import java.util.* ; import java.sql.*; import java.io.*; import java.security.*; class SignGen { public static long getCurrentTime() { java.util.Date date=Calendar.getInstance().getTime(); Timestamp a=new Timestamp(date.getTime()); long currentTime=Calendar.getInstance().getTimeInMillis(); // System.out.println("Time: "+currentTime); return currentTime; } public static void main(String args[]) { if(args.length!=1){ System.out.println("Usage: SignGen "); System.exit(0); } try{ /************************* BEGIN Generate a key pair ***************************/ KeyPairGenerator keygen = KeyPairGenerator.getInstance("DSA","SUN"); SecureRandom random = SecureRandom.getInstance("SHA1PRNG","SUN"); KeyPairGenerator rsaKeygen = KeyPairGenerator.getInstance("RSA"); rsaKeygen.initialize(1024,random); keygen.initialize(1024,random); KeyPair rsaKeypair = rsaKeygen.generateKeyPair(); KeyPair keypair = keygen.generateKeyPair(); PrivateKey rsaPrivatekey = rsaKeypair.getPrivate(); PublicKey rsaPublickey = rsaKeypair.getPublic(); PrivateKey privatekey = keypair.getPrivate(); PublicKey publickey = keypair.getPublic(); /************************* END Generate a key pair ***************************/ /************* Create a Signature object and initialize it with private key **************/ Signature dsa = Signature.getInstance("SHA1withDSA","SUN"); dsa.initSign(privatekey); Signature rsa= Signature.getInstance("SHA1withRSA"); rsa.initSign(rsaPrivatekey); /************************* Update and Sign the data ***************************/ FileInputStream fis = new FileInputStream(args[0]); BufferedInputStream bis = new BufferedInputStream(fis); StringBuffer sb=new StringBuffer(""); byte buffer[] = new byte[1024]; int length; while(bis.available() != 0){ length = bis.read(buffer); dsa.update(buffer,0,length); rsa.update(buffer,0,length); sb.append(new String(buffer)); } bis.close(); /* * Now, that all the data t obe signed is read in, * and hash generated ( using update method ) * generate a signature for it */ byte[] realsign = dsa.sign(); byte [] rsaSign=rsa.sign(); String data=new String(sb); /*********** Save signature in a file *************/ FileOutputStream sigfos = new FileOutputStream(args[0]+".dsa_sign"); sigfos.write(realsign); sigfos.close(); sigfos = new FileOutputStream(args[0]+".rsa_sign"); sigfos.write(rsaSign); sigfos.close(); /*********** Save Public key in a file ************/ FileOutputStream pubkeyfos = new FileOutputStream(args[0]+".dsa_sign_public_key"); pubkeyfos.write(publickey.getEncoded()); pubkeyfos.close(); pubkeyfos = new FileOutputStream(args[0]+".rsa_sign_public_key"); pubkeyfos.write(rsaPublickey.getEncoded()); pubkeyfos.close(); /*********** Save Private key in a file ************/ FileOutputStream prikeyfos = new FileOutputStream(args[0]+".dsa_sign_private_key"); prikeyfos.write(privatekey.getEncoded()); prikeyfos.close(); prikeyfos = new FileOutputStream(args[0]+".rsa_sign_private_key"); prikeyfos.write(rsaPrivatekey.getEncoded()); prikeyfos.close(); /*********Verification****************************/ Signature dsa1 = Signature.getInstance("SHA1withDSA","SUN"); //dsa.initSign(privatekey); Signature rsa1= Signature.getInstance("SHA1withRSA"); rsa1.initVerify(rsaPublickey); dsa1.initVerify(publickey); System.out.print("\n"+data); fis = new FileInputStream(args[0]); bis = new BufferedInputStream(fis); //byte buffer[] = new byte[1024]; //int length; while(bis.available() != 0){ length = bis.read(buffer); dsa1.update(buffer,0,length); rsa1.update(buffer,0,length); //sb.append(new String(buffer)); } bis.close(); //rsa1.update(data.getBytes()); //dsa1.update(data.getBytes()); if(rsa1.verify(rsaSign)) { System.out.println("RSA sign verified"); } else { System.out.println("RSA sign verification failed"); } if(dsa1.verify(realsign)) { System.out.println("DSA sign verified"); } else { System.out.println("DSA sign verification failed"); } /********Time ****************/ System.out.println( "Key_Size MSg_Size RSA_SIgning DSA_signing RSA_vrify DSA_Verify" ) ; String msg="Kanwal Rekhi School of Information Technology, IIT Bombay"; long start,end; for(int primeSize=512;primeSize<=2048;primeSize*=2) { System.out.print(""+primeSize); System.out.print(" "+msg.length()); rsaKeygen.initialize(primeSize,random); keygen.initialize(primeSize,random); rsaKeypair = rsaKeygen.generateKeyPair(); keypair = keygen.generateKeyPair(); rsaPrivatekey = rsaKeypair.getPrivate(); rsaPublickey = rsaKeypair.getPublic(); privatekey = keypair.getPrivate(); publickey = keypair.getPublic(); dsa.initSign(privatekey); rsa.initSign(rsaPrivatekey); rsa.update(msg.getBytes()); dsa.update(msg.getBytes()); start=getCurrentTime(); rsa.sign(); end=getCurrentTime(); System.out.print(" "+(end-start)); start=getCurrentTime(); dsa.sign(); end=getCurrentTime(); System.out.print(" "+(end-start)); rsa.initVerify(rsaPublickey); dsa.initVerify(publickey); rsa.update(msg.getBytes()); start=getCurrentTime(); rsa.verify(rsaSign); end=getCurrentTime(); System.out.print(" "+(end-start)); dsa.update(msg.getBytes()); start=getCurrentTime(); dsa.verify(realsign); end=getCurrentTime(); System.out.println(" "+(end-start)); if(primeSize==512) { int i,m=0; StringBuffer ptext=new StringBuffer(4096); StringBuffer ts=new StringBuffer(128); ts.append("RAMA"); while(ts.length()<128)//making a message of 128B length { ts.append(ts.toString()); } for(int mSize=0;mSize<=4096;) { System.out.print( ""+primeSize+" " ) ; System.out.print( ""+mSize+" " ) ; dsa.initSign(privatekey); rsa.initSign(rsaPrivatekey); msg=new String(ptext); rsa.update(msg.getBytes()); dsa.update(msg.getBytes()); start=getCurrentTime(); rsa.sign(); end=getCurrentTime(); System.out.print(""+(end-start)); start=getCurrentTime(); dsa.sign(); end=getCurrentTime(); System.out.print(" "+(end-start)); rsa.initVerify(rsaPublickey); dsa.initVerify(publickey); rsa.update(msg.getBytes()); start=getCurrentTime(); rsa.verify(rsaSign); end=getCurrentTime(); System.out.print(" "+(end-start)); dsa.update(msg.getBytes()); start=getCurrentTime(); dsa.verify(realsign); end=getCurrentTime(); System.out.println(" "+(end-start)); ptext.append(ts); mSize=ptext.length(); }//for msize }//if prime }//for prime }catch(Exception e){ e.printStackTrace(); } } }