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@warren-bank/ethereumjs-tx-sign

2.0.0 • Public • Published

ethereumjs-tx-sign

Description:

The goal of this project is to provide a light-weight minimal library to sign (and verify) raw Ethereum transactions.

Installation:

npm install --save '@warren-bank/ethereumjs-tx-sign'

Background:

ethereumjs-tx is the de-facto library used to sign raw transactions.

Clean installation of the ethereumjs-tx module results in a node_modules directory that is:

  • 10.4 MB
  • 24.9 MB on disk (ext4)

Clean installation of this module results in a node_modules directory that is:

  • 333.5 KB
  • 640.0 KB on disk (ext4)

API:

{rawData, msgHash, DER, signature, rawTx} = sign(txData, privateKey)

  • params:
    • txData
      • type: Object
      • keys can include: "nonce","gasPrice","gasLimit","to","value","data","chainId"
      • values:
        • type: String
        • format: hex-encoded (with '0x' prefix)
        • more generally: any value that can be converted to a Buffer: rlp.toBuffer(value)
        • exceptions:
          • "chainId":
            • type: native Number
            • notes:
              • EIP 155
              • value is used to modify msgHash
              • value is stored in rawData in the field corresponding to "v"
                (ie: the signature recovery shares its field with the chainId); consequently,
                value is stored in rawTx
    • privateKey
      • type: String
      • format: hex-encoded (with or without '0x' prefix)
  • returns:
    • rawData
      • type: Array of Buffers
      • length: 9
      • values (and order) correspond to the data fields: "nonce","gasPrice","gasLimit","to","value","data","v","r","s"
    • msgHash
      • description: sha3 hash of RLP encoded Array containing the first 6 elements of rawData
        • note:
          • if chainId > 0: Array is extended to 9 elements
            • 7th: Buffer containing chainId
            • 8th and 9th: zero-length Buffers
      • type: String
      • format: hex-encoded (without '0x' prefix)
    • DER
      • description: DER encoded signature
      • type: Array of Number
      • format: each Number is an Integer in the range [0..255] and represents a single Byte
    • signature
      • Buffer
      • length: 64 Bytes
      • contents: rawData.r (32 Bytes) + rawData.s (32 Bytes)
    • rawTx
      • description: RLP encoded rawData
      • type: String
      • format: hex-encoded (without '0x' prefix)

Example:

const {sign} = require('@warren-bank/ethereumjs-tx-sign')
 
const txData = {
  nonce:    '0x00',
  gasPrice: '0x6fc23ac00',
  gasLimit: '0x2710',
//to:       '0x00',
  value:    '0x00',
  data:     '0x7f7465737432000000000000000000000000000000000000000000000000000000600057',
  chainId:  1
}
 
const privateKey = 'e922354a3e5902b5ac474f3ff08a79cff43533826b8f451ae2190b65a9d26158'
 
const {rawTx} = sign(txData, privateKey)
 
const Web3 = require('web3')
const web3 = new Web3()
web3.setProvider(new web3.providers.HttpProvider('http://localhost:8545'))
 
web3.eth.sendRawTransaction(rawTx, function(err, hash) {
  if (err)
    console.log('error:', err.message)
  if ((!err) && hash)
    console.log('transaction hash:', hash)
})

More Complete Example:


verify(msgHash, signature, publicKey)

  • params:
    • msgHash
      • type: String
      • format: hex-encoded (without '0x' prefix)
    • signature
      • type:
        • Buffer: length of 64 Bytes
        • Object: {r, s}
          • r: Buffer w/ length of 32 Bytes
          • s: Buffer w/ length of 32 Bytes
        • (DER encoded) Array of Number
        • (DER encoded) String: hex-encoded (without '0x' prefix):
          let DER_string = require('elliptic').utils.encode(DER, 'hex')
    • publicKey
      • type: String
      • format: hex-encoded (with or without '0x' prefix)
  • returns:
    • Boolean
      • indicates whether the signature can be verified for the msgHash using the publicKey
        • true indicates that the signature was originally created using the (unavailable) privateKey that is paired to the (available) publicKey
        • false indicates that it was not

Example:

// continuation of the previous example:
 
const {verify} = require('@warren-bank/ethereumjs-tx-sign')
 
{
  let {msgHash, signature} = sign(txData, privateKey)
 
  let publicKey = '0493ff3bd23838a02f24adcb23aa90bf2de8becbd1abe688e0f6a3202bee2cc4c2ecf7cd2608cda0817d6223f81bed074f166b8b55de54d603817699b4c70feaac'
 
  let result = verify(msgHash, signature, publicKey)
}

More Complete Example:


{txData, signature, msgHash, publicKey, address} = unsign(rawTx)

  • params:
    • rawTx
      • type:
        • String: hex-encoded (with or without '0x' prefix)
        • Buffer
  • returns:
    • txData
      • type: Object
      • keys: "nonce","gasPrice","gasLimit","to","value","data","chainId"
      • values:
        • type: String
        • format: hex-encoded (with '0x' prefix)
        • exceptions:
          • "chainId":
            • type: native Number
    • signature
      • type: Object
      • keys: "r","s"
      • values:
        • type: String
        • format: hex-encoded (without '0x' prefix)
    • msgHash
      • type: String
      • format: hex-encoded (without '0x' prefix)
    • publicKey
      • type: String
      • format: hex-encoded (without '0x' prefix)
    • address
      • description: "from" address … seen by network as the sender of this signed transaction
      • type: String
      • format: hex-encoded (without '0x' prefix)

Example:

// continuation of the previous example:
 
const {unsign} = require('@warren-bank/ethereumjs-tx-sign')
 
{
  let {txData, msgHash, signature, publicKey} = unsign(rawTx)
 
  let result = verify(msgHash, signature, publicKey)
}

More Complete Example:

Related:

  • ethereumjs-tx-unsign
    • exports a variation of the function: unsign()
    • it is a minimal library to retrieve txData and (optionally) signature from rawTx
    • it doesn't include any external dependencies and (consequently) lacks the ability to calculate publicKey and address from signature

Bonus (Internal Library) APIs:

{privateKey, publicKey, address} = genKeyPair()

  • returns:
    • privateKey
      • type: String
      • format: hex-encoded (without '0x' prefix)
    • publicKey
      • type: String
      • format: hex-encoded (without '0x' prefix)
    • address
      • type: String
      • format: hex-encoded (without '0x' prefix)

Example:

const {genKeyPair} = require('@warren-bank/ethereumjs-tx-sign/lib/keypairs')
 
const {privateKey, publicKey, address} = genKeyPair()
 
console.log({privateKey, publicKey, address})

Output:

{
  privateKey: 'e922354a3e5902b5ac474f3ff08a79cff43533826b8f451ae2190b65a9d26158',
  publicKey:  '0493ff3bd23838a02f24adcb23aa90bf2de8becbd1abe688e0f6a3202bee2cc4c2ecf7cd2608cda0817d6223f81bed074f166b8b55de54d603817699b4c70feaac',
  address:    'f95abdf6ede4c3703e0e9453771fbee8592d31e9'
}

More Complete Example:


publicKey = privateToPublic(privateKey, compressed)

  • params:
    • privateKey
      • type:
        • String: hex-encoded (with or without '0x' prefix)
        • Buffer
    • compressed
  • returns:
    • publicKey
      • type: String
      • format: hex-encoded (without '0x' prefix)

Example:

// continuation of the previous example:
 
const {privateToPublic} = require('@warren-bank/ethereumjs-tx-sign/lib/keypairs')
 
{
  let pubKey = privateToPublic(privateKey)
 
  assert(pubKey === publicKey)
}

address = publicToAddress(publicKey)

  • params:
    • publicKey
      • type:
        • String: hex-encoded (with or without '0x' prefix)
        • Buffer
  • returns:
    • address
      • type: String
      • format: hex-encoded (without '0x' prefix)

Example:

// continuation of the previous example:
 
const {publicToAddress} = require('@warren-bank/ethereumjs-tx-sign/lib/keypairs')
 
{
  let addr = publicToAddress(publicKey)
 
  assert(addr === address)
}

hash = sha3(value, bits)

  • params:
    • value
    • bits
      • type: Number
      • supported values include: 224, 256, 384, 512
      • default: 256
  • returns:
    • hash
      • type: String
      • format: hex-encoded (without '0x' prefix)

Example:

const {sha3} = require('@warren-bank/ethereumjs-tx-sign/lib/keccak')
 
{
  let hash = sha3('hello world')
}

Credits (mostly) Belong To:

Special Thanks To:

  • elliptic
    • is a dependency of this module
    • is the work-horse that makes all of this possible

install

npm i @warren-bank/ethereumjs-tx-sign

Downloadsweekly downloads

22

version

2.0.0

license

GPL-2.0

homepage

github.com

repository

Gitgithub

last publish

collaborators

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