Bouncycastle PGP解密和验证

Question

我试图使用java BouncyCastle库解密和验证PGP消息，但遇到了一些问题，抱怨PartialInputStream过早结束。

我知道encrypt工作得很好，因为我可以在命令行上使用gpg解密和验证使用encrypt函数创建的消息。

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();
        }
    }

-----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)

Answer 1

让Bouncy Castle一起玩并不总是一件容易的事。来自Stackoverflow的代码嗅探使其工作正常，但它们大多是一些难以理解的代码，没有一个用户真正理解。

这样做的问题是：在生产系统中，复制'n'paste片段会很快变成“no go”和“do not touch”区域。

剥离可执行文件可能会带来一些严重的安全影响，尤其是处理命令行参数（谈论带有空格的文件名...我怎么知道？别问了...）

final InputStream plaintextStream = BouncyGPG
               .decryptAndVerifyStream()
               .withConfig(keyringConfig)
               .andRequireSignatureFromAllKeys("[e-mail]")
               .fromEncryptedInputStream(cipherTextStream)

该库可在https://github.com/neuhalje/bouncy-gpg：

// 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.+'