Method allZero

security/src/main/java/pro/tools/security/sm/SM2.java:187–194

判断字节数组是否全0 @param buffer @return

(byte[] buffer)

     * @return
     */
    private boolean allZero(byte[] buffer) {
        for (byte aBuffer : buffer) {
            if (aBuffer != 0) {
                return false;
            }
        }
        return true;
    }

    /**
     * 公钥加密