org.bouncycastle.crypto.signers

## Class SM2Signer

- java.lang.Object
- - org.bouncycastle.crypto.signers.SM2Signer

- All Implemented Interfaces:
    Signer, ECConstants

      public class SM2Signer
      extends java.lang.Object
      implements Signer, ECConstants

  The SM2 Digital Signature algorithm.

- - ### Field Summary

    - ### Fields inherited from interface org.bouncycastle.math.ec.ECConstants

      `EIGHT, FOUR, ONE, THREE, TWO, ZERO`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `SM2Signer()`
    `SM2Signer(Digest digest)`
    `SM2Signer(DSAEncoding encoding)`
    `SM2Signer(DSAEncoding encoding, Digest digest)`

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `protected java.math.BigInteger` | `calculateE(java.math.BigInteger n, byte[] message)`
    `protected ECMultiplier` | `createBasePointMultiplier()`
    `byte[]` | `generateSignature()` generate a signature for the message we've been loaded with using the key we were initialised with.
    `void` | `init(boolean forSigning, CipherParameters param)` Initialise the signer for signing or verification.
    `void` | `reset()` reset the internal state
    `void` | `update(byte b)` update the internal digest with the byte b
    `void` | `update(byte[] in, int off, int len)` update the internal digest with the byte array in
    `boolean` | `verifySignature(byte[] signature)` return true if the internal state represents the signature described in the passed in array.

    - ### Methods inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### SM2Signer

          public SM2Signer()

    - #### SM2Signer

          public SM2Signer(Digest digest)

    - #### SM2Signer

          public SM2Signer(DSAEncoding encoding)

    - #### SM2Signer

          public SM2Signer(DSAEncoding encoding,
                           Digest digest)

  - ### Method Detail

    - #### init

          public void init(boolean forSigning,
                           CipherParameters param)

      Description copied from interface: `Signer`
      Initialise the signer for signing or verification.
      Specified by:
        `init` in interface `Signer`
      Parameters:
        `forSigning` - true if for signing, false otherwise
        `param` - necessary parameters.

    - #### update

          public void update(byte b)

      Description copied from interface: `Signer`
      update the internal digest with the byte b
      Specified by:
        `update` in interface `Signer`

    - #### update

          public void update(byte[] in,
                             int off,
                             int len)

      Description copied from interface: `Signer`
      update the internal digest with the byte array in
      Specified by:
        `update` in interface `Signer`

    - #### verifySignature

          public boolean verifySignature(byte[] signature)

      Description copied from interface: `Signer`
      return true if the internal state represents the signature described in the passed in array.
      Specified by:
        `verifySignature` in interface `Signer`

    - #### reset

          public void reset()

      Description copied from interface: `Signer`
      reset the internal state
      Specified by:
        `reset` in interface `Signer`

    - #### generateSignature

          public byte[] generateSignature()
                                   throws CryptoException

      Description copied from interface: `Signer`
      generate a signature for the message we've been loaded with using the key we were initialised with.
      Specified by:
        `generateSignature` in interface `Signer`
      Throws:
        `CryptoException`

    - #### createBasePointMultiplier

          protected ECMultiplier createBasePointMultiplier()

    - #### calculateE

          protected java.math.BigInteger calculateE(java.math.BigInteger n,
                                                    byte[] message)