. Net programmers should understand several software protection methods. programs that work hard to develop need to establish effective protection mechanisms.

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• Method 1 the SQL toolbet represented by red gate needs to be connected to the server for verification.
• Method 2 Enterprise Management Software ERP license documents
• Method 3: serial number registration code
• Method 4: License to license2 dual-license verification
• Method 5 Microsoft batch activation Tool

Use. Net for developmentProgramBecause metadata exists in the Assembly, it can be easily decompiledSource code. When an assembly is decompiled, encryption software obfuscated with the assembly is applied to the customer,

It is difficult to understand and increase the difficulty of cracking. The following lists several common protection methods that can be applied to actual product protection.

Method 1 the SQL toolbet represented by red gate needs to be connected to the server for verification.

SQL tools developed by red gate are very well-known. For example, the famous SQL prompt can be used to implement smart prompting in SQL Server Management studio. Each time a new version is available

It appears (hopefully you can understand what I mean) and becomes one of the favorite tools. Its protection mechanism is typical. If you download and install the trial software, you need to connect

The server performs activation verification. Otherwise, the program is exited.

In this case, the network connection must be available. However, for various reasons, some machines cannot be connected to the Internet, or because development servers, data and materials are valuable, or because developers

You are not allowed to access the Internet. In this case, it also provides a verification mechanism to package verification information and send it to the official website via email or instant messaging software,

Obtain a string similar to the registration code, as shown in

These two methods work together, and this type of verification protection mechanism is relatively complete and user-friendly.

 

Method 2 Enterprise Management Software ERP license documents

Software licenses are often involved in enterprise management software ). This method is flexible, whether it is site-based (UF), feature-based (Kingdee), or user-based.

The user obtains a formal installer file from the official website or CD drive. A license file is required to activate the installation and access the system. Different license files are generated based on your actual purchase conditions,

When the system is running, the system checks whether the file is valid and authorized. All the secrets are generated for this license file, as shown in the following license file.

 <?  XML   Version  = "1.0"   Encoding  = "UTF-16" ? >  <  Solutionlicense  Xmlns: xsi  = "Http://www.w3.org/2001/XMLSchema-instance"   Xmlns: XSD  = "Http://www.w3.org/2001/XMLSchema"  >    <  Registrationname  > Enterprise Solution Limited </  Registrationname  >    <  Version  > 2.2 </  Version  >    < Maxuser  > 100 </  Maxuser  >    <  Maxviewer  > 100 </  Maxviewer  >    <  Maxdatabase  > 4 </  Maxdatabase  >    <  Withhaspkey  > False</  Withhaspkey  >    <  Allowinstallow.rtualmachine  > True </  Allowinstallow.rtualmachine  >    <  Issueddate  > 2013-05-27t15: 55: 15.3440758 + 08: 00 </  Issueddate  >    <  Expirydate  > 2013-06-26t23: 59: 59.997</  Expirydate  >    <  Licensetype  > Internal </  Licensetype  >    <  Hardwarefingerprint  > + MV/imkuxqv3rwdrd4rso4dplxmr5whddj37wdwe09ogghackwjp + twmdb5rvqfu/

 
Authorization = wfuhyiipi2dq/ksxym6tmx
 

0pcuwqa9v/large + KB/+ ajpm + yajgfp8epxyrofjjodgat + es1ksimh
 

 
T5vnb5al2fy1qlwqoiojk6q/clczseb6ielmhss0hlmc = gqqtpgtgrui4nsvlz803hhup + LF/fingerprint + omt1k3nevpt3fuymr + yydnrql
 

 
Qhah7/ktvc%vrs9ye7lywpwcgksjcjot/%+ 93 enloug = acvxke/wfgevjyruim + bvzty0nfxemfleqdztdqnslnfjdck
 

 export + export/jeo8j5ozv/3prls307fo69wpiz36o4y =    hardwarefingerprint       additionalinformations 
    />     signature 
      xmlns   = "http://www.w3.org/2000/09/xmldsig#"     signedinfo  ><   canonicalizationmethod   algorithm   = "http://www.w3.org/TR/2001/REC  

-Xml-c14n-20010315" /> <Signaturemethod Algorithm= "Http://www.w3.org/2000/09/xmldsig#rsa-sha1" /> <Reference Uri= ""> <Transforms> <T
 

 
Ransform Algorithm= "Http://www.w3.org/2000/09/xmldsig#enveloped-signature" /> </Transforms> <Digestmethod Algorithm= "Http: // ww
 

Export w3.org/2000/09/xmldsig1_sha1" /> <Digestvalue>Rudheihpzcctda4kh9vpm/n7abe =</Digestvalue> </Reference> </Signedinfo> <SIG
 

 
Naturevalue>Else // 0 yaqhky + qbczrbix
 

3 svfkb + dssm + wzvyruucntstp39rkutcim + fhat/wda2iarwdm1/ztpahooi + zzba =</Signaturevalue> </Signature> </Solutionlicense>
 

The format of the license file is a text file for easy viewing. In the above license file, I granted permissions to 100 users and four sets of accounts. Then, use signedxml to sign the file content,

Prevents tampering. In addition, if you want to restrict the user, you can add the machine identification (hardware fingerprint). If the received license file is detected, it will not run on the authorized machine,

It also throws an exception and terminates the program.

There is also a license generation tool whose prototype looks like this

Let's explain how to crack this encryption. First, if the Assembly has a strong signature (strong name), you need to find a tool to remove its signature. Second, findAlgorithmVerify license. in the XML file, replace its public key with its own public key, and then write a licnese generation tool generated with the private key to generate the license file, replace the modified verification Assembly file to verify the program.

The above-mentioned cracking process is ideal. If the Assembly has a strong name, and the Assembly has a verification that strong name exists, and strong name matches the public token generated by the author, in this case, a strong name is generated, replace the public tokens generated by the author and written to the Assembly. Second, you must be able to decompile the Assembly. The famous tool red gate reflector, ilspy, and dotpeek can all be used to decompile the assembly. If the Assembly has shelling, it should also be de-shelled.

 

Method 3: serial number registration code

Classic SourceCodeThe edit software ultraedit still maintains this protection method. Enter the registration code when you first run

A user name and registration code can change the trial software of multiple machines to the official version. This problem is common in our country. The license is generally a single PC license, and we often use the license file or serial number as long as it is downloaded from the official website. In this case, it is not a genuine license. You only need to enter the registration code and do not need to connect to the network verification server. If you want to connect to the server for further verification, you also need to connect to the network.

For more information about network connections. To activate windows from Windows 7, you must have a network connection available. For new machines, if you want to install the old Windows Server 2003, you cannot find the NIC Driver, connect to the network, or activate it. You have to install the latest system. There is a small suggestion. If your machine is under Windows 7, you can consider backing up your driver, Nic, graphics card, and Motherboard chipset. These drivers will become increasingly difficult to find in the future, and manufacturers will directly refuse to provide drivers for the old system (Windows 2003, XP), so that you are forced to use Windows 7 or newer systems. Hardware manufacturers are also premeditated to force you to change old machines.

 

Method 4: License to license2 dual-license verification

It is represented by the famous. Net encryption software. Net reactor. Two license files are required to pass its license verification.

After purchasing genuine software, the software supplier will provide a license. License file. Open dotnet_reactor.exe, choose "help"> "registeration", and obtain another license file online. Click the hyperlink to go to the official website: check emails and download the real license.

Open dotnet_reactor.exe, choose "help"> "registeration", and register the software.

Looking back at this registration process, it will generate a local hardware identifier, copy this to the web page to activate the software, so that the software needs to work with the hardware, even if there is a serial number, license file, however, the hardware IDs are different and the license file is invalid.

The hardware identifier is usually written to the license file, which is the only one that can be used but does not cause any problems. The hardware identifier is written to the Registry, which can be exported by the user and imported to other machines. The hardware indicates that it can be written to a hidden system file. Deletion by the user may cause an error.

 

Method 5 Microsoft batch activation Tool

It is represented by office 2010. the main interface of its batch activation tool is as follows: Console interface style, small and powerful

Another example is anti-virus software Kaspersky, which authorizes enterprises in batches. It is also a way to generate licenses in batches.

The advantage of this authorization method is that it can be called by the command line. In the enterprise infrastructure of domain management, you only need the domain administrator to modify the domain policy. When each client renews a domain, execute a script file to immediately activate all software licenses in the enterprise.

I understand that this encryption method also generates a license file. Because office software is so popular, you can easily find available versions. It is rarely difficult to get his license, but this method of generating a license is worth learning and researching.