一次RSA验证遇到的问题

情况大概描述下
只有一个pem形式的公钥，以及加密前的字符串，待验证加密结果，现需要用公钥对加密结果做验证
pem文件内容

—–BEGIN PUBLIC KEY—–
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCkNfthC+Ultlm0sNiBAce6NcW4
mujK3jebPuhg8C6Jh4ziXYZCJ/l0qNDgP7PV2lBMDgSG1CoDCEmJlKnXKU2E2nWT
T5AtXkmGREIOGKq+dUjelqDjEiPW4a2aAQp/N0TkdQeBB/mscvyPoHPFkD1O/eL+
wRXOVb+uuszvgBXTiwIDAQAB
—–END PUBLIC KEY—–

遇到的问题集合
1、ObjectIdentifier mismatch: 1.3.14.3.2.26
源代码

Signature signature = Signature.getInstance("MD5WithRSA");

修改过后

Signature signature = Signature.getInstance("SHA1WithRSA");

2、
java.lang.IllegalArgumentException: Illegal base64 character 2d
还有个什么too big 127 的都是需要把pem文件中的首位两行也就是带有”—–”的去掉

贴下最终代码

     /** 用公钥做RSA校验
     * @param data 加密前字符串
     * @param sign 待验证的解密结果
     * @param publikKeyPath 公钥路径
     * */
    public static boolean doVerifyPublicKey(String data, String sign, String publikKeyPath) {
        return verify(data.getBytes(),
                0,
                 data.getBytes().length,
                getKey(publikKeyPath),
                Base64Utils.decodeFromString(sign));
    }
    /**
     * 把pem文件解析为字节流
     * @param publikKeyPath pem文件路径
     */
    public static byte[] getKey(String publikKeyPath){
        byte[] keyBytes = null;
        try {
            File file = ResourceUtils.getFile("classpath:"+publikKeyPath);
            List<String> strLineList = Files.readAllLines(Paths.get(file.toURI()));
            StringBuilder builder = new StringBuilder();
            for (String string : strLineList){
                builder.append(string);
            }
            return Base64Utils.decodeFromString(builder.toString());
        } catch (FileNotFoundException ex) {
            logger.error("", ex);
        } catch (Exception ex) {
            logger.error("", ex);
        }
        return keyBytes;
    }
    public static boolean verify(byte[] data, int offset, int length, byte[] publicKeyBytes, byte[] dataSignature) {
        boolean result = false;
        try {
            X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(publicKeyBytes);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);

            Signature signature = Signature.getInstance("SHA1WithRSA");

            signature.initVerify(publicKey);

            signature.update(data, offset, length);

            result = signature.verify(dataSignature);
        } catch (Exception ex) {
            logger.error("", ex);
        }
        return result;
    }

另 由于公钥格式、公钥生成时选择的加密方式不同，验证时的代码也不尽相同