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  3. A quick way to 'protect' your code (or Howto crash Reflector .NET) [modified]

A quick way to 'protect' your code (or Howto crash Reflector .NET) [modified]

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  • L leppie

    .method static object Foo(object obj)
    {
    ldarg.0
    dup
    brtrue.s L1
    ret
    L1:
    callvirt instance class [mscorlib]System.Type [mscorlib]System.Object::GetType()
    ret
    }

    While there is no way***** you can write this in C#, it is still valid and verifiable IL. I picked this up when writing an accessor for chained properties to do null checks without having to store and load from locals (which is a 'tad' more complex than the example shown above). (I did report the bug to Redgate though) * Bonus points if someone can tell me how to emit the above code using the C# compiler

    xacc.ide
    IronScheme - 1.0 RC 1 - out now!
    ((λ (x) `(,x ',x)) '(λ (x) `(,x ',x))) The Scheme Programming Language – Fourth Edition

    modified on Thursday, April 22, 2010 6:21 AM

    L Offline
    L Offline
    Lost User
    wrote on last edited by
    #4

    leppie wrote:

    (I did report the bug to Redgate though) * Bonus points if someone can tell me how

    You sent them an email???

    L 1 Reply Last reply
    0
    • S Simon P Stevens

      Norm .net wrote:

      It would be a whole lot simpler if everyone coded in IL binary, then they'd be no need for C#,F# VB.net, IL, bytecode, C++, assembly etc.etc... One common lanugage to unite us all.

      FTFY

      Simon

      N Offline
      N Offline
      NormDroid
      wrote on last edited by
      #5

      I'm with you on that one.

      Two heads are better than one.

      1 Reply Last reply
      0
      • L Lost User

        leppie wrote:

        (I did report the bug to Redgate though) * Bonus points if someone can tell me how

        You sent them an email???

        L Offline
        L Offline
        leppie
        wrote on last edited by
        #6

        Josh Gray wrote:

        You sent them an email???

        No, I posted a message on their forums. Unless you are completely confused by the *. That is a reference to the * (next to no-way) in my message.

        xacc.ide
        IronScheme - 1.0 RC 1 - out now!
        ((λ (x) `(,x ',x)) '(λ (x) `(,x ',x))) The Scheme Programming Language – Fourth Edition

        1 Reply Last reply
        0
        • L leppie

          .method static object Foo(object obj)
          {
          ldarg.0
          dup
          brtrue.s L1
          ret
          L1:
          callvirt instance class [mscorlib]System.Type [mscorlib]System.Object::GetType()
          ret
          }

          While there is no way***** you can write this in C#, it is still valid and verifiable IL. I picked this up when writing an accessor for chained properties to do null checks without having to store and load from locals (which is a 'tad' more complex than the example shown above). (I did report the bug to Redgate though) * Bonus points if someone can tell me how to emit the above code using the C# compiler

          xacc.ide
          IronScheme - 1.0 RC 1 - out now!
          ((λ (x) `(,x ',x)) '(λ (x) `(,x ',x))) The Scheme Programming Language – Fourth Edition

          modified on Thursday, April 22, 2010 6:21 AM

          A Offline
          A Offline
          Adam Maras
          wrote on last edited by
          #7

          I'm versed in .NET and C#, but not CIL. What exactly does this do, and why does it 1) not have a C# equivalent and 2) make Reflector eat shit?

          Adam Maras | Software Developer Microsoft Certified Professional Developer

          L 1 Reply Last reply
          0
          • L leppie

            .method static object Foo(object obj)
            {
            ldarg.0
            dup
            brtrue.s L1
            ret
            L1:
            callvirt instance class [mscorlib]System.Type [mscorlib]System.Object::GetType()
            ret
            }

            While there is no way***** you can write this in C#, it is still valid and verifiable IL. I picked this up when writing an accessor for chained properties to do null checks without having to store and load from locals (which is a 'tad' more complex than the example shown above). (I did report the bug to Redgate though) * Bonus points if someone can tell me how to emit the above code using the C# compiler

            xacc.ide
            IronScheme - 1.0 RC 1 - out now!
            ((λ (x) `(,x ',x)) '(λ (x) `(,x ',x))) The Scheme Programming Language – Fourth Edition

            modified on Thursday, April 22, 2010 6:21 AM

            D Offline
            D Offline
            DaveAuld
            wrote on last edited by
            #8

            Contact form on red-gate.com website? :doh: Just seen your other post, how did you your write this bug is what you were asking..........em, you used your keyboard to enter information onto your computer, thats how :~

            Dave Don't forget to rate messages!
            Find Me On: Web|Facebook|Twitter|LinkedIn
            Waving? dave.m.auld[at]googlewave.com

            L 1 Reply Last reply
            0
            • D DaveAuld

              Contact form on red-gate.com website? :doh: Just seen your other post, how did you your write this bug is what you were asking..........em, you used your keyboard to enter information onto your computer, thats how :~

              Dave Don't forget to rate messages!
              Find Me On: Web|Facebook|Twitter|LinkedIn
              Waving? dave.m.auld[at]googlewave.com

              L Offline
              L Offline
              leppie
              wrote on last edited by
              #9

              That was not the question... I am asking how to create that MSIL code in C#, if possible. I cant think of any way to do so.

              xacc.ide
              IronScheme - 1.0 RC 1 - out now!
              ((λ (x) `(,x ',x)) '(λ (x) `(,x ',x))) The Scheme Programming Language – Fourth Edition

              1 Reply Last reply
              0
              • A Adam Maras

                I'm versed in .NET and C#, but not CIL. What exactly does this do, and why does it 1) not have a C# equivalent and 2) make Reflector eat shit?

                Adam Maras | Software Developer Microsoft Certified Professional Developer

                L Offline
                L Offline
                leppie
                wrote on last edited by
                #10
                1. It is similar to:

                static object Foo(object obj)
                {
                if (obj == null)
                {
                return obj;
                }
                return obj.GetType();
                }

                But when you compile this in C#, it will use a bunch of store and load instructions. 1) I am not sure if C# ever emits the dup opcode. 2) Because it is buggy, and you should never trust the output of Reflector's reconstructed C# code :)

                xacc.ide
                IronScheme - 1.0 RC 1 - out now!
                ((λ (x) `(,x ',x)) '(λ (x) `(,x ',x))) The Scheme Programming Language – Fourth Edition

                D 1 Reply Last reply
                0
                • S Simon P Stevens

                  Norm .net wrote:

                  It would be a whole lot simpler if everyone coded in IL binary, then they'd be no need for C#,F# VB.net, IL, bytecode, C++, assembly etc.etc... One common lanugage to unite us all.

                  FTFY

                  Simon

                  L Offline
                  L Offline
                  leppie
                  wrote on last edited by
                  #11

                  Binary??? Man, that's so high-level. We should be shorting out transistors with DIP switches!

                  xacc.ide
                  IronScheme - 1.0 RC 1 - out now!
                  ((λ (x) `(,x ',x)) '(λ (x) `(,x ',x))) The Scheme Programming Language – Fourth Edition

                  S 1 Reply Last reply
                  0
                  • L leppie

                    .method static object Foo(object obj)
                    {
                    ldarg.0
                    dup
                    brtrue.s L1
                    ret
                    L1:
                    callvirt instance class [mscorlib]System.Type [mscorlib]System.Object::GetType()
                    ret
                    }

                    While there is no way***** you can write this in C#, it is still valid and verifiable IL. I picked this up when writing an accessor for chained properties to do null checks without having to store and load from locals (which is a 'tad' more complex than the example shown above). (I did report the bug to Redgate though) * Bonus points if someone can tell me how to emit the above code using the C# compiler

                    xacc.ide
                    IronScheme - 1.0 RC 1 - out now!
                    ((λ (x) `(,x ',x)) '(λ (x) `(,x ',x))) The Scheme Programming Language – Fourth Edition

                    modified on Thursday, April 22, 2010 6:21 AM

                    S Offline
                    S Offline
                    Super Lloyd
                    wrote on last edited by
                    #12

                    Perhaps.... You can write a small "IL Project" and merge it in your C# assembly! (How To[^] with Visual Studio)

                    A train station is where the train stops. A bus station is where the bus stops. On my desk, I have a work station.... _________________________________________________________ My programs never have bugs, they just develop random features.

                    N L 2 Replies Last reply
                    0
                    • S Super Lloyd

                      Perhaps.... You can write a small "IL Project" and merge it in your C# assembly! (How To[^] with Visual Studio)

                      A train station is where the train stops. A bus station is where the bus stops. On my desk, I have a work station.... _________________________________________________________ My programs never have bugs, they just develop random features.

                      N Offline
                      N Offline
                      NormDroid
                      wrote on last edited by
                      #13

                      For people who have far too much time on their hands.

                      Two heads are better than one.

                      P 1 Reply Last reply
                      0
                      • L leppie
                        1. It is similar to:

                        static object Foo(object obj)
                        {
                        if (obj == null)
                        {
                        return obj;
                        }
                        return obj.GetType();
                        }

                        But when you compile this in C#, it will use a bunch of store and load instructions. 1) I am not sure if C# ever emits the dup opcode. 2) Because it is buggy, and you should never trust the output of Reflector's reconstructed C# code :)

                        xacc.ide
                        IronScheme - 1.0 RC 1 - out now!
                        ((λ (x) `(,x ',x)) '(λ (x) `(,x ',x))) The Scheme Programming Language – Fourth Edition

                        D Offline
                        D Offline
                        Daniel Grunwald
                        wrote on last edited by
                        #14

                        leppie wrote:

                        I am not sure if C# ever emits the dup opcode.

                        It does. For example, dup occurs when using the "??" operator, or when using the result of an assignment "return v = obj;".

                        L 1 Reply Last reply
                        0
                        • D Daniel Grunwald

                          leppie wrote:

                          I am not sure if C# ever emits the dup opcode.

                          It does. For example, dup occurs when using the "??" operator, or when using the result of an assignment "return v = obj;".

                          L Offline
                          L Offline
                          leppie
                          wrote on last edited by
                          #15

                          Interesting. Thanks :) Unfortunately, one still cannot 'utilize' the stack as I have via C#, not that I think it will make any difference to native code output, just easier to write IL without having to deal with locals as well.

                          xacc.ide
                          IronScheme - 1.0 RC 1 - out now!
                          ((λ (x) `(,x ',x)) '(λ (x) `(,x ',x))) The Scheme Programming Language – Fourth Edition

                          1 Reply Last reply
                          0
                          • S Super Lloyd

                            Perhaps.... You can write a small "IL Project" and merge it in your C# assembly! (How To[^] with Visual Studio)

                            A train station is where the train stops. A bus station is where the bus stops. On my desk, I have a work station.... _________________________________________________________ My programs never have bugs, they just develop random features.

                            L Offline
                            L Offline
                            leppie
                            wrote on last edited by
                            #16

                            Yes, ILMerge is nice. The original IL was generated from C# anyways, I just tweaked it to make it easier to write with Reflection.Emit. :)

                            xacc.ide
                            IronScheme - 1.0 RC 1 - out now!
                            ((λ (x) `(,x ',x)) '(λ (x) `(,x ',x))) The Scheme Programming Language – Fourth Edition

                            1 Reply Last reply
                            0
                            • N NormDroid

                              For people who have far too much time on their hands.

                              Two heads are better than one.

                              P Offline
                              P Offline
                              PIEBALDconsult
                              wrote on last edited by
                              #17

                              Nope; I won't touch it.

                              1 Reply Last reply
                              0
                              • L leppie

                                Binary??? Man, that's so high-level. We should be shorting out transistors with DIP switches!

                                xacc.ide
                                IronScheme - 1.0 RC 1 - out now!
                                ((λ (x) `(,x ',x)) '(λ (x) `(,x ',x))) The Scheme Programming Language – Fourth Edition

                                S Offline
                                S Offline
                                Steve Mayfield
                                wrote on last edited by
                                #18

                                I was looking at high end video card last night and the ATI Radeon 9850 has 2.15 billion transistors - I better get started on the driver - flip, flip, no flip.......

                                Steve _________________ I C(++) therefore I am

                                1 Reply Last reply
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