Using a strong name protects your assembly against manipulation.
For example your software using a class named Class1 in ClassLibrary1 namespace.
If you compile a new dll contains ClassLibrary1.Class1 then you can use this dll instead of original one.
This is very basic example but it can be applicable in real life.
To be sure that your software is using your assembly version then you can sign your project.
Microsoft description is:
This will create a pfx (Personal Information Exchange Format) file in your project folder.
For test change the code and recompile dll in outside of project folder.
For example your software using a class named Class1 in ClassLibrary1 namespace.
If you compile a new dll contains ClassLibrary1.Class1 then you can use this dll instead of original one.
This is very basic example but it can be applicable in real life.
To be sure that your software is using your assembly version then you can sign your project.
Microsoft description is:
When a strong-named assembly is created, it contains the simple text name of the assembly, the version number, optional culture information, a digital signature, and the public key that corresponds to the private key used for signing.Example here shows signing process in Visual Studio. You can use also command line tool (sn.exe).
Coding
Our solution has 2 projects, executable and a class library. Main program is using ClassLibrary1.Class1
using ClassLibrary1;
using System;
namespace strongname
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("strongname loaded");
Class1 c = new Class1();
Console.ReadKey();
}
}
}
using System;
namespace ClassLibrary1
{
public class Class1
{
public Class1()
{
Console.WriteLine("Hello from Class1");
}
}
}
Sign
Right click to project in VS and select Properties. In Signing tab check "Sign the assembly" and select "New" in listbox. Enter password for your private key.
This will create a pfx (Personal Information Exchange Format) file in your project folder.
Run
strongname loaded
Hello from Class1
Recompile
If you create a new project with the same namespace, class and functions then you can use the new dll with current executable.For test change the code and recompile dll in outside of project folder.
csc.exe /t:library /out:ClassLibrary1.dll Class1.csThen replace the old ClassLibrary1.dll with the new file.
Result
When you try to run your executable an error will be shown because the new dll has not signed with correct key.C:\strongname\bin\Debug\strongname.exeIf you completely remove signing from your projects then your manipulated dll will work.
Unhandled Exception: System.IO.FileLoadException: Could not load file or assembly 'ClassLibrary1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=77d705841860f240' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
at strongname.Program.Main(String[] args)
