9

在 Java 中,我有一个以字节数组形式发送的 ECDH 公钥。

收到字节数组后,如何将其转回公钥?

我正在使用 Bouncy Castle,但 Java 解决方案同样有用。

谢谢

4

3 回答 3

7

当您获得编码密钥时,假设您使用了默认的“[your keyPair].getPublic().getEncoded()”方法,这将起作用。

    X509EncodedKeySpec ks = new X509EncodedKeySpec(pubKeyByteString.toByteArray());
    KeyFactory kf;
    try {
         kf = java.security.KeyFactory.getInstance("ECDH");
    } catch (NoSuchAlgorithmException e) {
        log.error("Cryptography error: could not initialize ECDH keyfactory!", e);
        return;
    }

    ECPublicKey remotePublicKey;

    try {
        remotePublicKey = (ECPublicKey)kf.generatePublic(ks);
    } catch (InvalidKeySpecException e) {
        log.warn("Received invalid key specification from client",e);
        return;
    } catch (ClassCastException e) {
        log.warn("Received valid X.509 key from client but it was not EC Public Key material",e);
        return;
    }
于 2011-02-11T13:16:38.953 回答
5

我发现@LaceCard 的上述解决方案对我不起作用。一般来说,这并不明显,但密码学中也没有什么是;)

String key = "MihU9ztW9sEvkBL6BxyaOMgkSbodNS8yoHaHcio+WE...blahblah"
byte[] keyBytes = Base64.decode(key);

//If using Android and Spongycastle provider should be "SC"
KeyFactory kf = KeyFactory.getInstance("ECDH", "BC");
//CURVE_NAME e.g prime192v1
ECParameterSpec ecSpec = ECNamedCurveTable.getParameterSpec(CURVE_NAME);
ECPoint point = ecSpec.getCurve().decodePoint(keyBytes);
ECPublicKeySpec pubSpec = new ECPublicKeySpec(point, ecSpec);

ECPublicKey myECPublicKey = (ECPublicKey) kf.generatePublic(pubSpec);

注意:您需要适当地处理潜在的异常

于 2013-10-30T10:52:27.597 回答
-1

ECDH 密钥的原始字节如何格式化?你从哪里得到原始字节?

通常,使用适当的 *Spec 类将原始密钥材料转换为 Key,但ECPublicKeySpecDHPublicKeySpec类不接受原始字节数组。

于 2010-02-08T02:08:47.270 回答