java用ED25519算法實現簽名驗簽

首先要引入下面的jar包：

 <dependency>
     <groupId>net.i2p.crypto</groupId>
     <artifactId>eddsa</artifactId>
     <version>0.3.0</version>
 </dependency>

下面是ED25519算法實現簽名驗簽的一個demo：

@Slf4j
public class EDTest {

    // 公私鑰是由64個字節（128位16進制）構成的，前32個字節是私鑰，后32個字節是公鑰
    public static String key = "89680894b7ce1c5c91eba3468589787ffe340f357759bbf5bbfacb685ffc1bb914e0ea07e8766d71a15f7712fd1e2bebe8ad8080bf1ca2e6753caf64b61e80b3";


    public static void main(String[] args) throws Exception {
        // data數據（JSON）
        String data = "123456";
        // 公私鑰轉為byte[]
        byte[] seed = Utils.hexToBytes(key);
        // 取前32位字節私鑰
        byte[] privSeed = Arrays.copyOfRange(seed, 0, 32);
        // ed25519 簽名
        EdDSAParameterSpec spec = EdDSANamedCurveTable.getByName(EdDSANamedCurveTable.ED_25519);
        Signature signature = new EdDSAEngine(MessageDigest.getInstance(spec.getHashAlgorithm()));
        EdDSAPrivateKeySpec privKey = new EdDSAPrivateKeySpec(privSeed, spec);
        PrivateKey sKey = new EdDSAPrivateKey(privKey);
        // 私鑰 簽名
        signature.initSign(sKey);
        // 把你的data用SHA256加密
        signature.update(NodeUtils.getSHA256(data));
        // 簽名轉換為hex
        String sign = Utils.bytesToHex(signature.sign());

        // 取后32位字節公鑰
        byte[] pubSeed = Arrays.copyOfRange(seed, 32, seed.length);

        // 用公鑰驗證簽名
        EdDSAParameterSpec spec2 = EdDSANamedCurveTable.getByName(EdDSANamedCurveTable.ED_25519);
        Signature signature2 = new EdDSAEngine(MessageDigest.getInstance(spec2.getHashAlgorithm()));
        EdDSAPublicKeySpec pubKeySpec = new EdDSAPublicKeySpec(pubSeed, spec2);
        PublicKey pKey = new EdDSAPublicKey(pubKeySpec);
        // 公鑰 驗證返回的sign
        signature2.initVerify(pKey);
        // 對返回的data加密SHA256 驗證
        signature2.update(NodeUtils.getSHA256(data));
        boolean verify = signature2.verify(Utils.hexToBytes(sign));
        log.info("簽名驗證結果為：{}", verify);

    }
}

實現SHA256加密的方法：

/**
     * 用java原生的摘要實現SHA256加密
     *
     * @param str 加密前的報文
     * @return
     */
    public static byte[] getSHA256(String str) {
        try {
            MessageDigest messageDigest = MessageDigest.getInstance("SHA-256");
            messageDigest.update(str.getBytes("UTF-8"));
            return messageDigest.digest();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return null;
    }