PyBitmessage-2021-04-27/src/class_singleWorker.py

from __future__ import division

import time
import threading
import hashlib
from struct import pack
# used when the API must execute an outside program
from subprocess import call  # nosec
from binascii import hexlify, unhexlify

import tr
import l10n
import protocol
import queues
import state
import shared
import defaults
import highlevelcrypto
import proofofwork
import helper_inbox
import helper_random
import helper_msgcoding
from bmconfigparser import BMConfigParser
from debug import logger
from inventory import Inventory
from addresses import (
    decodeAddress, encodeVarint, decodeVarint, calculateInventoryHash
)
# from helper_generic import addDataPadding
from helper_threading import StoppableThread
from helper_sql import sqlQuery, sqlExecute


# This thread, of which there is only one, does the heavy lifting:
# calculating POWs.

def sizeof_fmt(num, suffix='h/s'):
    for unit in ['', 'k', 'M', 'G', 'T', 'P', 'E', 'Z']:
        if abs(num) < 1000.0:
            return "%3.1f%s%s" % (num, unit, suffix)
        num /= 1024.0
    return "%.1f%s%s" % (num, 'Yi', suffix)


class singleWorker(threading.Thread, StoppableThread):

    def __init__(self):
        # QThread.__init__(self, parent)
        threading.Thread.__init__(self, name="singleWorker")
        self.initStop()
        proofofwork.init()

    def stopThread(self):
        try:
            queues.workerQueue.put(("stopThread", "data"))
        except:
            pass
        super(singleWorker, self).stopThread()

    def run(self):

        while not state.sqlReady and state.shutdown == 0:
            self.stop.wait(2)
        if state.shutdown > 0:
            return

        # Initialize the neededPubkeys dictionary.
        queryreturn = sqlQuery(
            '''SELECT DISTINCT toaddress FROM sent'''
            ''' WHERE (status='awaitingpubkey' AND folder='sent')''')
        for row in queryreturn:
            toAddress, = row
            # toStatus
            _, toAddressVersionNumber, toStreamNumber, toRipe = \
                decodeAddress(toAddress)
            if toAddressVersionNumber <= 3:
                state.neededPubkeys[toAddress] = 0
            elif toAddressVersionNumber >= 4:
                doubleHashOfAddressData = hashlib.sha512(hashlib.sha512(
                    encodeVarint(toAddressVersionNumber) +
                    encodeVarint(toStreamNumber) + toRipe
                ).digest()).digest()
                # Note that this is the first half of the sha512 hash.
                privEncryptionKey = doubleHashOfAddressData[:32]
                tag = doubleHashOfAddressData[32:]
                # We'll need this for when we receive a pubkey reply:
                # it will be encrypted and we'll need to decrypt it.
                state.neededPubkeys[tag] = (
                    toAddress,
                    highlevelcrypto.makeCryptor(
                        hexlify(privEncryptionKey))
                )

        # Initialize the shared.ackdataForWhichImWatching data structure
        queryreturn = sqlQuery(
            '''SELECT ackdata FROM sent WHERE status = 'msgsent' ''')
        for row in queryreturn:
            ackdata, = row
            logger.info('Watching for ackdata ' + hexlify(ackdata))
            shared.ackdataForWhichImWatching[ackdata] = 0

        # Fix legacy (headerless) watched ackdata to include header
        for oldack in shared.ackdataForWhichImWatching.keys():
            if (len(oldack) == 32):
                # attach legacy header, always constant (msg/1/1)
                newack = '\x00\x00\x00\x02\x01\x01' + oldack
                shared.ackdataForWhichImWatching[newack] = 0
                sqlExecute(
                    'UPDATE sent SET ackdata=? WHERE ackdata=?',
                    newack, oldack
                )
                del shared.ackdataForWhichImWatching[oldack]

        # give some time for the GUI to start
        # before we start on existing POW tasks.
        self.stop.wait(10)

        if state.shutdown == 0:
            # just in case there are any pending tasks for msg
            # messages that have yet to be sent.
            queues.workerQueue.put(('sendmessage', ''))
            # just in case there are any tasks for Broadcasts
            # that have yet to be sent.
            queues.workerQueue.put(('sendbroadcast', ''))

        while state.shutdown == 0:
            self.busy = 0
            command, data = queues.workerQueue.get()
            self.busy = 1
            if command == 'sendmessage':
                try:
                    self.sendMsg()
                except:
                    pass
            elif command == 'sendbroadcast':
                try:
                    self.sendBroadcast()
                except:
                    pass
            elif command == 'doPOWForMyV2Pubkey':
                try:
                    self.doPOWForMyV2Pubkey(data)
                except:
                    pass
            elif command == 'sendOutOrStoreMyV3Pubkey':
                try:
                    self.sendOutOrStoreMyV3Pubkey(data)
                except:
                    pass
            elif command == 'sendOutOrStoreMyV4Pubkey':
                try:
                    self.sendOutOrStoreMyV4Pubkey(data)
                except:
                    pass
            elif command == 'resetPoW':
                try:
                    proofofwork.resetPoW()
                except:
                    pass
            elif command == 'stopThread':
                self.busy = 0
                return
            else:
                logger.error(
                    'Probable programming error: The command sent'
                    ' to the workerThread is weird. It is: %s\n',
                    command
                )

            queues.workerQueue.task_done()
        logger.info("Quitting...")

    def _getKeysForAddress(self, address):
        privSigningKeyBase58 = BMConfigParser().get(
            address, 'privsigningkey')
        privEncryptionKeyBase58 = BMConfigParser().get(
            address, 'privencryptionkey')

        privSigningKeyHex = hexlify(shared.decodeWalletImportFormat(
            privSigningKeyBase58))
        privEncryptionKeyHex = hexlify(shared.decodeWalletImportFormat(
            privEncryptionKeyBase58))

        # The \x04 on the beginning of the public keys are not sent.
        # This way there is only one acceptable way to encode
        # and send a public key.
        pubSigningKey = unhexlify(highlevelcrypto.privToPub(
            privSigningKeyHex))[1:]
        pubEncryptionKey = unhexlify(highlevelcrypto.privToPub(
            privEncryptionKeyHex))[1:]

        return privSigningKeyHex, privEncryptionKeyHex, \
            pubSigningKey, pubEncryptionKey

    def _doPOWDefaults(self, payload, TTL,
                       log_prefix='',
                       log_time=False):
        target = 2 ** 64 / (
            defaults.networkDefaultProofOfWorkNonceTrialsPerByte * (
                len(payload) + 8 +
                defaults.networkDefaultPayloadLengthExtraBytes + ((
                    TTL * (
                        len(payload) + 8 +
                        defaults.networkDefaultPayloadLengthExtraBytes
                    )) / (2 ** 16))
            ))
        initialHash = hashlib.sha512(payload).digest()
        logger.info(
            '%s Doing proof of work... TTL set to %s', log_prefix, TTL)
        if log_time:
            start_time = time.time()
        trialValue, nonce = proofofwork.run(target, initialHash)
        logger.info(
            '%s Found proof of work %s Nonce: %s',
            log_prefix, trialValue, nonce
        )
        try:
            delta = time.time() - start_time
            logger.info(
                'PoW took %.1f seconds, speed %s.',
                delta, sizeof_fmt(nonce / delta)
            )
        except:  # NameError
            pass
        payload = pack('>Q', nonce) + payload
        # inventoryHash = calculateInventoryHash(payload)
        return payload

    # This function also broadcasts out the pubkey message
    # once it is done with the POW
    def doPOWForMyV2Pubkey(self, adressHash):
        # Look up my stream number based on my address hash
        """configSections = shared.config.addresses()
        for addressInKeysFile in configSections:
            if addressInKeysFile != 'bitmessagesettings':
                status, addressVersionNumber, streamNumber, \
                    hashFromThisParticularAddress = \
                    decodeAddress(addressInKeysFile)
                if hash == hashFromThisParticularAddress:
                    myAddress = addressInKeysFile
                    break"""
        myAddress = shared.myAddressesByHash[adressHash]
        # status
        _, addressVersionNumber, streamNumber, adressHash = decodeAddress(myAddress)

        # 28 days from now plus or minus five minutes
        TTL = int(28 * 24 * 60 * 60 + helper_random.randomrandrange(-300, 300))
        embeddedTime = int(time.time() + TTL)
        payload = pack('>Q', (embeddedTime))
        payload += '\x00\x00\x00\x01'  # object type: pubkey
        payload += encodeVarint(addressVersionNumber)  # Address version number
        payload += encodeVarint(streamNumber)
        # bitfield of features supported by me (see the wiki).
        payload += protocol.getBitfield(myAddress)

        try:
            # privSigningKeyHex, privEncryptionKeyHex
            _, _, pubSigningKey, pubEncryptionKey = \
                self._getKeysForAddress(myAddress)
        except Exception as err:
            logger.error(
                'Error within doPOWForMyV2Pubkey. Could not read'
                ' the keys from the keys.dat file for a requested'
                ' address. %s\n', err
            )
            return

        payload += pubSigningKey + pubEncryptionKey

        # Do the POW for this pubkey message
        payload = self._doPOWDefaults(
            payload, TTL, log_prefix='(For pubkey message)')

        inventoryHash = calculateInventoryHash(payload)
        objectType = 1
        Inventory()[inventoryHash] = (
            objectType, streamNumber, payload, embeddedTime, '')

        logger.info('broadcasting inv with hash: %s', hexlify(inventoryHash))

        queues.invQueue.put((streamNumber, inventoryHash))
        queues.UISignalQueue.put(('updateStatusBar', ''))
        try:
            BMConfigParser().set(
                myAddress, 'lastpubkeysendtime', str(int(time.time())))
            BMConfigParser().save()
        except:
            # The user deleted the address out of the keys.dat file
            # before this finished.
            pass

    # If this isn't a chan address, this function assembles the pubkey data,
    # does the necessary POW and sends it out. If it *is* a chan then it
    # assembles the pubkey and stores is in the pubkey table so that we can
    # send messages to "ourselves".
    def sendOutOrStoreMyV3Pubkey(self, adressHash):
        try:
            myAddress = shared.myAddressesByHash[adressHash]
        except:
            # The address has been deleted.
            return
        if BMConfigParser().safeGetBoolean(myAddress, 'chan'):
            logger.info('This is a chan address. Not sending pubkey.')
            return
        _, addressVersionNumber, streamNumber, adressHash = decodeAddress(
            myAddress)

        # 28 days from now plus or minus five minutes
        TTL = int(28 * 24 * 60 * 60 + helper_random.randomrandrange(-300, 300))
        embeddedTime = int(time.time() + TTL)

        # signedTimeForProtocolV2 = embeddedTime - TTL
        # According to the protocol specification, the expiresTime
        # along with the pubkey information is signed. But to be
        # backwards compatible during the upgrade period, we shall sign
        # not the expiresTime but rather the current time. There must be
        # precisely a 28 day difference between the two. After the upgrade
        # period we'll switch to signing the whole payload with the
        # expiresTime time.

        payload = pack('>Q', (embeddedTime))
        payload += '\x00\x00\x00\x01'  # object type: pubkey
        payload += encodeVarint(addressVersionNumber)  # Address version number
        payload += encodeVarint(streamNumber)
        # bitfield of features supported by me (see the wiki).
        payload += protocol.getBitfield(myAddress)

        try:
            # , privEncryptionKeyHex
            privSigningKeyHex, _, pubSigningKey, pubEncryptionKey = \
                self._getKeysForAddress(myAddress)
        except Exception as err:
            logger.error(
                'Error within sendOutOrStoreMyV3Pubkey. Could not read'
                ' the keys from the keys.dat file for a requested'
                ' address. %s\n', err
            )
            return

        payload += pubSigningKey + pubEncryptionKey

        payload += encodeVarint(BMConfigParser().getint(
            myAddress, 'noncetrialsperbyte'))
        payload += encodeVarint(BMConfigParser().getint(
            myAddress, 'payloadlengthextrabytes'))

        signature = highlevelcrypto.sign(payload, privSigningKeyHex)
        payload += encodeVarint(len(signature))
        payload += signature

        # Do the POW for this pubkey message
        payload = self._doPOWDefaults(
            payload, TTL, log_prefix='(For pubkey message)')

        inventoryHash = calculateInventoryHash(payload)
        objectType = 1
        Inventory()[inventoryHash] = (
            objectType, streamNumber, payload, embeddedTime, '')

        logger.info('broadcasting inv with hash: ' + hexlify(inventoryHash))

        queues.invQueue.put((streamNumber, inventoryHash))
        queues.UISignalQueue.put(('updateStatusBar', ''))
        try:
            BMConfigParser().set(
                myAddress, 'lastpubkeysendtime', str(int(time.time())))
            BMConfigParser().save()
        except:
            # The user deleted the address out of the keys.dat file
            # before this finished.
            pass

    # If this isn't a chan address, this function assembles
    # the pubkey data, does the necessary POW and sends it out.
    def sendOutOrStoreMyV4Pubkey(self, myAddress):
        if not BMConfigParser().has_section(myAddress):
            # The address has been deleted.
            return
        if shared.BMConfigParser().safeGetBoolean(myAddress, 'chan'):
            logger.info('This is a chan address. Not sending pubkey.')
            return
        _, addressVersionNumber, streamNumber, addressHash = decodeAddress(
            myAddress)

        # 28 days from now plus or minus five minutes
        TTL = int(28 * 24 * 60 * 60 + helper_random.randomrandrange(-300, 300))
        embeddedTime = int(time.time() + TTL)
        payload = pack('>Q', (embeddedTime))
        payload += '\x00\x00\x00\x01'  # object type: pubkey
        payload += encodeVarint(addressVersionNumber)  # Address version number
        payload += encodeVarint(streamNumber)
        dataToEncrypt = protocol.getBitfield(myAddress)

        try:
            # , privEncryptionKeyHex
            privSigningKeyHex, _, pubSigningKey, pubEncryptionKey = \
                self._getKeysForAddress(myAddress)
        except Exception as err:
            logger.error(
                'Error within sendOutOrStoreMyV4Pubkey. Could not read'
                ' the keys from the keys.dat file for a requested'
                ' address. %s\n', err
            )
            return

        dataToEncrypt += pubSigningKey + pubEncryptionKey

        dataToEncrypt += encodeVarint(BMConfigParser().getint(
            myAddress, 'noncetrialsperbyte'))
        dataToEncrypt += encodeVarint(BMConfigParser().getint(
            myAddress, 'payloadlengthextrabytes'))

        # When we encrypt, we'll use a hash of the data
        # contained in an address as a decryption key. This way
        # in order to read the public keys in a pubkey message,
        # a node must know the address first. We'll also tag,
        # unencrypted, the pubkey with part of the hash so that nodes
        # know which pubkey object to try to decrypt
        # when they want to send a message.
        doubleHashOfAddressData = hashlib.sha512(hashlib.sha512(
            encodeVarint(addressVersionNumber) +
            encodeVarint(streamNumber) + addressHash
        ).digest()).digest()
        payload += doubleHashOfAddressData[32:]  # the tag
        signature = highlevelcrypto.sign(
            payload + dataToEncrypt, privSigningKeyHex
        )
        dataToEncrypt += encodeVarint(len(signature))
        dataToEncrypt += signature

        privEncryptionKey = doubleHashOfAddressData[:32]
        pubEncryptionKey = highlevelcrypto.pointMult(privEncryptionKey)
        payload += highlevelcrypto.encrypt(
            dataToEncrypt, hexlify(pubEncryptionKey))

        # Do the POW for this pubkey message
        payload = self._doPOWDefaults(
            payload, TTL, log_prefix='(For pubkey message)')

        inventoryHash = calculateInventoryHash(payload)
        objectType = 1
        Inventory()[inventoryHash] = (
            objectType, streamNumber, payload, embeddedTime,
            doubleHashOfAddressData[32:]
        )

        logger.info('broadcasting inv with hash: ' + hexlify(inventoryHash))

        queues.invQueue.put((streamNumber, inventoryHash))
        queues.UISignalQueue.put(('updateStatusBar', ''))
        try:
            BMConfigParser().set(
                myAddress, 'lastpubkeysendtime', str(int(time.time())))
            BMConfigParser().save()
        except Exception as err:
            logger.error(
                'Error: Couldn\'t add the lastpubkeysendtime'
                ' to the keys.dat file. Error message: %s', err
            )

    def sendBroadcast(self):
        # Reset just in case
        sqlExecute(
            '''UPDATE sent SET status='broadcastqueued' '''

            '''WHERE status = 'doingbroadcastpow' ''')
        queryreturn = sqlQuery(
            '''SELECT fromaddress, subject, message, '''
            ''' ackdata, ttl, encodingtype FROM sent '''
            ''' WHERE status=? and folder='sent' ''', 'broadcastqueued')

        for row in queryreturn:
            fromaddress, subject, body, ackdata, TTL, encoding = row
            # status
            _, addressVersionNumber, streamNumber, ripe = \
                decodeAddress(fromaddress)
            if addressVersionNumber <= 1:
                logger.error(
                    'Error: In the singleWorker thread, the '
                    ' sendBroadcast function doesn\'t understand'
                    ' the address version.\n')
                return
            # We need to convert our private keys to public keys in order
            # to include them.
            try:
                # , privEncryptionKeyHex
                privSigningKeyHex, _, pubSigningKey, pubEncryptionKey = \
                    self._getKeysForAddress(fromaddress)
            except:
                queues.UISignalQueue.put((
                    'updateSentItemStatusByAckdata', (
                        ackdata,
                        tr._translate(
                            "MainWindow",
                            "Error! Could not find sender address"
                            " (your address) in the keys.dat file."))
                ))
                continue

            sqlExecute(
                '''UPDATE sent SET status='doingbroadcastpow' '''
                ''' WHERE ackdata=? AND status='broadcastqueued' ''',
                ackdata)

            # At this time these pubkeys are 65 bytes long
            # because they include the encoding byte which we won't
            # be sending in the broadcast message.
            # pubSigningKey = \
            #     highlevelcrypto.privToPub(privSigningKeyHex).decode('hex')

            if TTL > 28 * 24 * 60 * 60:
                TTL = 28 * 24 * 60 * 60
            if TTL < 60 * 60:
                TTL = 60 * 60
            # add some randomness to the TTL
            TTL = int(TTL + helper_random.randomrandrange(-300, 300))
            embeddedTime = int(time.time() + TTL)
            payload = pack('>Q', embeddedTime)
            payload += '\x00\x00\x00\x03'  # object type: broadcast

            if addressVersionNumber <= 3:
                payload += encodeVarint(4)  # broadcast version
            else:
                payload += encodeVarint(5)  # broadcast version

            payload += encodeVarint(streamNumber)
            if addressVersionNumber >= 4:
                doubleHashOfAddressData = hashlib.sha512(hashlib.sha512(
                    encodeVarint(addressVersionNumber) +
                    encodeVarint(streamNumber) + ripe
                ).digest()).digest()
                tag = doubleHashOfAddressData[32:]
                payload += tag
            else:
                tag = ''

            dataToEncrypt = encodeVarint(addressVersionNumber)
            dataToEncrypt += encodeVarint(streamNumber)
            # behavior bitfield
            dataToEncrypt += protocol.getBitfield(fromaddress)
            dataToEncrypt += pubSigningKey + pubEncryptionKey
            if addressVersionNumber >= 3:
                dataToEncrypt += encodeVarint(BMConfigParser().getint(
                    fromaddress, 'noncetrialsperbyte'))
                dataToEncrypt += encodeVarint(BMConfigParser().getint(
                    fromaddress, 'payloadlengthextrabytes'))
            # message encoding type
            dataToEncrypt += encodeVarint(encoding)
            encodedMessage = helper_msgcoding.MsgEncode(
                {"subject": subject, "body": body}, encoding)
            dataToEncrypt += encodeVarint(encodedMessage.length)
            dataToEncrypt += encodedMessage.data
            dataToSign = payload + dataToEncrypt

            signature = highlevelcrypto.sign(
                dataToSign, privSigningKeyHex)
            dataToEncrypt += encodeVarint(len(signature))
            dataToEncrypt += signature

            # Encrypt the broadcast with the information
            # contained in the broadcaster's address.
            # Anyone who knows the address can generate
            # the private encryption key to decrypt the broadcast.
            # This provides virtually no privacy; its purpose is to keep
            # questionable and illegal content from flowing through the
            # Internet connections and being stored on the disk of 3rd parties.
            if addressVersionNumber <= 3:
                privEncryptionKey = hashlib.sha512(
                    encodeVarint(addressVersionNumber) +
                    encodeVarint(streamNumber) + ripe
                ).digest()[:32]
            else:
                privEncryptionKey = doubleHashOfAddressData[:32]

            pubEncryptionKey = highlevelcrypto.pointMult(privEncryptionKey)
            payload += highlevelcrypto.encrypt(
                dataToEncrypt, hexlify(pubEncryptionKey))

            queues.UISignalQueue.put((
                'updateSentItemStatusByAckdata', (
                    ackdata,
                    tr._translate(
                        "MainWindow",
                        "Doing work necessary to send broadcast..."))
            ))
            payload = self._doPOWDefaults(
                payload, TTL, log_prefix='(For broadcast message)')

            # Sanity check. The payload size should never be larger
            # than 256 KiB. There should be checks elsewhere in the code
            # to not let the user try to send a message this large
            # until we implement message continuation.
            if len(payload) > 2 ** 18:  # 256 KiB
                logger.critical(
                    'This broadcast object is too large to send.'
                    ' This should never happen. Object size: %s',
                    len(payload)
                )
                continue

            inventoryHash = calculateInventoryHash(payload)
            objectType = 3
            Inventory()[inventoryHash] = (
                objectType, streamNumber, payload, embeddedTime, tag)
            logger.info(
                'sending inv (within sendBroadcast function)'
                ' for object: %s',
                hexlify(inventoryHash)
            )
            queues.invQueue.put((streamNumber, inventoryHash))

            queues.UISignalQueue.put((
                'updateSentItemStatusByAckdata', (
                    ackdata,
                    tr._translate(
                        "MainWindow",
                        "Broadcast sent on %1"
                    ).arg(l10n.formatTimestamp()))
            ))

            # Update the status of the message in the 'sent' table to have
            # a 'broadcastsent' status
            sqlExecute(
                'UPDATE sent SET msgid=?, status=?, lastactiontime=?'
                ' WHERE ackdata=?',
                inventoryHash, 'broadcastsent', int(time.time()), ackdata
            )

    def sendMsg(self):
        # Reset just in case
        sqlExecute(
            '''UPDATE sent SET status='msgqueued' '''
            ''' WHERE status IN ('doingpubkeypow', 'doingmsgpow')''')
        queryreturn = sqlQuery(
            '''SELECT toaddress, fromaddress, subject, message, '''
            ''' ackdata, status, ttl, retrynumber, encodingtype FROM '''
            ''' sent WHERE (status='msgqueued' or status='forcepow') '''
            ''' and folder='sent' ''')
        # while we have a msg that needs some work
        for row in queryreturn:
            toaddress, fromaddress, subject, message, \
                ackdata, status, TTL, retryNumber, encoding = row
            # toStatus
            _, toAddressVersionNumber, toStreamNumber, toRipe = \
                decodeAddress(toaddress)
            # fromStatus, , ,fromRipe
            _, fromAddressVersionNumber, fromStreamNumber, _ = \
                decodeAddress(fromaddress)

            # We may or may not already have the pubkey
            # for this toAddress. Let's check.
            if status == 'forcepow':
                # if the status of this msg is 'forcepow'
                # then clearly we have the pubkey already
                # because the user could not have overridden the message
                # about the POW being too difficult without knowing
                # the required difficulty.
                pass
            elif status == 'doingmsgpow':
                # We wouldn't have set the status to doingmsgpow
                # if we didn't already have the pubkey so let's assume
                # that we have it.
                pass
            # If we are sending a message to ourselves or a chan
            # then we won't need an entry in the pubkeys table;
            # we can calculate the needed pubkey using the private keys
            # in our keys.dat file.
            elif BMConfigParser().has_section(toaddress):
                sqlExecute(
                    '''UPDATE sent SET status='doingmsgpow' '''
                    ''' WHERE toaddress=? AND status='msgqueued' ''',
                    toaddress
                )
                status = 'doingmsgpow'
            elif status == 'msgqueued':
                # Let's see if we already have the pubkey in our pubkeys table
                queryreturn = sqlQuery(
                    '''SELECT address FROM pubkeys WHERE address=?''',
                    toaddress
                )
                # If we have the needed pubkey in the pubkey table already,
                if queryreturn != []:
                    # set the status of this msg to doingmsgpow
                    sqlExecute(
                        '''UPDATE sent SET status='doingmsgpow' '''
                        ''' WHERE toaddress=? AND status='msgqueued' ''',
                        toaddress
                    )
                    status = 'doingmsgpow'
                    # mark the pubkey as 'usedpersonally' so that
                    # we don't delete it later. If the pubkey version
                    # is >= 4 then usedpersonally will already be set
                    # to yes because we'll only ever have
                    # usedpersonally v4 pubkeys in the pubkeys table.
                    sqlExecute(
                        '''UPDATE pubkeys SET usedpersonally='yes' '''
                        ''' WHERE address=?''',
                        toaddress
                    )
                # We don't have the needed pubkey in the pubkeys table already.
                else:
                    if toAddressVersionNumber <= 3:
                        toTag = ''
                    else:
                        toTag = hashlib.sha512(hashlib.sha512(
                            encodeVarint(toAddressVersionNumber) +
                            encodeVarint(toStreamNumber) + toRipe
                        ).digest()).digest()[32:]
                    if toaddress in state.neededPubkeys or \
                            toTag in state.neededPubkeys:
                        # We already sent a request for the pubkey
                        sqlExecute(
                            '''UPDATE sent SET status='awaitingpubkey', '''
                            ''' sleeptill=? WHERE toaddress=? '''
                            ''' AND status='msgqueued' ''',
                            int(time.time()) + 2.5 * 24 * 60 * 60,
                            toaddress
                        )
                        queues.UISignalQueue.put((
                            'updateSentItemStatusByToAddress', (
                                toaddress,
                                tr._translate(
                                    "MainWindow",
                                    "Encryption key was requested earlier."))
                        ))
                        # on with the next msg on which we can do some work
                        continue
                    else:
                        # We have not yet sent a request for the pubkey
                        needToRequestPubkey = True
                        # If we are trying to send to address
                        # version >= 4 then the needed pubkey might be
                        # encrypted in the inventory.
                        # If we have it we'll need to decrypt it
                        # and put it in the pubkeys table.

                        # The decryptAndCheckPubkeyPayload function
                        # expects that the shared.neededPubkeys dictionary
                        # already contains the toAddress and cryptor
                        # object associated with the tag for this toAddress.
                        if toAddressVersionNumber >= 4:
                            doubleHashOfToAddressData = hashlib.sha512(
                                hashlib.sha512(encodeVarint(
                                    toAddressVersionNumber) +
                                    encodeVarint(toStreamNumber) +
                                    toRipe
                                ).digest()
                            ).digest()
                            # The first half of the sha512 hash.
                            privEncryptionKey = doubleHashOfToAddressData[:32]
                            # The second half of the sha512 hash.
                            tag = doubleHashOfToAddressData[32:]
                            state.neededPubkeys[tag] = (
                                toaddress,
                                highlevelcrypto.makeCryptor(
                                    hexlify(privEncryptionKey))
                            )

                            for value in Inventory().by_type_and_tag(1, toTag):
                                # if valid, this function also puts it
                                # in the pubkeys table.
                                if shared.decryptAndCheckPubkeyPayload(
                                        value.payload, toaddress
                                ) == 'successful':
                                    needToRequestPubkey = False
                                    sqlExecute(
                                        '''UPDATE sent SET '''
                                        ''' status='doingmsgpow', '''
                                        ''' retrynumber=0 WHERE '''
                                        ''' toaddress=? AND '''
                                        ''' (status='msgqueued' or '''
                                        ''' status='awaitingpubkey' or '''
                                        ''' status='doingpubkeypow')''',
                                        toaddress)
                                    del state.neededPubkeys[tag]
                                    break
                                # else:
                                # There was something wrong with this
                                # pubkey object even though it had
                                # the correct tag- almost certainly
                                # because of malicious behavior or
                                # a badly programmed client. If there are
                                # any other pubkeys in our inventory
                                # with the correct tag then we'll try
                                # to decrypt those.
                        if needToRequestPubkey:
                            sqlExecute(
                                '''UPDATE sent SET '''
                                ''' status='doingpubkeypow' WHERE '''
                                ''' toaddress=? AND status='msgqueued' ''',
                                toaddress
                            )
                            queues.UISignalQueue.put((
                                'updateSentItemStatusByToAddress', (
                                    toaddress,
                                    tr._translate(
                                        "MainWindow",
                                        "Sending a request for the"
                                        " recipient\'s encryption key."))
                            ))
                            self.requestPubKey(toaddress)
                            # on with the next msg on which we can do some work
                            continue

            # At this point we know that we have the necessary pubkey
            # in the pubkeys table.

            TTL *= 2**retryNumber
            if TTL > 28 * 24 * 60 * 60:
                TTL = 28 * 24 * 60 * 60
            # add some randomness to the TTL
            TTL = int(TTL + helper_random.randomrandrange(-300, 300))
            embeddedTime = int(time.time() + TTL)

            # if we aren't sending this to ourselves or a chan
            if not BMConfigParser().has_section(toaddress):
                shared.ackdataForWhichImWatching[ackdata] = 0
                queues.UISignalQueue.put((
                    'updateSentItemStatusByAckdata', (
                        ackdata,
                        tr._translate(
                            "MainWindow",
                            "Looking up the receiver\'s public key"))
                ))
                logger.info('Sending a message.')
                logger.debug(
                    'First 150 characters of message: %s',
                    repr(message[:150])
                )

                # Let us fetch the recipient's public key out of
                # our database. If the required proof of work difficulty
                # is too hard then we'll abort.
                queryreturn = sqlQuery(
                    'SELECT transmitdata FROM pubkeys WHERE address=?',
                    toaddress)
                for row in queryreturn:
                    pubkeyPayload, = row

                # The pubkey message is stored with the following items
                # all appended:
                #    -address version
                #    -stream number
                #    -behavior bitfield
                #    -pub signing key
                #    -pub encryption key
                #    -nonce trials per byte (if address version is >= 3)
                #    -length extra bytes (if address version is >= 3)

                # to bypass the address version whose length is definitely 1
                readPosition = 1
                _, streamNumberLength = decodeVarint(
                    pubkeyPayload[readPosition:readPosition + 10])
                readPosition += streamNumberLength
                behaviorBitfield = pubkeyPayload[readPosition:readPosition + 4]
                # Mobile users may ask us to include their address's
                # RIPE hash on a message unencrypted. Before we actually
                # do it the sending human must check a box
                # in the settings menu to allow it.

                # if receiver is a mobile device who expects that their
                # address RIPE is included unencrypted on the front of
                # the message..
                if shared.isBitSetWithinBitfield(behaviorBitfield, 30):
                    # if we are Not willing to include the receiver's
                    # RIPE hash on the message..
                    if not shared.BMConfigParser().safeGetBoolean(
                            'bitmessagesettings', 'willinglysendtomobile'
                    ):
                        logger.info(
                            'The receiver is a mobile user but the'
                            ' sender (you) has not selected that you'
                            ' are willing to send to mobiles. Aborting'
                            ' send.'
                        )
                        queues.UISignalQueue.put((
                            'updateSentItemStatusByAckdata', (
                                ackdata,
                                tr._translate(
                                    "MainWindow",
                                    "Problem: Destination is a mobile"
                                    " device who requests that the"
                                    " destination be included in the"
                                    " message but this is disallowed in"
                                    " your settings.  %1"
                                ).arg(l10n.formatTimestamp()))
                        ))
                        # if the human changes their setting and then
                        # sends another message or restarts their client,
                        # this one will send at that time.
                        continue
                readPosition += 4  # to bypass the bitfield of behaviors
                # We don't use this key for anything here.
                # pubSigningKeyBase256 =
                # pubkeyPayload[readPosition:readPosition+64]
                readPosition += 64
                pubEncryptionKeyBase256 = pubkeyPayload[
                    readPosition:readPosition + 64]
                readPosition += 64

                # Let us fetch the amount of work required by the recipient.
                if toAddressVersionNumber == 2:
                    requiredAverageProofOfWorkNonceTrialsPerByte = \
                        defaults.networkDefaultProofOfWorkNonceTrialsPerByte
                    requiredPayloadLengthExtraBytes = \
                        defaults.networkDefaultPayloadLengthExtraBytes
                    queues.UISignalQueue.put((
                        'updateSentItemStatusByAckdata', (
                            ackdata,
                            tr._translate(
                                "MainWindow",
                                "Doing work necessary to send message.\n"
                                "There is no required difficulty for"
                                " version 2 addresses like this."))
                    ))
                elif toAddressVersionNumber >= 3:
                    requiredAverageProofOfWorkNonceTrialsPerByte, \
                        varintLength = decodeVarint(
                            pubkeyPayload[readPosition:readPosition + 10])
                    readPosition += varintLength
                    requiredPayloadLengthExtraBytes, varintLength = \
                        decodeVarint(
                            pubkeyPayload[readPosition:readPosition + 10])
                    readPosition += varintLength
                    # We still have to meet a minimum POW difficulty
                    # regardless of what they say is allowed in order
                    # to get our message to propagate through the network.
                    if requiredAverageProofOfWorkNonceTrialsPerByte < \
                            defaults.networkDefaultProofOfWorkNonceTrialsPerByte:
                        requiredAverageProofOfWorkNonceTrialsPerByte = \
                            defaults.networkDefaultProofOfWorkNonceTrialsPerByte
                    if requiredPayloadLengthExtraBytes < \
                            defaults.networkDefaultPayloadLengthExtraBytes:
                        requiredPayloadLengthExtraBytes = \
                            defaults.networkDefaultPayloadLengthExtraBytes
                    logger.debug(
                        'Using averageProofOfWorkNonceTrialsPerByte: %s'
                        ' and payloadLengthExtraBytes: %s.',
                        requiredAverageProofOfWorkNonceTrialsPerByte,
                        requiredPayloadLengthExtraBytes
                    )
                    queues.UISignalQueue.put((
                        'updateSentItemStatusByAckdata', (
                            ackdata,
                            tr._translate(
                                "MainWindow",
                                "Doing work necessary to send message.\n"
                                "Receiver\'s required difficulty: %1"
                                " and %2"
                            ).arg(str(float(
                                requiredAverageProofOfWorkNonceTrialsPerByte) /
                                defaults.networkDefaultProofOfWorkNonceTrialsPerByte
                                )).arg(str(float(
                                    requiredPayloadLengthExtraBytes) /
                                    defaults.networkDefaultPayloadLengthExtraBytes
                                    )))))
                    if status != 'forcepow':
                        if (requiredAverageProofOfWorkNonceTrialsPerByte
                            > BMConfigParser().getint(
                                'bitmessagesettings',
                                'maxacceptablenoncetrialsperbyte'
                            ) and
                            BMConfigParser().getint(
                                'bitmessagesettings',
                                'maxacceptablenoncetrialsperbyte'
                            ) != 0) or (
                                requiredPayloadLengthExtraBytes
                                > BMConfigParser().getint(
                                    'bitmessagesettings',
                                    'maxacceptablepayloadlengthextrabytes'
                                ) and
                                BMConfigParser().getint(
                                    'bitmessagesettings',
                                    'maxacceptablepayloadlengthextrabytes'
                                ) != 0):
                            # The demanded difficulty is more than
                            # we are willing to do.
                            sqlExecute(
                                '''UPDATE sent SET status='toodifficult' '''
                                ''' WHERE ackdata=? ''',
                                ackdata)
                            queues.UISignalQueue.put((
                                'updateSentItemStatusByAckdata', (
                                    ackdata,
                                    tr._translate(
                                        "MainWindow",
                                        "Problem: The work demanded by"
                                        " the recipient (%1 and %2) is"
                                        " more difficult than you are"
                                        " willing to do. %3"
                                    ).arg(str(float(
                                        requiredAverageProofOfWorkNonceTrialsPerByte)
                                        / defaults.networkDefaultProofOfWorkNonceTrialsPerByte
                                        )).arg(str(float(
                                            requiredPayloadLengthExtraBytes)
                                            / defaults.networkDefaultPayloadLengthExtraBytes
                                            )).arg(l10n.formatTimestamp()))
                            ))
                            continue
            else:  # if we are sending a message to ourselves or a chan..
                logger.info('Sending a message.')
                logger.debug(
                    'First 150 characters of message: %r', message[:150])
                behaviorBitfield = protocol.getBitfield(fromaddress)

                try:
                    privEncryptionKeyBase58 = BMConfigParser().get(
                        toaddress, 'privencryptionkey')
                except Exception as err:
                    queues.UISignalQueue.put((
                        'updateSentItemStatusByAckdata', (
                            ackdata,
                            tr._translate(
                                "MainWindow",
                                "Problem: You are trying to send a"
                                " message to yourself or a chan but your"
                                " encryption key could not be found in"
                                " the keys.dat file. Could not encrypt"
                                " message. %1"
                            ).arg(l10n.formatTimestamp()))
                    ))
                    logger.error(
                        'Error within sendMsg. Could not read the keys'
                        ' from the keys.dat file for our own address. %s\n',
                        err)
                    continue
                privEncryptionKeyHex = hexlify(shared.decodeWalletImportFormat(
                    privEncryptionKeyBase58))
                pubEncryptionKeyBase256 = unhexlify(highlevelcrypto.privToPub(
                    privEncryptionKeyHex))[1:]
                requiredAverageProofOfWorkNonceTrialsPerByte = \
                    defaults.networkDefaultProofOfWorkNonceTrialsPerByte
                requiredPayloadLengthExtraBytes = \
                    defaults.networkDefaultPayloadLengthExtraBytes
                queues.UISignalQueue.put((
                    'updateSentItemStatusByAckdata', (
                        ackdata,
                        tr._translate(
                            "MainWindow",
                            "Doing work necessary to send message."))
                ))

            # Now we can start to assemble our message.
            payload = encodeVarint(fromAddressVersionNumber)
            payload += encodeVarint(fromStreamNumber)
            # Bitfield of features and behaviors
            # that can be expected from me. (See
            # https://bitmessage.org/wiki/Protocol_specification#Pubkey_bitfield_features)
            payload += protocol.getBitfield(fromaddress)

            # We need to convert our private keys to public keys in order
            # to include them.
            try:
                privSigningKeyHex, privEncryptionKeyHex, \
                    pubSigningKey, pubEncryptionKey = self._getKeysForAddress(
                        fromaddress)
            except:
                queues.UISignalQueue.put((
                    'updateSentItemStatusByAckdata', (
                        ackdata,
                        tr._translate(
                            "MainWindow",
                            "Error! Could not find sender address"
                            " (your address) in the keys.dat file."))
                ))
                continue

            payload += pubSigningKey + pubEncryptionKey

            if fromAddressVersionNumber >= 3:
                # If the receiver of our message is in our address book,
                # subscriptions list, or whitelist then we will allow them to
                # do the network-minimum proof of work. Let us check to see if
                # the receiver is in any of those lists.
                if shared.isAddressInMyAddressBookSubscriptionsListOrWhitelist(
                        toaddress):
                    payload += encodeVarint(
                        defaults.networkDefaultProofOfWorkNonceTrialsPerByte)
                    payload += encodeVarint(
                        defaults.networkDefaultPayloadLengthExtraBytes)
                else:
                    payload += encodeVarint(BMConfigParser().getint(
                        fromaddress, 'noncetrialsperbyte'))
                    payload += encodeVarint(BMConfigParser().getint(
                        fromaddress, 'payloadlengthextrabytes'))

            # This hash will be checked by the receiver of the message
            # to verify that toRipe belongs to them. This prevents
            # a Surreptitious Forwarding Attack.
            payload += toRipe
            payload += encodeVarint(encoding)  # message encoding type
            encodedMessage = helper_msgcoding.MsgEncode(
                {"subject": subject, "body": message}, encoding
            )
            payload += encodeVarint(encodedMessage.length)
            payload += encodedMessage.data
            if BMConfigParser().has_section(toaddress):
                logger.info(
                    'Not bothering to include ackdata because we are'
                    ' sending to ourselves or a chan.'
                )
                fullAckPayload = ''
            elif not protocol.checkBitfield(
                    behaviorBitfield, protocol.BITFIELD_DOESACK):
                logger.info(
                    'Not bothering to include ackdata because'
                    ' the receiver said that they won\'t relay it anyway.'
                )
                fullAckPayload = ''
            else:
                # The fullAckPayload is a normal msg protocol message
                # with the proof of work already completed that the
                # receiver of this message can easily send out.
                fullAckPayload = self.generateFullAckMessage(
                    ackdata, toStreamNumber, TTL)
            payload += encodeVarint(len(fullAckPayload))
            payload += fullAckPayload
            dataToSign = pack('>Q', embeddedTime) + '\x00\x00\x00\x02' + \
                encodeVarint(1) + encodeVarint(toStreamNumber) + payload
            signature = highlevelcrypto.sign(dataToSign, privSigningKeyHex)
            payload += encodeVarint(len(signature))
            payload += signature

            # We have assembled the data that will be encrypted.
            try:
                encrypted = highlevelcrypto.encrypt(
                    payload, "04" + hexlify(pubEncryptionKeyBase256)
                )
            except:
                sqlExecute(
                    '''UPDATE sent SET status='badkey' WHERE ackdata=?''',
                    ackdata
                )
                queues.UISignalQueue.put((
                    'updateSentItemStatusByAckdata', (
                        ackdata,
                        tr._translate(
                            "MainWindow",
                            "Problem: The recipient\'s encryption key is"
                            " no good. Could not encrypt message. %1"
                        ).arg(l10n.formatTimestamp()))
                ))
                continue

            encryptedPayload = pack('>Q', embeddedTime)
            encryptedPayload += '\x00\x00\x00\x02'  # object type: msg
            encryptedPayload += encodeVarint(1)  # msg version
            encryptedPayload += encodeVarint(toStreamNumber) + encrypted
            target = 2 ** 64 / (
                requiredAverageProofOfWorkNonceTrialsPerByte * (
                    len(encryptedPayload) + 8 +
                    requiredPayloadLengthExtraBytes + ((
                        TTL * (
                            len(encryptedPayload) + 8 +
                            requiredPayloadLengthExtraBytes
                        )) / (2 ** 16))
                ))
            logger.info(
                '(For msg message) Doing proof of work. Total required'
                ' difficulty: %f. Required small message difficulty: %f.',
                float(requiredAverageProofOfWorkNonceTrialsPerByte) /
                defaults.networkDefaultProofOfWorkNonceTrialsPerByte,
                float(requiredPayloadLengthExtraBytes) /
                defaults.networkDefaultPayloadLengthExtraBytes
            )

            powStartTime = time.time()
            initialHash = hashlib.sha512(encryptedPayload).digest()
            trialValue, nonce = proofofwork.run(target, initialHash)
            logger.info(
                '(For msg message) Found proof of work %s Nonce: %s',
                trialValue, nonce
            )
            try:
                logger.info(
                    'PoW took %.1f seconds, speed %s.',
                    time.time() - powStartTime,
                    sizeof_fmt(nonce / (time.time() - powStartTime))
                )
            except:
                pass

            encryptedPayload = pack('>Q', nonce) + encryptedPayload

            # Sanity check. The encryptedPayload size should never be
            # larger than 256 KiB. There should be checks elsewhere
            # in the code to not let the user try to send a message
            # this large until we implement message continuation.
            if len(encryptedPayload) > 2 ** 18:  # 256 KiB
                logger.critical(
                    'This msg object is too large to send. This should'
                    ' never happen. Object size: %i',
                    len(encryptedPayload)
                )
                continue

            inventoryHash = calculateInventoryHash(encryptedPayload)
            objectType = 2
            Inventory()[inventoryHash] = (
                objectType, toStreamNumber, encryptedPayload, embeddedTime, '')
            if BMConfigParser().has_section(toaddress) or \
                not protocol.checkBitfield(
                    behaviorBitfield, protocol.BITFIELD_DOESACK):
                queues.UISignalQueue.put((
                    'updateSentItemStatusByAckdata', (
                        ackdata,
                        tr._translate(
                            "MainWindow",
                            "Message sent. Sent at %1"
                        ).arg(l10n.formatTimestamp()))
                ))
            else:
                # not sending to a chan or one of my addresses
                queues.UISignalQueue.put((
                    'updateSentItemStatusByAckdata', (
                        ackdata,
                        tr._translate(
                            "MainWindow",
                            "Message sent. Waiting for acknowledgement."
                            " Sent on %1"
                        ).arg(l10n.formatTimestamp()))
                ))
            logger.info(
                'Broadcasting inv for my msg(within sendmsg function): %s',
                hexlify(inventoryHash)
            )
            queues.invQueue.put((toStreamNumber, inventoryHash))

            # Update the sent message in the sent table with the
            # necessary information.
            if BMConfigParser().has_section(toaddress) or \
                not protocol.checkBitfield(
                    behaviorBitfield, protocol.BITFIELD_DOESACK):
                newStatus = 'msgsentnoackexpected'
            else:
                newStatus = 'msgsent'
            # wait 10% past expiration
            sleepTill = int(time.time() + TTL * 1.1)
            sqlExecute(
                '''UPDATE sent SET msgid=?, status=?, retrynumber=?, '''
                ''' sleeptill=?, lastactiontime=? WHERE ackdata=?''',
                inventoryHash, newStatus, retryNumber + 1,
                sleepTill, int(time.time()), ackdata
            )

            # If we are sending to ourselves or a chan, let's put
            # the message in our own inbox.
            if BMConfigParser().has_section(toaddress):
                # Used to detect and ignore duplicate messages in our inbox
                sigHash = hashlib.sha512(hashlib.sha512(
                    signature).digest()).digest()[32:]
                t = (inventoryHash, toaddress, fromaddress, subject, int(
                    time.time()), message, 'inbox', encoding, 0, sigHash)
                helper_inbox.insert(t)

                queues.UISignalQueue.put(('displayNewInboxMessage', (
                    inventoryHash, toaddress, fromaddress, subject, message)))

                # 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"])

    def requestPubKey(self, toAddress):
        toStatus, addressVersionNumber, streamNumber, ripe = decodeAddress(
            toAddress)
        if toStatus != 'success':
            logger.error(
                'Very abnormal error occurred in requestPubKey.'
                ' toAddress is: %r. Please report this error to Atheros.',
                toAddress
            )
            return

        queryReturn = sqlQuery(
            '''SELECT retrynumber FROM sent WHERE toaddress=? '''
            ''' AND (status='doingpubkeypow' OR status='awaitingpubkey') '''
            ''' LIMIT 1''',
            toAddress
        )
        if len(queryReturn) == 0:
            logger.critical(
                'BUG: Why are we requesting the pubkey for %s'
                ' if there are no messages in the sent folder'
                ' to that address?', toAddress
            )
            return
        retryNumber = queryReturn[0][0]

        if addressVersionNumber <= 3:
            state.neededPubkeys[toAddress] = 0
        elif addressVersionNumber >= 4:
            # If the user just clicked 'send' then the tag
            # (and other information) will already be in the
            # neededPubkeys dictionary. But if we are recovering
            # from a restart of the client then we have to put it in now.

            # Note that this is the first half of the sha512 hash.
            privEncryptionKey = hashlib.sha512(hashlib.sha512(
                encodeVarint(addressVersionNumber) +
                encodeVarint(streamNumber) + ripe
            ).digest()).digest()[:32]
            # Note that this is the second half of the sha512 hash.
            tag = hashlib.sha512(hashlib.sha512(
                encodeVarint(addressVersionNumber) +
                encodeVarint(streamNumber) + ripe
            ).digest()).digest()[32:]
            if tag not in state.neededPubkeys:
                # We'll need this for when we receive a pubkey reply:
                # it will be encrypted and we'll need to decrypt it.
                state.neededPubkeys[tag] = (
                    toAddress,
                    highlevelcrypto.makeCryptor(hexlify(privEncryptionKey))
                )

        # 2.5 days. This was chosen fairly arbitrarily.
        TTL = 2.5 * 24 * 60 * 60
        TTL *= 2 ** retryNumber
        if TTL > 28 * 24 * 60 * 60:
            TTL = 28 * 24 * 60 * 60
        # add some randomness to the TTL
        TTL = TTL + helper_random.randomrandrange(-300, 300)
        embeddedTime = int(time.time() + TTL)
        payload = pack('>Q', embeddedTime)
        payload += '\x00\x00\x00\x00'  # object type: getpubkey
        payload += encodeVarint(addressVersionNumber)
        payload += encodeVarint(streamNumber)
        if addressVersionNumber <= 3:
            payload += ripe
            logger.info(
                'making request for pubkey with ripe: %s', hexlify(ripe))
        else:
            payload += tag
            logger.info(
                'making request for v4 pubkey with tag: %s', hexlify(tag))

        # print 'trial value', trialValue
        statusbar = 'Doing the computations necessary to request' +\
            ' the recipient\'s public key.'
        queues.UISignalQueue.put(('updateStatusBar', statusbar))
        queues.UISignalQueue.put((
            'updateSentItemStatusByToAddress', (
                toAddress,
                tr._translate(
                    "MainWindow",
                    "Doing work necessary to request encryption key."))
        ))

        payload = self._doPOWDefaults(payload, TTL)

        inventoryHash = calculateInventoryHash(payload)
        objectType = 1
        Inventory()[inventoryHash] = (
            objectType, streamNumber, payload, embeddedTime, '')
        logger.info('sending inv (for the getpubkey message)')
        queues.invQueue.put((streamNumber, inventoryHash))

        # wait 10% past expiration
        sleeptill = int(time.time() + TTL * 1.1)
        sqlExecute(
            '''UPDATE sent SET lastactiontime=?, '''
            ''' status='awaitingpubkey', retrynumber=?, sleeptill=? '''
            ''' WHERE toaddress=? AND (status='doingpubkeypow' OR '''
            ''' status='awaitingpubkey') ''',
            int(time.time()), retryNumber + 1, sleeptill, toAddress)

        queues.UISignalQueue.put((
            'updateStatusBar',
            tr._translate(
                "MainWindow",
                "Broadcasting the public key request. This program will"
                " auto-retry if they are offline.")
        ))
        queues.UISignalQueue.put((
            'updateSentItemStatusByToAddress', (
                toAddress,
                tr._translate(
                    "MainWindow",
                    "Sending public key request. Waiting for reply."
                    " Requested at %1"
                ).arg(l10n.formatTimestamp()))
        ))

    def generateFullAckMessage(self, ackdata, toStreamNumber, TTL):
        # It might be perfectly fine to just use the same TTL for
        # the ackdata that we use for the message. But I would rather
        # it be more difficult for attackers to associate ackData with
        # the associated msg object. However, users would want the TTL
        # of the acknowledgement to be about the same as they set
        # for the message itself. So let's set the TTL of the
        # acknowledgement to be in one of three 'buckets': 1 hour, 7
        # days, or 28 days, whichever is relatively close to what the
        # user specified.
        if TTL < 24 * 60 * 60:  # 1 day
            TTL = 24 * 60 * 60  # 1 day
        elif TTL < 7 * 24 * 60 * 60:  # 1 week
            TTL = 7 * 24 * 60 * 60  # 1 week
        else:
            TTL = 28 * 24 * 60 * 60  # 4 weeks
        # Add some randomness to the TTL
        TTL = int(TTL + helper_random.randomrandrange(-300, 300))
        embeddedTime = int(time.time() + TTL)

        # type/version/stream already included
        payload = pack('>Q', (embeddedTime)) + ackdata

        payload = self._doPOWDefaults(
            payload, TTL, log_prefix='(For ack message)', log_time=True)

        return protocol.CreatePacket('object', payload)