Question

我正在研究区块链脚本。它可以运行，但是我遇到了正在打印的密钥的问题，有时它们似乎正在重用先前代码块中的密钥，而不是指“ prevhash”

代码：

import hashlib
import json

class Block():
    def __init__(self, nonce, tstamp, transaction, prevhash=""):
        self.nonce = nonce
        self.tstamp = tstamp
        self.transaction = transaction
        self.prevhash = prevhash
        self.hash = self.calcHash()

    def calcHash(self):
        block_string = json.dumps({
                                    "nonce":self.nonce,
                                    "tstamp":self.tstamp,
                                    "transaction":self.transaction,
                                    "prevhash":self.prevhash
                                    },sort_keys=True).encode

        # hashId = hashlib.sha256(block_string).hexdigest()

        hashId = hashlib.sha256()

        hashId.update(repr(block_string).encode('utf-8'))
        hashId = hashId.hexdigest()

        return hashId

    def __str__(self):
        string = "nonce: " + str(self.nonce) + "\n"
        # string += "tstamp: " + str(self.tstamp) + "\n"
        # string += "transaction: " + str(self.transaction) + "\n"
        string += "phash: " + str(self.prevhash) + "\n"
        string += "chash: " + str(self.hash)

        return string

    def printHashes(self):
        print("phash: ",self.prevhash)
        print("chash: ",self.hash)


class Blockchain():
    def __init__(self):
        self.chain = [self.generateGenesisBlock(),]

    def generateGenesisBlock(self):
        return Block(0, '01/01/2018', '1000000')

    def getLastBlock(self):
        return self.chain[-1]

    def addBlock(self, newBlock):
        newBlock.prevhash = self.getLastBlock().hash
        newBlock.hash = newBlock.calcHash()
        self.chain.append(newBlock)

    def isChainValid(self):
        for i in range(1,len(self.chain)):
            prevBlock = self.chain[i-1]
            currentBlock = self.chain[i]

            if(currentBlock.hash != currentBlock.calcHash()):
                return False

            if(currentBlock.prevhash != prevBlock.hash):
                return False

        return True


BCoin = Blockchain()

BCoin.addBlock(Block(1, '01/02/2018', 100))
BCoin.addBlock(Block(2, '01/14/2018', 200))
BCoin.addBlock(Block(3, '01/15/2018', 15))
BCoin.addBlock(Block(4, '01/16/2018', 324))
BCoin.addBlock(Block(5, '01/02/2018', 100))
BCoin.addBlock(Block(6, '01/14/2018', 200))
BCoin.addBlock(Block(7, '01/15/2018', 15))
BCoin.addBlock(Block(8, '01/16/2018', 324))
BCoin.addBlock(Block(9, '01/02/2018', 100))
BCoin.addBlock(Block(10, '01/14/2018', 200))



for block in BCoin.chain:
    print(block)

# print(BCoin.isChainValid())

输出：

phash: 
chash: 19b00835428d29d63f2229933bf7067e7cec2057c19a90a51f22401c6571fd24

phash: 19b00835428d29d63f2229933bf7067e7cec2057c19a90a51f22401c6571fd24
chash: 687f54d1fbaabb7d43a009e87a9da34cd550a7e1a1c6499fb35a790bfbfd2bc4

phash: 687f54d1fbaabb7d43a009e87a9da34cd550a7e1a1c6499fb35a790bfbfd2bc4
chash: 687f54d1fbaabb7d43a009e87a9da34cd550a7e1a1c6499fb35a790bfbfd2bc4

phash: 687f54d1fbaabb7d43a009e87a9da34cd550a7e1a1c6499fb35a790bfbfd2bc4
chash: 6788d68d048817fd40a2c01e7f80a26efd23a3ae1f6fcb5fce87ae07f26cc18c

phash: 6788d68d048817fd40a2c01e7f80a26efd23a3ae1f6fcb5fce87ae07f26cc18c
chash: 687f54d1fbaabb7d43a009e87a9da34cd550a7e1a1c6499fb35a790bfbfd2bc4

注意重用先前区块（1,2，＆4）中的（chash）键

部分问题与hashlib.sha256函数有关。原始代码给了我一个错误，替换代码应该解决了这个错误，但确实如此，但是后来我遇到了这个重新哈希问题。

        # hashId = hashlib.sha256(block_string).hexdigest()

        hashId = hashlib.sha256()

        hashId.update(repr(block_string).encode('utf-8'))
        hashId = hashId.hexdigest()

有人对导致这种情况的原因有任何想法吗？

Hashlib.sha256问题具有重复的哈希输出

0 个答案: