClaimedByMsgLength
inventoryHash = calculateInventoryHash(self.data[24:self.payloadLength+24]) self.inventoryHash = calculateInventoryHash(self.data[24:self.payloadLength+24])
inventoryLock.acquire() inventoryLock.acquire()
if inventoryHash in inventory: if self.inventoryHash in inventory:
print 'We have already received this msg message. Ignoring.' print 'We have already received this msg message. Ignoring.'
inventoryLock.release() inventoryLock.release()
return return
elif isInSqlInventory(inventoryHash): elif isInSqlInventory(self.inventoryHash):
print 'We have already received this msg message (it is stored on disk in the SQL inventory). Ignoring it.' print 'We have already received this msg message (it is stored on disk in the SQL inventory). Ignoring it.'
inventoryLock.release() inventoryLock.release()
return return
#This msg message is valid. Let's let our peers know about it. #This msg message is valid. Let's let our peers know about it.
objectType = 'msg' objectType = 'msg'
inventory[inventoryHash] = (objectType, self.streamNumber, self.data[24:self.payloadLength+24], embeddedTime) inventory[self.inventoryHash] = (objectType, self.streamNumber, self.data[24:self.payloadLength+24], embeddedTime)
inventoryLock.release() inventoryLock.release()
self.broadcastinv(inventoryHash) self.broadcastinv(self.inventoryHash)
self.emit(SIGNAL("incrementNumberOfMessagesProcessed()")) self.emit(SIGNAL("incrementNumberOfMessagesProcessed()"))
#Let's check whether this is a message acknowledgement bound for us. self.processmsg(readPosition) #When this function returns, we will have either successfully processed the message bound for us, ignored it because it isn't bound for us, or found problem with the message that warranted ignoring it.
if self.data[readPosition:24+self.payloadLength] in ackdataForWhichImWatching:
printLock.acquire()
print 'This msg IS an acknowledgement bound for me.'
printLock.release()
del ackdataForWhichImWatching[self.data[readPosition:24+self.payloadLength]]
t = ('ackreceived',self.data[readPosition:24+self.payloadLength])
sqlLock.acquire()
sqlSubmitQueue.put('UPDATE sent SET status=? WHERE ackdata=?')
sqlSubmitQueue.put(t)
sqlReturnQueue.get()
sqlLock.release()
self.emit(SIGNAL("updateSentItemStatusByAckdata(PyQt_PyObject,PyQt_PyObject)"),self.data[readPosition:24+self.payloadLength],'Acknowledgement of the message received just now.')
return
else:
printLock.acquire()
print 'This was NOT an acknowledgement bound for me.' #Msg potential ack data:', repr(self.data[readPosition:24+self.payloadLength])
#print 'ackdataForWhichImWatching', ackdataForWhichImWatching
printLock.release()
#This is not an acknowledgement bound for me. See if it is a message bound for me by trying to decrypt it with my private keys. # Let us now set lengthOfTimeWeShouldUseToProcessThisMessage. If we haven't used the specified amount of time, we shall sleep. These values are based on test timings and you may change them at-will.
for key, cryptorObject in myECAddressHashes.items(): if self.payloadLength > 100000000: #Size is greater than 100 megabytes
try: lengthOfTimeWeShouldUseToProcessThisMessage = 100 #seconds. Actual length of time it took my computer to decrypt and verify the signature of a 100 MB message: 3.7 seconds.
data = cryptorObject.decrypt(self.data[readPosition:self.payloadLength+24]) elif self.payloadLength > 10000000: #Between 100 and 10 megabytes
toRipe = key #This is the RIPE hash of my pubkeys. We need this below to compare to the destination_ripe included in the encrypted data. lengthOfTimeWeShouldUseToProcessThisMessage = 20 #seconds. Actual length of time it took my computer to decrypt and verify the signature of a 10 MB message: 0.53 seconds. Actual length of time it takes in practice when processing a real message: 1.44 seconds.
initialDecryptionSuccessful = True elif self.payloadLength > 1000000: #Between 10 and 1 megabyte
print 'EC decryption successful using key associated with ripe hash:', key.encode('hex') lengthOfTimeWeShouldUseToProcessThisMessage = 3 #seconds. Actual length of time it took my computer to decrypt and verify the signature of a 1 MB message: 0.18 seconds. Actual length of time it takes in practice when processing a real message: 0.30 seconds.
break else: #Less than 1 megabyte
except Exception, err: lengthOfTimeWeShouldUseToProcessThisMessage = .6 #seconds. Actual length of time it took my computer to decrypt and verify the signature of a 100 KB message: 0.15 seconds. Actual length of time it takes in practice when processing a real message: 0.25 seconds.
pass
#print 'cryptorObject.decrypt Exception:', err
if not initialDecryptionSuccessful:
#This is not a message bound for me.
printLock.acquire()
print 'Length of time program spent failing to decrypt this message:', time.time()- messageProcessingStartTime, 'seconds.'
printLock.release()
else:
#This is a message bound for me.
readPosition = 0
messageVersion, messageVersionLength = decodeVarint(data[readPosition:readPosition+10])
readPosition += messageVersionLength
if messageVersion != 1:
print 'Cannot understand message versions other than one. Ignoring message.'
return
sendersAddressVersionNumber, sendersAddressVersionNumberLength = decodeVarint(data[readPosition:readPosition+10])
readPosition += sendersAddressVersionNumberLength
if sendersAddressVersionNumber == 0:
print 'Cannot understand sendersAddressVersionNumber = 0. Ignoring message.'
return
if sendersAddressVersionNumber >= 3:
print 'Sender\'s address version number', sendersAddressVersionNumber, ' not yet supported. Ignoring message.'
return
if len(data) < 170:
print 'Length of the unencrypted data is unreasonably short. Sanity check failed. Ignoring message.'
return
sendersStreamNumber, sendersStreamNumberLength = decodeVarint(data[readPosition:readPosition+10])
if sendersStreamNumber == 0:
print 'sender\'s stream number is 0. Ignoring message.'
return
readPosition += sendersStreamNumberLength
behaviorBitfield = data[readPosition:readPosition+4]
readPosition += 4
pubSigningKey = '\x04' + data[readPosition:readPosition+64]
readPosition += 64
pubEncryptionKey = '\x04' + data[readPosition:readPosition+64]
readPosition += 64
endOfThePublicKeyPosition = readPosition #needed for when we store the pubkey in our database of pubkeys for later use.
if toRipe != data[readPosition:readPosition+20]:
printLock.acquire()
print 'The original sender of this message did not send it to you. Someone is attempting a Surreptitious Forwarding Attack.'
print 'See: http://tools.ietf.org/html/draft-ietf-smime-sender-auth-00'
print 'your toRipe:', toRipe.encode('hex')
print 'embedded destination toRipe:', data[readPosition:readPosition+20].encode('hex')
printLock.release()
return
readPosition += 20
messageEncodingType, messageEncodingTypeLength = decodeVarint(data[readPosition:readPosition+10])
readPosition += messageEncodingTypeLength
messageLength, messageLengthLength = decodeVarint(data[readPosition:readPosition+10])
readPosition += messageLengthLength
message = data[readPosition:readPosition+messageLength]
#print 'First 150 characters of message:', repr(message[:150])
readPosition += messageLength
ackLength, ackLengthLength = decodeVarint(data[readPosition:readPosition+10])
readPosition += ackLengthLength
ackData = data[readPosition:readPosition+ackLength]
readPosition += ackLength
positionOfBottomOfAckData = readPosition #needed to mark the end of what is covered by the signature
signatureLength, signatureLengthLength = decodeVarint(data[readPosition:readPosition+10])
readPosition += signatureLengthLength
signature = data[readPosition:readPosition+signatureLength]
try:
highlevelcrypto.verify(data[:positionOfBottomOfAckData],signature,pubSigningKey.encode('hex'))
print 'ECDSA verify passed'
except Exception, err:
print 'ECDSA verify failed', err
return
printLock.acquire()
print 'As a matter of intellectual curiosity, here is the Bitcoin address associated with the keys owned by the other person:', calculateBitcoinAddressFromPubkey(pubSigningKey), ' ..and here is the testnet address:',calculateTestnetAddressFromPubkey(pubSigningKey),'. The other person must take their private signing key from Bitmessage and import it into Bitcoin (or a service like Blockchain.info) for it to be of any use. Do not use this unless you know what you are doing.'
printLock.release()
#calculate the fromRipe.
sha = hashlib.new('sha512')
sha.update(pubSigningKey+pubEncryptionKey)
ripe = hashlib.new('ripemd160')
ripe.update(sha.digest())
#Let's store the public key in case we want to reply to this person.
#We don't have the correct nonce or time (which would let us send out a pubkey message) so we'll just fill it with 1's. We won't be able to send this pubkey to others (without doing the proof of work ourselves, which this program is programmed to not do.)
t = (ripe.digest(),False,'\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF'+'\xFF\xFF\xFF\xFF'+data[messageVersionLength:endOfThePublicKeyPosition],int(time.time())+2419200) #after one month we may remove this pub key from our database. (2419200 = a month)
sqlLock.acquire()
sqlSubmitQueue.put('''INSERT INTO pubkeys VALUES (?,?,?,?)''')
sqlSubmitQueue.put(t)
sqlReturnQueue.get()
sqlLock.release()
blockMessage = False #Gets set to True if the user shouldn't see the message according to black or white lists.
fromAddress = encodeAddress(sendersAddressVersionNumber,sendersStreamNumber,ripe.digest())
if config.get('bitmessagesettings', 'blackwhitelist') == 'black': #If we are using a blacklist
t = (fromAddress,)
sqlLock.acquire()
sqlSubmitQueue.put('''SELECT label, enabled FROM blacklist where address=?''')
sqlSubmitQueue.put(t)
queryreturn = sqlReturnQueue.get()
sqlLock.release()
for row in queryreturn:
label, enabled = row
if enabled:
print 'Message ignored because address is in blacklist.'
blockMessage = True
else: #We're using a whitelist
t = (fromAddress,)
sqlLock.acquire()
sqlSubmitQueue.put('''SELECT label, enabled FROM whitelist where address=?''')
sqlSubmitQueue.put(t)
queryreturn = sqlReturnQueue.get()
sqlLock.release()
if queryreturn == []:
print 'Message ignored because address not in whitelist.'
blockMessage = True
for row in queryreturn: #It could be in the whitelist but disabled. Let's check.
label, enabled = row
if not enabled:
print 'Message ignored because address in whitelist but not enabled.'
blockMessage = True
if not blockMessage:
print 'fromAddress:', fromAddress
print 'First 150 characters of message:', repr(message[:150])
#Look up the destination address (my address) based on the destination ripe hash.
#I realize that I could have a data structure devoted to this task, or maintain an indexed table
#in the sql database, but I would prefer to minimize the number of data structures this program
#uses. Searching linearly through the user's short list of addresses doesn't take very long anyway.
configSections = config.sections()
for addressInKeysFile in configSections:
if addressInKeysFile <> 'bitmessagesettings':
status,addressVersionNumber,streamNumber,hash = decodeAddress(addressInKeysFile)
if hash == key:
toAddress = addressInKeysFile
toLabel = config.get(addressInKeysFile, 'label')
if toLabel == '':
toLabel = addressInKeysFile
if messageEncodingType == 2: sleepTime = lengthOfTimeWeShouldUseToProcessThisMessage - (time.time()- self.messageProcessingStartTime)
bodyPositionIndex = string.find(message,'\nBody:')
if bodyPositionIndex > 1:
subject = message[8:bodyPositionIndex]
body = message[bodyPositionIndex+6:]
else:
subject = ''
body = message
elif messageEncodingType == 1:
body = message
subject = ''
elif messageEncodingType == 0:
print 'messageEncodingType == 0. Doing nothing with the message. They probably just sent it so that we would store their public key or send their ack data for them.'
else:
body = 'Unknown encoding type.\n\n' + repr(message)
subject = ''
print 'within recmsg, inventoryHash is', inventoryHash.encode('hex')
if messageEncodingType <> 0:
sqlLock.acquire()
t = (inventoryHash,toAddress,fromAddress,subject,int(time.time()),body,'inbox')
sqlSubmitQueue.put('''INSERT INTO inbox VALUES (?,?,?,?,?,?,?)''')
sqlSubmitQueue.put(t)
sqlReturnQueue.get()
sqlLock.release()
self.emit(SIGNAL("displayNewMessage(PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject)"),inventoryHash,toAddress,fromAddress,subject,body)
print 'Time: messageProcessingStartTime +', time.time() - messageProcessingStartTime
#Now let's consider sending the acknowledgement. We'll need to make sure that our client will properly process the ackData; if the packet is malformed, we could clear out self.data and an attacker could use that behavior to determine that we were capable of decoding this message.
ackDataValidThusFar = True
if len(ackData) < 24:
print 'The length of ackData is unreasonably short. Not sending ackData.'
ackDataValidThusFar = False
elif ackData[0:4] != '\xe9\xbe\xb4\xd9':
print 'Ackdata magic bytes were wrong. Not sending ackData.'
ackDataValidThusFar = False
if ackDataValidThusFar:
ackDataPayloadLength, = unpack('>L',ackData[16:20])
if len(ackData)-24 != ackDataPayloadLength:
print 'ackData payload length doesn\'t match the payload length specified in the header. Not sending ackdata.'
ackDataValidThusFar = False
if ackDataValidThusFar:
print 'ackData is valid. Will process it.'
self.ackDataThatWeHaveYetToSend.append(ackData) #When we have processed all data, the processData function will pop the ackData out and process it as if it is a message received from our peer.
#Display timing data
timeRequiredToAttemptToDecryptMessage = time.time()- messageProcessingStartTime
successfullyDecryptMessageTimings.append(timeRequiredToAttemptToDecryptMessage)
sum = 0
for item in successfullyDecryptMessageTimings:
sum += item
printLock.acquire()
print 'Time to decrypt this message successfully:', timeRequiredToAttemptToDecryptMessage
print 'Average time for all message decryption successes since startup:', sum / len(successfullyDecryptMessageTimings)
printLock.release()
sleepTime = 0.6- (time.time()- messageProcessingStartTime)
if sleepTime > 0: if sleepTime > 0:
printLock.acquire() printLock.acquire()
print 'Timing attack mitigation: Sleeping for', sleepTime ,'seconds.' print 'Timing attack mitigation: Sleeping for', sleepTime ,'seconds.'
printLock.release() printLock.release()
time.sleep(sleepTime) time.sleep(sleepTime)
printLock.acquire() printLock.acquire()
print 'Total message processing time:', time.time()- messageProcessingStartTime, 'seconds.' print 'Total message processing time:', time.time()- self.messageProcessingStartTime, 'seconds.'
printLock.release() printLock.release()
if initialDecryptionSuccessful:
return
#This section is for my RSA keys (version 1 addresses). If we don't have any version 1 addresses it will never run. This code will soon be removed. #This section is for my RSA keys (version 1 addresses). If we don't have any version 1 addresses it will never run. This code will soon be removed.
initialDecryptionSuccessful = False initialDecryptionSuccessful = False
@ -1127,15 +935,15 @@ class receiveDataThread(QThread):
else: else:
body = 'Unknown encoding type.\n\n' + repr(message) body = 'Unknown encoding type.\n\n' + repr(message)
subject = '' subject = ''
print 'within recmsg, inventoryHash is', repr(inventoryHash) print 'within recmsg, self.inventoryHash is', repr(self.inventoryHash)
if messageEncodingType <> 0: if messageEncodingType <> 0:
sqlLock.acquire() sqlLock.acquire()
t = (inventoryHash,toAddress,fromAddress,subject,int(time.time()),body,'inbox') t = (self.inventoryHash,toAddress,fromAddress,subject,int(time.time()),body,'inbox')
sqlSubmitQueue.put('''INSERT INTO inbox VALUES (?,?,?,?,?,?,?)''') sqlSubmitQueue.put('''INSERT INTO inbox VALUES (?,?,?,?,?,?,?)''')
sqlSubmitQueue.put(t) sqlSubmitQueue.put(t)
sqlReturnQueue.get() sqlReturnQueue.get()
sqlLock.release() sqlLock.release()
self.emit(SIGNAL("displayNewMessage(PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject)"),inventoryHash,toAddress,fromAddress,subject,body) self.emit(SIGNAL("displayNewMessage(PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject)"),self.inventoryHash,toAddress,fromAddress,subject,body)
#Now let us worry about the acknowledgement data #Now let us worry about the acknowledgement data
#We'll need to make sure that our client will properly process the ackData; if the packet is malformed, it might cause us to clear out self.data and an attacker could use that behavior to determine that we decoded this message. #We'll need to make sure that our client will properly process the ackData; if the packet is malformed, it might cause us to clear out self.data and an attacker could use that behavior to determine that we decoded this message.
ackDataValidThusFar = True ackDataValidThusFar = True
@ -1167,6 +975,221 @@ class receiveDataThread(QThread):
infile.close() infile.close()
outfile.close() outfile.close()
#A msg message has a valid time and POW and requires processing. The recmsg function calls this one.
def processmsg(self,readPosition):
initialDecryptionSuccessful = False
#Let's check whether this is a message acknowledgement bound for us.
if self.data[readPosition:24+self.payloadLength] in ackdataForWhichImWatching:
printLock.acquire()
print 'This msg IS an acknowledgement bound for me.'
printLock.release()
del ackdataForWhichImWatching[self.data[readPosition:24+self.payloadLength]]
t = ('ackreceived',self.data[readPosition:24+self.payloadLength])
sqlLock.acquire()
sqlSubmitQueue.put('UPDATE sent SET status=? WHERE ackdata=?')
sqlSubmitQueue.put(t)
sqlReturnQueue.get()
sqlLock.release()
self.emit(SIGNAL("updateSentItemStatusByAckdata(PyQt_PyObject,PyQt_PyObject)"),self.data[readPosition:24+self.payloadLength],'Acknowledgement of the message received just now.')
return
else:
printLock.acquire()
print 'This was NOT an acknowledgement bound for me.' #Msg potential ack data:', repr(self.data[readPosition:24+self.payloadLength])
#print 'ackdataForWhichImWatching', ackdataForWhichImWatching
printLock.release()
#This is not an acknowledgement bound for me. See if it is a message bound for me by trying to decrypt it with my private keys.
for key, cryptorObject in myECAddressHashes.items():
try:
data = cryptorObject.decrypt(self.data[readPosition:self.payloadLength+24])
toRipe = key #This is the RIPE hash of my pubkeys. We need this below to compare to the destination_ripe included in the encrypted data.
initialDecryptionSuccessful = True
print 'EC decryption successful using key associated with ripe hash:', key.encode('hex')
break
except Exception, err:
pass
#print 'cryptorObject.decrypt Exception:', err
if not initialDecryptionSuccessful:
#This is not a message bound for me.
printLock.acquire()
print 'Length of time program spent failing to decrypt this message:', time.time()- self.messageProcessingStartTime, 'seconds.'
printLock.release()
else:
#This is a message bound for me.
readPosition = 0
messageVersion, messageVersionLength = decodeVarint(data[readPosition:readPosition+10])
readPosition += messageVersionLength
if messageVersion != 1:
print 'Cannot understand message versions other than one. Ignoring message.'
return
sendersAddressVersionNumber, sendersAddressVersionNumberLength = decodeVarint(data[readPosition:readPosition+10])
readPosition += sendersAddressVersionNumberLength
if sendersAddressVersionNumber == 0:
print 'Cannot understand sendersAddressVersionNumber = 0. Ignoring message.'
return
if sendersAddressVersionNumber >= 3:
print 'Sender\'s address version number', sendersAddressVersionNumber, ' not yet supported. Ignoring message.'
return
if len(data) < 170:
print 'Length of the unencrypted data is unreasonably short. Sanity check failed. Ignoring message.'
return
sendersStreamNumber, sendersStreamNumberLength = decodeVarint(data[readPosition:readPosition+10])
if sendersStreamNumber == 0:
print 'sender\'s stream number is 0. Ignoring message.'
return
readPosition += sendersStreamNumberLength
behaviorBitfield = data[readPosition:readPosition+4]
readPosition += 4
pubSigningKey = '\x04' + data[readPosition:readPosition+64]
readPosition += 64
pubEncryptionKey = '\x04' + data[readPosition:readPosition+64]
readPosition += 64
endOfThePublicKeyPosition = readPosition #needed for when we store the pubkey in our database of pubkeys for later use.
if toRipe != data[readPosition:readPosition+20]:
printLock.acquire()
print 'The original sender of this message did not send it to you. Someone is attempting a Surreptitious Forwarding Attack.'
print 'See: http://tools.ietf.org/html/draft-ietf-smime-sender-auth-00'
print 'your toRipe:', toRipe.encode('hex')
print 'embedded destination toRipe:', data[readPosition:readPosition+20].encode('hex')
printLock.release()
return
readPosition += 20
messageEncodingType, messageEncodingTypeLength = decodeVarint(data[readPosition:readPosition+10])
readPosition += messageEncodingTypeLength
messageLength, messageLengthLength = decodeVarint(data[readPosition:readPosition+10])
readPosition += messageLengthLength
message = data[readPosition:readPosition+messageLength]
#print 'First 150 characters of message:', repr(message[:150])
readPosition += messageLength
ackLength, ackLengthLength = decodeVarint(data[readPosition:readPosition+10])
readPosition += ackLengthLength
ackData = data[readPosition:readPosition+ackLength]
readPosition += ackLength
positionOfBottomOfAckData = readPosition #needed to mark the end of what is covered by the signature
signatureLength, signatureLengthLength = decodeVarint(data[readPosition:readPosition+10])
readPosition += signatureLengthLength
signature = data[readPosition:readPosition+signatureLength]
try:
highlevelcrypto.verify(data[:positionOfBottomOfAckData],signature,pubSigningKey.encode('hex'))
print 'ECDSA verify passed'
except Exception, err:
print 'ECDSA verify failed', err
return
printLock.acquire()
print 'As a matter of intellectual curiosity, here is the Bitcoin address associated with the keys owned by the other person:', calculateBitcoinAddressFromPubkey(pubSigningKey), ' ..and here is the testnet address:',calculateTestnetAddressFromPubkey(pubSigningKey),'. The other person must take their private signing key from Bitmessage and import it into Bitcoin (or a service like Blockchain.info) for it to be of any use. Do not use this unless you know what you are doing.'
printLock.release()
#calculate the fromRipe.
sha = hashlib.new('sha512')
sha.update(pubSigningKey+pubEncryptionKey)
ripe = hashlib.new('ripemd160')
ripe.update(sha.digest())
#Let's store the public key in case we want to reply to this person.
#We don't have the correct nonce or time (which would let us send out a pubkey message) so we'll just fill it with 1's. We won't be able to send this pubkey to others (without doing the proof of work ourselves, which this program is programmed to not do.)
t = (ripe.digest(),False,'\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF'+'\xFF\xFF\xFF\xFF'+data[messageVersionLength:endOfThePublicKeyPosition],int(time.time())+2419200) #after one month we may remove this pub key from our database. (2419200 = a month)
sqlLock.acquire()
sqlSubmitQueue.put('''INSERT INTO pubkeys VALUES (?,?,?,?)''')
sqlSubmitQueue.put(t)
sqlReturnQueue.get()
sqlLock.release()
blockMessage = False #Gets set to True if the user shouldn't see the message according to black or white lists.
fromAddress = encodeAddress(sendersAddressVersionNumber,sendersStreamNumber,ripe.digest())
if config.get('bitmessagesettings', 'blackwhitelist') == 'black': #If we are using a blacklist
t = (fromAddress,)
sqlLock.acquire()
sqlSubmitQueue.put('''SELECT label, enabled FROM blacklist where address=?''')
sqlSubmitQueue.put(t)
queryreturn = sqlReturnQueue.get()
sqlLock.release()
for row in queryreturn:
label, enabled = row
if enabled:
print 'Message ignored because address is in blacklist.'
blockMessage = True
else: #We're using a whitelist
t = (fromAddress,)
sqlLock.acquire()
sqlSubmitQueue.put('''SELECT label, enabled FROM whitelist where address=?''')
sqlSubmitQueue.put(t)
queryreturn = sqlReturnQueue.get()
sqlLock.release()
if queryreturn == []:
print 'Message ignored because address not in whitelist.'
blockMessage = True
for row in queryreturn: #It could be in the whitelist but disabled. Let's check.
label, enabled = row
if not enabled:
print 'Message ignored because address in whitelist but not enabled.'
blockMessage = True
if not blockMessage:
print 'fromAddress:', fromAddress
print 'First 150 characters of message:', repr(message[:150])
#Look up the destination address (my address) based on the destination ripe hash.
#I realize that I could have a data structure devoted to this task, or maintain an indexed table
#in the sql database, but I would prefer to minimize the number of data structures this program
#uses. Searching linearly through the user's short list of addresses doesn't take very long anyway.
configSections = config.sections()
for addressInKeysFile in configSections:
if addressInKeysFile <> 'bitmessagesettings':
status,addressVersionNumber,streamNumber,hash = decodeAddress(addressInKeysFile)
if hash == key:
toAddress = addressInKeysFile
toLabel = config.get(addressInKeysFile, 'label')
if toLabel == '':
toLabel = addressInKeysFile
if messageEncodingType == 2:
bodyPositionIndex = string.find(message,'\nBody:')
if bodyPositionIndex > 1:
subject = message[8:bodyPositionIndex]
body = message[bodyPositionIndex+6:]
else:
subject = ''
body = message
elif messageEncodingType == 1:
body = message
subject = ''
elif messageEncodingType == 0:
print 'messageEncodingType == 0. Doing nothing with the message. They probably just sent it so that we would store their public key or send their ack data for them.'
else:
body = 'Unknown encoding type.\n\n' + repr(message)
subject = ''
print 'within processmsg, self.inventoryHash is', self.inventoryHash.encode('hex')
if messageEncodingType <> 0:
sqlLock.acquire()
t = (self.inventoryHash,toAddress,fromAddress,subject,int(time.time()),body,'inbox')
sqlSubmitQueue.put('''INSERT INTO inbox VALUES (?,?,?,?,?,?,?)''')
sqlSubmitQueue.put(t)
sqlReturnQueue.get()
sqlLock.release()
self.emit(SIGNAL("displayNewMessage(PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject,PyQt_PyObject)"),self.inventoryHash,toAddress,fromAddress,subject,body)
#Now let's consider sending the acknowledgement. We'll need to make sure that our client will properly process the ackData; if the packet is malformed, we could clear out self.data and an attacker could use that behavior to determine that we were capable of decoding this message.
ackDataValidThusFar = True
if len(ackData) < 24:
print 'The length of ackData is unreasonably short. Not sending ackData.'
ackDataValidThusFar = False
elif ackData[0:4] != '\xe9\xbe\xb4\xd9':
print 'Ackdata magic bytes were wrong. Not sending ackData.'
ackDataValidThusFar = False
if ackDataValidThusFar:
ackDataPayloadLength, = unpack('>L',ackData[16:20])
if len(ackData)-24 != ackDataPayloadLength:
print 'ackData payload length doesn\'t match the payload length specified in the header. Not sending ackdata.'
ackDataValidThusFar = False
if ackDataValidThusFar:
print 'ackData is valid. Will process it.'
self.ackDataThatWeHaveYetToSend.append(ackData) #When we have processed all data, the processData function will pop the ackData out and process it as if it is a message received from our peer.
#Display timing data
timeRequiredToAttemptToDecryptMessage = time.time()- self.messageProcessingStartTime
successfullyDecryptMessageTimings.append(timeRequiredToAttemptToDecryptMessage)
sum = 0
for item in successfullyDecryptMessageTimings:
sum += item
printLock.acquire()
print 'Time to decrypt this message successfully:', timeRequiredToAttemptToDecryptMessage
print 'Average time for all message decryption successes since startup:', sum / len(successfullyDecryptMessageTimings)
printLock.release()
#We have received a pubkey #We have received a pubkey
def recpubkey(self): def recpubkey(self):
if self.payloadLength < 32: #sanity check if self.payloadLength < 32: #sanity check
@ -3295,7 +3318,6 @@ class MyForm(QtGui.QMainWindow):
newItem = myTableWidgetItem('Unknown status. ' + strftime(config.get('bitmessagesettings', 'timeformat'),localtime(int(lastactiontime)))) newItem = myTableWidgetItem('Unknown status. ' + strftime(config.get('bitmessagesettings', 'timeformat'),localtime(int(lastactiontime))))
newItem.setData(Qt.UserRole,QByteArray(ackdata)) newItem.setData(Qt.UserRole,QByteArray(ackdata))
newItem.setData(33,int(lastactiontime)) newItem.setData(33,int(lastactiontime))
print 'setting lastactiontime:', lastactiontime
newItem.setFlags( QtCore.Qt.ItemIsSelectable | QtCore.Qt.ItemIsEnabled ) newItem.setFlags( QtCore.Qt.ItemIsSelectable | QtCore.Qt.ItemIsEnabled )
self.ui.tableWidgetSent.setItem(0,3,newItem) self.ui.tableWidgetSent.setItem(0,3,newItem)
@ -4079,7 +4101,9 @@ class MyForm(QtGui.QMainWindow):
broadcastToSendDataQueues((0, 'shutdown', 'all')) broadcastToSendDataQueues((0, 'shutdown', 'all'))
printLock.acquire()
print 'Closing. Flushing inventory in memory out to disk...' print 'Closing. Flushing inventory in memory out to disk...'
printLock.release()
self.statusBar().showMessage('Flushing inventory in memory out to disk.') self.statusBar().showMessage('Flushing inventory in memory out to disk.')
flushInventory() flushInventory()
@ -4096,7 +4120,9 @@ class MyForm(QtGui.QMainWindow):
output.close() output.close()
self.trayIcon.hide() self.trayIcon.hide()
printLock.acquire()
print 'Done.' print 'Done.'
printLock.release()
self.statusBar().showMessage('All done. Closing user interface...') self.statusBar().showMessage('All done. Closing user interface...')
event.accept() event.accept()
raise SystemExit raise SystemExit
@ -4389,8 +4415,8 @@ averageProofOfWorkNonceTrialsPerByte = 320 #The amount of work that should be pe
payloadLengthExtraBytes = 14000 #To make sending short messages a little more difficult, this value is added to the payload length for use in calculating the proof of work target. payloadLengthExtraBytes = 14000 #To make sending short messages a little more difficult, this value is added to the payload length for use in calculating the proof of work target.
if useVeryEasyProofOfWorkForTesting: if useVeryEasyProofOfWorkForTesting:
averageProofOfWorkNonceTrialsPerByte = averageProofOfWorkNonceTrialsPerByte / 10 averageProofOfWorkNonceTrialsPerByte = averageProofOfWorkNonceTrialsPerByte / 16
payloadLengthExtraBytes = payloadLengthExtraBytes / 10 payloadLengthExtraBytes = payloadLengthExtraBytes / 7000
if __name__ == "__main__": if __name__ == "__main__":
# Check the Major version, the first element in the array # Check the Major version, the first element in the array

1
highlevelcrypto.py
View File

@ -1,6 +1,5 @@
import pyelliptic import pyelliptic
from pyelliptic import arithmetic as a from pyelliptic import arithmetic as a
import time
def makeCryptor(privkey): def makeCryptor(privkey):
privkey_bin = '\x02\xca\x00 '+a.changebase(privkey,16,256,minlen=32) privkey_bin = '\x02\xca\x00 '+a.changebase(privkey,16,256,minlen=32)
pubkey = a.changebase(a.privtopub(privkey),16,256,minlen=65)[1:] pubkey = a.changebase(a.privtopub(privkey),16,256,minlen=65)[1:]