Package org.web3j.crypto

Class Sign

java.lang.Object
org.web3j.crypto.Sign
public class Sign extends Object
Transaction signing logic.

Adapted from the BitcoinJ ECKey implementation.

  • Field Details

    • CURVE_PARAMS

      public static final org.bouncycastle.asn1.x9.X9ECParameters CURVE_PARAMS

    • CHAIN_ID_INC

      public static final int CHAIN_ID_INC
      See Also:

    • LOWER_REAL_V

      public static final int LOWER_REAL_V
      See Also:

    • REPLAY_PROTECTED_V_MIN

      public static final int REPLAY_PROTECTED_V_MIN
      See Also:

  • Constructor Details

    • Sign

      public Sign()

  • Method Details

    • getEthereumMessageHash

      public static byte[] getEthereumMessageHash(byte[] message)

    • signPrefixedMessage

      public static Sign.SignatureData signPrefixedMessage(byte[] message, ECKeyPair keyPair)

    • signMessage

      public static Sign.SignatureData signMessage(byte[] message, ECKeyPair keyPair)

    • signTypedData

      public static Sign.SignatureData signTypedData(String jsonData, ECKeyPair keyPair) throws IOException
      Throws:
      IOException

    • signMessage

      public static Sign.SignatureData signMessage(byte[] message, ECKeyPair keyPair, boolean needToHash)

    • createSignatureData

      public static Sign.SignatureData createSignatureData(ECDSASignature sig, BigInteger publicKey, byte[] messageHash)
      Signature without EIP-155 (Simple replay attack protection) https://eips.ethereum.org/EIPS/eip-155 To add EIP-155 call TransactionEncoder.createEip155SignatureData after that.

    • recoverFromSignature

      public static BigInteger recoverFromSignature(int recId, ECDSASignature sig, byte[] message)
      Given the components of a signature and a selector value, recover and return the public key that generated the signature according to the algorithm in SEC1v2 section 4.1.6.

      The recId is an index from 0 to 3 which indicates which of the 4 possible keys is the correct one. Because the key recovery operation yields multiple potential keys, the correct key must either be stored alongside the signature, or you must be willing to try each recId in turn until you find one that outputs the key you are expecting.

      If this method returns null it means recovery was not possible and recId should be iterated.

      Given the above two points, a correct usage of this method is inside a for loop from 0 to 3, and if the output is null OR a key that is not the one you expect, you try again with the next recId.

      Parameters:
      recId - Which possible key to recover.
      sig - the R and S components of the signature, wrapped.
      message - Hash of the data that was signed.
      Returns:
      An ECKey containing only the public part, or null if recovery wasn't possible.

    • signedMessageToKey

      public static BigInteger signedMessageToKey(byte[] message, Sign.SignatureData signatureData) throws SignatureException
      Given an arbitrary piece of text and an Ethereum message signature encoded in bytes, returns the public key that was used to sign it. This can then be compared to the expected public key to determine if the signature was correct.
      Parameters:
      message - RLP encoded message.
      signatureData - The message signature components
      Returns:
      the public key used to sign the message
      Throws:
      SignatureException - If the public key could not be recovered or if there was a signature format error.

    • signedPrefixedMessageToKey

      public static BigInteger signedPrefixedMessageToKey(byte[] message, Sign.SignatureData signatureData) throws SignatureException
      Given an arbitrary message and an Ethereum message signature encoded in bytes, returns the public key that was used to sign it. This can then be compared to the expected public key to determine if the signature was correct.
      Parameters:
      message - The message.
      signatureData - The message signature components
      Returns:
      the public key used to sign the message
      Throws:
      SignatureException - If the public key could not be recovered or if there was a signature format error.

    • signedMessageHashToKey

      public static BigInteger signedMessageHashToKey(byte[] messageHash, Sign.SignatureData signatureData) throws SignatureException
      Given an arbitrary message hash and an Ethereum message signature encoded in bytes, returns the public key that was used to sign it. This can then be compared to the expected public key to determine if the signature was correct.
      Parameters:
      messageHash - The message hash.
      signatureData - The message signature components
      Returns:
      the public key used to sign the message
      Throws:
      SignatureException - If the public key could not be recovered or if there was a signature format error.

    • getRecId

      public static int getRecId(Sign.SignatureData signatureData, long chainId)
      Returns recovery ID.
      Parameters:
      signatureData - The message signature components
      chainId - of the network
      Returns:
      int recovery ID

    • getVFromRecId

      public static byte[] getVFromRecId(int recId)
      Returns the header 'v'.
      Parameters:
      recId - The recovery id.
      Returns:
      byte[] header 'v'.

    • publicKeyFromPrivate

      public static BigInteger publicKeyFromPrivate(BigInteger privKey)
      Returns public key from the given private key.
      Parameters:
      privKey - the private key to derive the public key from
      Returns:
      BigInteger encoded public key

    • publicPointFromPrivate

      public static org.bouncycastle.math.ec.ECPoint publicPointFromPrivate(BigInteger privKey)
      Returns public key point from the given private key.
      Parameters:
      privKey - the private key to derive the public key from
      Returns:
      ECPoint public key

    • publicFromPoint

      public static BigInteger publicFromPoint(byte[] bits)
      Returns public key point from the given curve.
      Parameters:
      bits - representing the point on the curve
      Returns:
      BigInteger encoded public key