Solana/交易/区块哈希与时效性

示例交易

为了避免读者不停切换页面, 我将待分析的交易复制在了每一小节的开头.

{
    "signatures": [
        "3NPdLTf2Xp1XUu82VVVKgQoHfiUau3wGPTKAhbNzm8Rx5ebNQfHBzCGVsagXyQxRCeEiGr1jgr4Vn32UEAx1Aov3"
    ],
    "message": {
        "header": [
            1,
            0,
            1
        ],
        "account_keys": [
            "6ASf5EcmmEHTgDJ4X4ZT5vT6iHVJBXPg5AN5YoTCpGWt",
            "8pM1DN3RiT8vbom5u1sNryaNT1nyL8CTTW3b5PwWXRBH",
            "11111111111111111111111111111111"
        ],
        "recent_blockhash": "6vAwzjtGMrN3mJ8o7iGVDjMM46e2AnctqmjvLbqtESrx",
        "instructions": [
            {
                "program": 2,
                "account": [
                    0,
                    1
                ],
                "data": "3Bxs3zzLZLuLQEYX"
            }
        ]
    }
}

最近区块哈希

在 solana 交易中, tx.message.recent_blockhash 是一个看似不起眼却至关重要的字段. 它确保交易不会无限期有效, 也防止重复执行交易.

"recent_blockhash": "6vAwzjtGMrN3mJ8o7iGVDjMM46e2AnctqmjvLbqtESrx"

这个值由交易创建时从网络节点实时获取. 代码如下.

import pxsol

print(pxsol.rpc.get_latest_blockhash({})['blockhash'])
# 6vAwzjtGMrN3mJ8o7iGVDjMM46e2AnctqmjvLbqtESrx

在交易中引入最近区块哈希有以下几个目的:

1. solana 要求交易在某个时间窗口内提交(通常几分钟, 具体取决于网络配置). 如果交易中提交的最近区块哈希太旧, 交易会被拒绝.
2. 防止重放攻击. 每次交易绑定一个唯一的区块哈希, 即使交易内容相同, 使用不同的哈希也能区分它们, 避免重复执行.
3. 它将交易锚定到时间线, 确保网络能够快速验证和排序交易.

习题

例: 尝试将 ada 的交易重新发送, 看看会发生什么?

答:

import base64
import pxsol

tx = bytearray([
    0x01, 0x76, 0x7a, 0xe2, 0x66, 0x60, 0xc1, 0x42, 0x94, 0x1a, 0x59, 0x61, 0xf6, 0xde, 0xc7, 0x23,
    0x7c, 0xae, 0x73, 0x3e, 0xdf, 0xe6, 0x51, 0x7c, 0x37, 0xfb, 0xb8, 0x48, 0x1f, 0x46, 0xbb, 0xb5,
    0x3c, 0xe3, 0x00, 0xe7, 0x14, 0xb4, 0x78, 0x40, 0x14, 0x2c, 0x93, 0xa4, 0xe6, 0x60, 0x0c, 0x50,
    0xfd, 0xa9, 0x75, 0x60, 0xab, 0x64, 0x1d, 0xb0, 0xce, 0x19, 0x55, 0x9b, 0x25, 0x1d, 0x66, 0xdf,
    0x04, 0x01, 0x00, 0x01, 0x03, 0x4c, 0xb5, 0xab, 0xf6, 0xad, 0x79, 0xfb, 0xf5, 0xab, 0xbc, 0xca,
    0xfc, 0xc2, 0x69, 0xd8, 0x5c, 0xd2, 0x65, 0x1e, 0xd4, 0xb8, 0x85, 0xb5, 0x86, 0x9f, 0x24, 0x1a,
    0xed, 0xf0, 0xa5, 0xba, 0x29, 0x74, 0x22, 0xb9, 0x88, 0x75, 0x98, 0x06, 0x8e, 0x32, 0xc4, 0x44,
    0x8a, 0x94, 0x9a, 0xdb, 0x29, 0x0d, 0x0f, 0x4e, 0x35, 0xb9, 0xe0, 0x1b, 0x0e, 0xe5, 0xf1, 0xa1,
    0xe6, 0x00, 0xfe, 0x26, 0x74, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x57, 0xe9, 0x77, 0x4a, 0x3c, 0xad, 0x5c, 0x33, 0xf1, 0xfb, 0x6b,
    0x37, 0xa0, 0x3d, 0x4f, 0x00, 0x9a, 0x31, 0x09, 0x81, 0x18, 0xd2, 0xce, 0xae, 0xbf, 0x43, 0x0a,
    0xf3, 0x01, 0xad, 0x25, 0x0d, 0x01, 0x02, 0x02, 0x00, 0x01, 0x0c, 0x02, 0x00, 0x00, 0x00, 0x00,
    0xca, 0x9a, 0x3b, 0x00, 0x00, 0x00, 0x00,
])

pxsol.rpc.send_transaction(base64.b64encode(tx).decode(), {})

# Exception: {
#     'code': -32002,
#     'message': 'Transaction simulation failed: This transaction has already been processed',
#     'data': {
#         'accounts': None,
#         'err': 'AlreadyProcessed',
#         'innerInstructions': None,
#         'logs': [],
#         'replacementBlockhash': None,
#         'returnData': None,
#         'unitsConsumed': 0,
#     }
# }

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