2

我在下面有这个测试，我试图验证我的压缩/解压缩的 AES 加密/解密是否正常工作。我对加密/解密进行了测试，对压缩/解压缩进行了测试，我知道它们单独工作正常，但由于某种原因，当我将它们组合在一起时，IV 在解压后搞砸了。我被卡住了，不知道还要寻找什么，有人可以提供任何建议或帮助吗？如果我需要发布更多代码，请告诉我。我想我包括了重要的东西。

对于上下文：我要做的是获取一些敏感数据，用 AES 加密，用 RSA 公钥加密 AES 密钥，然后压缩这两个数据，以便它们可以通过网络发送。然后在另一端我想解压缩数据，使用 RSA 私钥解密 AES 密钥，然后用它来解密数据。如果有另一种方法可以做到这一点，我不会被锁定在自己写所有东西上。如果您建议一个库，请只建议我可以在商业产品中使用的库。

@Test
public void testEncryptionDecryptionProcesses() throws SSHException {

    SSHKey key1 = generateKeyPair();

    UnencryptedData data = new UnencryptedData();
    data.setUserName("hardy");
    data.setHashedPassword("somepassword");
    data.setRequest("eat");
    data.setResponse("");
    data.setTimestamp(new Timestamp(new Date().getTime()).toString());
    data.setPublicKeyMod(key1.getPublicMod().toString());
    data.setPublicKey(key1.getPublicKey().toString());

    byte[] bytes = encryptAndCompress(data, key1);

    assertTrue(bytes != null);
    assertTrue(bytes.length > 0);

    UnencryptedData decryptedData = decompressAndDecrypt(bytes, key1);
    assertEquals(data.getDataForEncryption(), decryptedData.getDataForEncryption());

}

public static byte[] encryptAndCompress(UnencryptedData data, SSHKey sshKey) {

    byte[] results = null;

    try {
        byte[] aesKey = createKeyForAES(AES_BIT_LENGTH);
        //this should use the servers public key so that only the server can decrypt it
        //gather data, get a digest, encrypt the data
        UnencryptedData digestedData = createDigest(data);
        //encrypt it
        EncryptedData toCompress = encryptDataAES(digestedData, aesKey);
        String encryptedAESKey = encryptKey(sshKey, aesKey);
        toCompress.setEncryptedAESKey(encryptedAESKey);
        //compress it
        byte[] compressed = compressString(toCompress.getDataForCompression());
        //return the compressed and encrypted data.
        results = compressed;
    } catch(SSHException e) {

        Log.e("SSHFunctions.encryption", "Unable to run the encryption/compression process on the data");
    } catch (UnsupportedEncodingException e) {

        Log.e("SSHFunctions.encryption", "Charset not supported");
    } 

    return results;
}

public static UnencryptedData decompressAndDecrypt(byte[] data, SSHKey sshKey) {

    UnencryptedData results = null;

    try {
        //take the data and decompress it, should result in encryptedData|encryptedAESKey
        byte[] decompressed = decompressString(data);
        String decompressedStr = new String(decompressed, CHAR_SET);
        String[] decompressedArr = decompressedStr.split(SPLIT_STRING);
        //using the users private key decrypt the data
        byte[] decryptedKey = decryptKey(sshKey, decompressedArr[1]);
        EncryptedData encryptedData = new EncryptedData();
        encryptedData.setAesEncryptedData(decompressedArr[0].getBytes(CHAR_SET));
        encryptedData.setIV(decompressedArr[2].getBytes(CHAR_SET)); //TODO: this doesn't seem to decompress correctly
        //create a digest from the decrypted data and compare it with the digest that was included.
        UnencryptedData decryptedDate = decryptDataAES(encryptedData, decryptedKey);
        if(validDigest(decryptedDate)) {

            results = decryptedDate;
        }
        //if equal return the data, if not equal return null
    } catch(Exception e) {

        Log.e("SSHFunctions.decryption", "Unable to run the uncompress/decrypt process on the data");
    }

    return results;
}

public static byte[] decompressString(byte[] toDecompress) {

    ByteArrayInputStream bis = new ByteArrayInputStream(toDecompress);
    byte[] uncompressed;

    try {

        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
        GZIPInputStream is = new GZIPInputStream(bis);

        byte[] tmp = new byte[256];

        while (true) {

            int r = is.read(tmp);
            if (r < 0) {

                break;
            }
            buffer.write(tmp, 0, r);
        }
        is.close();

        uncompressed = buffer.toByteArray();

        try {
            bis.close();
        } catch (IOException e) {
            ;
        }

        try {
            buffer.close();
        } catch (IOException e) {
            ;
        }
    } catch(IOException e) {

        uncompressed = null;
        Log.e("Zipfunctions.decompress", "Unable to decompress");
    }

    return uncompressed;    
}

public static byte[] compressString(byte[] toCompress) {

    byte[] toCompressBytes = toCompress;
    byte[] compressed;

    ByteArrayOutputStream bos = new ByteArrayOutputStream(toCompressBytes.length);
    try {
        GZIPOutputStream compressor = new GZIPOutputStream(bos);

        compressor.write(toCompressBytes, 0, toCompress.length);
        compressor.close();

        compressed = bos.toByteArray();

        try {
            bos.close();
        } catch(IOException e) {
            ;
        }
    } catch(IOException e) {

        compressed = null;
        Log.e("ZipFunctions.compress", "Unable to compress data");
    }

    return compressed;      
}
4

2 回答 2

2

您正在尝试实现类似于OpenPGP的加密系统。也就是说，您希望使用对称密钥加密任意数量的数据，并与接收者安全地共享此密钥（和加密数据）。

因此，我建议您考虑使用BouncyCastle 团队提供的 Java OpenPGP 库。

他们的执照很宽松。然而，他们的文档是出了名的差，所以你需要谷歌很多例子来看看如何实现你的目标。

于 2013-01-14T12:07:50.640 回答
0

首先，您不应该使用字符串分隔符来分隔字节缓冲区的各个部分。如果您的数据中存在分隔符，则会导致问题。

我建议您阅读有关TLV 结构的信息！

这是传输数据的简单实现！

class TransportData {
private byte[] iv;
private byte[] aesKey;
private byte[] encryptedData;

public TransportData() {
}

public TransportData(byte[] iv, byte[] aesKey, byte[] encryptedData) {
this.iv = iv;
this.aesKey = aesKey;
this.encryptedData = encryptedData;
}

public byte[] encode() throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
DataOutputStream dos = new DataOutputStream(baos);
dos.writeInt(iv.length);
dos.write(iv);
dos.writeInt(aesKey.length);
dos.write(aesKey);
dos.writeInt(encryptedData.length);
dos.write(encryptedData);
dos.close();
return baos.toByteArray();
}

public void decode(byte[] buffer) throws IOException {
ByteArrayInputStream bais = new ByteArrayInputStream(buffer);
DataInputStream dis = new DataInputStream(bais);
iv = new byte[dis.readInt()];
dis.read(iv);
aesKey = new byte[dis.readInt()];
dis.read(aesKey);
encryptedData = new byte[dis.readInt()];
dis.read(encryptedData);
dis.close();
}

public byte[] getAesKey() {
return aesKey;
}
public byte[] getEncryptedData() {
return encryptedData;
}
public byte[] getIv() {
return iv;
}
}
于 2013-01-08T19:14:33.530 回答