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System.Diagnostics.Debugger.IsAttached is what iam looking for?
Thanks for ur reply.
Pranu.
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I am building a server based (ASP) application in VS2005. Together with that, i have also built an accompanying small "Licencer" application to be used by the same person that performs the installation so as to create an encrypted file on the HD of the server.The encrypted file will maintain the variables under which the Application was licenced.
When the technician performing the installation runs "Licencer" he inputs the [Product Key], [number of max. concurrent users], [company name] and together with that, "Licencer" also retrieves from the server the [CPUID],[OS],[DATE]. Then, those data are combined in an XML Document which "Licencer" encrypts (using symmetric encryption) and stores in the HD of the server.
When the Application starts-up it will have to decrypt the file that "Licencer" created and check it against the current system variables to see if all things are ok. If not, should stop working (lock).
My question is how am i going to implement a secure model for the creation and safe strorage of the Symmetric Key on the server, in order for nobody to be able to use it from another application?
By reading various articles on symmetric encryption i found out that i can use DPAPI in order to encrypt the Symmetric Key in the Windows registry. That could work for me but how can i be sure that my application will be the only one that will be able to decrypt the DPAPI-encrypted string from the registry?
How will it be possible not to hard-code critical information?
Apart from these questions i am open to alternate ways of managing licencing information.
Thank you in advance. I wouldn't be posting this message but i have reached a dead end.
Vasilis
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sleepless_b wrote: how am i going to implement a secure model for the creation and safe strorage of the Symmetric Key on the server
You can't.
http://en.wikipedia.org/wiki/Symmetric-key_algorithm[^]
The disadvantage of symmetric-key algorithms is the requirement of a shared secret key, with one copy at each end. Since keys are subject to potential discovery by a cryptographic adversary, they need to be changed often and kept secure during distribution and in service. The consequent requirement to choose, distribute and store keys without error and without loss, known as key management, is difficult to reliably achieve.
You would have to use asymmetric encryption, provide a server and require a network connection during installation.
led mike
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led mike wrote: You would have to use asymmetric encryption, provide a server and require a network connection during installation.
First of all thank u for replying..
I don't think i got that. I know all about asymmetric encryption but how could it help me on this? What does a network connection has to do during installation?
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It allows you to keep the private key on your server so it can't be hacked locally during installation.
sleepless_b wrote: When the Application starts-up
Yeah.. missed that.  That would require the same to occur at application start up. 
Sorry but there is no "absolute" way of protecting symmetric encryption locally, all you can do is make it more difficult.
led mike
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Hi
If you are storing your license information on server why can't you use a server based license checker?
Consider this scenario:
App Starts
App Sends its licensing data to server (it's been encrpyted by the server the first time the app is installed and client dosen't know how to decrypt it actually no one but the server should not know how to decrypt it)
Server decrpyts the data and checks its validity and if every thing is OK it let's App to work.
Regards
Nima H
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Hello!
If i got it right, you mean that i should have an in-house server responsible for keeping licencing info(+encrypted keys) and every installed instance of my server-based softwrare in different servers of different companys that i have distributed it, should communicate with my in-house server in order to check the validity of its environment based on the encrypted licence i have stored in my in-house server. And this, for each time an application starts or a user tries to log himself in.
Is this what you mean?
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Hi
Yes.I mean that if there can be a (or some) server(s) that can handle the licescing issues ,then clients don't have to know anything about them.
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Hi,
I have an ArrayList populated by a text file made up of lines comprising 3 columns: ID, Duration, Description. They roughly look like this
12345678.abc 020 This is a description
12345678.abd 030 This is another description
etc
The ID column is always 12 characters, the duration is always 3 numbers, the description obviously can change from line to line.
Each line of the text file is read into the array in sequence, I need to be able to break each element of the ArrayList into the appropriate columns. The problem is with the description column as it contains multiple spaces. I can't work out how to break each string into the columns required
Please can anyone help?
Thank you very much in advance
Scott
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If the format is as you described then using substring would probably be easiest.
<br />
string s = "12345678.abc 020 This is a description";<br />
string id = s.Substring(0, 12);<br />
string duration = s.Substring(13, 3);<br />
string description = s.Substring(17);<br />
You might want to put this in a catch block if there is a chance an line is incorrect. For more complex string manipulation you might want to look at regular expressions.
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Thank you for replying, I see where you're going with this. It does however raise another question in as much as I then need to bind those strings into a datagrid under the same headings.
Any ideas how?
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Create a class to store the id,duration and description. Then create an arraylist with instances of that class instead of strings.
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Alternatively use Split - it has a parameter specifying the maximum number of strings in the array result.
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I need to send an email message to receipients in my program. My problem is that I need it to send without an smtp relay. I found an example on this site on how to do it but it was written in C++ when I need it in C#. If someone can send me a link or code of how to do this, it would be greatly appreciated.
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numbers1thru9 wrote: I need it to send without an smtp relay.
numbers1thru9 wrote: I found an example on this site
Please supply the link for that example. I have no idea how to send a SMTP message without a SMTP server.  
led mike
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As part of your mail methods you could make your own SMTP that can only send messages generated internally. Then it would seem as though its being sent without the use of an SMTP server.
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eggsovereasy wrote: that can only send messages generated internally.
Send them where?
led mike
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How do I capture packets sent to a specific application?
I want to know how can I place a kind of Hook that capture all packets sent to and from a specific application. I know that this can be done by pInvoke, but don’t know how. In the articles I only found how to capture mouse and keyboards events.
Another thing that I would like to know is how can I change the title of a specific win32 application running (that could b done by pInvoke too…)
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Hi
There is a good article title Packet Capture and Analayzer[^] on how to capture packets using C#. Check that out...
You can use SetWindowText(...) Api function for setting up window's title.
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I am writing ImageViewer application which is suppose to display high resolution images with zoomIn, ZoomOut. If I use Bicubic interpolation mode, I get high qulaity image covering most of details but speed is unaccepatable.
I looked at Netvue viewer(http://www.accusoft.com product). It displays blur image initially, smoothes it slowly and finally sharpen it, All phases are clearly visible. While my application applies scaling and hangs for a while(1.75-2Second) and displays image instanteniously.
Though i know Geometric transformations, I am novice to image processing and Siganl processing which most of articles talk about(Kernels, Gaussianl filter, box filter, mitchell filter etc...)
Any help on Progressive rendering and what filters would be useful would be appreciated.
Thanks
Regards,
MaulikCE
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Display the image without using any interpolation - this should be fairly fast. Start a background thread rendering the image to an in memory bitmap in the intended target size using interpolation. When it completes, render this menory bitmap to the screen instead of the "non-interpolated" image.
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It means image just changes twice, instantaneously.I would like to show image changing process.
Regards,
MaulikCE
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I want to connect my computer to all workstations in our domain to get specifications of each machine. How can to connect to remote registry?
DoobiDoo
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Hi all,
Im baffled by some code Ive written and need some help.
I have a simple class which holds a property:
<br />
public class Person<br />
{<br />
private string myName = string.Empty;<br />
<br />
public string MyName<br />
{<br />
get { return myName; }<br />
set { myName = value; }<br />
}<br />
<br />
public Person(string name)<br />
{<br />
myName = name;<br />
}<br />
<br />
}<br />
And I have another class, which is pretty self explanatry:
<br />
public class Depoll<br />
{<br />
public static void NewName(Person obj, string newName)<br />
{<br />
obj.MyName = newName;<br />
}<br />
}<br />
And finally, here are my tests:
<br />
[Test]<br />
public void TestChangeName()<br />
{<br />
Person me = new Person("Andy");<br />
Depoll.NewName(me, "Bill");<br />
Assert.AreEqual("Bill", me.MyName);<br />
}<br />
I dont understand why my test passes.
When I provide the Depoll.NewName function with my object, I assume that Im passing an instance. Therefore, any change to that object, will not affect the original, unless the Depoll.NewName returns it.
The Depoll.NewName function doesnt return the object once its been changed, therefore my original object should still have a name property of "Andy".
Can anyone help explain this?
Regards
Andy
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