Re: Encryption question. - C# Discussion Boards

Re: Remoting & IServiceProvider

31-Dec-02 13:11

What I need is to get two applications to be able to communicate. I am very happy with IServiceProvider and System.ComponentModel.Design.ServiceContainer. They allow me to easily give access to my shared classes/components, to other classes. What I want now is to pass the IServiceProvider to the other application through remoting. All the objects that are added to the IServiceProvider are in their own Dll library. (I also referenced this dll library from the second application).

I created a remotable class (inheriting from Marshalobjbyref), that contains the IServiceProvider. (This remotable class is in a dll that is referenced by both applications) I published this remotable class with remoting. The second application is able to see the published class and call methods in it.

Here is the problem:
When I try to use the IServiceProvider - I get an error. It woun't let me use it. Is it possible to remote IServiceProvider?

IServiceProvider sure makes life easier for me, but I can't figure out how to use it remotely.

THANKS A LOT, if you can help me out.

Alex Korchemniy3-Jan-03 7:40

3-Jan-03 7:40

I figured it out now.

Here's some help if anyone has the same problem:

- you can remote only classes that inherit Marshalobjbyref
- all objects that are passed/access in the class have to be serializable
- interfaces cannot be access in the class

Encryption question.

jtmtv1831-Dec-02 11:30

jtmtv18

31-Dec-02 11:30

i was just wondering. is it possible to find what type of encryption was used to encrypt a file. ? i have a program im working on that encrypt's decrypt's i want too add a "Auto detect" feature so they dont have to pick the algorithm it will detect it for them. do i have to use filestream with and write a small flag into the file to let me know what encryption was used (then erase the flag from the file and proceed with decryption) or does DES and RC2 have a unique identity that i can find inside each encryption too dectect that encryption.
im pretty sure the file stream would work...but im looking for a cleaner approach, i dont want to do it and find out theres a easyer/nicer way to do it.

thank you for reading this question.

Jesse M.

Re: Encryption question.

David Stone1-Jan-03 6:17

David Stone

1-Jan-03 6:17

I don't think it's possible to detect the type of encryption that you used on a file without putting a little data somewhere in the file itself indicating which one you used. I think it would be very insecure to broadcast to everybody what encryption protocol you used.

I don't know whether it's just the light but I swear the database server gives me dirty looks everytime I wander past.
-Chris Maunder

Microsoft has reinvented the wheel, this time they made it round.
-Peterchen on VS.NET

Re: Encryption question.

jtmtv181-Jan-03 16:15

jtmtv18

1-Jan-03 16:15

thanks david. i wont do it.. i saw a guys source (it was a tourial) he had a way to detect if the file was encrypted or not.. i orignally though there was a way to detect which encryption was being used. but reviewing the code i do see that he added a flag into each file. it was a boolean number (011011 or something) while that does over some security... if i could crack that number and know that means "des" encryption to the program then someone else could too. anyways.. thanks agian.

Re: Encryption question.

Pete Bassett2-Jan-03 1:15

Pete Bassett

2-Jan-03 1:15

Hi.

Like you said, I would just go with the flag describing the file if I were you. It doesn't reduce the security of the file at all if you are using industry standard encryption methods like 3des or Rijndael. Infact, you should write your security routines with the full knowledge that a hacker WILL be able to deduce exactly what techniques you are using in your system. The secret it to use techniques that are hard to break even if you do know the algorithm.

Just use the flag.

Pete

Insert Sig. Here!

ip?

imran_rafique31-Dec-02 9:24

imran_rafique

31-Dec-02 9:24

how to get ip address of different computers on the network?

r00d0034@yahoo.com

Re: ip?

Alex Korchemniy31-Dec-02 17:58

31-Dec-02 17:58

You can only get the IP if you have the DNS of the computer, or the MAC address. You have to use System.Net classes for this.

Stripping Punctuation

MStanbrook31-Dec-02 5:23

MStanbrook

31-Dec-02 5:23

Anyone have an "efficient" routine for stripping punctuation for a string?

Mike Stanbrook
mstanbrook@yahoo.com

Nnamdi Onyeyiri31-Dec-02 5:41

Nnamdi Onyeyiri

31-Dec-02 5:41

public string StripPunctuation(string source)
{
   // any chars you want to keep, put between the [] brakets.
   // i think the ^ has to remain where it is though.
   string pattern = "[^a-zA-Z ]";
 
   // use regular expressions.
   System.Text.RegularExpressions.Regex regex;
   regex = new System.Text.RegularExpressions.Regex(pattern);
   return regex.Replace(source, "");
}

That should do it. I think .NET's regular expression classes are effiecient enough.

1001111111011101111100111100101011110011110100101110010011010010
Sonork | 100.21142 | TheEclypse

David Stone31-Dec-02 6:10

David Stone

31-Dec-02 6:10

Why not just rewrite:

string pattern = "[^a-zA-Z ]";
System.Text.RegularExpressions.Regex regex;
regex = new System.Text.RegularExpressions.Regex(pattern);
return regex.Replace(source, "");

Regex regex = new Regex("[^a-zA-z]");
regex.Replace(source, "");

Makes things a lot simpler if you skip the first string and move the declaration and instantiation on to one line.

leppie1-Jan-03 6:04

leppie

1-Jan-03 6:04

David Stone wrote:
Regex regex = new Regex("[^a-zA-z]");regex.Replace(source, "");

or return new Regex("[^a-zA-z]").Replace(source, ""); Smile | :)

WebBoxes - Yet another collapsable control, but it relies on a "graphics server" for dynamic pretty rounded corners, cool arrows and unlimited font support.

Change the title bar etc?

David Stone1-Jan-03 6:12

David Stone

1-Jan-03 6:12

Bah, it's all the same IL-wise. Big Grin | :-D

anotherside200031-Dec-02 4:53

anotherside2000

31-Dec-02 4:53

Hi there

I was wondering if it is possible to customize the title bar, buttons etc. in a Form. I want to change the color and maybe draw my own "maximize" button etc. The user should still be able to do all the "normal" things with the form, like changing the position.

Really appreciate if someone could help me!

Sincerely
Pat

SHaroz31-Dec-02 6:46

SHaroz

31-Dec-02 6:46

The only way I know of to do this is to set the FormBorderStyle to None. Then, add controls and modify their behavior and appearance however you want.

This probably isn't the answer you were looking for, but I hope it helps.

-Steve

Alex Korchemniy31-Dec-02 17:56

31-Dec-02 17:56

The caption bar and the maximize, minimize, close buttons are drawn by the windows operating system. I did some research, and there is very little you can do about it. The only way you can do it is to make a form with no border, make your program skinable (which is a pain), and add draging and resizing support.

At least this is the way I had to do it. If there is a better way tell me too.

Stephane Rodriguez.31-Dec-02 23:08

Stephane Rodriguez.

31-Dec-02 23:08

anotherside2000 wrote:
I was wondering if it is possible to customize the title bar, buttons etc.

What about checking out the CodeProject articles about Balloon Windows with C# ?

When you know a Form is mostly an oriented-object event-based class running on top of a standard WIN32 Window, you can figure out that this is possible.

The form is created with hardcoded window styles (managed by an hardcoded default .NET System.Windows.Forms.CreateParams instance). But, once that form is created (this.Handle!=0), you could just start hacking the underlying window just like with C/C++ code. For that purpose, use P/Invoke unsafe native methods like SetWindowStyle, ...
You'll need the hwnd of that window : that's this.Handle (cast the returned IntPtr to an int if you like).

Be also sure to Hide the SizeGrip (drawn around the window) with a simple this.SizeGripStyle = System.Windows.Forms.SizeGripStyle.Hide;

Good luck!