[区块链]区块链技术-校验metaMask钱包签名

/**
     * 校验以太坊签名是否合法
     * 先通过 signature 解码出 v，r，s 签名数据，再求出公钥，再求出地址并校验
     *
     * @param from      发送者地址
     * @param resource  被签名的原数据
     * @param signature 签名
     * @return match
     */
    public boolean verifySignature(String from, String resource, String signature) {

        //  这里一个字符都不能少，eth签名规则必须拼上 "\u0019Ethereum Signed Message:\n"
        String prefix = "\u0019Ethereum Signed Message:\n" + resource.length();
        byte[] msgHash = Hash.sha3((prefix + resource).getBytes());

        byte[] signatureBytes = Numeric.hexStringToByteArray(signature);
        //取出v
        byte v = signatureBytes[64];
        if (v < 27) {
            v += 27;
        }
        //取出r,s,和v一起可以求出公钥
        Sign.SignatureData sd = new Sign.SignatureData(
                v,
                Arrays.copyOfRange(signatureBytes, 0, 32),
                Arrays.copyOfRange(signatureBytes, 32, 64));

        String addressRecovered = null;
        boolean match = false;
        // 遍历recId
        for (int i = 0; i < 4; i++) {
            //计算公钥
            BigInteger publicKey = Sign.recoverFromSignature(
                    (byte) i,
                    new ECDSASignature(new BigInteger(1, sd.getR()), new BigInteger(1, sd.getS())),
                    msgHash);
            if (publicKey != null) {
                //通过公钥计算地址
                addressRecovered = "0x" + Keys.getAddress(publicKey);
                if (addressRecovered.equals(from)) {
                    match = true;
                    break;
                }
            }
        }
        log.info("verify:" + resource + " : " + signature + " ==> " + addressRecovered);
        return match;
    }