计算块的 Merkle 根的代码

Posted 2023-03-29

【中文标题】计算块的 Merkle 根的代码

【英文标题】：code to compute the Merkle root for the block

【发布时间】：2020-08-27 12:38:15

【问题描述】：

我想使用下面的代码来计算块的 Merkle 根。详细链接是here 这是block，我想使用给定的代码生成其 Merkle 根。

我有这个错误：

*

文件“merkle.py”，第 126 行，在 print(merkle(txHashes)) 中

文件“merkle.py”，第 10 行，在 merkle newHashList.append(hash2(hashList[i], hashList[i+1])) 文件“merkle.py”，第 18 行，在 hash2 a1 = a.decode('hex')[::-1]

AttributeError: 'str' 对象没有属性 'decode'

*

当我尝试在 python 3.8.2 中执行此代码时：

import hashlib

# Hash pairs of items recursively until a single value is obtained
def merkle(hashList):
    if len(hashList) == 1:
        return hashList[0]
    newHashList = []
    # Process pairs. For odd length, the last is skipped
    for i in range(0, len(hashList)-1, 2):
        newHashList.append(hash2(hashList[i], hashList[i+1]))
    if len(hashList) % 2 == 1: # odd, hash last item twice
        newHashList.append(hash2(hashList[-1], hashList[-1]))
    return merkle(newHashList)

def hash2(a, b):
    # Reverse inputs before and after hashing
    # due to big-endian / little-endian nonsense
    a1 = a.decode('hex')[::-1]
    b1 = b.decode('hex')[::-1]
    h = hashlib.sha256(hashlib.sha256(a1+b1).digest()).digest()
    return h[::-1].encode('hex')

# https://blockexplorer.com/rawblock/0000000000000000e067a478024addfecdc93628978aa52d91fabd4292982a50
txHashes = [
  "00baf6626abc2df808da36a518c69f09b0d2ed0a79421ccfde4f559d2e42128b",
  "91c5e9f288437262f218c60f986e8bc10fb35ab3b9f6de477ff0eb554da89dea",
  "46685c94b82b84fa05b6a0f36de6ff46475520113d5cb8c6fb060e043a0dbc5c",
  "ba7ed2544c78ad793ef5bb0ebe0b1c62e8eb9404691165ffcb08662d1733d7a8",
  "b8dc1b7b7ed847c3595e7b02dbd7372aa221756b718c5f2943c75654faf48589",
  "25074ef168a061fcc8663b4554a31b617683abc33b72d2e2834f9329c93f8214",
  "0fb8e311bffffadc6dc4928d7da9e142951d3ba726c8bde2cf1489b62fb9ebc5",
  "c67c79204e681c8bb453195db8ca7d61d4692f0098514ca198ccfd1b59dbcee3",
  "bd27570a6cbd8ad026bfdb8909fdae9321788f0643dea195f39cd84a60a1901b",
  "41a06e53ffc5108358ddcec05b029763d714ae9f33c5403735e8dee78027fe74",
  "cc2696b44cb07612c316f24c07092956f7d8b6e0d48f758572e0d611d1da6fb9",
  "8fc508772c60ace7bfeb3f5f3a507659285ea6f351ac0474a0a9710c7673d4fd",
  "62fed508c095446d971580099f976428fc069f32e966a40a991953b798b28684",
  "928eadbc39196b95147416eedf6f635dcff818916da65419904df8fde977d5db",
  "b137e685df7c1dffe031fb966a0923bb5d0e56f381e730bc01c6d5244cfe47c1",
  "b92207cee1f9e0bfbd797b05a738fab9de9c799b74f54f6b922f20bd5ec23dd6",
  "29d6f37ada0481375b6903c6480a81f8deaf2dcdba03411ed9e8d3e5684d02dd",
  "48158deb116e4fd0429fbbbae61e8e68cb6d0e0c4465ff9a6a990037f88c489c",
  "be64ea86960864cc0a0236bbb11f232faf5b19ae6e2c85518628f5fae37ec1ca",
  "081363552e9fff7461f1fc6663e1abd0fb2dd1c54931e177479a18c4c26260e8",
  "eb87c25dd2b2537b1ff3dbabc420e422e2a801f1bededa6fa49ef7980feaef70",
  "339e16fcc11deb61ccb548239270af43f5ad34c321416bada4b8d66467b1c697",
  "4ad6417a3a04179482ed2e4b7251c396e38841c6fba8d2ce9543337ab7c93c02",
  "c28a45cded020bf424b400ffc9cb6f2f85601934f18c34a4f78283247192056a",
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  "104643385619adb848593eb668a8066d1f32650edf35e74b0fc3306cb6719448",
  "87ac990808239c768182a752f4f71cd98558397072883c7e137efb49d22b9231",
  "9b3e2f1c47d59a444e9b6dc725f0ac6baf160d22f3a9d399434e5e65b14eccb0",
  "fbe123066ae5add633a542f151663db4eb5a7053e388faadb40240671ae1b09b",
  "1dd07e92e20b3cb9208af040031f7cfc4efd46cc31ec27be20a1047965a42849",
  "2709bb9ed27353c1fd76b9240cab7576a44de68945e256ad44b2cb8d849a8060",
  "d0174db2c712573432a7869c1508f371f3a1058aeedddc1b53a7e04d7c56c725",
  "b4a16f724cddb8f77ddf3d2146a12c4be13d503885eaba3518a03da005009f62",
  "2aa706d75decbe57745e01d46f9f5d30a08dedaf3288cee14cc4948e3684e1d4",
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  "f1e88ffc2b1de2aa4827002f06943ce5468735f7433f960bf01e75885b9f832b",
  "19247d017e002fb9143d1a89eb921222a94f8a3d0faaf2e05b0f594989edc4c4",
  "13f714ff62ee7d26b6d69ca980c141ebc54e9f71d2697083fe6c5efc1b02bd0f",
  "0c78cbb8246572f015fbdc53dc9798fa54d1119ec77c1f07ac310bcbcc40dbf8",
  "4bcde0ef92a6d24a2be7be50ac5e5299d776df2e6229ba5d475c2491da94f255",
  "0cfd7d1058502730cf0b2ffa880c78ef534651e06832b5d87c0d7eb84eac5b0c",
  "3a168f794d6e0c614429ad874317cc4cd67a8177214880ff6ea1704d29228c2f",
  "f9a555d817334397b402518d6fd959dc73d981ee7f5fe67969b63974ebbef127",
  "24b52691f66eaed4ce391a473902e309018257c98b9f02aaa33b399c9e6f3168",
  "a37b5e623dc26a180d9e2c9510d06885b014e86e533adb63ec40511e10b55046",
  "9dbaeb485e51d9e25a5621dc46e0bc0aaf51fb26be5acc4e370b96f62c469b80",
  "a6431d3d39f6c38c5df48405090752cab03bfdf5c77cf881b18a946807fba74a",
  "faa77e309f125373acf19855dd496fffe2f74962e545420844557a3adc7ebc11",
  "3523f52543ecfea2f78486dc91550fad0e6467d46d9d9c82ca63b2e0230bfa71",
  "a0583e358e42d77d18d1fd0533ff0a65615fc3b3112061ef92f168a00bf640c1",
  "42ae900888d5e5dde59c8e3d06e13db9e84ef05d27726d4b67fd00c50cd9406a",
  "154940777d3ff78f592ef02790131a59263c36b4958bbc836f9a767ea1a9f178",
  "6a0337de6ac75eecf748306e8ebc5bfe5c811a1481ae50f6956a9e7f26a679f5",
  "c99530c2148e09688d0b88795625943371183bf1f5d56c7446c6ed51ea133589",
  "626421dbe8ad6a0fd0d622d5dd3308a1cdc00b98575a41a91fe01a439e6f40bd",
  "b2f3a559f605a158cc395126c3cf394a7e92a53b7514c75157e1dc43a6c7f93e",
  "dffe06d1bea81f2a01c76786404bb867258f9e68013bf25454097ce935090738",
  "0860159ec7a2a51ce107c182a988c40b4bc2057a734354a1219b6c65e72640ed",
  "a405ff1bb51846b1867acc0b0da17f6f9616e592a0a7ff5ef3297c1ecfd60911",
  "a7d451924263284765f6343bca8a21b79b89ebfe611c7355dd88e0ec1c29e232",
  "41c758d08a4d3fe4d90645711589b832a2cd54dd25bd5b66e463e5d389a53aff",
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  "90997920aa9786e10f513cfdd14e294feee6739cee1ab61b3fb1e3f42e7a915d",
  "99fcb9cb62c20a3135484a70bd3f73983f8f3b7b26266dad34f3993958a7642c",
  "e05f9a668b37e5f78bd3b9d047f29f92b33a87f11dd48390410006f858188b7b",
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  "1c4d72ce733b971b9ec4e24f37d733355f6f2ea635cc67ffb3e22748484df446",
  "2a6f89769f3272ac8c7a36a42a57627eca6b260ab2c76d8046a27d44d4034893",
  "f8d11df51a2cc113698ebf39a958fe81179d7d973d2044322771c0fe63f4d7c9",
  "f2287f17a4fa232dca5715c24a92f7112402a8101b9a7b276fb8c8f617376b90",
  "bb5ee510a4fda29cae30c97e7eee80569d3ec3598465f2d7e0674c395e0256e9",
  "647ab8c84365620d60f2523505d14bd230b5e650c96dee48be47770063ee7461",
  "34b06018fcc33ba6ebb01198d785b0629fbdc5d1948f688059158f053093f08b",
  "ff58b258dab0d7f36a2908e6c75229ce308d34806289c912a1a5f39a5aa71f9f",
  "232fc124803668a9f23b1c3bcb1134274303f5c0e1b0e27c9b6c7db59f0e2a4d",
  "27a0797cc5b042ba4c11e72a9555d13a67f00161550b32ede0511718b22dbc2c",
]       

print (merkle(txHashes))

注意：我是“python 中的区块链、编码和解码”的新手

【问题讨论】：

请提供完整的错误输出。

decode 函数未定义，或调用不正确，在哪里定义？试试这个在 python 中反转字节顺序：github.com/JBaczuk/blockchain-dev-tools/blob/master/…

我试图用codecs.decode 替换它，但它并没有真正起作用。我还尝试了 binascii 模块。我没有成功。在上面的代码中，函数def hash2(a, b)、a 和 b 被认为是字符串中的十六进制数字序列。并且当调用a.decode 时，由于无法解码字符串对象而引发错误。我正在探索编码和解码它的其他方法。

@AMC 我已经更新了帖子中的完整错误输出。

【参考方案1】：

在 Python 3 中

你可以这样做

def hash2(a, b):
    # Reverse inputs before and after hashing
    # due to big-endian / little-endian nonsense
    
    a1 = a[::-1]
    b1 = b[::-1]
    
    contcat = a1+b1
            
    h = hashlib.sha256(hashlib.sha256(b"concat").digest()).digest()
    return h

不知道为什么它会应用两次sha256。

要获得十六进制的结果，您可以将.hexdigest() 作为hashlib.sha256(hashlib.sha256(b"concat").digest()).hexdigest() 返回。

再次不确定为什么我们需要两次申请sha256