PGP Decryption Will Work From Java1.5/1.6 Cmd Prom, Java Example Java Io WriteUTF8

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Pramod

PGP decryption will work from Java1.5/1.6 cmd prom,
July 3, 2009 at 11:26 AM

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.NoSuchProviderException;
import java.security.Security;
import java.util.Iterator;

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.openpgp.PGPCompressedData;
import org.bouncycastle.openpgp.PGPEncryptedDataList;
import org.bouncycastle.openpgp.PGPException;
import org.bouncycastle.openpgp.PGPLiteralData;
import org.bouncycastle.openpgp.PGPObjectFactory;
import org.bouncycastle.openpgp.PGPOnePassSignatureList;
import org.bouncycastle.openpgp.PGPPrivateKey;
import org.bouncycastle.openpgp.PGPPublicKeyEncryptedData;
import org.bouncycastle.openpgp.PGPSecretKey;
import org.bouncycastle.openpgp.PGPSecretKeyRingCollection;
import org.bouncycastle.openpgp.PGPUtil;

public class Test {
private static File privateKeyFile = new File("Private Key path");

private static String privateKeyPassword = "Password/passphrase";

private static PGPPrivateKey findSecretKey(InputStream keyIn, long keyID, char[] pass) throws IOException, PGPException, NoSuchProviderException {
PGPSecretKeyRingCollection pgpSec = new PGPSecretKeyRingCollection(PGPUtil.getDecoderStream(keyIn));
PGPSecretKey secretKey = pgpSec.getSecretKey(keyID);
if (secretKey == null) {
return null;
}
return secretKey.extractPrivateKey(pass, "BC");

}

public static String decrypt(byte[] encdata) {
System.out.println("decrypt(): data length=" + encdata.length);

try {
ByteArrayInputStream bais = new ByteArrayInputStream(encdata);
FileInputStream privKey = new FileInputStream(privateKeyFile);
return _decrypt(bais, privKey, privateKeyPassword.toCharArray());
} catch (Exception e) {
System.out.println(e.getMessage());
e.printStackTrace();
}
return null;
}

private static String _decrypt(InputStream in, InputStream keyIn, char[] passwd) throws Exception {
in = PGPUtil.getDecoderStream(in);
try {
PGPObjectFactory pgpF = new PGPObjectFactory(in);
PGPEncryptedDataList enc;
Object o = pgpF.nextObject();
//
// the first object might be a PGP marker packet.
//
if (o instanceof PGPEncryptedDataList) {
enc = (PGPEncryptedDataList) o;
} else {
enc = (PGPEncryptedDataList) pgpF.nextObject();
}
//
// find the secret key
//
Iterator iterator = enc.getEncryptedDataObjects();
PGPPrivateKey privateKey = null;
PGPPublicKeyEncryptedData publicKeyEncryptedData = null;
while (privateKey == null && iterator.hasNext()) {
publicKeyEncryptedData = (PGPPublicKeyEncryptedData) iterator.next();
System.out.println("publicKeyEncryptedData id=" + publicKeyEncryptedData.getKeyID());
privateKey = findSecretKey(keyIn, publicKeyEncryptedData.getKeyID(), passwd);
}
if (privateKey == null) {
throw new IllegalArgumentException("secret key for message not found.");
}
System.out.println("my-alg:" + privateKey.getKey().getAlgorithm());
System.out.println("private key" + privateKey.toString());
InputStream inputStream = publicKeyEncryptedData.getDataStream(privateKey, "BC", "BC");
PGPObjectFactory objectFactory = new PGPObjectFactory(inputStream);
Object message = objectFactory.nextObject();
if (message instanceof PGPCompressedData) {
PGPCompressedData cData = (PGPCompressedData) message;
PGPObjectFactory pgpFact = new PGPObjectFactory(cData.getDataStream());
message = pgpFact.nextObject();
}
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
if (message instanceof PGPLiteralData) {
PGPLiteralData pgpLiteralData = (PGPLiteralData) message;
InputStream unc = pgpLiteralData.getInputStream();
int ch;
while ((ch = unc.read()) >= 0) {
byteArrayOutputStream.write(ch);
}
} else if (message instanceof PGPOnePassSignatureList) {
throw new PGPException("encrypted message contains a signed message - not literal data.");
} else {
throw new PGPException("message is not a simple encrypted file - type unknown.");
}
if (publicKeyEncryptedData.isIntegrityProtected()) {
if (!publicKeyEncryptedData.verify()) {
System.err.println("message failed integrity check");
} else {
System.err.println("message integrity check passed");
}
} else {
System.err.println("no message integrity check");
}
return byteArrayOutputStream.toString();
} catch (PGPException e) {
System.err.println(e);
if (e.getUnderlyingException() != null) {
e.getUnderlyingException().printStackTrace();
}
}
return null;
}

public static void main(String[] args) throws IOException {
Security.addProvider(new BouncyCastleProvider());
byte[] newB = null;
try {
FileInputStream fileInputStream = new FileInputStream("encrypted file");
newB = new byte[fileInputStream.available()];
System.out.println("read bytes: " + fileInputStream.read(newB));
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("byte array" + newB.length);
// ----- Decrypt the token that
String result = decrypt(newB);
FileOutputStream decryptedFile = new FileOutputStream("C:/new.txt");

while(result.length()!= -1)
{
decryptedFile.write(result.getBytes());
}

System.out.println("Decrypted: " + result);
}

}

Copy the bc jar files into jre/ext directory and copy jce_policy jars into jre/lib/security folder

It works....
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