javascriptcryptographyblockchainethereumweb3js

How can I re create raw transaction from the transaction receipt to verify v,r,s signature?


I am trying to verify Ethereum transaction.

Here are my steps.

  1. make a transaction
  2. get transaction with eth.getTransaction()
  3. re-create transaction with ethereumjs-tx

But sometimes I can not verify a transaction.

Case 1: simple send ether transaction on private test net

  1. get a transaction detail
    {
      blockHash: "0x2125539ac67b4569828737ffb1731048e00121954f0555d0dc96af665071a62b",
      blockNumber: 24615,
      from: "0x81c24515cdf1a4b68f34e3e2824d44b28d00f010",
      gas: 90000,
      gasPrice: 18000000000,
      hash: "0x9e4ce952759eae925173c6c6055c1afe577a48462caacd8d4fb742e911eae053",
      input: "0x",
      nonce: 0,
      r: "0x826b5348acbec72bab39c5debc8493e34d23b351bc7c20ded25d2a4eed736093",
      s: "0x2a87e18b22c76d61ce9d6a4d56949afa025f1611aa6bb9fd9d6c502d61f7361b",
      to: "0x487f5eea74ea5f3e94093d8b0501f1d2b0d5310a",
      transactionIndex: 0,
      v: "0x10f469",
      value: 1000000000000000000
    }
  1. then create a transactin with the transaction detail and ethereumjs-tx.
    const EthereumTx = require('ethereumjs-tx')
    const test_arr1 = {
      nounce: "0x"+parseInt(0, 10).toString(16),
      gasPrice: "0x"+parseInt(18000000000, 10).toString(16),
      gasLimit: "0x"+parseInt(90000, 10).toString(16),
      to: '0x487f5eea74ea5f3e94093d8b0501f1d2b0d5310a',
      value: "0x"+parseInt(1000000000000000000, 10).toString(16),
      data: '0x',
      v: '0x10f469',
      r: '0x826b5348acbec72bab39c5debc8493e34d23b351bc7c20ded25d2a4eed736093',
      s: '0x2a87e18b22c76d61ce9d6a4d56949afa025f1611aa6bb9fd9d6c502d61f7361b'
    }
    const tx = new EthereumTx(test_arr1);
    
    const recoveredAddress = "0x"+tx.getSenderAddress().toString('hex')
    recoveredAddress is 0x81c24515cdf1a4b68f34e3e2824d44b28d00f010 which is correct

Case 2: smart contract in ropsten testnet

  1. get a transaction detail
    {
      blockHash: "0xead9335751dbdb4a874b2bb48ac15ddafbec6f2ba55a5932bf6ec1a0475166e7",
      blockNumber: 3026266,
      from: "0x0d6883a0e7071513c7d90a27bf2715bc71ecf107",
      gas: 309588,
      gasPrice: 18000000000,
      hash: "0xe69d8b108af59198857dd5b045769748dbe1ca3ad9bba7dbbb512643b9d85b5a",
      input: "0x03e63bdb000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000890000000b000000012e507fe5cce2f11c2a520a265f593c08372834fec925f84bbe5a72793ec5096d03fd11970afed8b767adfed60caf3f0c1de0dbda06d48f9afc3661717dbf85641b3f011114d3a41bf16a8d8cc33769aba2abe14efb14487295c80da13b3e333707202d1bdea56f75616202491b4bcc437b6a5b7a79284a08e28bcd0a90e3d87bf10000000000000000000000000000000000000000000000",
      nonce: 129,
      r: "0xdd4fe550275bd35ffd4babf6ac3578575594011f027923046da78a7b179ffb66",
      s: "0x2584e1f3f36185f6cd9358146f2479dde41dbb85ced5859c845a065cb5bdc42b",
      to: "0xad5e2d5cb93f098423597c891d2f1ed35f904ca1",
      transactionIndex: 0,
      v: "0x2a",
      value: 0
    }
  1. then create a transactin with the transaction detail and ethereumjs-tx.
    const EthereumTx = require('ethereumjs-tx')
    const test_arr2 = {
      nounce: "0x"+parseInt(129, 10).toString(16),
      gasPrice: "0x"+parseInt(18000000000, 10).toString(16),
      gasLimit: "0x"+parseInt(309588, 10).toString(16),
      to: '0xad5e2d5cb93f098423597c891d2f1ed35f904ca1',
      value: "0x",
      data: '0x03e63bdb000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000890000000b000000012e507fe5cce2f11c2a520a265f593c08372834fec925f84bbe5a72793ec5096d03fd11970afed8b767adfed60caf3f0c1de0dbda06d48f9afc3661717dbf85641b3f011114d3a41bf16a8d8cc33769aba2abe14efb14487295c80da13b3e333707202d1bdea56f75616202491b4bcc437b6a5b7a79284a08e28bcd0a90e3d87bf10000000000000000000000000000000000000000000000',
      v: '0x2a',
      r: '0xdd4fe550275bd35ffd4babf6ac3578575594011f027923046da78a7b179ffb66',
      s: '0x2584e1f3f36185f6cd9358146f2479dde41dbb85ced5859c845a065cb5bdc42b',
      chainId: 3
    }
    const tx2 = new EthereumTx(test_arr2);
    
    const recoveredAddress = "0x"+tx2.getSenderAddress().toString('hex')
    
    recoveredAddress is 0x9c9d4315824275f545b2e96026a7075f75125b9b which is NOT correct. It should be 0x0d6883a0e7071513c7d90a27bf2715bc71ecf107

Why is that? How can I re-create raw transaction correctly?

Or is there any other way to verify transaction with v, r, s signature?


Solution

  • If you're using web3js v1.0, you can simply use web3.eth.accounts.recover. Example from their documentation:

    web3.eth.accounts.recover({
        messageHash: '0x1da44b586eb0729ff70a73c326926f6ed5a25f5b056e7f47fbc6e58d86871655',
        v: '0x1c',
        r: '0xb91467e570a6466aa9e9876cbcd013baba02900b8979d43fe208a4a4f339f5fd',
        s: '0x6007e74cd82e037b800186422fc2da167c747ef045e5d18a5f5d4300f8e1a029'
    })
    > "0x2c7536E3605D9C16a7a3D7b1898e529396a65c23"
    

    Another option is you can call a view function in a contract that uses Solidity's ecrecover(). From the Solidity docs:

    ecrecover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) returns (address): recover address associated with the public key from elliptic curve signature, return zero on error

    Example:

    function verify(bytes prefix, bytes32 msgHash, uint8 v, bytes32 r, bytes32 s) external pure returns(address) {
      bytes32 prefixedHash = keccak256(prefix, msgHash);
      return ecrecover(prefixedHash, v, r, s);
    }
    

    You have to be careful with the prefix though. Different clients may use a different prefix. For example, geth signs transactions with prefix = "\x19Ethereum Signed Message:\n32".