在 Java 中使用 BouncyCastle 使用 ECIES 进行加密

Question

我正在尝试使用 Java 中的 BouncyCastle 使用 ECC 算法加密一些内容。但是我得到了 BouncyCastle 库的例外，说不能投射JCEECPublicKey到IESKey. 据我所知，生成的公钥KeyPairGenerator是JCEECPublicKey不能在javaCipher.init方法中使用的。有人可以告诉我如何将其转换为公钥或 X509 规范，以便我可以在加密中使用它。

这是我试过的代码

// add instance of provider class
Security.addProvider(new BouncyCastleProvider());

// initializing parameter specs secp256r1/prime192v1
ECParameterSpec ecSpec = ECNamedCurveTable.getParameterSpec("prime192v1");

// key pair generator to generate public and private key
KeyPairGenerator generator = KeyPairGenerator.getInstance("ECDH", new BouncyCastleProvider());

// initialize key pair generator
generator.initialize(ecSpec);

// Key pair to store public and private key
KeyPair keyPair = generator.generateKeyPair();

Cipher iesCipher = Cipher.getInstance("ECIES", new BouncyCastleProvider());
iesCipher.init(Cipher.ENCRYPT_MODE, keyPair.getPublic());

我也尝试将公钥转换为 X509EncodedSpec 但我得到了同样的异常

X509EncodedKeySpec spec = new X509EncodedKeySpec(keyPair.getPublic().getEncoded());
KeyFactory factory = KeyFactory.getInstance("ECDH");

PublicKey publicKey = factory.generatePublic(spec);

我得到的例外是

java.lang.ClassCastException: org.bouncycastle.jce.provider.JCEECPublicKey cannot be cast to org.bouncycastle.jce.interfaces.IESKey
    at org.bouncycastle.jce.provider.JCEIESCipher.engineGetKeySize(JCEIESCipher.java:49)
    at javax.crypto.Cipher.passCryptoPermCheck(Cipher.java:1057)
    at javax.crypto.Cipher.checkCryptoPerm(Cipher.java:1015)
    at javax.crypto.Cipher.init(Cipher.java:1229)
    at javax.crypto.Cipher.init(Cipher.java:1173)
    at com.test.EciesTest.main(EciesTest.java:45)

编辑

根据评论，我使用的 JDK 版本是 JDK 7 - 我使用的 Oracle 导入语句：

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.Security;
import java.security.spec.ECGenParameterSpec;
import javax.crypto.Cipher;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

Answer 1

请尝试以下操作：

// add instance of provider class
Security.addProvider(new BouncyCastleProvider());

String name = "secp256r1";

// NOTE just "EC" also seems to work here
KeyPairGenerator kpg = KeyPairGenerator.getInstance("ECDH", BouncyCastleProvider.PROVIDER_NAME);
kpg.initialize(new ECGenParameterSpec(name));

// Key pair to store public and private key
KeyPair keyPair = kpg.generateKeyPair();

Cipher iesCipher = Cipher.getInstance("ECIES", BouncyCastleProvider.PROVIDER_NAME);
iesCipher.init(Cipher.ENCRYPT_MODE, keyPair.getPublic());

请注意，一般来说，当尝试通过 JCE 使用 Bouncy 时，最好保留 JCE 类而不是 Bouncy Castle 类。在这种情况下，问题可能是给密钥生成器的参数。

在上面的代码中，我使用了BouncyCastleProvider.PROVIDER_NAME但"BC"当然也同样有效。每次都重新实例化提供者不是一个好主意，尽管它不应该影响最终结果。

确保您有一个最新的系统来运行此代码。此代码在以下系统上进行了测试：

// add instance of provider class
Security.addProvider(new BouncyCastleProvider());

String name = "secp256r1";

// NOTE just "EC" also seems to work here
KeyPairGenerator kpg = KeyPairGenerator.getInstance("ECDH", BouncyCastleProvider.PROVIDER_NAME);
kpg.initialize(new ECGenParameterSpec(name));

// Key pair to store public and private key
KeyPair keyPair = kpg.generateKeyPair();

Cipher iesCipher = Cipher.getInstance("ECIES", BouncyCastleProvider.PROVIDER_NAME);
iesCipher.init(Cipher.ENCRYPT_MODE, keyPair.getPublic());