Package org.web3j.crypto

Class Sign

  • public class Sign
extends java.lang.Object
    Transaction signing logic.

    Adapted from the BitcoinJ ECKey implementation.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  Sign.SignatureData  

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static org.bouncycastle.asn1.x9.X9ECParameters CURVE_PARAMS  

    • Constructor Summary

      Constructors 
      Constructor Description
      Sign()  

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static byte[] getEthereumMessageHash​(byte[] message)  
      static java.math.BigInteger publicFromPoint​(byte[] bits)
      Returns public key point from the given curve.
      static java.math.BigInteger publicKeyFromPrivate​(java.math.BigInteger privKey)
      Returns public key from the given private key.
      static org.bouncycastle.math.ec.ECPoint publicPointFromPrivate​(java.math.BigInteger privKey)
      Returns public key point from the given private key.
      static java.math.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.
      static java.math.BigInteger signedMessageHashToKey​(byte[] messageHash, Sign.SignatureData signatureData)
      Given an arbitrary message hash and an Ethereum message signature encoded in bytes, returns the public key that was used to sign it.
      static java.math.BigInteger signedMessageToKey​(byte[] message, Sign.SignatureData signatureData)
      Given an arbitrary piece of text and an Ethereum message signature encoded in bytes, returns the public key that was used to sign it.
      static java.math.BigInteger signedPrefixedMessageToKey​(byte[] message, Sign.SignatureData signatureData)
      Given an arbitrary message and an Ethereum message signature encoded in bytes, returns the public key that was used to sign it.
      static Sign.SignatureData signMessage​(byte[] message, ECKeyPair keyPair)  
      static Sign.SignatureData signMessage​(byte[] message, ECKeyPair keyPair, boolean needToHash)  
      static Sign.SignatureData signPrefixedMessage​(byte[] message, ECKeyPair keyPair)  

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • CURVE_PARAMS

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

    • Constructor Detail

      • Sign

        public Sign()

    • Method Detail

      • getEthereumMessageHash

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

      • recoverFromSignature

        public static java.math.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 java.math.BigInteger signedMessageToKey​(byte[] message,
                                                      Sign.SignatureData signatureData)
                                               throws java.security.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:
        java.security.SignatureException - If the public key could not be recovered or if there was a signature format error.

      • signedPrefixedMessageToKey

        public static java.math.BigInteger signedPrefixedMessageToKey​(byte[] message,
                                                              Sign.SignatureData signatureData)
                                                       throws java.security.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:
        java.security.SignatureException - If the public key could not be recovered or if there was a signature format error.

      • signedMessageHashToKey

        public static java.math.BigInteger signedMessageHashToKey​(byte[] messageHash,
                                                          Sign.SignatureData signatureData)
                                                   throws java.security.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:
        java.security.SignatureException - If the public key could not be recovered or if there was a signature format error.

      • publicKeyFromPrivate

        public static java.math.BigInteger publicKeyFromPrivate​(java.math.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​(java.math.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 java.math.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