java - 从 jPBC 保存和加载非对称 key

Question

我想要类似的功能，如规定 Easy way to store/restore encryption key for decrypting string in java

但我的情况有所不同。在上面的链接中，他们使用 javax.crypto.* 但在我的例子中，我使用 org.bouncycaSTLe.crypto.* 和 it.unisa.dia。 Gas.crypto.jpbc.fe.abe.gghsw13.generators.*

我想将主 key 、公钥和私钥存储在不同的文件中，并从文件中检索这些 key 。怎么做？

下面是我留下 TODO 的代码。工作代码可以在 github 上找到.

import it.unisa.dia.gas.crypto.circuit.BooleanCircuit;
import it.unisa.dia.gas.crypto.circuit.BooleanCircuit.BooleanCircuitGate;
import it.unisa.dia.gas.crypto.jpbc.fe.abe.gghsw13.engines.GGHSW13KEMEngine;
import it.unisa.dia.gas.crypto.jpbc.fe.abe.gghsw13.generators.GGHSW13KeyPairGenerator;
import it.unisa.dia.gas.crypto.jpbc.fe.abe.gghsw13.generators.GGHSW13ParametersGenerator;
import it.unisa.dia.gas.crypto.jpbc.fe.abe.gghsw13.generators.GGHSW13SecretKeyGenerator;
import it.unisa.dia.gas.crypto.jpbc.fe.abe.gghsw13.params.*;
import it.unisa.dia.gas.crypto.kem.cipher.engines.KEMCipher;
import it.unisa.dia.gas.crypto.kem.cipher.params.KEMCipherDecryptionParameters;
import it.unisa.dia.gas.crypto.kem.cipher.params.KEMCipherEncryptionParameters;
import it.unisa.dia.gas.plaf.jpbc.pairing.PairingFactory;
import it.unisa.dia.gas.plaf.jpbc.util.concurrent.ExecutorServiceUtils;
import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import java.security.GeneralSecurityException;
import java.security.SecureRandom;
import java.security.Security;
import java.security.spec.AlgorithmParameterSpec;
import java.util.ArrayList;
import java.util.List;

import static it.unisa.dia.gas.crypto.circuit.Gate.Type.*;

public class Example {
    protected KEMCipher kemCipher;
    protected AlgorithmParameterSpec iv;

    protected AsymmetricCipherKeyPair keyPair;


    public Example() throws GeneralSecurityException {
        this.kemCipher = new KEMCipher(
                Cipher.getInstance("AES/CBC/PKCS7Padding", "BC"),
                new GGHSW13KEMEngine()
        );

        // build the initialization vector.  This example is all zeros, but it
        // could be any value or generated using a random number generator.
        iv = new IvParameterSpec(new byte[]{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0});
    }


    public AsymmetricCipherKeyPair setup(int n) {
        GGHSW13KeyPairGenerator setup = new GGHSW13KeyPairGenerator();
        setup.init(new GGHSW13KeyPairGenerationParameters(
                new SecureRandom(),
                new GGHSW13ParametersGenerator().init(
                        PairingFactory.getPairing("params/mm/ctl13/toy.properties"),
                        n).generateParameters()
        ));

        return (keyPair = setup.generateKeyPair());
    }


    public byte[] initEncryption(String assignment) {
        try {
            return kemCipher.init(
                    true,
                    new KEMCipherEncryptionParameters(
                            128,
                            new GGHSW13EncryptionParameters(
                                    (GGHSW13PublicKeyParameters) keyPair.getPublic(),
                                    assignment
                            )
                    ),
                    iv
            );
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public byte[] encrypt(String message) {
        try {
            return kemCipher.doFinal(message.getBytes());
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }


    public CipherParameters keyGen(BooleanCircuit circuit) {
        GGHSW13SecretKeyGenerator keyGen = new GGHSW13SecretKeyGenerator();
        keyGen.init(new GGHSW13SecretKeyGenerationParameters(
                ((GGHSW13PublicKeyParameters) keyPair.getPublic()),
                ((GGHSW13MasterSecretKeyParameters) keyPair.getPrivate()),
                circuit
        ));

        return keyGen.generateKey();
    }

    public byte[] decrypt(CipherParameters secretKey, byte[] encapsulation, byte[] ciphertext) {
        try {
            kemCipher.init(
                    false,
                    new KEMCipherDecryptionParameters(secretKey, encapsulation, 128),
                    iv
            );
            return kemCipher.doFinal(ciphertext);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }



    public static void main(String[] args) {
        Security.addProvider(new BouncyCastleProvider());

        try {
            // Setup
            int n = 4;
            Example engine = new Example();
            engine.setup(n);

            // TODO: Here I want to store (GGHSW13PublicKeyParameters) keyPair.getPublic() and 
            // (GGHSW13MasterSecretKeyParameters) keyPair.getPrivate() in files and later to retrieve from file

            // Encrypt
            String message = "Hello World!!!";
            byte[] encapsulation = engine.initEncryption("1101");
            byte[] ciphertext = engine.encrypt(message);

            BooleanCircuitGate bcg1 = new BooleanCircuitGate(INPUT, 0, 1);

            BooleanCircuitGate[] bcgs = new BooleanCircuitGate[]{
                    new BooleanCircuitGate(INPUT, 0, 1),
                    new BooleanCircuitGate(INPUT, 1, 1),
                    new BooleanCircuitGate(INPUT, 2, 1),
                    new BooleanCircuitGate(INPUT, 3, 1),

                    new BooleanCircuitGate(AND, 4, 2, new int[]{0, 1}),
                    new BooleanCircuitGate(OR, 5, 2, new int[]{2, 3}),

                    new BooleanCircuitGate(AND, 6, 3, new int[]{4, 5}),
            };

            List<BooleanCircuitGate> bcgList = new ArrayList<BooleanCircuitGate>();

            bcgList.add(bcg1);
            bcgList.add(new BooleanCircuitGate(INPUT, 1, 1));
            bcgList.add(new BooleanCircuitGate(INPUT, 2, 1));
            bcgList.add(new BooleanCircuitGate(INPUT, 3, 1));
            bcgList.add(new BooleanCircuitGate(AND, 4, 2, new int[]{0, 1}));
            bcgList.add(new BooleanCircuitGate(OR, 5, 2, new int[]{2, 3}));
            bcgList.add(new BooleanCircuitGate(AND, 6, 3, new int[]{4, 5}));

            // Decrypt
            int q = 3;
            BooleanCircuit circuit = new BooleanCircuit(n, q, 3, bcgList.toArray(new BooleanCircuitGate[bcgList.size()]));

            GGHSW13SecretKeyParameters secretKey = (GGHSW13SecretKeyParameters) engine.keyGen(circuit);

            // TODO: Want to store secretKey in file and later to retrieve from file

            byte[] plaintext = engine.decrypt(secretKey, encapsulation, ciphertext);

            System.out.println(new String(plaintext));

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            ExecutorServiceUtils.shutdown();
        }
    }

}

Answer 1

生成主 key 和公共(public)参数后，您应该存储它们，以便稍后实际使用它们。 jPBC 不为您提供存储这些 key 的方法。另外，由于 key 继承自 org.bouncycaSTLe.crypto.params.AmetryKeyParameter，因此您无法使用 Java 的序列化，因为 AmetryKeyParameter 没有实现 Serializable 接口(interface)。它doesn't无需工作。

您需要自己实现序列化。首先，您必须考虑要序列化的键中包含哪些类型的对象。对于 GGHSW13MasterSecretKeyParameters 类，这是一个 Element、一个 int 和一个 Pairing。

首先，您必须考虑是否要在序列化 key 中包含配对。如果这样做，则必须将其写入开头，以便稍后能够使用它来反序列化 Element。

如果我们假设 Pairing 实例是常量或始终由外部代码提供，则序列化非常容易。您应该在前面编写一个格式版本，这样您就可以一路更改格式，而无需丢弃所有以前序列化的 key 。由于我两年前遇到的一个错误，编写元素有点棘手。基本思想是写入元素字节的长度，后跟元素的内容。

public void serialize(GGHSW13MasterSecretKeyParameters msk, OutputStream out) throws IOException {
    DataOutputStream dOut = new DataOutputStream(out);

    dOut.writeInt(1); // version of the serialized format
    dOut.writeInt(msk.getParameters().getN());

    serialize(msk.getAlpha(), dOut, msk.getParameters().getPairing());
}

public void serialize(Element elem, DataOutputStream dOut, Pairing pairing) throws IOException {
    dOut.writeBoolean(elem == null);
    if (elem == null) {
        return;
    }

    dOut.writeInt(pairing.getFieldIndex(elem.getField()));
    byte[] bytes = elem.toBytes();
    dOut.writeInt(bytes.length);
    dOut.write(bytes);

    // this is a workaround because it.unisa.dia.gas.plaf.jpbc.field.curve.CurveElement does not serialize the infFlag
    dOut.writeBoolean(elem instanceof CurveElement && elem.isZero());
    if (elem instanceof CurveElement && elem.isZero()) {
        throw new IOException("Infinite element detected. They should not happen.");
    }
}

OutputStream 可以类似于 FileOutputSteam 或 ByteArrayOutputStream。

反序列化同样容易，但您需要显式提供配对，并且需要确保始终读取完全您请求的字节数。您请求的字节数可以从数据前面写入的 length int 得知。如果您不检查该长度是否有意义，则可能会引入安全问题，例如拒绝服务漏洞或远程代码执行。

public GGHSW13MasterSecretKeyParameters deserialize(InputStream in, Pairing pairing) throws IOException {
    DataInputStream dIn = new DataInputStream(in);

    int version = dIn.readInt();
    if (version != 1) {
        throw new RuntimeException("Unknown key format version: " + version);
    }

    int n = dIn.getInt();
    Element alpha = deserialize(dIn, pairing);

    return new GGHSW13MasterSecretKeyParameters(
            new GGHSW13Parameters(pairing, n),
            alpha
    );
}

public Element deserialize(DataInputStream dIn, Pairing pairing) throws IOException {
    if (dIn.readBoolean()) {
        return null;
    }

    int fieldIndex = dIn.readInt(); // TODO: check if this is in a sensible range
    int length = dIn.readInt(); // TODO: check if this is in a sensible range
    byte[] bytes = new byte[length];
    dIn.readFully(bytes); // throws an exception if there is a premature EOF
    Element e = pairing.getFieldAt(fieldIndex).newElementFromBytes(bytes);

    // this is a workaround because it.unisa.dia.gas.plaf.jpbc.field.curve.CurveElement does not serialize the infFlag
    boolean instOfCurveElementAndInf = dIn.readBoolean();
    if (instOfCurveElementAndInf) {
        //e.setToZero(); // according to the code this simply sets the infFlag to 1
        throw new IOException("The point is infinite. This shouldn't happen.");
    }
    return e;
}

这是一个很小的二进制序列化。还有其他可能性，例如将所有组件编码为字符串并使用 JSON。