aspose-slides-22.5-jdk16

官网下载地址：Aspose Repository Browser /repo/com/aspose/aspose-slides/22.5/

一、分析

1、官方验证部分为：

        InputStream is = new FileInputStream("license.xml");
        License license = new License();
        license.setLicense(is);

以下为一个过期的证书：license.xml

<License>
    <Data>
        <Products>
            <Product>Aspose.Total for Java</Product>
            <Product>Aspose.Words for Java</Product>
        </Products>
        <EditionType>Enterprise</EditionType>
        <SubscriptionExpiry>20991231</SubscriptionExpiry>
        <LicenseExpiry>20991231</LicenseExpiry>
        <SerialNumber>8bfe198c-7f0c-4ef8-8ff0-acc3237bf0d7</SerialNumber>
    </Data>
    <Signature>
        sNLLKGMUdF0r8O1kKilWAGdgfs2BvJb/2Xp8p5iuDVfZXmhppo+d0Ran1P9TKdjV4ABwAgKXxJ3jcQTqE/2IRfqwnPf8itN8aFZlV3TJPYeD3yWE7IT55Gz6EijUpC7aKeoohTb4w2fpox58wWoF3SNp6sK6jDfiAUGEHYJ9pjU=
    </Signature>
</License>

2、分析License类的setLicense方法找到关键代码

使用jd-gui反编译jar包，搜索 License

分析setLicense方法,设置许可证,完成许可的验证，有2个一个是文件路径，一个是io流，但是最终都是走的io流那个方法。

  public final void setLicense(InputStream stream) throws AsposeLicenseException {
    try {
      ByteArrayInputStream byteArrayInputStream = null;
      if (stream != null) {
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        byte[] arrayOfByte = new byte[1024];
        int i;
        while ((i = stream.read(arrayOfByte)) > 0)
          byteArrayOutputStream.write(arrayOfByte, 0, i); 
        byteArrayOutputStream.flush();
        byteArrayInputStream = new ByteArrayInputStream(byteArrayOutputStream.toByteArray());
      } 
      return return = new return();
      return.do(byteArrayInputStream);
    } catch (IOException iOException) {
      throw new InvalidOperationException("License stream is not available for reading");
    } 
  }

      return return = new return();
      return.do(byteArrayInputStream);

在 com.aspose.slides.internal.oh 包下

  public final void do(InputStream paramInputStream) {
    if (paramInputStream != null) {
      if(paramInputStream);
      for(this.for);
      for(this.do);
      do(this.int);
      if(this.new);
      try = this;
      public.do(try);
    } else {
      try = null;
      public.do(try);
    } 
  }

定位到RSA验证签名，签名错误抛出异常。把这个方法体清空不抛异常就可以了。

private static void do(Node paramNode1, Node paramNode2, String[] paramArrayOfString) {
    try {
      String str1 = (paramNode1 != null) ? do(paramNode1) : "";
      byte[] arrayOfByte1 = str1.getBytes("UTF-16LE");
      String str2 = (paramNode2 != null) ? paramNode2.getFirstChild().getNodeValue() : "";
      byte[] arrayOfByte2 = try.do(str2);
      PublicKey publicKey = null;
      try {
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        RSAPublicKeySpec rSAPublicKeySpec = this.do(if(paramArrayOfString), arrayOfByte2);
        publicKey = keyFactory.generatePublic(rSAPublicKeySpec);
      } catch (Exception exception) {
        (new final() {
          
          }).do((new boolean() {
            
            },  ).if, exception);
      } 
      if (arrayOfByte2.length == 128) {
        Signature signature = Signature.getInstance("SHA1withRSA");
        signature.initVerify(publicKey);
        signature.update(arrayOfByte1);
        do(signature, arrayOfByte2);
      } else {
        try {
          Signature signature = Signature.getInstance("SHA256withRSA");
          signature.initVerify(publicKey);
          signature.update(arrayOfByte1);
          do(signature, arrayOfByte2);
        } catch (InvalidOperationException invalidOperationException) {
          try {
            String str3;
            if (if(paramArrayOfString)) {
              str3 = long.if(arrayOfByte2);
            } else {
              str3 = long.do(arrayOfByte2);
            } 
            String str4 = "AQAB";
            byte[] arrayOfByte3 = try.do(str3);
            byte[] arrayOfByte4 = try.do(str4);
            if (!instanceof.do(arrayOfByte1, arrayOfByte2, arrayOfByte3, arrayOfByte4))
              (new final() {
                
                }).do((new boolean() {
                  
                  },  ).int, (Exception)invalidOperationException); 
          } catch (Exception exception) {
            (new final() {
              
              }).do((new boolean() {
                
                },  ).int, (Exception)invalidOperationException);
          } 
        } 
      } 
    } catch (Exception exception) {
      (new final() {
        
        }).do((new boolean() {
          
          },  ).int, exception);
    } 
  }

3、分析结果

清空方法  void do(Node paramNode1, Node paramNode2, String[] paramArrayOfString)

  private static void do(Node paramNode1, Node paramNode2, String[] paramArrayOfString) {
    
  }

二、修改方式

1、添加Javassist修改class字节码文件

        <dependency>
            <groupId>org.javassist</groupId>
            <artifactId>javassist</artifactId>
            <version>3.29.0-GA</version>
        </dependency>

2、修改方法

package test;
 
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtMethod;
 
public class Demo6 {
    public static void main(String[] args) {
        try {
            ClassPool pool = ClassPool.getDefault();
            //取得需要反编译的jar文件，设定路径
            pool.insertClassPath("F:/aspose-slides-22.5-jdk16.jar");
 
            CtClass ctClass = pool.get("com.aspose.slides.internal.oh.return");
            CtMethod[] methods = ctClass.getDeclaredMethods("do");
            for (CtMethod method : methods) {
                CtClass[] ps = method.getParameterTypes();
                //参数个数为3个
                if (ps.length == 3 && method.getName().equals("do")) {
                    method.setBody("{}");//重新设置方法体的内容
                }
            }
            ctClass.writeFile("F:/");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

3、替换class文件

重命名 aspose-slides-22.5-jdk16.jar 为 aspose-slides-22.5-jdk16.jar.zip 解压

 MANIFEST.MF只保留以下部分

Manifest-Version: 1.0
Application-Name: Aspose.Slides for Java
Implementation-Title: Aspose.Slides for Java
Copyright: Copyright 2004-2022 Aspose Pty Ltd
Bundle-SymbolicName: com.aspose.slides
Implementation-Version: 22.5
Release-Date: 2022.05.31
Specification-Vendor: Aspose Pty Ltd
Bundle-ManifestVersion: 2
Specification-Title: Aspose.Slides for Java
Bundle-Vendor: Aspose Pty Ltd
Application-Library-Allowable-Codebase: *
Import-Package: javax.xml.parsers;resolution:=optional,javax.imageio;r
 esolution:=optional,org.xml.sax;resolution:=optional
Implementation-Vendor: Aspose Pty Ltd
Ant-Version: Apache Ant 1.9.7
Export-Package: com.aspose.slides;version=22.5,com.aspose.slides.Colle
 ctions;version=22.5,com.aspose.slides.exceptions;version=22.5
Bundle-Version: 22.5
Bundle-Name: Aspose.Slides for Java
Caller-Allowable-Codebase: *
Permissions: all-permissions
Created-By: 1.8.0_162-b12 (Oracle Corporation)
Specification-Version: 22.5

替换class文件：直接将生成的com文件夹覆盖到解压包的com文件夹

 将压缩成的zip重新命名为jar包