Android Open Source - amanaje Pgp Helper

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License

The source code is released under:

Apache License

Java Source Code

package org.jdamico.bc.openpgp.utils;
/*  ww  w.  j  a  v  a 2 s  .c  o m*/
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.NoSuchProviderException;
import java.security.SecureRandom;
import java.security.Security;
import java.util.Iterator;

import org.spongycastle.bcpg.ArmoredOutputStream;
import org.spongycastle.jce.provider.BouncyCastleProvider;
import org.spongycastle.openpgp.PGPCompressedData;
import org.spongycastle.openpgp.PGPCompressedDataGenerator;
import org.spongycastle.openpgp.PGPEncryptedData;
import org.spongycastle.openpgp.PGPEncryptedDataGenerator;
import org.spongycastle.openpgp.PGPEncryptedDataList;
import org.spongycastle.openpgp.PGPException;
import org.spongycastle.openpgp.PGPLiteralData;
import org.spongycastle.openpgp.PGPObjectFactory;
import org.spongycastle.openpgp.PGPOnePassSignatureList;
import org.spongycastle.openpgp.PGPPrivateKey;
import org.spongycastle.openpgp.PGPPublicKey;
import org.spongycastle.openpgp.PGPPublicKeyEncryptedData;
import org.spongycastle.openpgp.PGPPublicKeyRing;
import org.spongycastle.openpgp.PGPPublicKeyRingCollection;
import org.spongycastle.openpgp.PGPSecretKey;
import org.spongycastle.openpgp.PGPSecretKeyRingCollection;
import org.spongycastle.openpgp.PGPUtil;
import org.spongycastle.openpgp.operator.PBESecretKeyDecryptor;
import org.spongycastle.openpgp.operator.PublicKeyDataDecryptorFactory;
import org.spongycastle.openpgp.operator.jcajce.JcaPGPDigestCalculatorProviderBuilder;
import org.spongycastle.openpgp.operator.jcajce.JcePBESecretKeyDecryptorBuilder;
import org.spongycastle.openpgp.operator.jcajce.JcePGPDataEncryptorBuilder;
import org.spongycastle.openpgp.operator.jcajce.JcePublicKeyDataDecryptorFactoryBuilder;
import org.spongycastle.openpgp.operator.jcajce.JcePublicKeyKeyEncryptionMethodGenerator;

/**
 * Taken from org.bouncycastle.openpgp.examples
 *
 * @author seamans
 * @author jdamico <damico@dcon.com.br>
 *
 */
public class PgpHelper {
  
  private static PgpHelper INSTANCE = null;
  
  public static PgpHelper getInstance(){
    
    if(INSTANCE == null) INSTANCE = new PgpHelper();
    return INSTANCE;
  }
  
  private PgpHelper(){}


  public PGPPublicKey readPublicKey(InputStream in) throws IOException, PGPException {
        in = PGPUtil.getDecoderStream(in);
        PGPPublicKeyRingCollection pgpPub = new PGPPublicKeyRingCollection(in);

        //
        // we just loop through the collection till we find a key suitable for encryption, in the real
        // world you would probably want to be a bit smarter about this.
        //
        PGPPublicKey key = null;

        //
        // iterate through the key rings.
        //
        Iterator<PGPPublicKeyRing> rIt = pgpPub.getKeyRings();

        while (key == null && rIt.hasNext()) {
            PGPPublicKeyRing kRing = rIt.next();
            Iterator<PGPPublicKey> kIt = kRing.getPublicKeys();
            while (key == null && kIt.hasNext()) {
                PGPPublicKey k = kIt.next();

                if (k.isEncryptionKey()) {
                    key = k;
                }
            }
        }

        if (key == null) {
            throw new IllegalArgumentException("Can't find encryption key in key ring.");
        }

        return key;
    }

    /**
     * Load a secret key ring collection from keyIn and find the secret key corresponding to
     * keyID if it exists.
     *
     * @param keyIn input stream representing a key ring collection.
     * @param keyID keyID we want.
     * @param pass passphrase to decrypt secret key with.
     * @return
     * @throws IOException
     * @throws PGPException
     * @throws NoSuchProviderException
     */
    public PGPPrivateKey findSecretKey(InputStream keyIn, long keyID, char[] pass)
      throws IOException, PGPException, NoSuchProviderException
    {
        PGPSecretKeyRingCollection pgpSec = new PGPSecretKeyRingCollection(PGPUtil.getDecoderStream(keyIn));

        PGPSecretKey pgpSecKey = pgpSec.getSecretKey(keyID);

        if (pgpSecKey == null) {
            return null;
        }
        
        PBESecretKeyDecryptor a = new JcePBESecretKeyDecryptorBuilder(new JcaPGPDigestCalculatorProviderBuilder().setProvider("SC").build()).setProvider("SC").build(pass);
        
        return pgpSecKey.extractPrivateKey(a);
    }

    /**
     * decrypt the passed in message stream
     */
    @SuppressWarnings("unchecked")
  public void decryptFile(InputStream in, OutputStream out, InputStream keyIn, char[] passwd)
      throws Exception
    {
      Security.addProvider(new BouncyCastleProvider());
        in = PGPUtil.getDecoderStream(in);
        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<PGPPublicKeyEncryptedData> it = enc.getEncryptedDataObjects();
        PGPPrivateKey sKey = null;
        PGPPublicKeyEncryptedData pbe = null;

        while (sKey == null && it.hasNext()) {
            pbe = it.next();
            sKey = findSecretKey(keyIn, pbe.getKeyID(), passwd);
        }

        if (sKey == null) {
            throw new IllegalArgumentException("Secret key for message not found.");
        }

        PublicKeyDataDecryptorFactory b = new JcePublicKeyDataDecryptorFactoryBuilder().setProvider("SC").setContentProvider("SC").build(sKey);
        
        InputStream clear = pbe.getDataStream(b);

        PGPObjectFactory plainFact = new PGPObjectFactory(clear);

        Object message = plainFact.nextObject();

        if (message instanceof  PGPCompressedData) {
            PGPCompressedData cData = (PGPCompressedData) message;
            PGPObjectFactory pgpFact = new PGPObjectFactory(cData.getDataStream());

            message = pgpFact.nextObject();
        }

        if (message instanceof  PGPLiteralData) {
            PGPLiteralData ld = (PGPLiteralData) message;
            InputStream unc = ld.getInputStream();
            int ch;
            while ((ch = unc.read()) >= 0) {
                out.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 (pbe.isIntegrityProtected()) {
            if (!pbe.verify()) {
              throw new PGPException("Message failed integrity check");
            }
        }
    }

    public void encryptFile(OutputStream out, File msgFile, PGPPublicKey encKey, boolean armor, boolean withIntegrityCheck) throws IOException, NoSuchProviderException, PGPException
    {
      Security.addProvider(new BouncyCastleProvider());

        if (armor) {
            out = new ArmoredOutputStream(out);
        }

        ByteArrayOutputStream bOut = new ByteArrayOutputStream();

        PGPCompressedDataGenerator comData = new PGPCompressedDataGenerator(PGPCompressedData.ZIP);

        PGPUtil.writeFileToLiteralData(comData.open(bOut), PGPLiteralData.BINARY, msgFile);
        
        comData.close();

        JcePGPDataEncryptorBuilder c = new JcePGPDataEncryptorBuilder(PGPEncryptedData.CAST5).setWithIntegrityPacket(withIntegrityCheck).setSecureRandom(new SecureRandom()).setProvider("SC");
        
        PGPEncryptedDataGenerator cPk = new PGPEncryptedDataGenerator(c);
        
        JcePublicKeyKeyEncryptionMethodGenerator d = new JcePublicKeyKeyEncryptionMethodGenerator(encKey).setProvider(new BouncyCastleProvider()).setSecureRandom(new SecureRandom());

        cPk.addMethod(d);

        byte[] bytes = bOut.toByteArray();

        OutputStream cOut = cPk.open(out, bytes.length);

        cOut.write(bytes);

        cOut.close();

        out.close();
    }

}

Java Source Code List

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