Пример #1
0
    def processmsg(self, data):
        messageProcessingStartTime = time.time()
        shared.numberOfMessagesProcessed += 1
#        queues.UISignalQueue.put((
#            'updateNumberOfMessagesProcessed', 'no data'))
        readPosition = 20 # bypass the nonce, time, and object type
        msgVersion, msgVersionLength = decodeVarint(data[readPosition:readPosition + 9])
        if msgVersion != 1:
            logger.info('Cannot understand message versions other than one. Ignoring message.') 
            return
        readPosition += msgVersionLength
        
        streamNumberAsClaimedByMsg, streamNumberAsClaimedByMsgLength = decodeVarint(
            data[readPosition:readPosition + 9])
        readPosition += streamNumberAsClaimedByMsgLength
        inventoryHash = calculateInventoryHash(data)
        initialDecryptionSuccessful = False

        # 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 shared.myECCryptorObjects.items():
            try:
                if initialDecryptionSuccessful: # continue decryption attempts to avoid timing attacks
                    cryptorObject.decrypt(data[readPosition:])
                else:
                    decryptedData = cryptorObject.decrypt(data[readPosition:])
                    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
                    logger.info('EC decryption successful using key associated with ripe hash: %s.' % hexlify(key))
            except Exception as err:
                pass
        if not initialDecryptionSuccessful:
            # This is not a message bound for me.
            logger.info('Length of time program spent failing to decrypt this message: %s seconds.' % (time.time() - messageProcessingStartTime,)) 
            return

        # This is a message bound for me.
        toAddress = shared.myAddressesByHash[
            toRipe]  # Look up my address based on the RIPE hash.
        readPosition = 0
        sendersAddressVersionNumber, sendersAddressVersionNumberLength = decodeVarint(
            decryptedData[readPosition:readPosition + 10])
        readPosition += sendersAddressVersionNumberLength
        if sendersAddressVersionNumber == 0:
            logger.info('Cannot understand sendersAddressVersionNumber = 0. Ignoring message.') 
            return
        if sendersAddressVersionNumber > 4:
            logger.info('Sender\'s address version number %s not yet supported. Ignoring message.' % sendersAddressVersionNumber)  
            return
        if len(decryptedData) < 170:
            logger.info('Length of the unencrypted data is unreasonably short. Sanity check failed. Ignoring message.')
            return
        sendersStreamNumber, sendersStreamNumberLength = decodeVarint(
            decryptedData[readPosition:readPosition + 10])
        if sendersStreamNumber == 0:
            logger.info('sender\'s stream number is 0. Ignoring message.')
            return
        readPosition += sendersStreamNumberLength
        behaviorBitfield = decryptedData[readPosition:readPosition + 4]
        readPosition += 4
        pubSigningKey = '\x04' + decryptedData[
            readPosition:readPosition + 64]
        readPosition += 64
        pubEncryptionKey = '\x04' + decryptedData[
            readPosition:readPosition + 64]
        readPosition += 64
        if sendersAddressVersionNumber >= 3:
            requiredAverageProofOfWorkNonceTrialsPerByte, varintLength = decodeVarint(
                decryptedData[readPosition:readPosition + 10])
            readPosition += varintLength
            logger.info('sender\'s requiredAverageProofOfWorkNonceTrialsPerByte is %s' % requiredAverageProofOfWorkNonceTrialsPerByte)
            requiredPayloadLengthExtraBytes, varintLength = decodeVarint(
                decryptedData[readPosition:readPosition + 10])
            readPosition += varintLength
            logger.info('sender\'s requiredPayloadLengthExtraBytes is %s' % requiredPayloadLengthExtraBytes)
        endOfThePublicKeyPosition = readPosition  # needed for when we store the pubkey in our database of pubkeys for later use.
        if toRipe != decryptedData[readPosition:readPosition + 20]:
            logger.info('The original sender of this message did not send it to you. Someone is attempting a Surreptitious Forwarding Attack.\n\
                See: http://world.std.com/~dtd/sign_encrypt/sign_encrypt7.html \n\
                your toRipe: %s\n\
                embedded destination toRipe: %s' % (hexlify(toRipe), hexlify(decryptedData[readPosition:readPosition + 20]))
                       )
            return
        readPosition += 20
        messageEncodingType, messageEncodingTypeLength = decodeVarint(
            decryptedData[readPosition:readPosition + 10])
        readPosition += messageEncodingTypeLength
        messageLength, messageLengthLength = decodeVarint(
            decryptedData[readPosition:readPosition + 10])
        readPosition += messageLengthLength
        message = decryptedData[readPosition:readPosition + messageLength]
        # print 'First 150 characters of message:', repr(message[:150])
        readPosition += messageLength
        ackLength, ackLengthLength = decodeVarint(
            decryptedData[readPosition:readPosition + 10])
        readPosition += ackLengthLength
        ackData = decryptedData[readPosition:readPosition + ackLength]
        readPosition += ackLength
        positionOfBottomOfAckData = readPosition  # needed to mark the end of what is covered by the signature
        signatureLength, signatureLengthLength = decodeVarint(
            decryptedData[readPosition:readPosition + 10])
        readPosition += signatureLengthLength
        signature = decryptedData[
            readPosition:readPosition + signatureLength]
        signedData = data[8:20] + encodeVarint(1) + encodeVarint(streamNumberAsClaimedByMsg) + decryptedData[:positionOfBottomOfAckData]
        
        if not highlevelcrypto.verify(signedData, signature, hexlify(pubSigningKey)):
            logger.debug('ECDSA verify failed')
            return
        logger.debug('ECDSA verify passed')
        logger.debug('As a matter of intellectual curiosity, here is the Bitcoin address associated with the keys owned by the other person: %s  ..and here is the testnet address: %s. 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.' %
                     (helper_bitcoin.calculateBitcoinAddressFromPubkey(pubSigningKey), helper_bitcoin.calculateTestnetAddressFromPubkey(pubSigningKey))
                     )
        sigHash = hashlib.sha512(hashlib.sha512(signature).digest()).digest()[32:] # Used to detect and ignore duplicate messages in our inbox

        # calculate the fromRipe.
        sha = hashlib.new('sha512')
        sha.update(pubSigningKey + pubEncryptionKey)
        ripe = hashlib.new('ripemd160')
        ripe.update(sha.digest())
        fromAddress = encodeAddress(
            sendersAddressVersionNumber, sendersStreamNumber, ripe.digest())
        
        # Let's store the public key in case we want to reply to this
        # person.
        sqlExecute(
            '''INSERT INTO pubkeys VALUES (?,?,?,?,?)''',
            fromAddress,
            sendersAddressVersionNumber,
            decryptedData[:endOfThePublicKeyPosition],
            int(time.time()),
            'yes')
        
        # Check to see whether we happen to be awaiting this
        # pubkey in order to send a message. If we are, it will do the POW
        # and send it.
        self.possibleNewPubkey(fromAddress)
        
        # If this message is bound for one of my version 3 addresses (or
        # higher), then we must check to make sure it meets our demanded
        # proof of work requirement. If this is bound for one of my chan
        # addresses then we skip this check; the minimum network POW is
        # fine.
        if decodeAddress(toAddress)[1] >= 3 and not BMConfigParser().safeGetBoolean(toAddress, 'chan'):  # If the toAddress version number is 3 or higher and not one of my chan addresses:
            if not shared.isAddressInMyAddressBookSubscriptionsListOrWhitelist(fromAddress):  # If I'm not friendly with this person:
                requiredNonceTrialsPerByte = BMConfigParser().getint(
                    toAddress, 'noncetrialsperbyte')
                requiredPayloadLengthExtraBytes = BMConfigParser().getint(
                    toAddress, 'payloadlengthextrabytes')
                if not protocol.isProofOfWorkSufficient(data, requiredNonceTrialsPerByte, requiredPayloadLengthExtraBytes):
                    logger.info('Proof of work in msg is insufficient only because it does not meet our higher requirement.')
                    return
        blockMessage = False  # Gets set to True if the user shouldn't see the message according to black or white lists.
        if BMConfigParser().get('bitmessagesettings', 'blackwhitelist') == 'black':  # If we are using a blacklist
            queryreturn = sqlQuery(
                '''SELECT label FROM blacklist where address=? and enabled='1' ''',
                fromAddress)
            if queryreturn != []:
                logger.info('Message ignored because address is in blacklist.')

                blockMessage = True
        else:  # We're using a whitelist
            queryreturn = sqlQuery(
                '''SELECT label FROM whitelist where address=? and enabled='1' ''',
                fromAddress)
            if queryreturn == []:
                logger.info('Message ignored because address not in whitelist.')
                blockMessage = True

        toLabel = BMConfigParser().get(toAddress, 'label')
        if toLabel == '':
            toLabel = toAddress

        decodedMessage = helper_msgcoding.MsgDecode(messageEncodingType, message)
        subject = decodedMessage.subject
        body = decodedMessage.body

        # Let us make sure that we haven't already received this message
        if helper_inbox.isMessageAlreadyInInbox(sigHash):
            logger.info('This msg is already in our inbox. Ignoring it.')
            blockMessage = True
        if not blockMessage:
            if messageEncodingType != 0:
                t = (inventoryHash, toAddress, fromAddress, subject, int(
                    time.time()), body, 'inbox', messageEncodingType, 0, sigHash)
                helper_inbox.insert(t)

                queues.UISignalQueue.put(('displayNewInboxMessage', (
                    inventoryHash, toAddress, fromAddress, subject, body)))

            # If we are behaving as an API then we might need to run an
            # outside command to let some program know that a new message
            # has arrived.
            if BMConfigParser().safeGetBoolean('bitmessagesettings', 'apienabled'):
                try:
                    apiNotifyPath = BMConfigParser().get(
                        'bitmessagesettings', 'apinotifypath')
                except:
                    apiNotifyPath = ''
                if apiNotifyPath != '':
                    call([apiNotifyPath, "newMessage"])

            # Let us now check and see whether our receiving address is
            # behaving as a mailing list
            if BMConfigParser().safeGetBoolean(toAddress, 'mailinglist') and messageEncodingType != 0:
                try:
                    mailingListName = BMConfigParser().get(
                        toAddress, 'mailinglistname')
                except:
                    mailingListName = ''
                # Let us send out this message as a broadcast
                subject = self.addMailingListNameToSubject(
                    subject, mailingListName)
                # Let us now send this message out as a broadcast
                message = time.strftime("%a, %Y-%m-%d %H:%M:%S UTC", time.gmtime(
                )) + '   Message ostensibly from ' + fromAddress + ':\n\n' + body
                fromAddress = toAddress  # The fromAddress for the broadcast that we are about to send is the toAddress (my address) for the msg message we are currently processing.
                ackdataForBroadcast = OpenSSL.rand(
                    32)  # We don't actually need the ackdataForBroadcast for acknowledgement since this is a broadcast message but we can use it to update the user interface when the POW is done generating.
                toAddress = '[Broadcast subscribers]'
                ripe = ''

                # We really should have a discussion about how to
                # set the TTL for mailing list broadcasts. This is obviously
                # hard-coded. 
                TTL = 2*7*24*60*60 # 2 weeks
                t = ('', 
                     toAddress, 
                     ripe, 
                     fromAddress, 
                     subject, 
                     message, 
                     ackdataForBroadcast, 
                     int(time.time()), # sentTime (this doesn't change)
                     int(time.time()), # lastActionTime
                     0, 
                     'broadcastqueued', 
                     0, 
                     'sent', 
                     messageEncodingType, 
                     TTL)
                helper_sent.insert(t)

                queues.UISignalQueue.put(('displayNewSentMessage', (
                    toAddress, '[Broadcast subscribers]', fromAddress, subject, message, ackdataForBroadcast)))
                queues.workerQueue.put(('sendbroadcast', ''))

        # Don't send ACK if invalid, blacklisted senders, invisible messages, disabled or chan
        if self.ackDataHasAValidHeader(ackData) and \
            not blockMessage and \
            messageEncodingType != 0 and \
            not BMConfigParser().safeGetBoolean(toAddress, 'dontsendack') and \
            not BMConfigParser().safeGetBoolean(toAddress, 'chan'):
            shared.checkAndShareObjectWithPeers(ackData[24:])

        # Display timing data
        timeRequiredToAttemptToDecryptMessage = time.time(
        ) - messageProcessingStartTime
        shared.successfullyDecryptMessageTimings.append(
            timeRequiredToAttemptToDecryptMessage)
        sum = 0
        for item in shared.successfullyDecryptMessageTimings:
            sum += item
        logger.debug('Time to decrypt this message successfully: %s\n\
                     Average time for all message decryption successes since startup: %s.' %
                     (timeRequiredToAttemptToDecryptMessage, sum / len(shared.successfullyDecryptMessageTimings)) 
                     )
Пример #2
0
    def processbroadcast(self, data):
        messageProcessingStartTime = time.time()
        shared.numberOfBroadcastsProcessed += 1
        queues.UISignalQueue.put(
            ('updateNumberOfBroadcastsProcessed', 'no data'))
        inventoryHash = calculateInventoryHash(data)
        readPosition = 20  # bypass the nonce, time, and object type
        broadcastVersion, broadcastVersionLength = decodeVarint(
            data[readPosition:readPosition + 9])
        readPosition += broadcastVersionLength
        if broadcastVersion < 4 or broadcastVersion > 5:
            logger.info(
                'Cannot decode incoming broadcast versions less than 4'
                ' or higher than 5. Assuming the sender isn\'t being silly,'
                ' you should upgrade Bitmessage because this message shall'
                ' be ignored.')
            return
        cleartextStreamNumber, cleartextStreamNumberLength = decodeVarint(
            data[readPosition:readPosition + 10])
        readPosition += cleartextStreamNumberLength
        if broadcastVersion == 4:
            # v4 broadcasts are encrypted the same way the msgs are
            # encrypted. To see if we are interested in a v4 broadcast,
            # we try to decrypt it. This was replaced with v5 broadcasts
            # which include a tag which we check instead, just like we do
            # with v4 pubkeys.
            signedData = data[8:readPosition]
            initialDecryptionSuccessful = False
            for key, cryptorObject in sorted(
                    shared.MyECSubscriptionCryptorObjects.items(),
                    key=lambda x: random.random()):
                try:
                    # continue decryption attempts to avoid timing attacks
                    if initialDecryptionSuccessful:
                        cryptorObject.decrypt(data[readPosition:])
                    else:
                        decryptedData = cryptorObject.decrypt(
                            data[readPosition:])
                        # This is the RIPE hash of the sender's pubkey.
                        # We need this below to compare to the RIPE hash
                        # of the sender's address to verify that it was
                        # encrypted by with their key rather than some
                        # other key.
                        toRipe = key
                        initialDecryptionSuccessful = True
                        logger.info(
                            'EC decryption successful using key associated'
                            ' with ripe hash: %s', hexlify(key))
                except Exception:
                    logger.debug('cryptorObject.decrypt Exception:',
                                 exc_info=True)
            if not initialDecryptionSuccessful:
                # This is not a broadcast I am interested in.
                logger.debug(
                    'Length of time program spent failing to decrypt this'
                    ' v4 broadcast: %s seconds.',
                    time.time() - messageProcessingStartTime)
                return
        elif broadcastVersion == 5:
            embeddedTag = data[readPosition:readPosition + 32]
            readPosition += 32
            if embeddedTag not in shared.MyECSubscriptionCryptorObjects:
                logger.debug('We\'re not interested in this broadcast.')
                return
            # We are interested in this broadcast because of its tag.
            # We're going to add some more data which is signed further down.
            signedData = data[8:readPosition]
            cryptorObject = shared.MyECSubscriptionCryptorObjects[embeddedTag]
            try:
                decryptedData = cryptorObject.decrypt(data[readPosition:])
                logger.debug('EC decryption successful')
            except Exception:
                logger.debug('Broadcast version %s decryption Unsuccessful.',
                             broadcastVersion)
                return
        # At this point this is a broadcast I have decrypted and am
        # interested in.
        readPosition = 0
        sendersAddressVersion, sendersAddressVersionLength = decodeVarint(
            decryptedData[readPosition:readPosition + 9])
        if broadcastVersion == 4:
            if sendersAddressVersion < 2 or sendersAddressVersion > 3:
                logger.warning(
                    'Cannot decode senderAddressVersion other than 2 or 3.'
                    ' Assuming the sender isn\'t being silly, you should'
                    ' upgrade Bitmessage because this message shall be'
                    ' ignored.')
                return
        elif broadcastVersion == 5:
            if sendersAddressVersion < 4:
                logger.info(
                    'Cannot decode senderAddressVersion less than 4 for'
                    ' broadcast version number 5. Assuming the sender'
                    ' isn\'t being silly, you should upgrade Bitmessage'
                    ' because this message shall be ignored.')
                return
        readPosition += sendersAddressVersionLength
        sendersStream, sendersStreamLength = decodeVarint(
            decryptedData[readPosition:readPosition + 9])
        if sendersStream != cleartextStreamNumber:
            logger.info(
                'The stream number outside of the encryption on which the'
                ' POW was completed doesn\'t match the stream number'
                ' inside the encryption. Ignoring broadcast.')
            return
        readPosition += sendersStreamLength
        readPosition += 4
        sendersPubSigningKey = '\x04' + \
            decryptedData[readPosition:readPosition + 64]
        readPosition += 64
        sendersPubEncryptionKey = '\x04' + \
            decryptedData[readPosition:readPosition + 64]
        readPosition += 64
        if sendersAddressVersion >= 3:
            requiredAverageProofOfWorkNonceTrialsPerByte, varintLength = \
                decodeVarint(decryptedData[readPosition:readPosition + 10])
            readPosition += varintLength
            logger.debug(
                'sender\'s requiredAverageProofOfWorkNonceTrialsPerByte'
                ' is %s', requiredAverageProofOfWorkNonceTrialsPerByte)
            requiredPayloadLengthExtraBytes, varintLength = decodeVarint(
                decryptedData[readPosition:readPosition + 10])
            readPosition += varintLength
            logger.debug('sender\'s requiredPayloadLengthExtraBytes is %s',
                         requiredPayloadLengthExtraBytes)
        endOfPubkeyPosition = readPosition

        sha = hashlib.new('sha512')
        sha.update(sendersPubSigningKey + sendersPubEncryptionKey)
        ripeHasher = hashlib.new('ripemd160')
        ripeHasher.update(sha.digest())
        calculatedRipe = ripeHasher.digest()

        if broadcastVersion == 4:
            if toRipe != calculatedRipe:
                logger.info('The encryption key used to encrypt this message'
                            ' doesn\'t match the keys inbedded in the message'
                            ' itself. Ignoring message.')
                return
        elif broadcastVersion == 5:
            calculatedTag = hashlib.sha512(
                hashlib.sha512(
                    encodeVarint(sendersAddressVersion) +
                    encodeVarint(sendersStream) +
                    calculatedRipe).digest()).digest()[32:]
            if calculatedTag != embeddedTag:
                logger.debug('The tag and encryption key used to encrypt this'
                             ' message doesn\'t match the keys inbedded in the'
                             ' message itself. Ignoring message.')
                return
        messageEncodingType, messageEncodingTypeLength = decodeVarint(
            decryptedData[readPosition:readPosition + 9])
        if messageEncodingType == 0:
            return
        readPosition += messageEncodingTypeLength
        messageLength, messageLengthLength = decodeVarint(
            decryptedData[readPosition:readPosition + 9])
        readPosition += messageLengthLength
        message = decryptedData[readPosition:readPosition + messageLength]
        readPosition += messageLength
        readPositionAtBottomOfMessage = readPosition
        signatureLength, signatureLengthLength = decodeVarint(
            decryptedData[readPosition:readPosition + 9])
        readPosition += signatureLengthLength
        signature = decryptedData[readPosition:readPosition + signatureLength]
        signedData += decryptedData[:readPositionAtBottomOfMessage]
        if not highlevelcrypto.verify(signedData, signature,
                                      hexlify(sendersPubSigningKey)):
            logger.debug('ECDSA verify failed')
            return
        logger.debug('ECDSA verify passed')
        # Used to detect and ignore duplicate messages in our inbox
        sigHash = hashlib.sha512(
            hashlib.sha512(signature).digest()).digest()[32:]

        fromAddress = encodeAddress(sendersAddressVersion, sendersStream,
                                    calculatedRipe)
        logger.info('fromAddress: %s' % fromAddress)

        # Let's store the public key in case we want to reply to this person.
        sqlExecute('''INSERT INTO pubkeys VALUES (?,?,?,?,?)''', fromAddress,
                   sendersAddressVersion, decryptedData[:endOfPubkeyPosition],
                   int(time.time()), 'yes')

        # Check to see whether we happen to be awaiting this
        # pubkey in order to send a message. If we are, it will do the POW
        # and send it.
        self.possibleNewPubkey(fromAddress)

        fromAddress = encodeAddress(sendersAddressVersion, sendersStream,
                                    calculatedRipe)
        logger.debug('fromAddress: ' + fromAddress)

        try:
            decodedMessage = helper_msgcoding.MsgDecode(
                messageEncodingType, message)
        except helper_msgcoding.MsgDecodeException:
            return
        subject = decodedMessage.subject
        body = decodedMessage.body

        toAddress = '[Broadcast subscribers]'
        if helper_inbox.isMessageAlreadyInInbox(sigHash):
            logger.info('This broadcast is already in our inbox. Ignoring it.')
            return
        t = (inventoryHash, toAddress, fromAddress, subject, int(time.time()),
             body, 'inbox', messageEncodingType, 0, sigHash)
        helper_inbox.insert(t)

        queues.UISignalQueue.put(
            ('displayNewInboxMessage', (inventoryHash, toAddress, fromAddress,
                                        subject, body)))

        # If we are behaving as an API then we might need to run an
        # outside command to let some program know that a new message
        # has arrived.
        if BMConfigParser().safeGetBoolean('bitmessagesettings', 'apienabled'):
            try:
                apiNotifyPath = BMConfigParser().get('bitmessagesettings',
                                                     'apinotifypath')
            except:
                apiNotifyPath = ''
            if apiNotifyPath != '':
                call([apiNotifyPath, "newBroadcast"])

        # Display timing data
        logger.info('Time spent processing this interesting broadcast: %s',
                    time.time() - messageProcessingStartTime)