Exemplo n.º 1
0
    def createAtomicSwapTx(self, callback):
        fromAccount = Accounts.getAccountByAddress(self.fromAddress)
        toMultiSigAccount = Accounts.getAccountByAddress(self.toAddress)

        '''
            A picks a random number x
        '''
        hashPrivKey = Crypto.generateHash(toMultiSigAccount.private)

        '''
            A creates TX1: "Pay w BTC to <B's public key> if (x for H(x) known and signed by B) or (signed by A & B)"
        '''
        transactionA1 = MemoryPool.createUnconfirmedAtomicSwapTransaction(fromAccount, toMultiSigAccount.address, self.value, self.gasLimit, self.gasPrice, Script.verifyAtomicSwapSignature(), self.threshold)

        if transactionA1 != None:
            '''
                A creates TX2: "Pay w BTC from TX1 to <A's public key>, locked 48 hours in the future, signed by A"
            '''
            transactionA2 = MemoryPool.createUnconfirmedAtomicSwapTransaction(fromAccount, toMultiSigAccount.address, self.value, self.gasLimit, self.gasPrice, Script.verifyAtomicSwapLock())
            if transactionA2 != None:
                tx = transactionA1.serialize()
                unsignedTx = transactionA2.serialize()
                result = {
                    'tx': DataType.toHex(tx),
                    'unsignedTx': DataType.toHex(unsignedTx)
                }
                callback(
                    JSONRPC.createResultObject(result, self.id)
                )
            else:
                self.onFailure(callback)
        else:
            self.onFailure(callback)
Exemplo n.º 2
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 def verifyTxOutputDuplicateInPool(self, transaction):
     for txIn in transaction.inputs:
         outpoint = txIn.outpoint
         for txId in MemoryPool.getMemoryPool():
             tx = MemoryPool.getTransactionById(txId)
             for i in tx.inputs:
                 if outpoint == i.outpoint:
                     return False
     return True
Exemplo n.º 3
0
    def deploy(self, isLocal, callback):
        result = None
        fromAccount = Accounts.getAccountByAddress(self.fromAddress)
        if fromAccount != None:
            if isLocal:
                toAddress = Crypto.generateAddress(fromAccount.address)

                _script = bytearray()
                _script.append(Config.getIntValue("EXTENSION_SCRIPT_VERSION"))
                _script.extend(self.script)
                _script = DataType.serialize(_script)

                extraData = None
                if len(self.parameters) > 0:
                    extraData = self.parameters
                    extraData.append(fromAccount.address)

                output = Output(toAddress, _script, self.value, extraData)

                result = self.handleLocalScript(fromAccount, output, True)
                if result != None:
                    Contracts.addContract(Contract(toAddress), False)
            else:
                result = MemoryPool.addUnconfirmedTransaction(
                    fromAccount, None, self.value, self.gasLimit,
                    self.gasPrice, self.script, self.parameters)
                try:
                    result = DataType.toHex(result)
                except:
                    pass
        if result != None:
            callback(JSONRPC.createResultObject(result, self.id))
        else:
            self.onFailure(callback)
Exemplo n.º 4
0
 def call(self, isLocal, callback):
     result = None
     fromAccount = Accounts.getAccountByAddress(self.fromAddress)
     if fromAccount != None:
         if isLocal:
             _output = PersistentStorage.get(self.script, True)
             if _output == None:
                 unspentTransactionScript = UXTO.getUnspentTransactionScript(
                     self.script)
                 if unspentTransactionScript != None:
                     _output = unspentTransactionScript.output
             if _output != None:
                 result = self.handleLocalScript(fromAccount, _output,
                                                 False)
         else:
             result = MemoryPool.addUnconfirmedTransaction(
                 fromAccount, self.script, self.value, self.gasLimit,
                 self.gasPrice, None, self.parameters)
             try:
                 result = DataType.toHex(result)
             except:
                 pass
     if result != None:
         callback(JSONRPC.createResultObject(result, self.id))
     else:
         self.onFailure(callback)
Exemplo n.º 5
0
    def __init__(self):
        super().__init__()
        self.type = MessageType.GETDATA
        self.inventory = []

        self.chain = Chain.getChain()
        self.memoryPool = MemoryPool.getMemoryPool()
Exemplo n.º 6
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 def sendAtomicSwapTx(self, callback):
     transaction = None
     if MemoryPool.addSignedTransaction(transaction):
         callback(
             JSONRPC.createResultObject(result, self.id)
         )
     else:
         self.onFailure(callback)
Exemplo n.º 7
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 def addUnconfirmedMultiSigTransaction(self, callback=None):
     fromAccount = Accounts.getAccountByAddress(self.fromAddress)
     txId = None
     if fromAccount != None:
         txId = MemoryPool.addUnconfirmedMultiSigTransaction(
             fromAccount, self.publicKeys, self.signatures, self.toAddress,
             self.value, self.gasLimit, self.gasPrice, self.threshold)
     if txId != None:
         callback(JSONRPC.createResultObject(DataType.toHex(txId), self.id))
     else:
         self.onFailure(callback)
Exemplo n.º 8
0
 def signAtomicSwapTx(self, callback):
     transaction = Transaction()
     transaction.deserialize(self.unsignedTx)
     transaction.sign()
     if MemoryPool.addSignedTransaction(transaction):
         txId = transaction.hash()
         callback(
             JSONRPC.createResultObject(DataType.toHex(txId), self.id)
         )
     else:
         self.onFailure(callback)
Exemplo n.º 9
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 def onSuccess(self, callback=None):
     message = MessageFactory.getInstance(MessageType.GETDATA)
     message.addrRecv = self.addrFrom
     for inventory in self.inventory:
         if inventory.invType == InventoryType.BLOCK:
             if self.chain.getBlockByHash(inventory.getInvHash()) == None:
                 message.inventory.append(inventory)
         elif inventory.invType == InventoryType.TRANSACTION:
             if MemoryPool.getTransactionById(
                     inventory.getInvHash()) == None:
                 message.inventory.append(inventory)
     if len(message.inventory) > 0:
         message.send()
Exemplo n.º 10
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    def getNewBlock(self, address, previousHash, bits, extraNonce):
        previousIndexBlock = self.getIndexBlockByHash(previousHash)
        block = Block()

        gasLimit = Config.getIntValue("BLOCK_REWARDS_GAS_LIMIT")
        gasPrice = Config.getIntValue("BLOCK_REWARDS_GAS_PRICE")
        transaction = Transaction(gasLimit, gasPrice)

        height = previousIndexBlock.height + 1
        coinbaseData = [
            DataType.asString(height), 
            DataType.asString(bits), 
            DataType.asString(extraNonce)
        ]
        transaction.addCoinbaseInput(coinbaseData)
        block.transactions.append(transaction) 
        txFees = 0
        totalTxGasUsed = 0
        unconfirmedTransactions = MemoryPool.getMemoryPool()
        for txId in unconfirmedTransactions:
            unconfirmedTransaction = unconfirmedTransactions[txId]
            block.transactions.append(unconfirmedTransaction)  
            txFees += unconfirmedTransaction.calculateTxFee()
            totalTxGasUsed += unconfirmedTransaction.calculateTxGasUsed()
        blockRewards = Config.getDecimalValue("BLOCK_REWARDS")
        blockRewards = Units.toUnits(blockRewards)
        coinbaseValue = blockRewards + txFees
        script = Script.verifySignature()

        transaction.addOutput(address, script, coinbaseValue)
        transaction.hash()

        #Include coinbase tx gas used
        totalTxGasUsed += transaction.calculateTxGasUsed()

        block.merkleRoot = MerkleTree.getMerkleRoot(block.transactions, False)
        block.witnessRoot = MerkleTree.getMerkleRoot(block.transactions, True)

        blockGasLimit = previousIndexBlock.gasLimit + (previousIndexBlock.gasLimit * (1 / 1024))
        blockGasLimit = math.ceil(blockGasLimit)

        block.gasLimit = blockGasLimit
        block.gasUsed = totalTxGasUsed
        block.nonce = 0
        block.bits = bits
        block.previousHash = previousHash
        return block
Exemplo n.º 11
0
 def signMultiSigOutput(self, callback=None):
     signatures = []
     multiSigAccount = Accounts.getAccountByAddress(self.fromAddress)
     if multiSigAccount != None:
         transaction = MemoryPool.createUnconfirmedMultiSigTransaction(
             multiSigAccount, self.toAddress, self.value, self.gasLimit,
             self.gasPrice, self.threshold)
         if transaction != None:
             for txIn in transaction.inputs:
                 multiSigAddress = DataType.toHex(multiSigAccount.address)
                 _publicKeys = txIn.witness[::2]
                 _signatures = txIn.witness[1::2]
                 for publicKey, signature in zip(_publicKeys, _signatures):
                     publicKey = DataType.toHex(publicKey)
                     signature = DataType.toHex(signature)
                     signatures.append({
                         'address': multiSigAddress,
                         'public': publicKey,
                         'signature': signature
                     })
     callback(JSONRPC.createResultObject(signatures, self.id))
Exemplo n.º 12
0
    def __init__(self):
        super().__init__()
        self.type = MessageType.MEMPOOL

        self.memoryPool = MemoryPool.getMemoryPool()
Exemplo n.º 13
0
 def onSuccess(self, callback=None):
     transaction = Transaction()
     transaction.deserialize(self.transaction)
     if not MemoryPool.addSignedTransaction(transaction):
         self.onFailure(callback)
Exemplo n.º 14
0
    def addBlock(self, block):
        if self.blkValidator.validate(block):
            try:
                self.acquireBlockLock()
            
                blockHash = block.hash()
                blockHashBytes = DataType.serialize(blockHash)
                
                if self.index.get(blockHashBytes) == None:
                    if not OrphanManager.hasBlock(blockHash):
                        bits = block.bits
                        previousChainWork = None
                        previousHash = block.previousHash
                        blockGasLimit = block.gasLimit
                        blockHeight = 0
                        
                        chainHeadBlock = self.getChainHeadBlock()
                        chainHeadIndexBlock = self.getIndexBlockByHash(self.CHAIN_HEAD_INDEX)
                        previousIndexBlock = self.getIndexBlockByHash(previousHash)
                        
                        if chainHeadIndexBlock == None:
                            chainHeadIndexBlock = IndexBlock()
                        if previousIndexBlock != None:
                            blockHeight = previousIndexBlock.height + 1
                            previousChainWork = previousIndexBlock.chainWork
                            
                        if blockHash == Config.getBytesValue('GENESIS_BLOCK_HASH'):
                            previousChainWork = Config.getIntValue('GENESIS_BLOCK_CHAIN_WORK', 16)
                        
                        '''        
                            For case 1, adding to main branch:
                        '''
                        if previousHash == chainHeadIndexBlock.previousHash or blockHash == Config.getBytesValue('GENESIS_BLOCK_HASH'):                
                            '''
                                For all but the coinbase transaction, apply the following:
                            '''
                            if not self.blkValidator.verifyNonCoinbaseTransactions(block):
                                return False
                                 
                            '''
                                Reject if coinbase value > sum of block creation fee and transaction fees
                            '''   
                            if not self.blkValidator.verifyCoinbaseValue(block):
                                return False
                                    
                            for transaction in block.transactions:
                                for txIn in transaction.inputs:
                                    UXTO.removeUnspentTransactionCoin(txIn.outpoint)
                                uxtoOutputs = []
                                uxtoOutputs.extend(transaction.outputs)
                                uxtoOutputs.extend(transaction.internalOutputs)
                                txOutputSize = 0
                                for txOut in uxtoOutputs:
                                    if txOut.store:
                                        txOutputSize += 1
                                outputIndex = 0
                                for txOut in uxtoOutputs:
                                    UXTO.removeStaleUnspentTransactionScript(txOut)
                                    if txOut.store:
                                        coin = Coin()
                                        coin.output = txOut
                                        coin.txOutputSize = txOutputSize
                                        coin.height = blockHeight
                                        coin.coinbase = transaction.isCoinbase()
                                        UXTO.addUnspentTransactionCoin(Outpoint(transaction.hash(), outputIndex), coin)
                                        outputIndex += 1
                                        '''
                                            For each transaction, "Add to wallet if mine"
                                        '''

                                '''
                                    For each transaction in the block, delete any matching transaction from the transaction pool
                                '''
                                MemoryPool.removeTransaction(transaction)
                                
                            chainHeadIndexBlock.chainWork = Bits.getChainworkFromBits(previousChainWork, bits)
                            chainHeadIndexBlock.previousHash = blockHash
                            chainHeadIndexBlock.gasLimit = blockGasLimit
                            chainHeadIndexBlock.height = blockHeight
                            self.index.set(self.CHAIN_HEAD_INDEX, chainHeadIndexBlock.serialize())
                        else:
                            blockChainWork = Bits.getChainworkFromBits(previousChainWork, bits)
                            chainHeadWork = chainHeadIndexBlock.chainWork
                            
                            hasNewMainChain = blockChainWork > chainHeadWork
                            
                            if hasNewMainChain:
                                '''
                                    For case 3, a side branch becoming the main branch:
                                '''
                            else:
                                '''
                                    For case 2, adding to a side branch, we don't do anything.
                                '''
                
                            if hasNewMainChain:
                                '''
                                    Find the fork block on the main branch which this side branch forks off of
                                '''
                                forkBlockHash = self.searchForkBlockHash(previousIndexBlock, chainHeadIndexBlock)
                                
                                '''
                                    Redefine the main branch to only go up to this fork block
                                    
                                    We will set new main chain head below
                                '''
                                
                                isNewMainChainValid = True
                                
                                '''
                                    For each block on the side branch, from the child of the fork block to the leaf, add to the main branch:
                                '''
                                prevBlock = self.getBlockByHash(block.previousHash)
                                while prevBlock.hash() != forkBlockHash:
                                    '''
                                        Do "branch" checks 3-11
                                    '''
                                    '''
                                        3) Transaction list must be non-empty
                                    '''
                                    if not self.blkValidator.verifyTransactionsNonEmpty(prevBlock):
                                        isNewMainChainValid = False
                                    
                                    '''
                                        4) Block hash must satisfy claimed nBits proof of work
                                    '''
                                    if not self.blkValidator.validateBlockBits(prevBlock.serializeHeader(), prevBlock.bits):
                                        isNewMainChainValid = False
                                    
                                    '''
                                        5) Block timestamp must not be more than two hours in the future
                                    '''
                                    if not self.blkValidator.verifyFutureTimestamp(prevBlock):
                                        isNewMainChainValid = False
                                        
                                    '''
                                        6) First transaction must be coinbase (i.e. only 1 input, with hash=0, n=-1), the rest must not be
                                    '''
                                    if not self.blkValidator.verifyInitialCoinbaseTransaction(prevBlock):
                                        isNewMainChainValid = False
                                        
                                    '''
                                        7) For each transaction, apply "tx" checks 2-4
                                            2) Make sure neither in or out lists are empty
                                            3) Size in bytes <= TRANSACTION_SIZE_LIMIT
                                            4) Each output value, as well as the total, must be in legal money range
                                    '''
                                    for transaction in prevBlock.transactions:
                                        if not self.txValidator.verifyInputOutputNonEmpty(transaction):
                                            isNewMainChainValid = False
                                        if not self.txValidator.verifyTransactionSizeLimit(transaction):
                                            isNewMainChainValid = False
                                        if not self.txValidator.verifyAllowedOutputValueRange(transaction):
                                            isNewMainChainValid = False
                                        
                                        '''
                                            8) For the coinbase (first) transaction, scriptSig length must be 2-100
                                        '''
                                        if not self.blkValidator.verifyCoinbaseWitnessLength(transaction):
                                            isNewMainChainValid = False
                                        
                                        '''
                                            9) Reject if sum of transaction sig opcounts > MAX_BLOCK_SIGOPS
                                        '''
                                        if not self.blkValidator.verifyMaxBlockSigOps(transaction):
                                            isNewMainChainValid = False
                                        
                                    '''
                                        10) Verify Merkle hash
                                    '''
                                    if not self.blkValidator.verifyMerkleHash(prevBlock):
                                        isNewMainChainValid = False
                                        
                                    '''
                                        Verify Witness hash
                                    '''
                                    if not self.blkValidator.verifyWitnessHash(prevBlock):
                                        isNewMainChainValid = False
                                        
                                    '''
                                        11) Check if prev block (matching prev hash) is in main branch or side branches. If not, add this to orphan blocks, 
                                        then query peer we got this from for 1st missing orphan block in prev chain; done with block
                                    '''
                                    if blockHash != Config.getBytesValue('GENESIS_BLOCK_HASH') and self.getBlockByHash(prevBlock.previousHash) == None:
                                        OrphanManager.addBlock(prevBlock)
                                        isNewMainChainValid = False
                                
                                    '''
                                        For all but the coinbase transaction, apply the following:
                                    '''
                                    if not self.blkValidator.verifyNonCoinbaseTransactions(prevBlock):
                                        isNewMainChainValid = False
                                    
                                    '''
                                        Reject if coinbase value > sum of block creation fee and transaction fees
                                    '''   
                                    if not self.blkValidator.verifyCoinbaseValue(prevBlock):
                                        isNewMainChainValid = False
                                    
                                    '''
                                        (If we have not rejected):
                                    '''
                                    if not isNewMainChainValid:
                                        break
                                    
                                    '''         
                                        For each transaction, "Add to wallet if mine"
                                    '''
                                        
                                    prevBlock = self.getBlockByHash(prevBlock.previousHash)
                                
                                '''
                                    If we reject at any point, leave the main branch as what it was originally, done with block
                                '''
                                if isNewMainChainValid:
                                    chainHeadIndexBlock.chainWork = blockChainWork
                                    chainHeadIndexBlock.previousHash = blockHash 
                                    chainHeadIndexBlock.gasLimit = blockGasLimit
                                    chainHeadIndexBlock.height = blockHeight
                                    self.index.set(self.CHAIN_HEAD_INDEX, chainHeadIndexBlock.serialize())
                                    
                                    '''
                                        For each block in the old main branch, from the leaf down to the child of the fork block:
                                    '''
                                    oldBlock = chainHeadBlock
                                    while oldBlock.hash() != forkBlockHash:
                                        '''
                                            For each non-coinbase transaction in the block:
                                        '''
                                        for transaction in oldBlock.transactions:
                                            if not transaction.isCoinbase():
                                                '''
                                                    Apply "tx" checks 2-9
                                                '''
                                                isTxValid = True
                                                
                                                '''
                                                    2) Make sure neither in or out lists are empty
                                                '''
                                                if not self.txValidator.verifyInputOutputNonEmpty(transaction):
                                                    isTxValid = False
                                                
                                                '''
                                                    3) Size in bytes <= TRANSACTION_SIZE_LIMIT
                                                '''
                                                if not self.txValidator.verifyTransactionSizeLimit(transaction):
                                                    isTxValid = False
                                                
                                                '''
                                                    4) Each output value, as well as the total, must be in legal money range
                                                '''
                                                if not self.txValidator.verifyAllowedOutputValueRange(transaction):
                                                    isTxValid = False
                                                
                                                '''
                                                    5) Make sure none of the inputs have hash=0, n=-1 (coinbase transactions)
                                                '''
                                                if not self.txValidator.verifyInputsNonCoinbase(transaction):
                                                    isTxValid = False
                                                
                                                '''
                                                    6) size in bytes >= 100[2]
                                                '''
                                                if not self.txValidator.verifyTransactionRequiredSize(transaction):
                                                    isTxValid = False
                                                
                                                '''
                                                    sig opcount <= 2[3]
                                                    3) The number of signature operands in the signature (no, that is not redundant) for standard transactions will never exceed two
                                                    7) Reject "nonstandard" transactions: scriptSig doing anything other than pushing numbers on the stack, 
                                                    or script not matching the two usual forms[4]
                                                '''
                                                if not self.txValidator.verifyAddress(transaction):
                                                    isTxValid = False
                                                if not self.txValidator.verifyExtraData(transaction):
                                                    isTxValid = False
                                                if not self.txValidator.verifyScript(transaction):
                                                    isTxValid = False
                                                if not self.txValidator.verifyWitness(transaction):
                                                    isTxValid = False
                                                
                                                '''
                                                    8) Reject if we already have matching tx in the pool,
                                                    except in step 8, only look in the transaction pool for duplicates, not the main branch
                                                '''
                                                if not self.txValidator.verifyTransactionDuplicateInPool(transaction):
                                                    isTxValid = False
                                                
                                                '''
                                                    9) For each input, if the referenced output exists in any other tx in the pool, reject this transaction
                                                '''
                                                if not self.txValidator.verifyTxOutputDuplicateInPool(transaction):
                                                    isTxValid = False
                                                
                                                '''
                                                    Add to transaction pool if accepted, else go on to next transaction
                                                '''
                                                if isTxValid:
                                                    MemoryPool.addSignedTransaction(transaction)

                                            outputIndex = 0
                                            for txOut in transaction.outputs:
                                                UXTO.removeUnspentTransactionCoin(Outpoint(transaction.hash(), outputIndex))
                                                outputIndex += 1

                                        oldBlock = self.getBlockByHash(oldBlock.previousHash)
                                    
                                    '''
                                        For each block in the new main branch, from the child of the fork node to the leaf:
                                    '''
                                    newMainBranchBlocks = []
                                        
                                    prevBlock = block
                                    while prevBlock.hash() != forkBlockHash:
                                        newMainBranchBlocks.insert(0, prevBlock)
                                        prevBlock = self.getBlockByHash(prevBlock.previousHash)
                                        
                                    for newMainBranchBlock in newMainBranchBlocks:
                                        newMainBranchBlockHash = newMainBranchBlock.hash()
                                        newMainBranchIndexBlock = None
                                        if newMainBranchBlockHash == blockHash:
                                            newMainBranchIndexBlock = chainHeadIndexBlock
                                        else:
                                            newMainBranchIndexBlock = self.getIndexBlockByHash(newMainBranchBlockHash)
                                        for transaction in newMainBranchBlock.transactions:
                                            for txIn in transaction.inputs:
                                                UXTO.removeUnspentTransactionCoin(txIn.outpoint)
                                            uxtoOutputs = []
                                            uxtoOutputs.extend(transaction.outputs)
                                            uxtoOutputs.extend(transaction.internalOutputs)
                                            txOutputSize = 0
                                            for txOut in uxtoOutputs:
                                                if txOut.store:
                                                    txOutputSize += 1
                                            outputIndex = 0
                                            for txOut in uxtoOutputs:
                                                UXTO.removeStaleUnspentTransactionScript(txOut)
                                                if txOut.store:
                                                    coin = Coin()
                                                    coin.output = txOut
                                                    coin.txOutputSize = txOutputSize
                                                    coin.height = newMainBranchIndexBlock.height
                                                    coin.coinbase = transaction.isCoinbase()
                                                    UXTO.addUnspentTransactionCoin(Outpoint(transaction.hash(), outputIndex), coin)
                                                    outputIndex += 1
                                                    '''
                                                        For each transaction, "Add to wallet if mine"
                                                    '''

                                            '''
                                                For each transaction in the block, delete any matching transaction from the transaction pool
                                            '''
                                            MemoryPool.removeTransaction(transaction)
                        '''
                            (If we have not rejected):
                        '''
                        self.storage.set(blockHashBytes, block.serialize())

                        blockHeightKey = "{0}{1}{2}".format(self.BLOCK_HEIGHT_KEY, '_', blockHeight)
                        blockHeightKey = DataType.serialize(blockHeightKey)
                        self.index.set(blockHeightKey, blockHashBytes)
                        
                        indexBlock = IndexBlock()
                        indexBlock.chainWork = Bits.getChainworkFromBits(previousChainWork, bits)
                        indexBlock.previousHash = previousHash 
                        indexBlock.gasLimit = blockGasLimit
                        indexBlock.height = blockHeight
                        self.index.set(blockHashBytes, indexBlock.serialize())
        
                        '''
                            Relay block to our peers
                        '''
                        Sync.inv(InventoryType.BLOCK, blockHash)
                    
                    '''
                        For each orphan block for which this block is its prev, run all these steps (including this one) recursively on that orphan
                    '''
                    self.syncOrphanBlocks()
                    
                    return True
            finally:
                self.releaseBlockLock()
        '''
            For each orphan block for which this block is its prev, run all these steps (including this one) recursively on that orphan
        '''
        self.syncOrphanBlocks()
            
        '''     
            If we rejected, the block is not counted as part of the main branch
        '''
        return False
Exemplo n.º 15
0
 def verifyTransactionDuplicateInPool(self, transaction):
     txId = transaction.hash()
     if txId in MemoryPool.getMemoryPool():
         return False
     return True
Exemplo n.º 16
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    def validate(self, transaction):
        if transaction == None:
            return False
        '''
            The transaction’s syntax and data structure must be correct
        '''
        if transaction.version == None or transaction.version != Config.getIntValue(
                'TRANSACTION_VERSION'):
            return False

        if not self.verifyInputOutputNonEmpty(transaction):
            return False

        for txIn in transaction.inputs:
            '''
                Check outpoint
            '''
            if txIn.outpoint == None:
                return False
            outpoint = txIn.outpoint
            if outpoint.txId == None or len(
                    outpoint.txId) != Config.getIntValue('HASH_LEN'):
                return False
            if outpoint.outputIndex == None or outpoint.outputIndex < 0:
                return False
        '''
            Check Output Value
        '''
        for txOut in transaction.outputs:
            if txOut.value == None:
                return False
            if txOut.hasExtScript():
                if not txOut.value >= 0:
                    return False
            elif not txOut.value > 0:
                return False
        '''
            Check tx gas price and gas limit
        '''
        if transaction.gasPrice == None or transaction.gasPrice < 0:
            return False
        if transaction.gasLimit == None or transaction.gasLimit < 0:
            return False
        '''
            Internal Outputs are created from the result of a smart contract.
            Only the RVM should create them.
        '''
        if len(transaction.internalOutputs) > 0:
            return False

        if not self.verifyAddress(transaction):
            return False

        if not self.verifyExtraData(transaction):
            return False

        if not self.verifyScript(transaction):
            return False

        if not self.verifyWitness(transaction):
            return False

        if not self.verifyTransactionSizeLimit(transaction):
            return False
        '''
           Check for duplicate outpoints. 
        '''
        outpoints = set()
        for txIn in transaction.inputs:
            if txIn.outpoint in outpoints:
                return False
            outpoints.add(txIn.outpoint)

        if not self.verifyAllowedOutputValueRange(transaction):
            return False

        if not self.verifyInputsNonCoinbase(transaction):
            return False

        if not self.verifyTransactionRequiredSize(transaction):
            return False

        if not self.verifyTransactionDuplicateInPool(transaction):
            return False
        '''
            or txId in a block in the main branch
        '''
        txId = transaction.hash()
        try:
            UXTOStorage.uxto.open()
            with UXTOStorage.uxto.db.begin() as uxto:
                cursor = uxto.cursor(db=UXTOStorage.uxto.subDb)
                while cursor.next():
                    outpointBytes = cursor.key()
                    outpoint = Outpoint()
                    outpoint.deserialize(outpointBytes)
                    if txId == outpoint.txId:
                        return False
        except IOError:
            Log.error(
                'Unable to determine if txId is in a block in the main branch.'
            )
        finally:
            UXTOStorage.uxto.close()

        if not self.verifyTxOutputDuplicateInPool(transaction):
            return False
        '''
            For each input, look in the main branch and the transaction pool to find the referenced output transaction. 
            If the output transaction is missing for any input, this will be an orphan transaction. Add to the orphan transactions, 
            if a matching transaction is not in there already.
        '''
        for txIn in transaction.inputs:
            outpoint = txIn.outpoint
            if not UXTO.hasUnspentTransactionCoin(outpoint):
                tx = MemoryPool.getTransactionById(outpoint.txId)
                if tx == None or len(tx.outputs) - 1 < outpoint.outputIndex:
                    OrphanManager.addTransaction(transaction)
                    return False

        if not self.verifyCoinbaseMaturity(transaction):
            return False

        if not self.verifyUxtoReferencedOutput(transaction):
            return False

        if not self.verifyAllowedInputValueRange(transaction):
            return False

        if not self.verifySumInputOutputValues(transaction):
            return False

        if not self.verifyUnlockingScripts(transaction):
            return False
        '''
            7) Note that when the transaction is accepted into the memory pool, an additional check is made to ensure that the coinbase value does not exceed 
            the transaction fees plus the expected BTC value (25BTC as of this writing).
        '''
        if transaction.isCoinbase():
            txOut = transaction.outputs
            blockRewards = Config.getDecimalValue("BLOCK_REWARDS")
            blockRewards = Units.toUnits(blockRewards)
            if txOut.value > blockRewards:
                return False

        return True