我正在尝试使用Java中的BouncyCastle使用ECC算法对某些内容进行加密。但是我对BouncyCastle库的说法例外：无法转换JCEECPublicKey为IESKey。我理解的是，所产生的公共密钥KeyPairGenerator是JCEECPublicKey不能在java的使用Cipher.init方法。有人可以告诉我如何将其转换为公钥或X509规范，以便可以将其用于加密。

这是我尝试过的代码

// 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，但出现相同的异常

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

基于注释，我正在使用的JDK版本是JDK 7-我正在使用的Oracle Import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;