Python中如何实现用签名提交备注信息上链

import hashlib
import json
from eth_account import Account
from web3 import Web3

class BlockchainCommit:
    def __init__(self, rpc_url, private_key):
        self.w3 = Web3(Web3.HTTPProvider(rpc_url))
        self.account = Account.from_key(private_key)
        
    def create_commitment(self, remark, timestamp=None):
        """创建带时间戳的备注数据结构"""
        if timestamp is None:
            timestamp = int(self.w3.eth.get_block('latest')['timestamp'])
            
        commitment = {
            'remark': remark,
            'timestamp': timestamp,
            'address': self.account.address
        }
        return commitment
    
    def hash_commitment(self, commitment):
        """计算备注数据的哈希值"""
        # 将字典转换为排序后的JSON字符串确保一致性
        commitment_str = json.dumps(commitment, sort_keys=True, separators=(',', ':'))
        return hashlib.sha256(commitment_str.encode()).hexdigest()
    
    def sign_commitment(self, commitment):
        """对备注数据进行签名"""
        # 先计算哈希
        commitment_hash = self.hash_commitment(commitment)
        
        # 使用以太坊账户签名
        signed_message = self.account.signHash(commitment_hash)
        
        return {
            'commitment': commitment,
            'signature': signed_message.signature.hex(),
            'hash': commitment_hash
        }
    
    def verify_signature(self, signed_data, signer_address=None):
        """验证签名"""
        if signer_address is None:
            signer_address = self.account.address
            
        # 重新计算哈希
        recalculated_hash = self.hash_commitment(signed_data['commitment'])
        
        # 恢复签名者地址
        recovered_address = Account.recoverHash(
            recalculated_hash,
            signature=signed_data['signature']
        )
        
        return recovered_address.lower() == signer_address.lower()
    
    def submit_to_contract(self, contract_address, abi, signed_data):
        """提交到智能合约（示例）"""
        contract = self.w3.eth.contract(address=contract_address, abi=abi)
        
        # 构建交易
        tx = contract.functions.commitRemark(
            signed_data['commitment']['remark'],
            signed_data['commitment']['timestamp'],
            signed_data['signature']
        ).build_transaction({
            'from': self.account.address,
            'nonce': self.w3.eth.get_transaction_count(self.account.address),
            'gas': 200000,
            'gasPrice': self.w3.eth.gas_price
        })
        
        # 签名并发送交易
        signed_tx = self.w3.eth.account.sign_transaction(tx, self.account.key)
        tx_hash = self.w3.eth.send_raw_transaction(signed_tx.rawTransaction)
        
        return tx_hash.hex()

# 使用示例
if __name__ == "__main__":
    # 配置（实际使用时替换为真实值）
    RPC_URL = "https://mainnet.infura.io/v3/YOUR_INFURA_KEY"
    PRIVATE_KEY = "0x你的私钥"
    CONTRACT_ADDRESS = "0x合约地址"
    
    # 初始化
    committer = BlockchainCommit(RPC_URL, PRIVATE_KEY)
    
    # 1. 创建备注
    remark = "项目里程碑完成 - 2024Q1"
    commitment = committer.create_commitment(remark)
    
    # 2. 签名
    signed_data = committer.sign_commitment(commitment)
    print(f"签名数据: {json.dumps(signed_data, indent=2)}")
    
    # 3. 验证签名
    is_valid = committer.verify_signature(signed_data)
    print(f"签名验证: {'通过' if is_valid else '失败'}")
    
    # 4. 提交到链上（需要合约支持）
    # tx_hash = committer.submit_to_contract(CONTRACT_ADDRESS, CONTRACT_ABI, signed_data)
    # print(f"交易哈希: {tx_hash}")

核心步骤：

1. 数据结构化：将备注信息、时间戳、地址打包成标准格式
2. 哈希计算：使用SHA-256生成数据指纹
3. 私钥签名：用以太坊账户对哈希进行ECDSA签名
4. 链上提交：通过智能合约存储签名数据

关键点：

• 时间戳防重放
• JSON序列化保持一致性
• 签名验证确保数据完整性

一句话建议： 确保使用安全的私钥管理和合适的哈希算法。