ethers-crypto

ethers-crypto

Includes cryptographic utilities for both signing and verifying ECDSA signatures on the secp256k1 curve, and computing the keccak256 hash. All signatures are canonicalized so the s value is always in the lower half of the curve.

The ECDSASignerRecoverable has been forked from the Bouncy Castle library and modified to support returning the y value of the signature when signing a hash. This makes it possible to compute the recovery id of the signature without brute-forcing it. This file should be kept in sync with the upstream version, with minimal modifications.

💻 Code Examples

• Use keccak256 to hash raw data or a message based on the EIP-191 standard.

  val messageToHash = "ethers-crypto"
  
  val dataHash = Hashing.keccak256(messageToHash.toByteArray())
  val msgHash = Hashing.hashMessage(messageToHash.toByteArray())

• Use the Secp256k1.SigningKey to derive the address from a public key, sign a hash, recover the public key from the signature.

  val privateKey = "1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef"
  val signingKey = Secp256k1.SigningKey(BigInteger(privateKey, 16))
  
  val address = Secp256k1.publicKeyToAddress(signingKey.publicKey)
  
  val messageToSign = "ethers-crypto"
  val messageHash = Hashing.hashMessage(messageToSign.toByteArray())
  val signature = signingKey.signHash(messageHash)
  
  val recoveredPublicKey = Secp256k1.recoverPublicKey(
      messageHash,
      signature[0], // r
      signature[1], // s
      signature[2].toLong() // v 
  )

Alternative usages can be found in tests.