C# Discussion Boards - CodeProject

Re: Intellectual Property Protection BEYOND OBSFUCATION

7-Mar-07 12:23

mike montagne wrote:
The issue I have at the moment is with custom licensing, and handling the licensing scheme. I just don't find much information in the documentation as to custom features... handling additional fields... that sort of thing. Do you use the SDK for such purposes?

I am using 2.7.1.5 and have just visited their site and notice the newer version - which I shall look at shortly.

I agree - the documentation is poor and frankly after reading a fair bit of their competitor's help/manuals it left me wondering if their program would do what it claimed. If you boil it all down though, their competitors help/manuals need to be considerably thicker because they allow far more options/fine tuning. Having said that, that is also why their competitors programs take so much longer.

I tested out the licencing part of the package AFTER I had already incorporated my own into my program. I figured that providing my program couldn't be de-compiled then that was sufficient for me to use my own method of key generation/validation. I looked at the licencing SDK but didn't use it for that reason. My program is one that probably wouldn't be used by a "hacker", reports are hard-coded etc so that was good enough for me.

mike montagne wrote:
That's a pretty strong recommendation.

It is and I mean it Smile | :)

. Adding .dll's is easy and cuts down on distribution. As far as scrambling my code is concerned it's a breeze. I don't need all the bells and whistles and I don't need to convince a boss that loves to see confusing screens, multilayed and configurable levels, pick and chose which strings to obfuscate etc.

I don't think you can customise the licencing side of it very well at all (at least I didn't think so). It was/is one of the reasons I don't use their licencing module. I also don't like linking my program to a computer (and this may detract from your product sales). Having said that, geting a user to use HID.exe shouldn't be a problem. HID just identifies some hardware components and creates a code based on that hardware. HID is not used again unless the user makes a hardware change. I believe .Net Reactor checks the hardware itself and compares the supplied code if you have configured it to use hardware checking.

You shouldn't be issuing a key until after they have paid so running HID.exe and sending you the resultant code shouldn't be a problem. I haven't tried it but you could include HID in your distributable and have your own program run it and send you the code without any difficulty.

Performance should not be an issue at all. There must be some degredation but I haven't had any adverse comments nor have I noticed any degredation - except of course a minor unnoticable (to the user)delay at startup. It's so minor I couldn't really bother to measure it.

I'll have a look at Version 3 and let you know if I have any other comments to make.

Another point about the licencing module is you should check with whoever is going to collect the funds/issue the keys as to their requirements. If your doing it yourself then no worries Smile | :)

.

Let me know how you go - your the first person I know of that's actually using (or at least thinking) of using it. I have searched the net high and low for feedback etc without any luck.

Regards,

Glen Harvy

mike montagne7-Mar-07 13:20

Re: Intellectual Property Protection BEYOND OBSFUCATION

7-Mar-07 13:20

Wow. Thanks so much for so much to think about!

Glen Harvy wrote:
If you boil it all down though, their competitors help/manuals need to be considerably thicker because they allow far more options/fine tuning.

I think my needs are like yours. The intellectual property protection is a must have issue -- and the decision comes down to whether or not it will be cracked by people who will damage my market.

Glen Harvy wrote:
I also don't like linking my program to a computer (and this may detract from your product sales).

I'm interested in your thinking here. What I want to do is offer a basic license, with extra (multiple installations) extensions costing enough to cover processing costs with a small profit. In other words, a $50 product with $15 multiple installation extensions.

In my experience, people don't pay for things if they don't have to. But like you say, if *I* buy software, I want to be able to install it on multiple systems. Sometimes I'll take it with me. Most of the time I'll work on it at the office. My hope is to make those further installations formal, yet not an abuse of the client (like so many licenses are).

As to .NET Reactor, I'm waiting to hear back from Denis there. I haven't tried to decompile yet, but I am about to do that. I just finished testing of the output .dll (my product is a library), and it went fine, although, like you, I didn't test 64-bit (which may prove to be an issue).

I really don't know what's supposed to be functional in the trial version. Everything appears to be working fine as far as reproduced CIL is concerned. Not even a detectable slowdown. That's very good. However, in my NR project, I have set an Inbuild Evaluation period (15) and Inbuild Number of Uses (50), with Show Expiration Screen, Show Nag Screen, and Shutdown Process after Expiration all set to true. Yet whether I copy the output license file to my test directory or not, I'm not seeing an Expiration or Nag screen, nor is my process shut down without the license. That doesn't bode well, but I'm waiting on an answer as to whether that is supposed to work in the demo installation. He *did* write me earlier that I *would* be able to test locally -- whether that means these features are not enforced I don't know.

I don't know why he has the separate Lock Settings and License Manager tab. I had to manually set the License Manager tab information to match the Lock Settings information -- which was simply ignored (?).

I like to see these kinds of (simple) things work perfectly. I may still use the product (even anxiously), but it may end up being with the same caveats you have raised. I've asked a number of questions about custom licensing and the SDK. I just don't have those yet -- and like you probably, I hope to avoid programming down any dead ends there.

In the past, in Windows executables, I have used a licensing scheme which marks the system and which is practically tamper proof (efforts far exceed the potential benefits). That was custom coded.

You don't happen to know of any material/guidelines for doing that with .NET libraries do you? The issues are somewhat different, and it would be nice to have a launching point from which to custom develop my own system, versus relying on the NR SDK for that.

tia,

m

Glen Harvy7-Mar-07 14:17

7-Mar-07 14:17

Let's break this discussion into two sections - Obfuscation and Licencing.

Licencing:

From what I can tell the SDK allows you to customize the licence file but not much else. I don't see how any of those customizations can be practically used in determining whether your program works or not. I have not examined the SDK or made any use of it but it may be possible for your program to read the licence file and do something based on the content of that file.

You either accept the licencing options NR provides or you don't. BTW: In my testing, the licencing options did work and I was very impressed. I think you must be doing something wrong if it's not working for you Frown | :(

My program and it's licencing are linked to the Club's Name. The licence code is generated by the combination of the Club's name and a secret word hardcoded into my program. The 30 day trial period is also "hardcoded" into my program. If the local Womens Association Smile | :)

have a hacker with heaps of time and the knowledge then I guess I've lost a sale Hmmm | :|

.

My registration company is ShareIt and they generate the keys by using their key generator software which I have also NR'ed so the all important secret word is obfuscated even to them.

In your scenario I don't see how you can use the NR licencing module without using HID.exe.

Obfuscation:

I tried to run various de-obfuscators on my NR'ed program, ILDasm etc on the output without success.

In other words - it works for me Smile | :)

Cheers,

Glen Harvy

mike montagne8-Mar-07 5:40

8-Mar-07 5:40

Similarly, I studied .NET licensing classes last night, and it's not really clear just how I'll want to go about writing a licensing scheme -- whether to use file I/O classes.

From what I see in the .Net SDK documentation, our license must be marked with a *.LIC extension.

The name of the file must be the fully qualified name, including the namespace, of the class with the file name extension .LIC. For example:<br />
<br />
Namespace1.Class1.LIC

This is not the case for the NR license (.license), so the NR system must be proprietary. That's OK with me -- it may be a much better thing to do, because I find the VS .Net SDK documentation quite ambiguous too. For instance,

The content of the license file should contain the following text string:<br />
<br />
"myClassName is a licensed component."<br />
<br />
myClassName is the fully qualified name of the class. For example:<br />
<br />
"Namespace1.Class1 is a licensed component."

Personally, I read this stuff and ask myself what it can mean to anyone. I want to know how this string, "Namespace1.Class1 is a licensed component." is processed. You would suppose that if it is removed or altered that this invalidates the license, but how and why -- and what alternate processes take over then? By the time you have deciphered all the cryptic documentation an unexplained issues (by costly experimentation), you can have far too much time in a small bit of functionality. A crux of the design issues is splitting the design time behavior and runtime behavior of distributables. The documentation seems to suggest this happens, but not how. You return a validation value by overriding a method.

Unfortunately, I don't see the path as being very clear here either. Like you, I most appreciate the fact that the NR licensing scheme will be hidden by a process beyond obsfucation -- and that is presently the deciding factor in the fork I'm going to take here, especially as I have now heard from Denis, and he's agreed to let me help him improve NR's documentation. My thinking is that I'll get my job done faster with more direct help, and that if we can improve the documentation, it may be very clear what to do with what my intuition tells me is the most promising way to distribute commercial .Net assemblies which require (or benefit from) intellectual property protection.

I'll read your other posts now, but will report back in the next few days if I can, on what progress Denis and I have made with his documentation. This should be interesting.

m

Glen Harvy8-Mar-07 11:50

8-Mar-07 11:50

You should move this topic to a new Subject and see if anyone else can help you as well.

I didn't know that there was a licencing method in the .Net SDK until you mentioned it. I wrote all my own code which, being obfuscated Smile | :)

is good enough for my program and it's target market.

I did find this interesting [^] which may assist you. There may even be sources available to you on codeproject!

Good luck.

Glen Harvy

mike montagne8-Mar-07 12:26

8-Mar-07 12:26

Denis and I are working on this together now, but I'll look at your link in a second here.

mike montagne8-Mar-07 12:34

8-Mar-07 12:34

Hey, great article. He says, "While I believe that for completeness I should describe how you use LicFileLicenseProvider, I also believe that anyone serious about licensing their software will most likely avoid such a simple scheme in favor of their own, more creative schemes, one of which I'll introduce to you after describing LicFileLicenseProvider."

I was pretty quickly convinced of as much last night as I explored the "documentation."

THANKS A BUNCH!

mike montagne8-Mar-07 12:39

Re: Intellectual Property Protection BEYOND OBSFUCATION

8-Mar-07 12:39

Denis and I are hashing out some ideas about licensing. Hopefully we will come up with a boilerplate which will solve issues right out of the box.

mike montagne7-Mar-07 13:40

Re: Intellectual Property Protection BEYOND OBSFUCATION

7-Mar-07 13:40

Ouch. I haven't even done this before (ILDASM), and (I'm wondering if I have my head up my hind), but I'd certainly tend to assume that I'm looking at my source as CIL.

?

.method family hidebysig instance valuetype [System.Drawing]System.Drawing.Color
Color_IncOrDecLum(valuetype [System.Drawing]System.Drawing.Color C,
int32 LumDif) cil managed
{
// Code size 85 (0x55)
.maxstack 14
IL_0000: ldarga C
IL_0004: call instance bool [System.Drawing]System.Drawing.Color::get_IsEmpty()
IL_0009: brtrue IL_0053
IL_000e: ldarg.2
IL_000f: brfalse IL_0053
IL_0014: ldarga C
IL_0018: call instance uint8 [System.Drawing]System.Drawing.Color::get_A()
IL_001d: ldarga C
IL_0021: call instance uint8 [System.Drawing]System.Drawing.Color::get_R()
IL_0026: ldarg.2
IL_0027: add
IL_0028: call int32 ADVANCEIS.Controls_N.GCServer_Base::RectifyTo_0_255(int32)
IL_002d: ldarga C
IL_0031: call instance uint8 [System.Drawing]System.Drawing.Color::get_G()
IL_0036: ldarg.2
IL_0037: add
IL_0038: call int32 ADVANCEIS.Controls_N.GCServer_Base::RectifyTo_0_255(int32)
IL_003d: ldarga C
IL_0041: call instance uint8 [System.Drawing]System.Drawing.Color::get_B()
IL_0046: ldarg.2
IL_0047: add
IL_0048: call int32 ADVANCEIS.Controls_N.GCServer_Base::RectifyTo_0_255(int32)
IL_004d: call valuetype [System.Drawing]System.Drawing.Color [System.Drawing]System.Drawing.Color::FromArgb(int32,
int32,
int32,
int32)
IL_0052: ret
IL_0053: ldarg.1
IL_0054: ret
} // end of method GCServer_Base::Color_IncOrDecLum

mike montagne7-Mar-07 14:12

Re: Intellectual Property Protection BEYOND OBSFUCATION

7-Mar-07 14:12

I've run it all a few more times.

Step 1 [Examining] :
Successful

Step 2 [Protection Layer 1] :
Successful

Step 3 [Protection Layer 2] :
Information: DEMO MODE! Obfuscation(50%).
Successful

Step 4 [Resign Assembly] :
Successful

.NET Assembly Successfully Protected

New Protected Version Of Your .NET Assembly Created In:
C:\VS2005\N\GC\obj\Release\GCControls_N_Secure\GCControls_N.dll

As to what this means... "Information: DEMO MODE! Obfuscation(50%)."... I do not know.

This is not looking good. It's like all settings are ignored in trial mode, or... ehem. Have you looked at your output with ILDasm? I'm getting the same thing every time -- readable IL, not even obsfucated.

Glen Harvy7-Mar-07 14:20

Re: Intellectual Property Protection BEYOND OBSFUCATION

7-Mar-07 14:20

Send me your test program and I'll NR it for you.

I thought the demo output was pretty descriptive - it only obfuscated half your code.

Xenocode only obfuscates 10% of the code and only hides 50% of strings in demo mode.

Glen Harvy

mike montagne7-Mar-07 14:54

Re: Intellectual Property Protection BEYOND OBSFUCATION

7-Mar-07 14:54

No can send the demo, but I sure do appreciate the offer. I can't get a rise out of Denis. I surely would like to know what's going on here. I have the settings tweaked that should be protecting output. I would think NR would like to show that off in demo mode. This stuff is simple. It shouldn't be a big deal.

Glen Harvy7-Mar-07 15:04

Re: Intellectual Property Protection BEYOND OBSFUCATION

7-Mar-07 15:04

I dunno where you are but Denis probably isn't even at work yet - he is in Germany.

I don't want to do their technical support but if you send me the .nrpoj file I can glance over that and see if there are any obvious setup problems.

Cheers,

Glen Harvy

mike montagne7-Mar-07 19:42

Re: Intellectual Property Protection BEYOND OBSFUCATION

7-Mar-07 19:42

I think my first mail should have caught him.

Thanks again for the offer again. Maybe you might want to do a little beta *installation* testing for a free license when I get this rolling? That should be more fun.

Just for the heck of it I looked things over again and decided to turn Compact Framework compatibility off. (I guess I was stupid to think the option meant extended versatility.)

So now when I protect, I get this (different) message string:

Step 1 [Examining] :
Successful

Step 2 [Protection Layer 1] :
Successful

Step 3 [Protection Layer 2] :
Successful

Step 4 [Resign Assembly] :
Successful

.NET Assembly Successfully Protected

New Protected Version Of Your .NET Assembly Created In:
C:\VS2005\N\GC\obj\Release\GCControls_N_Secure\GCControls_N.dll

Please Only Ship Your Protected Assembly Together With 'GCControls_N_nat.dll'

-----

What do you know. That's the first I saw a *nat.dll, and *nat.dll cannot be disassembled. Nor does my GCControls_N.dll seem to have but a little information in it now -- and not much at that.

I don't know what to make of the resource multiplication yet. We have grown from a 60K library to two libraries, one being 67K and the other (*nat.dll) being a whopping 212. Ouch. I expect that means ultimate distributables will be bloated that much.

I am a happier camper however with the arfie dog part barking.

Researching what I can do with a license scheme. I think the cleanest thing will be to do as you have -- write your own.

Glen Harvy8-Mar-07 0:38

Re: Intellectual Property Protection BEYOND OBSFUCATION

8-Mar-07 0:38

There ya go - it worked.

I have compression turned on and the .exe that I distribute is 791k verses about 1.8 meg for the executable and three included dll's.

Glen Harvy

mike montagne7-Mar-07 19:49

Re: Intellectual Property Protection BEYOND OBSFUCATION

7-Mar-07 19:49

Wow. Pretty interesting content in *nat.dll, including a string, "This program must be run under Win32"

I wonder if that has anything to do with the 64-bit behavior. In any case, some of the widely spaced strings have me wondering what I'm looking at here (in Notepad). Have you looked at this stuff?

Glen Harvy8-Mar-07 0:40

Re: Intellectual Property Protection BEYOND OBSFUCATION

8-Mar-07 0:40

That's interesting - perhaps NR will explain it.

I haven't bothered with looking at theend result - just as long as no one can easily de-obfuscate it I'm happy.

Glen Harvy

Glen Harvy7-Mar-07 14:38

Re: Intellectual Property Protection BEYOND OBSFUCATION

7-Mar-07 14:38

mike montagne wrote:
This is not looking good. It's like all settings are ignored in trial mode, or... ehem. Have you looked at your output with ILDasm? I'm getting the same thing every time -- readable IL, not even obsfucated.

I can send you a screen shot if you like:

---------------------------
ERROR
---------------------------
error : 'D:\VS2005 Projects\MyClubV2\bin\Debug\myclubv2_Secure\myclubv2.exe' has no valid CLR header and cannot be disassembled
---------------------------
OK
---------------------------

Cheers,

Glen Harvy

mike montagne7-Mar-07 14:46

Re: Intellectual Property Protection BEYOND OBSFUCATION

7-Mar-07 14:46

I'll get back to you in a bit. I can't send the demo, but... at least it looks like your installation is working. I have no idea why mine won't NR as advertised.

BIG THANKS.

Glen Harvy7-Mar-07 12:52

Re: Intellectual Property Protection BEYOND OBSFUCATION

7-Mar-07 12:52

Have you had a look at http://www.earthsoft.co.uk/products/reactorrobot/[^]

Glen Harvy

mike montagne7-Mar-07 13:02