java - 字符串到公钥

Question

那里。我正在 java 应用程序和 php 服务器之间实现 Diffie Hellman key 交换协议(protocol)。当我从 php 服务器获取 key 时遇到一些问题，该 key 是字符串格式，我想将其转换为 PublicKey 来执行协议(protocol)。代码如下:

public static PublicKey getPublicKey(String publicKey) throws Exception {
    byte[] byteKey =publicKey.getBytes();
    X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(byteKey);
    KeyFactory keyFact = KeyFactory.getInstance("DH");
    PublicKey pubKey = keyFact.generatePublic(x509KeySpec);
    DHPublicKey dhPublicKey;
    return pubKey;
}

当我运行这个函数时，我遇到了这个异常:

Exception in thread "main" java.security.spec.InvalidKeySpecException: Inappropriate key specification
at com.sun.crypto.provider.DHKeyFactory.engineGeneratePublic(DHKeyFactory.java:87)
at java.security.KeyFactory.generatePublic(Unknown Source)
at main2.getPublicKey(main2.java:47)
at main2.main(main2.java:108)

key 是一个大整数类型，例如:“2730833911517276610828829348409530515930034154987099616280024338836450623403836102419905982575105923164305996 145622906355021487887788144551871008554848191"我该如何纠正这个问题？感谢您的宝贵时间

Answer 1

感谢用户3062946，我已经解决了该问题。代码如下:

public static PublicKey getPublicKey(BigInteger publicKey, BigInteger p, BigInteger g) throws Exception {
    DHPublicKeySpec dhspec=new DHPublicKeySpec(publicKey,p,g);
    KeyFactory keyFact = KeyFactory.getInstance("DH");
    PublicKey pubKey = keyFact.generatePublic(dhspec);

    return pubKey;
}