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//***************************************//
package cryptage;
import java.io.IOException;
import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.PublicKey;
import java.security.SecureRandom;
import javax.crypto.spec.*;
import org.bouncycastle.crypto.AsymmetricBlockCipher;
import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.InvalidCipherTextException;
import org.bouncycastle.crypto.encodings.PKCS1Encoding;
import org.bouncycastle.crypto.engines.RSAEngine;
import org.bouncycastle.crypto.generators.RSAKeyPairGenerator;
import org.bouncycastle.crypto.params.RSAKeyGenerationParameters;
import org.bouncycastle.crypto.params.RSAKeyParameters;
import org.bouncycastle.crypto.params.RSAPrivateCrtKeyParameters;
import org.bouncycastle.util.encoders.Base64;
import sun.misc.BASE64Encoder;
import java.security.spec.RSAPublicKeySpec;
public class Encryption {
private RSAPrivateCrtKeyParameters _RSAPrivateKey;
private RSAKeyParameters _RSAPublicKey;
RSAKeyParameters rsaKeysFromWS;
private BigInteger exponent;
private BigInteger modulus;
public static void main(String[] args) {
Encryption theEncryption = new Encryption();
String theStringBeforeEncryption="salu tout le monde";
String theEncryptedString;
String theDecryptedString;
try {
//generation de la paire des clés
theEncryption.generateRSAKeyPair();
//cryptage de la chaine
//le resultat est un chaine encodée Base64
theEncryptedString = theEncryption.RSAEncrypt(theStringBeforeEncryption,theEncryption.get_RSAPublicKey());
System.out.println(theEncryptedString);
//decodage de la chaine
String s1=new String(Base64.decode(theEncryptedString));
//affiche de la chaine decodée et sa longueur
System.out.println(s1+":"+s1.length());
//decryptage de la chaine
//resultat encodée en Base64
theDecryptedString = theEncryption.RSADecrypt(s1,theEncryption.get_RSAPrivateKey());
System.out.println(theDecryptedString);
//decodeage de la chaine
String s2=new String(Base64.decode(theDecryptedString));
//affichage de la chaine decryptée puis decodée
System.out.println(s2);
} catch (Exception e) {
// TODO Handle exception!
e.printStackTrace();
}
}
public void generateRSAKeyPair() throws Exception {
System.out.println("on est en train de generrer les cles");
SecureRandom theSecureRandom = new SecureRandom();
BigInteger thePublicExponent = new BigInteger("10001", 20);
RSAKeyGenerationParameters theRSAKeyGenParam = new RSAKeyGenerationParameters(
thePublicExponent, theSecureRandom, 512, 100);
RSAKeyPairGenerator theRSAKeyPairGen = new RSAKeyPairGenerator();
theRSAKeyPairGen.init(theRSAKeyGenParam);
AsymmetricCipherKeyPair theKeyPair = theRSAKeyPairGen.generateKeyPair();
_RSAPrivateKey = (RSAPrivateCrtKeyParameters) theKeyPair.getPrivate();
_RSAPublicKey = (RSAKeyParameters) theKeyPair.getPublic();
String s1=getMod(_RSAPublicKey);
String s2=getExp(_RSAPublicKey);
modulus = new BigInteger(1,Base64.decode(s1));
exponent = new BigInteger(1,Base64.decode(s2));
rsaKeysFromWS = new RSAKeyParameters(false, modulus, exponent);
set_RSAPrivateKey(_RSAPrivateKey);
set_RSAPublicKey(_RSAPublicKey);
}
public String RSAEncrypt(String Encrypt,RSAKeyParameters rsaKeysFromWS1) throws Exception {
if (rsaKeysFromWS1 == null) {
throw new Exception(
"Please generate RSA keys first in order to work");
}
byte[] toEncrypt = Encrypt.getBytes();
AsymmetricBlockCipher theEngine = new RSAEngine();
theEngine = new PKCS1Encoding(theEngine);
theEngine.init(true, rsaKeysFromWS1);
//return theEngine.processBlock(toEncrypt, 0, toEncrypt.length);
try
{
byte[] raw = theEngine.processBlock(toEncrypt, 0, toEncrypt.length);
String tmpStr = new String(Base64.encode(raw));
return tmpStr;
} catch (InvalidCipherTextException err) {
return "";
}
}
public String RSADecrypt(String Decrypt,RSAPrivateCrtKeyParameters RSAPrivateKey) throws Exception {
if (RSAPrivateKey == null) {
throw new Exception(
"Please generate RSA keys first in order to work");
}
byte[] toDecrypt = Decrypt.getBytes();
System.out.println(toDecrypt);
System.out.println(toDecrypt.length);
AsymmetricBlockCipher theEngine = new RSAEngine();
theEngine = new PKCS1Encoding(theEngine);
theEngine.init(false,RSAPrivateKey);
//return theEngine.processBlock(toDecrypt, 0, toDecrypt.length);
try
{
byte[] raw = theEngine.processBlock(toDecrypt, 0,toDecrypt.length);
String tmpStr = new String(Base64.encode(raw));
return tmpStr;
} catch (InvalidCipherTextException err) {
return "";
}
}
/*****************************************/
// Public key specific parameter.
public static String getMod(RSAKeyParameters rsaKey) throws Exception {
return (new String(Base64.encode(rsaKey.getModulus().toByteArray())));
}
// General key parameter. pubExp is the same as pubKey.getExponent()
public static String getExp(RSAKeyParameters rsaKey) throws Exception {
return (new String(Base64.encode(rsaKey.getExponent().toByteArray())));
}
// General key parameter. pubExp is the same as pubKey.getExponent()
public String getPubExp(RSAKeyParameters rsaKey) throws Exception {
return (new String(Base64.encode(rsaKey.getExponent().toByteArray())));
}
public RSAPrivateCrtKeyParameters get_RSAPrivateKey() {
return _RSAPrivateKey;
}
public void set_RSAPrivateKey(RSAPrivateCrtKeyParameters privateKey) {
_RSAPrivateKey = privateKey;
}
public RSAKeyParameters get_RSAPublicKey() {
return _RSAPublicKey;
}
public void set_RSAPublicKey(RSAKeyParameters publicKey) {
_RSAPublicKey = publicKey;
}
} |
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