Class SM2Signer

java.lang.Object

org.bouncycastle.crypto.signers.SM2Signer

All Implemented Interfaces:

Signer, ECConstants

public class SM2Signer
extends Object
implements Signer, ECConstants

The SM2 Digital Signature algorithm.

Field Summary

Fields inherited from interface ECConstants

EIGHT, FOUR, ONE, THREE, TWO, ZERO

Constructor Summary

Constructors

Constructor	Description
SM2Signer()
SM2Signer(Digest digest)
SM2Signer(DSAEncoding encoding)
SM2Signer(DSAEncoding encoding, Digest digest)

Method Summary

Modifier and Type	Method	Description
protected BigInteger	calculateE(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.
protected byte[]	getZ(byte[] userID)	Compute the SM2 Z value - H(ENTL || ID || a || b || xG || yG || xA || yA) as given in 5.1.4.4 of the draft RFC "SM2 Public Key Algorithms".
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 Object

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

Constructor Details

SM2Signer

public SM2Signer()

SM2Signer

public SM2Signer(Digest digest)

SM2Signer

public SM2Signer(DSAEncoding encoding)

SM2Signer

public SM2Signer(DSAEncoding encoding,
 Digest digest)

Method Details

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

getZ

protected byte[] getZ(byte[] userID)

Compute the SM2 Z value - H(ENTL || ID || a || b || xG || yG || xA || yA) as given in 5.1.4.4 of the draft RFC "SM2 Public Key Algorithms". This is called once from init with the digest freshly reset, and the value returned is prepended to the message before e is calculated.

An override must leave the digest empty on return - this implementation feeds the digest and then consumes it with a doFinal(). Returning a zero-length array leaves the message unprefixed, so a signer constructed with a NullDigest will then sign and verify a caller-supplied pre-hashed e as passed in, for the case where Z and the message hash are calculated elsewhere.

Parameters:

userID - the SM2 user ID passed in at init, or the default one if none was given.

Returns:

the Z value the message is to be prefixed with.

createBasePointMultiplier

protected ECMultiplier createBasePointMultiplier()

calculateE

protected BigInteger calculateE(BigInteger n,
 byte[] message)