Java Bouncycastle PGP 解密和验证

Bouncycastle PGP decrypt and verify

提问by Ramo

I'm trying to decrypt and verify a PGP message using the java BouncyCastle libraries, but am running into issues, complaining about premature ends of PartialInputStream.

我正在尝试使用 java BouncyCastle 库解密和验证 PGP 消息，但遇到了问题，抱怨 PartialInputStream 过早结束。

I know the encrypt works fine, because I can decrypt and verify messages created with the encrypt function using gpg on the command line.

我知道加密工作正常，因为我可以在命令行上使用 gpg 解密和验证使用加密函数创建的消息。

Here's the code:

这是代码：

public static void signEncryptMessage(InputStream in, OutputStream out, PGPPublicKey publicKey, PGPPrivateKey secretKey, SecureRandom rand) throws Exception {
        out = new ArmoredOutputStream(out);

        PGPEncryptedDataGenerator encryptedDataGenerator = new PGPEncryptedDataGenerator(new BcPGPDataEncryptorBuilder(PGPEncryptedData.AES_256).setWithIntegrityPacket(true).setSecureRandom(rand));
        encryptedDataGenerator.addMethod(new BcPublicKeyKeyEncryptionMethodGenerator(publicKey));

        OutputStream compressedOut = new PGPCompressedDataGenerator(PGPCompressedData.ZIP).open(encryptedDataGenerator.open(out, 4096), new byte[4096]);

        PGPSignatureGenerator signatureGenerator = new PGPSignatureGenerator(new BcPGPContentSignerBuilder(publicKey.getAlgorithm(), HashAlgorithmTags.SHA512));
        signatureGenerator.init(PGPSignature.BINARY_DOCUMENT, secretKey);
        signatureGenerator.generateOnePassVersion(true).encode(compressedOut);

        OutputStream finalOut = new PGPLiteralDataGenerator().open(compressedOut, PGPLiteralData.BINARY, "", new Date(), new byte[4096]);

        byte[] buf = new byte[4096];
        int len;
        while ((len = in.read(buf)) > 0) {
            finalOut.write(buf, 0, len);
            signatureGenerator.update(buf, 0, len);
        }

        finalOut.close();
        in.close();
        signatureGenerator.generate().encode(compressedOut);
        compressedOut.close();
        encryptedDataGenerator.close();
        out.close();
    }

    public static void decryptVerifyMessage(InputStream in, OutputStream out, PGPPrivateKey secretKey, PGPPublicKey publicKey) throws Exception {
        in = new ArmoredInputStream(in);

        PGPObjectFactory pgpF = new PGPObjectFactory(in);
        PGPEncryptedDataList enc = (PGPEncryptedDataList) pgpF.nextObject();

        PGPObjectFactory plainFact = new PGPObjectFactory(((PGPPublicKeyEncryptedData) enc.getEncryptedDataObjects().next()).getDataStream(new JcePublicKeyDataDecryptorFactoryBuilder().setProvider("BC").build(secretKey)));

        Object message = null;

        PGPOnePassSignatureList onePassSignatureList = null;
        PGPSignatureList signatureList = null;
        PGPCompressedData compressedData = null;

        message = plainFact.nextObject();
        ByteArrayOutputStream actualOutput = new ByteArrayOutputStream();

        while (message != null) {
            System.out.println(message.toString());
            if (message instanceof PGPCompressedData) {
                compressedData = (PGPCompressedData) message;
                plainFact = new PGPObjectFactory(compressedData.getDataStream());
                message = plainFact.nextObject();
                System.out.println(message.toString());
            }

            if (message instanceof PGPLiteralData) {
                Streams.pipeAll(((PGPLiteralData) message).getInputStream(), actualOutput);
            } else if (message instanceof PGPOnePassSignatureList) {
                onePassSignatureList = (PGPOnePassSignatureList) message;
            } else if (message instanceof PGPSignatureList) {
                signatureList = (PGPSignatureList) message;
            } else {
                throw new PGPException("message unknown message type.");
            }
            message = plainFact.nextObject();
        }
        actualOutput.close();
        byte[] output = actualOutput.toByteArray();
        if (onePassSignatureList == null || signatureList == null) {
            throw new PGPException("Poor PGP. Signatures not found.");
        } else {

            for (int i = 0; i < onePassSignatureList.size(); i++) {
                PGPOnePassSignature ops = onePassSignatureList.get(0);
                System.out.println("verifier : " + ops.getKeyID());
                if (publicKey != null) {
                    ops.init(new JcaPGPContentVerifierBuilderProvider().setProvider("BC"), publicKey);
                    ops.update(output);
                    PGPSignature signature = signatureList.get(i);
                    if (ops.verify(signature)) {
                        Iterator<?> userIds = publicKey.getUserIDs();
                        while (userIds.hasNext()) {
                            String userId = (String) userIds.next();
                            System.out.println("Signed by " + userId);
                        }
                        System.out.println("Signature verified");
                    } else {
                        throw new SignatureException("Signature verification failed");
                    }
                }
            }

        }

        out.write(output);
        out.flush();
        out.close();
    }

    public static void main(String args[]) {
        Security.insertProviderAt(new BouncyCastleProvider(), 0);
        byte inBytes[] = "The quick brown fox jumps over the lazy dog.".getBytes();

        try {
            SecureRandom rand = new SecureRandom();

            RSAKeyPairGenerator kpg = new RSAKeyPairGenerator();
            kpg.init(new RSAKeyGenerationParameters(BigInteger.valueOf(0x10001), rand, 1024, 90));

            BcPGPKeyPair sender = new BcPGPKeyPair(PGPPublicKey.RSA_GENERAL, kpg.generateKeyPair(), new Date());
            BcPGPKeyPair recip = new BcPGPKeyPair(PGPPublicKey.RSA_GENERAL, kpg.generateKeyPair(), new Date());

            ByteArrayOutputStream sendMessage = new ByteArrayOutputStream();
            ByteArrayOutputStream recvMessage = new ByteArrayOutputStream();
            signEncryptMessage(new ByteArrayInputStream(inBytes), sendMessage, recip.getPublicKey(), sender.getPrivateKey(), rand);

            System.out.println(sendMessage.toString());

            decryptVerifyMessage(new ByteArrayInputStream(sendMessage.toByteArray()), recvMessage, recip.getPrivateKey(), sender.getPublicKey());

            System.out.println(recvMessage.toString());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

After a few runs of message = plainFact.nextObject();the exception is thrown:

几次运行后message = plainFact.nextObject();抛出异常：

-----BEGIN PGP MESSAGE-----
Version: BCPG v1.49
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=ApMf
-----END PGP MESSAGE-----

org.bouncycastle.openpgp.PGPCompressedData@cd36a6d
org.bouncycastle.openpgp.PGPOnePassSignatureList@7e224235
org.bouncycastle.openpgp.PGPLiteralData@7b28e644
java.io.EOFException: premature end of stream in PartialInputStream
    at org.bouncycastle.bcpg.BCPGInputStream$PartialInputStream.read(Unknown Source)
    at org.bouncycastle.bcpg.BCPGInputStream.read(Unknown Source)
    at java.io.InputStream.read(InputStream.java:101)
    at javax.crypto.CipherInputStream.getMoreData(CipherInputStream.java:103)
    at javax.crypto.CipherInputStream.read(CipherInputStream.java:177)
    at org.bouncycastle.bcpg.BCPGInputStream.read(Unknown Source)
    at org.bouncycastle.openpgp.PGPEncryptedData$TruncatedStream.read(Unknown Source)
    at java.io.InputStream.read(InputStream.java:170)
    at org.bouncycastle.util.io.TeeInputStream.read(Unknown Source)
    at org.bouncycastle.bcpg.BCPGInputStream.read(Unknown Source)
    at org.bouncycastle.bcpg.BCPGInputStream$PartialInputStream.read(Unknown Source)
    at org.bouncycastle.bcpg.BCPGInputStream.read(Unknown Source)
    at org.bouncycastle.openpgp.PGPCompressedData.fill(Unknown Source)
    at java.util.zip.InflaterInputStream.read(InflaterInputStream.java:158)
    at org.bouncycastle.bcpg.BCPGInputStream.read(Unknown Source)
    at org.bouncycastle.bcpg.BCPGInputStream$PartialInputStream.read(Unknown Source)
    at org.bouncycastle.bcpg.BCPGInputStream.read(Unknown Source)
    at org.bouncycastle.util.io.Streams.readFully(Unknown Source)
    at org.bouncycastle.bcpg.BCPGInputStream.readFully(Unknown Source)
    at org.bouncycastle.bcpg.BCPGInputStream.readFully(Unknown Source)
    at org.bouncycastle.bcpg.MPInteger.<init>(Unknown Source)
    at org.bouncycastle.bcpg.SignaturePacket.<init>(Unknown Source)
    at org.bouncycastle.bcpg.BCPGInputStream.readPacket(Unknown Source)
    at org.bouncycastle.openpgp.PGPSignature.<init>(Unknown Source)
    at org.bouncycastle.openpgp.PGPObjectFactory.nextObject(Unknown Source)
    at main.decryptVerifyMessage(main.java:113)
    at main.main(main.java:167)

Any ideas?

有任何想法吗？

Side note, this decryption code came from How to decrypt a signed pgp encrypted file?, slightly modified to suit: Messages will only be coming from that encryption method, and handling of the keys directly instead of key streams.

旁注，此解密代码来自如何解密已签名的 pgp 加密文件？，稍作修改以适应：消息将仅来自该加密方法，并直接处理密钥而不是密钥流。

Cheers

干杯

Ramo

拉莫

回答by Stephen B.

I was recently trying to do the same kind of thing and put together this method based on code I found in the Bouncycastle examples and on tutorials I found on the web. For my purposes, my code has a singleton crypto object that has a public/private key pair. In the example code, you could replace

我最近试图做同样的事情，并根据我在 Bouncycastle 示例和我在网上找到的教程中找到的代码将这种方法组合在一起。出于我的目的，我的代码有一个具有公钥/私钥对的单例加密对象。在示例代码中，您可以替换

    INSTANCE._secretKeyRingCollection.getSecretKey(pbe.getKeyID());

with your secret key. I've tested this method with a long-lived process that did several tens of encrypt & sign / decrypt & verify actions and didn't get the exception you're seeing.

用你的密钥。我已经用一个长期的过程测试了这种方法，该过程执行了数十次加密和签名/解密和验证操作，但没有出现您看到的异常。

public static void decryptAndVerify(InputStream in, OutputStream fOut, InputStream publicKeyIn) throws IOException, SignatureException, PGPException {
    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();
        PBESecretKeyDecryptor decryptor = new BcPBESecretKeyDecryptorBuilder(new BcPGPDigestCalculatorProvider()).build(INSTANCE._secretKeyPass.toCharArray());
        PGPSecretKey psKey = INSTANCE._secretKeyRingCollection.getSecretKey(pbe.getKeyID());
        if (psKey != null) {
            sKey = psKey.extractPrivateKey(decryptor);
        }
    }
    if (sKey == null) {
        throw new IllegalArgumentException("Unable to find secret key to decrypt the message");
    }

    InputStream clear = pbe.getDataStream(new BcPublicKeyDataDecryptorFactory(sKey));

    PGPObjectFactory plainFact = new PGPObjectFactory(clear);

    Object message;

    PGPOnePassSignatureList onePassSignatureList = null;
    PGPSignatureList signatureList = null;
    PGPCompressedData compressedData;

    message = plainFact.nextObject();
    ByteArrayOutputStream actualOutput = new ByteArrayOutputStream();

    while (message != null) {
        __l.trace(message.toString());
        if (message instanceof PGPCompressedData) {
            compressedData = (PGPCompressedData) message;
            plainFact = new PGPObjectFactory(compressedData.getDataStream());
            message = plainFact.nextObject();
        }

        if (message instanceof PGPLiteralData) {
            // have to read it and keep it somewhere.
            Streams.pipeAll(((PGPLiteralData) message).getInputStream(), actualOutput);
        } else if (message instanceof PGPOnePassSignatureList) {
            onePassSignatureList = (PGPOnePassSignatureList) message;
        } else if (message instanceof PGPSignatureList) {
            signatureList = (PGPSignatureList) message;
        } else {
            throw new PGPException("message unknown message type.");
        }
        message = plainFact.nextObject();
    }
    actualOutput.close();
    PGPPublicKey publicKey = null;
    byte[] output = actualOutput.toByteArray();
    if (onePassSignatureList == null || signatureList == null) {
        throw new PGPException("Poor PGP. Signatures not found.");
    } else {

        for (int i = 0; i < onePassSignatureList.size(); i++) {
            PGPOnePassSignature ops = onePassSignatureList.get(0);
            __l.trace("verifier : " + ops.getKeyID());
            PGPPublicKeyRingCollection pgpRing = new PGPPublicKeyRingCollection(
                    PGPUtil.getDecoderStream(publicKeyIn));
            publicKey = pgpRing.getPublicKey(ops.getKeyID());
            if (publicKey != null) {
                ops.init(new JcaPGPContentVerifierBuilderProvider().setProvider("BC"), publicKey);
                ops.update(output);
                PGPSignature signature = signatureList.get(i);
                if (ops.verify(signature)) {
                    Iterator<?> userIds = publicKey.getUserIDs();
                    while (userIds.hasNext()) {
                        String userId = (String) userIds.next();
                        __l.trace(String.format("Signed by {%s}", userId));
                    }
                    __l.trace("Signature verified");
                } else {
                    throw new SignatureException("Signature verification failed");
                }
            }
        }

    }

    if (pbe.isIntegrityProtected() && !pbe.verify()) {
        throw new PGPException("Data is integrity protected but integrity is lost.");
    } else if (publicKey == null) {
        throw new SignatureException("Signature not found");
    } else {
        fOut.write(output);
        fOut.flush();
        fOut.close();
    }
}

回答by Michael Kanis

You are calling:

您正在致电：

encryptedDataGenerator.open(out, 4096)

where you probably meant:

你可能的意思是：

encryptedDataGenerator.open(out, new byte[4096])

The first version is giving a size to open (which is wrong), the second version is giving a byte buffer.

第一个版本给出了打开的大小（这是错误的），第二个版本给出了一个字节缓冲区。

(I know this is old, but came here because I had the same problem with some example code and so might others)

（我知道这是旧的，但来到这里是因为我对一些示例代码有同样的问题，其他人也有同样的问题）

回答by Jens

Getting Bouncy Castle to play along is not always easy. Code-snipets from Stackoverflow make it work just so, but they are mostly arcane pieces of code that none of the users really understand.

让充气城堡一起玩并不总是那么容易。Stackoverflow 的代码片段使它能够正常工作，但它们大多是用户真正理解的晦涩难懂的代码片段。

The problem with this is: In a production system copy'n'paste snippetsquickly become "no go" and "do not touch" areas.

这样做的问题是：在生产系统中，copy'n'paste 片段很快就会变成“no go”和“do not touch”区域。

Shelling out executables can have some serious security implications, least of all is handling command line parameters (talking about filenames with spaces ... how do I know? Don't ask ...)

删除可执行文件可能会产生一些严重的安全隐患，最重要的是处理命令行参数（谈论带空格的文件名......我怎么知道？不要问......）

I had all of these (and more..) problems, and after some yak shaving I wrote a library to handle PGP with Bouncycastle.

我遇到了所有这些（以及更多……）问题，在剃须后我写了一个库来处理 Bouncycastle 的 PGP。

Decrypting works like this:

解密工作是这样的：

final InputStream plaintextStream = BouncyGPG
               .decryptAndVerifyStream()
               .withConfig(keyringConfig)
               .andRequireSignatureFromAllKeys("[email protected]")
               .fromEncryptedInputStream(cipherTextStream)

The library can be found at https://github.com/neuhalje/bouncy-gpg:

该库可以在https://github.com/neuhalje/bouncy-gpg找到：

// in build.gradle add a dependency to bouncy castle and bouncy-gpg
//  ...
dependencies {
    compile 'org.bouncycastle:bcprov-jdk15on:1.56'
    compile 'org.bouncycastle:bcpg-jdk15on:1.56'
    //  ...
    compile 'name.neuhalfen.projects.crypto.bouncycastle.openpgp:bouncy-gpg:2.+'