public Spkac(String challenge,SignatureType signatureAlgorithm,SpkacSubject subject,PublicKey publicKey,PrivateKey privateKey) throws SpkacException {
  this.challenge=challenge;
  this.signatureAlgorithm=signatureAlgorithm;
  this.subject=subject;
  this.publicKey=publicKey;
  this.signature=createSignature(privateKey);
}

public Spkac ( String challenge , SignatureType signatureAlgorithm , SpkacSubject subject , PublicKey publicKey , PrivateKey privateKey ) throws SpkacException { this . challenge = challenge ; this . signatureAlgorithm = signatureAlgorithm ; this . subject = subject ; this . publicKey = publicKey ; this . signature = createSignature ( privateKey ) ; }
construct a new spkac .
