基于Java代码进行GPG加解密

依赖

<!-- https://mvnrepository.com/artifact/org.bouncycastle/bcpg-jdk15on -->
<dependency>
    <groupId>org.bouncycastle</groupId>
    <artifactId>bcpg-jdk15on</artifactId>
    <version>1.65</version>
</dependency>

初始化

Security.addProvider(new BouncyCastleProvider());

辅助类

@Slf4j
public class PGPFileProcessor {

    public static void decryptFile(String inputFilePath, String keyFilePath, char[] passWd, String outputFilePath)
            throws IOException, NoSuchProviderException {
        InputStream in = new BufferedInputStream(new FileInputStream(inputFilePath));
        InputStream keyIn = new BufferedInputStream(new FileInputStream(keyFilePath));
        decryptFile(in, keyIn, passWd, outputFilePath);
        keyIn.close();
        in.close();
    }

    public static void decryptFile(File inputFile, String keyFilePath, char[] passWd, File outputFile)
            throws IOException, NoSuchProviderException {
        InputStream in = new BufferedInputStream(new FileInputStream(inputFile));
        InputStream keyIn = new BufferedInputStream(new FileInputStream(keyFilePath));
        decryptFile(in, keyIn, passWd, outputFile.getAbsolutePath());
        keyIn.close();
        in.close();
    }

    /**
     * decrypt the passed in message stream
     */
    private static void decryptFile(InputStream in, InputStream keyIn, char[] passWd, String outputFilePath)
            throws IOException, NoSuchProviderException {
        in = PGPUtil.getDecoderStream(in);
        try {
            JcaPGPObjectFactory pgpF = new JcaPGPObjectFactory(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<PGPEncryptedData> it = enc.getEncryptedDataObjects();
            PGPPrivateKey sKey = null;
            PGPPublicKeyEncryptedData pbe = null;
            PGPSecretKeyRingCollection pgpSec = new PGPSecretKeyRingCollection(
                    PGPUtil.getDecoderStream(keyIn), new JcaKeyFingerprintCalculator());
            while (sKey == null && it.hasNext()) {
                pbe = (PGPPublicKeyEncryptedData) it.next();
                sKey = PGPHelper.findSecretKey(pgpSec, pbe.getKeyID(), passWd);
            }
            if (sKey == null) {
                throw new IllegalArgumentException("secret key for message not found.");
            }
            InputStream clear = pbe.getDataStream(new JcePublicKeyDataDecryptorFactoryBuilder().setProvider("BC").build(sKey));
            JcaPGPObjectFactory plainFact = new JcaPGPObjectFactory(clear);
            Object message = plainFact.nextObject();
            if (message instanceof PGPCompressedData) {
                PGPCompressedData cData = (PGPCompressedData) message;
                JcaPGPObjectFactory pgpFact = new JcaPGPObjectFactory(cData.getDataStream());
                message = pgpFact.nextObject();
            }
            if (message instanceof PGPLiteralData) {
                PGPLiteralData ld = (PGPLiteralData) message;
                String outFilePath = ld.getFileName();
                if (outFilePath.length() == 0) {
                    outFilePath = outputFilePath;
                } else {
                    outFilePath = outputFilePath;
                }
                InputStream unc = ld.getInputStream();
                OutputStream fOut = new BufferedOutputStream(new FileOutputStream(outFilePath));
                Streams.pipeAll(unc, fOut);
                fOut.close();
            } 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()) {
                    log.error("PGP.decryptFile: message failed integrity check");
                } else {
                    log.info("PGP.decryptFile: message integrity check passed");
                }
            } else {
                log.error("PGP.decryptFile: no message integrity check");
            }
        } catch (PGPException e) {
            log.error("PGP.decryptFile exception: ", e);
            if (e.getUnderlyingException() != null) {
                log.error("PGP.decryptFile underlying exception: ", e.getUnderlyingException());
            }
        }
    }

    public static void encryptFile(String outputFilePath, String inputFilePath, String encKeyFilePath,
                                    boolean armor, boolean withIntegrityCheck)
            throws IOException, NoSuchProviderException, PGPException {
        OutputStream out = new BufferedOutputStream(new FileOutputStream(outputFilePath));
        PGPPublicKey encKey = PGPHelper.readPublicKey(encKeyFilePath);
        encryptFile(out, inputFilePath, encKey, armor, withIntegrityCheck);
        out.close();
    }

    private static void encryptFile(OutputStream out, String inputFilePath, PGPPublicKey encKey,
            boolean armor, boolean withIntegrityCheck)
            throws IOException, NoSuchProviderException {
        if (armor) {
            out = new ArmoredOutputStream(out);
        }

        try {
            byte[] bytes = PGPHelper.compressFile(inputFilePath, CompressionAlgorithmTags.ZIP);
            PGPEncryptedDataGenerator encGen = new PGPEncryptedDataGenerator(
                    new JcePGPDataEncryptorBuilder(PGPEncryptedData.CAST5).setWithIntegrityPacket(withIntegrityCheck).setSecureRandom(new SecureRandom()).setProvider("BC"));
            encGen.addMethod(new JcePublicKeyKeyEncryptionMethodGenerator(encKey).setProvider("BC"));
            OutputStream cOut = encGen.open(out, bytes.length);
            cOut.write(bytes);
            cOut.close();
            if (armor) {
                out.close();
            }
        } catch (PGPException e) {
            log.error("PGP.encryptFile exception: ", e);
            if (e.getUnderlyingException() != null) {
                log.error("PGP.encryptFile underlying exception: ", e.getUnderlyingException());
            }
        }
    }

    //主方法
    public static void main(String[] s) throws Exception {
        Security.addProvider(new BouncyCastleProvider());
        String inputPath = "E:\\AppBlog\\test.csv.gpg";
        String outputPath = "E:\\AppBlog\\test.csv";
        String password = "appblog.cn";  //私钥的Key
        String privateKey = "E:\\AppBlog\\test.key"; //私钥地址
        decryptFile(inputPath, privateKey, password.toCharArray(), outputPath);
    }

}

public class PGPHelper {

    public static byte[] compressFile(String fileName, int algorithm) throws IOException {
        ByteArrayOutputStream bOut = new ByteArrayOutputStream();
        PGPCompressedDataGenerator comData = new PGPCompressedDataGenerator(algorithm);
        PGPUtil.writeFileToLiteralData(comData.open(bOut), PGPLiteralData.BINARY,
                new File(fileName));
        comData.close();
        return bOut.toByteArray();
    }

    /**
     * Search a secret key ring collection for a secret key corresponding to keyID if it exists.
     *
     * @param pgpSec a secret key ring collection.
     * @param keyID  keyID we want.
     * @param pass   passphrase to decrypt secret key with.
     * @return the private key.
     * @throws PGPException
     * @throws NoSuchProviderException
     */
    public static PGPPrivateKey findSecretKey(PGPSecretKeyRingCollection pgpSec, long keyID, char[] pass)
            throws PGPException, NoSuchProviderException {
        PGPSecretKey pgpSecKey = pgpSec.getSecretKey(keyID);
        if (pgpSecKey == null) {
            return null;
        }
        return pgpSecKey.extractPrivateKey(new JcePBESecretKeyDecryptorBuilder().setProvider("BC").build(pass));
    }

    public static PGPPublicKey readPublicKey(String fileName) throws IOException, PGPException {
        InputStream keyIn = new BufferedInputStream(new FileInputStream(fileName));
        PGPPublicKey pubKey = readPublicKey(keyIn);
        keyIn.close();
        return pubKey;
    }

    /**
     * A simple routine that opens a key ring file and loads the first available key
     * suitable for encryption.
     *
     * @param input data stream containing the public key data
     * @return the first public key found.
     * @throws IOException
     * @throws PGPException
     */

    public static PGPPublicKey readPublicKey(InputStream input) throws IOException, PGPException {
        PGPPublicKeyRingCollection pgpPub = new PGPPublicKeyRingCollection(
                PGPUtil.getDecoderStream(input), new JcaKeyFingerprintCalculator());
        // 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.
        Iterator<PGPPublicKeyRing> keyRingIter = pgpPub.getKeyRings();
        while (keyRingIter.hasNext()) {
            PGPPublicKeyRing keyRing = keyRingIter.next();
            Iterator<PGPPublicKey> keyIter = keyRing.getPublicKeys();
            while (keyIter.hasNext()) {
                PGPPublicKey key = keyIter.next();
                if (key.isEncryptionKey()) {
                    return key;
                }
            }
        }
        throw new IllegalArgumentException("Can't find encryption key in key ring.");
    }

    public static PGPSecretKey readSecretKey(String fileName) throws IOException, PGPException {
        InputStream keyIn = new BufferedInputStream(new FileInputStream(fileName));
        PGPSecretKey secKey = readSecretKey(keyIn);
        keyIn.close();
        return secKey;
    }

    /**
     * A simple routine that opens a key ring file and loads the first available key
     * suitable for signature generation.
     *
     * @param input stream to read the secret key ring collection from.
     * @return a secret key.
     * @throws IOException  on a problem with using the input stream.
     * @throws PGPException if there is an issue parsing the input stream.
     */
    public static PGPSecretKey readSecretKey(InputStream input) throws IOException, PGPException {
        PGPSecretKeyRingCollection pgpSec = new PGPSecretKeyRingCollection(
                PGPUtil.getDecoderStream(input), new JcaKeyFingerprintCalculator());
        // 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.
        Iterator<PGPSecretKeyRing> keyRingIter = pgpSec.getKeyRings();
        while (keyRingIter.hasNext()) {
            PGPSecretKeyRing keyRing = keyRingIter.next();
            Iterator<PGPSecretKey> keyIter = keyRing.getSecretKeys();
            while (keyIter.hasNext()) {
                PGPSecretKey key = keyIter.next();
                if (key.isSigningKey()) {
                    return key;
                }
            }
        }
        throw new IllegalArgumentException("Can't find signing key in key ring.");
    }

}