erc20的签名值为629680c82f82ad9ea02704a988d70565741def2d93ec95efe07d8bd6976340e15b87a837d96406516436eef6d88491598e9c4f1c15aaf7260db8ef25af5b5851c，使用js求erc20的permit的r，s，v的值

以下是使用JavaScript计算ERC20 permit的r，s，v值的示例代码：

const ethers = require('ethers');
const abi = require('ethereumjs-abi');

const signature = '629680c82f82ad9ea02704a988d70565741def2d93ec95efe07d8bd6976340e15b87a837d96406516436eef6d88491598e9c4f1c15aaf7260db8ef25af5b5851c';
const owner = '0x1234567890123456789012345678901234567890';
const spender = '0x0987654321098765432109876543210987654321';
const value = 100;
const nonce = 1;
const deadline = 1634028589;

// Define the EIP712 domain separator
const domainType = [
    { name: 'name', type: 'string' },
    { name: 'version', type: 'string' },
    { name: 'chainId', type: 'uint256' },
    { name: 'verifyingContract', type: 'address' }
];
const domainData = {
    name: 'My Token',
    version: '1.0',
    chainId: 1, // Change to the correct chain ID
    verifyingContract: '0x1234567890123456789012345678901234567890' // Change to the correct contract address
};
const domainSeparator = '0x' + ethers.utils.keccak256(
    ethers.utils.defaultAbiCoder.encode(
        ['bytes32', 'bytes32', 'bytes32', 'uint256', 'address'],
        [
            ethers.utils.keccak256(ethers.utils.defaultAbiCoder.encode(domainType, [domainData])),
            ethers.utils.keccak256(Buffer.from('1901', 'hex')),
            ethers.utils.keccak256(Buffer.from('This is my typed data message!')),
            1,
            domainData.verifyingContract
        ]
    )
).substring(2);

// Define the permit type
const permitType = [
    { name: 'owner', type: 'address' },
    { name: 'spender', type: 'address' },
    { name: 'value', type: 'uint256' },
    { name: 'nonce', type: 'uint256' },
    { name: 'deadline', type: 'uint256' }
];
const permitData = {
    owner,
    spender,
    value,
    nonce,
    deadline
};
const permitStructHash = '0x' + abi.soliditySHA3(
    ['bytes32', ...permitType.map(({ type }) => type)],
    [ethers.utils.keccak256(Buffer.from('Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)')), ...Object.values(permitData)]
).toString('hex');

// Recover the signer from the signature
const { v, r, s } = ethers.utils.splitSignature(Buffer.from(signature, 'hex'));
const digest = ethers.utils.keccak256(
    ethers.utils.defaultAbiCoder.encode(
        ['bytes1', 'bytes1', 'bytes32', 'bytes32'],
        [
            '0x19',
            '0x01',
            domainSeparator,
            permitStructHash
        ]
    )
);
const recoveredAddress = ethers.utils.recoverAddress(digest, { v, r, s });

// Verify that the recovered signer matches the owner
if (recoveredAddress.toLowerCase() !== owner.toLowerCase()) {
    throw new Error('Invalid signature');
}

// Print the r, s, v values
console.log('r:', r.toString());
console.log('s:', s.toString());
console.log('v:', v.toString());

在上面的示例代码中，我们使用ethers.js和ethereumjs-abi库来计算ERC20 permit的r，s，v值。具体来说，我们首先定义了EIP712 domain separator和permit type，并将其编码为字节数组。然后，我们将这些字节数组哈希为domain separator和permit struct hash，使用签名值来恢复签名者的地址，并验证签名者是否与owner相匹配。最后，我们将r，s，v值打印到控制台上。

需要注意的是，上面的示例代码中的domainData.verifyingContract和domainData.chainId需要根据具体的ERC20代币合约进行修改。