Bouncy Castle Cryptography Library 1.37

org.bouncycastle.crypto.signers
Class ECNRSigner

java.lang.Object
  extended by org.bouncycastle.crypto.signers.ECNRSigner
All Implemented Interfaces:
DSA

public class ECNRSigner
extends java.lang.Object
implements DSA

EC-NR as described in IEEE 1363-2000


Constructor Summary
ECNRSigner()
           
 
Method Summary
 java.math.BigInteger[] generateSignature(byte[] digest)
          generate a signature for the given message using the key we were initialised with.
 void init(boolean forSigning, CipherParameters param)
          initialise the signer for signature generation or signature verification.
 boolean verifySignature(byte[] digest, java.math.BigInteger r, java.math.BigInteger s)
          return true if the value r and s represent a signature for the message passed in.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

ECNRSigner

public ECNRSigner()
Method Detail

init

public void init(boolean forSigning,
                 CipherParameters param)
Description copied from interface: DSA
initialise the signer for signature generation or signature verification.

Specified by:
init in interface DSA
Parameters:
forSigning - true if we are generating a signature, false otherwise.
param - key parameters for signature generation.

generateSignature

public java.math.BigInteger[] generateSignature(byte[] digest)
generate a signature for the given message using the key we were initialised with. Generally, the order of the curve should be at least as long as the hash of the message of interest, and with ECNR it *must* be at least as long.

Specified by:
generateSignature in interface DSA
Parameters:
digest - the digest to be signed.
Returns:
two big integers representing the r and s values respectively.
Throws:
DataLengthException - if the digest is longer than the key allows

verifySignature

public boolean verifySignature(byte[] digest,
                               java.math.BigInteger r,
                               java.math.BigInteger s)
return true if the value r and s represent a signature for the message passed in. Generally, the order of the curve should be at least as long as the hash of the message of interest, and with ECNR, it *must* be at least as long. But just in case the signer applied mod(n) to the longer digest, this implementation will apply mod(n) during verification.

Specified by:
verifySignature in interface DSA
Parameters:
digest - the digest to be verified.
r - the r value of the signature.
s - the s value of the signature.
Throws:
DataLengthException - if the digest is longer than the key allows

Bouncy Castle Cryptography Library 1.37