java - Apache Thrift 中的对称加密 (AES)

Question

我有两个使用 Thrift 进行交互的应用程序。他们共享相同的 key ，我需要加密他们的消息。使用对称算法(例如 AES)是有意义的，但我还没有找到任何库来执行此操作。所以我做了一个研究，看到了以下选项:

使用内置的 SSL 支持

我可以使用内置的 SSL 支持，建立安全连接并使用我的 key 作为身份验证 token 。除了证书已有的 key 外，它还需要安装证书，但除了检查从客户端收到的 key 是否与本地存储的 key 相同外，我不需要执行任何操作。

实现对称加密

到目前为止，有以下选项:

1. 扩展 TSocket 并覆盖 write() 和 read() 方法并在其中加密/解密数据。小型写入的流量将会增加。例如，如果 TBinaryProtocol 写入 4 字节整数，它将在加密状态下占用一个 block (16 字节)。
2. 扩展TSocket 并用CipherInputStream 和CipherOutputStream 包装InputStream 和OutputStream。 CipherOutputStream 不会立即加密小字节数组，用它们更新 Cipher。在我们有足够的数据后，它们将被加密并写入底层的OutputStream。所以它会等到你添加 4 个 4 字节的整数然后加密它们。它允许我们不浪费流量，但也是问题的原因 - 如果最后一个值不会填充 block ，它将永远不会被加密并写入底层流。它希望我写入可被其 block 大小(16 字节)整除的字节数，但我无法使用 TBinaryProtocol 执行此操作。
3. 重新实现TBinaryProtocol，缓存所有写入而不是将它们写入流并在writeMessageEnd() 方法中加密。在 readMessageBegin() 中实现解密。我认为加密应该在传输层执行，而不是协议(protocol)层。

请与我分享您的想法。

更新

基于 TFramedTransport 的 Java 实现

TEncryptedFramedTransport.java

package tutorial;

import org.apache.thrift.TByteArrayOutputStream;
import org.apache.thrift.transport.TMemoryInputTransport;
import org.apache.thrift.transport.TTransport;
import org.apache.thrift.transport.TTransportException;
import org.apache.thrift.transport.TTransportFactory;

import javax.crypto.Cipher;
import java.security.Key;
/**
 * TEncryptedFramedTransport is a buffered TTransport. It encrypts fully read message
 * with the "AES/ECB/PKCS5Padding" symmetric algorithm and send it, preceeding with a 4-byte frame size.
 */
public class TEncryptedFramedTransport extends TTransport {
    public static final String ALGORITHM = "AES/ECB/PKCS5Padding";

    private Cipher encryptingCipher;
    private Cipher decryptingCipher;

    protected static final int DEFAULT_MAX_LENGTH = 0x7FFFFFFF;

    private int maxLength_;

    private TTransport transport_ = null;

    private final TByteArrayOutputStream writeBuffer_ = new TByteArrayOutputStream(1024);
    private TMemoryInputTransport readBuffer_ = new TMemoryInputTransport(new byte[0]);

    public static class Factory extends TTransportFactory {
        private int maxLength_;
        private Key secretKey_;

        public Factory(Key secretKey) {
            this(secretKey, DEFAULT_MAX_LENGTH);
        }

        public Factory(Key secretKey, int maxLength) {
            maxLength_ = maxLength;
            secretKey_ = secretKey;
        }

        @Override
        public TTransport getTransport(TTransport base) {
            return new TEncryptedFramedTransport(base, secretKey_, maxLength_);
        }
    }

    /**
     * Constructor wraps around another tranpsort
     */
    public TEncryptedFramedTransport(TTransport transport, Key secretKey, int maxLength) {
        transport_ = transport;
        maxLength_ = maxLength;

        try {
            encryptingCipher = Cipher.getInstance(ALGORITHM);
            encryptingCipher.init(Cipher.ENCRYPT_MODE, secretKey);

            decryptingCipher = Cipher.getInstance(ALGORITHM);
            decryptingCipher.init(Cipher.DECRYPT_MODE, secretKey);
        } catch (Exception e) {
            throw new RuntimeException("Unable to initialize ciphers.");
        }
    }

    public TEncryptedFramedTransport(TTransport transport, Key secretKey) {
        this(transport, secretKey, DEFAULT_MAX_LENGTH);
    }

    public void open() throws TTransportException {
        transport_.open();
    }

    public boolean isOpen() {
        return transport_.isOpen();
    }

    public void close() {
        transport_.close();
    }

    public int read(byte[] buf, int off, int len) throws TTransportException {
        if (readBuffer_ != null) {
            int got = readBuffer_.read(buf, off, len);
            if (got > 0) {
                return got;
            }
        }

        // Read another frame of data
        readFrame();

        return readBuffer_.read(buf, off, len);
    }

    @Override
    public byte[] getBuffer() {
        return readBuffer_.getBuffer();
    }

    @Override
    public int getBufferPosition() {
        return readBuffer_.getBufferPosition();
    }

    @Override
    public int getBytesRemainingInBuffer() {
        return readBuffer_.getBytesRemainingInBuffer();
    }

    @Override
    public void consumeBuffer(int len) {
        readBuffer_.consumeBuffer(len);
    }

    private final byte[] i32buf = new byte[4];

    private void readFrame() throws TTransportException {
        transport_.readAll(i32buf, 0, 4);
        int size = decodeFrameSize(i32buf);

        if (size < 0) {
            throw new TTransportException("Read a negative frame size (" + size + ")!");
        }

        if (size > maxLength_) {
            throw new TTransportException("Frame size (" + size + ") larger than max length (" + maxLength_ + ")!");
        }

        byte[] buff = new byte[size];
        transport_.readAll(buff, 0, size);

        try {
            buff = decryptingCipher.doFinal(buff);
        } catch (Exception e) {
            throw new TTransportException(0, e);
        }

        readBuffer_.reset(buff);
    }

    public void write(byte[] buf, int off, int len) throws TTransportException {
        writeBuffer_.write(buf, off, len);
    }

    @Override
    public void flush() throws TTransportException {
        byte[] buf = writeBuffer_.get();
        int len = writeBuffer_.len();
        writeBuffer_.reset();

        try {
            buf = encryptingCipher.doFinal(buf, 0, len);
        } catch (Exception e) {
            throw new TTransportException(0, e);
        }

        encodeFrameSize(buf.length, i32buf);
        transport_.write(i32buf, 0, 4);
        transport_.write(buf);
        transport_.flush();
    }

    public static void encodeFrameSize(final int frameSize, final byte[] buf) {
        buf[0] = (byte) (0xff & (frameSize >> 24));
        buf[1] = (byte) (0xff & (frameSize >> 16));
        buf[2] = (byte) (0xff & (frameSize >> 8));
        buf[3] = (byte) (0xff & (frameSize));
    }

    public static int decodeFrameSize(final byte[] buf) {
        return
                ((buf[0] & 0xff) << 24) |
                        ((buf[1] & 0xff) << 16) |
                        ((buf[2] & 0xff) << 8) |
                        ((buf[3] & 0xff));
    }
}

MultiplicationServer.java

package tutorial;

import co.runit.prototype.CryptoTool;
import org.apache.thrift.server.TNonblockingServer;
import org.apache.thrift.server.TServer;
import org.apache.thrift.transport.TNonblockingServerSocket;
import org.apache.thrift.transport.TNonblockingServerTransport;

import java.security.Key;

public class MultiplicationServer {
    public static MultiplicationHandler handler;

    public static MultiplicationService.Processor processor;

    public static void main(String[] args) {
        try {
            handler = new MultiplicationHandler();
            processor = new MultiplicationService.Processor(handler);

            Runnable simple = () -> startServer(processor);

            new Thread(simple).start();
        } catch (Exception x) {
            x.printStackTrace();
        }
    }

    public static void startServer(MultiplicationService.Processor processor) {
        try {
            Key key = CryptoTool.decodeKeyBase64("1OUXS3MczVFp3SdfX41U0A==");

            TNonblockingServerTransport serverTransport = new TNonblockingServerSocket(9090);
            TServer server = new TNonblockingServer(new TNonblockingServer.Args(serverTransport)
                    .transportFactory(new TEncryptedFramedTransport.Factory(key))
                    .processor(processor));

            System.out.println("Starting the simple server...");
            server.serve();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

MultiplicationClient.java

package tutorial;

import co.runit.prototype.CryptoTool;
import org.apache.thrift.TException;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.transport.TSocket;
import org.apache.thrift.transport.TTransport;

import java.security.Key;

public class MultiplicationClient {
    public static void main(String[] args) {
        Key key = CryptoTool.decodeKeyBase64("1OUXS3MczVFp3SdfX41U0A==");

        try {
            TSocket baseTransport = new TSocket("localhost", 9090);
            TTransport transport = new TEncryptedFramedTransport(baseTransport, key);
            transport.open();

            TProtocol protocol = new TBinaryProtocol(transport);
            MultiplicationService.Client client = new MultiplicationService.Client(protocol);

            perform(client);

            transport.close();
        } catch (TException x) {
            x.printStackTrace();
        }
    }

    private static void perform(MultiplicationService.Client client) throws TException {
        int product = client.multiply(3, 5);
        System.out.println("3*5=" + product);
    }
}

当然，客户端和服务端的 key 必须相同。生成并存储在 Base64 中:

public static String generateKey() throws NoSuchAlgorithmException, InvalidAlgorithmParameterException {
    KeyGenerator generator = KeyGenerator.getInstance("AES");
    generator.init(128);
    Key key = generator.generateKey();
    return encodeKeyBase64(key);
}

public static String encodeKeyBase64(Key key) {
    return Base64.getEncoder().encodeToString(key.getEncoded());
}

public static Key decodeKeyBase64(String encodedKey) {
    byte[] keyBytes = Base64.getDecoder().decode(encodedKey);
    return new SecretKeySpec(keyBytes, ALGORITHM);
}

更新 2

基于 TFramedTransport 的 Python 实现

TEncryptedTransport.py

from cStringIO import StringIO
from struct import pack, unpack
from Crypto.Cipher import AES

from thrift.transport.TTransport import TTransportBase, CReadableTransport

__author__ = 'Marboni'

BLOCK_SIZE = 16

pad = lambda s: s + (BLOCK_SIZE - len(s) % BLOCK_SIZE) * chr(BLOCK_SIZE - len(s) % BLOCK_SIZE)
unpad = lambda s: '' if not s else s[0:-ord(s[-1])]

class TEncryptedFramedTransportFactory:
    def __init__(self, key):
        self.__key = key

    def getTransport(self, trans):
        return TEncryptedFramedTransport(trans, self.__key)


class TEncryptedFramedTransport(TTransportBase, CReadableTransport):
    def __init__(self, trans, key):
        self.__trans = trans
        self.__rbuf = StringIO()
        self.__wbuf = StringIO()

        self.__cipher = AES.new(key)

    def isOpen(self):
        return self.__trans.isOpen()

    def open(self):
        return self.__trans.open()

    def close(self):
        return self.__trans.close()

    def read(self, sz):
        ret = self.__rbuf.read(sz)
        if len(ret) != 0:
            return ret

        self.readFrame()
        return self.__rbuf.read(sz)

    def readFrame(self):
        buff = self.__trans.readAll(4)
        sz, = unpack('!i', buff)
        encrypted = StringIO(self.__trans.readAll(sz)).getvalue()

        decrypted = unpad(self.__cipher.decrypt(encrypted))

        self.__rbuf = StringIO(decrypted)

    def write(self, buf):
        self.__wbuf.write(buf)

    def flush(self):
        wout = self.__wbuf.getvalue()
        self.__wbuf = StringIO()

        encrypted = self.__cipher.encrypt(pad(wout))
        encrypted_len = len(encrypted)
        buf = pack("!i", encrypted_len) + encrypted
        self.__trans.write(buf)
        self.__trans.flush()

    # Implement the CReadableTransport interface.
    @property
    def cstringio_buf(self):
        return self.__rbuf

    def cstringio_refill(self, prefix, reqlen):
        while len(prefix) < reqlen:
            self.readFrame()
            prefix += self.__rbuf.getvalue()
        self.__rbuf = StringIO(prefix)
        return self.__rbuf

MultiplicationClient.py

import base64
from thrift import Thrift
from thrift.transport import TSocket
from thrift.protocol import TBinaryProtocol

from tutorial import MultiplicationService, TEncryptedTransport

key = base64.b64decode("1OUXS3MczVFp3SdfX41U0A==")

try:
    transport = TSocket.TSocket('localhost', 9090)
    transport = TEncryptedTransport.TEncryptedFramedTransport(transport, key)

    protocol = TBinaryProtocol.TBinaryProtocol(transport)
    client = MultiplicationService.Client(protocol)

    transport.open()

    product = client.multiply(4, 5, 'Echo!')
    print '4*5=%d' % product

    transport.close()
except Thrift.TException, tx:
    print tx.message

Answer 1

正如 JensG 所述，发送外部加密的二进制文件或提供分层密码传输是两个最佳选择。如果您需要模板，请查看 TFramedTransport。它是一种简单的分层传输，可以轻松用作创建 TCipherTransport 的起始 block 。