Bouncycastle PGP解密并验证

Question

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

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。

以下是代码：

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();
        }
    }

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

-----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$1.fill(Unknown Source)
    at java.util.zip.InflaterInputStream.read(InflaterInputStream.java:158)
    at org.bouncycastle.bcpg.BCPGInputStream.read(Unknown Source)
    at org.bouncycastle.bcpg.BCPGInputStream$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)

有什么想法吗？

旁注，这个解密代码来自How to decrypt a signed pgp encrypted file?，略微修改以适应：消息只来自该加密方法，直接处理密钥而不是密钥流。

干杯

拉​​莫

Answer 1

我最近尝试做同样的事情，并根据我在Bouncycastle示例中找到的代码以及我在网络上找到的教程将这种方法组合在一起。出于我的目的，我的代码有一个单独的加密对象，它有一个公钥/私钥对。在示例代码中，您可以替换

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

使用您的密钥。我已经用一个长期的过程测试了这个方法，这个过程做了几十次加密＆amp;签名/解密＆amp;验证操作并且没有得到您所看到的异常。

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();
    }
}

Answer 2

让Bouncy Castle一起玩并不容易。来自Stackoverflow的代码snipets使它正常工作，但它们大多是神秘的代码片段，没有任何用户真正理解。

问题在于：在生产系统中，复制＆＃39; n＆＃39; n＆＃39;粘贴代码段很快成为＆＃34; no go＆＃34;并且＆＃34;不要触摸＆＃34;领域

销毁可执行文件会产生一些严重的安全隐患，最重要的是处理命令行参数（用空格谈论文件名......我怎么知道？不要问......）

我遇到了所有这些（以及更多......）问题，经过一些牦牛剃须后，我写了一个库，用Bouncycastle来处理PGP。

解密就像这样：

final InputStream plaintextStream = BouncyGPG
               .decryptAndVerifyStream()
               .withConfig(keyringConfig)
               .andRequireSignatureFromAllKeys("sender@example.com")
               .fromEncryptedInputStream(cipherTextStream)

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

// 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.+'

Answer 3

您正在致电：

encryptedDataGenerator.open(out, 4096)

你可能意味着：

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

第一个版本是打开一个大小（这是错误的），第二个版本给出一个字节缓冲区。

（我知道这已经过时了，但是来到这里因为我遇到了一些示例代码的问题，所以可能会有其他问题）