Re: Weird error - C# Discussion Boards

18-Jul-08 7:55

Judah Himango wrote:
In Visual Studio, you can go to your project properties and click on the Security tab to discover this information.

Diabolical! putting security properties on the Security tab! Laugh | :laugh:

led mike

Digital Signatures

stormcandi18-Jul-08 6:30

18-Jul-08 6:30

Hello all,
I really hope someone can assist me because I am totally lost here.

I have a program that users will access through a mass generated email (about 4000 users). They are filling out a form on a website and then I need to allow them to submit a digital signature with the form. I have read about RSA and DES Encryption but still a little foggy on how I can use it.

Does each person need to have a key generated when the email is sent out?

How do I mach up the key with the user when they go to the website in order to encrypt the signature correctly?

Can I just do the encryption and store it in the database and leave there? The only time I would need to unencrypt it is if someone is disputing a digital signature or if the user disputes the signature.

Can it be used over and over by the user? So if they need to go back to the site their digital signature can still be encrypted using the same key as previously.

As you can see I have a lot of questions about this. And I sure hope someone can help me?

Confused | :confused:

~Candi

led mike18-Jul-08 6:51

18-Jul-08 6:51

stormcandi wrote:
I have read about RSA and DES Encryption but still a little foggy on how I can use it.

Have you read this?[^]

led mike

stormcandi18-Jul-08 7:34

18-Jul-08 7:34

led mike wrote:
Have you read this?[^]

led mike

led mike,
I did look at that and it explains the concept of digital signatures, but I cannot translate that to the how. I mean how do the users get their key in order to encrypt the signature? Plus all the other questions in my original post.

~Candi

led mike18-Jul-08 7:40

18-Jul-08 7:40

Here's a tip for you, voting down my post is not the way to motivate me to help you.

led mike

stormcandi18-Jul-08 7:43

18-Jul-08 7:43

I apologize. I did not realize that's what I did.

~Candi

led mike18-Jul-08 7:52

18-Jul-08 7:52

stormcandi wrote:
I apologize. I did not realize that's what I did.

Oh, ok no problem.

stormcandi wrote:
I mean how do the users get their key in order to encrypt the signature?

Well that is possibly the largest problem in your scenario. If you issue them the key then it wouldn't be private would it. Making or even obtaining your own private key isn't difficult but it is not something that the average non technical person is going to do/want to do/be capable of doing ( PGP didn't take off and it's fall down simple ). So yeah, I don't know, it sounds like you might be between a rock and a hard place.

Have you considered alternative solutions? I mean you asked us how to do this particular solution for whatever problem you are trying to solve, you did not explain the problem. In most cases there is more than one way to solve a problem. Perhaps there is a way that would not require users having private keys.

led mike

stormcandi18-Jul-08 8:01

18-Jul-08 8:01

led mike wrote:
Have you considered alternative solutions? I mean you asked us how to do this particular solution for whatever problem you are trying to solve, you did not explain the problem. In most cases there is more than one way to solve a problem. Perhaps there is a way that would not require users having private keys.

I am not sure of alternative solutions. The articles I have read have all pretty much agreed that the RSA and DES encryption are how digital signatures are done. I am able to generate a key on a button click event, so I wonder if I couldn't do that when the user submits the form and do this symmetrically so user/admin have the same key. Then store it in a table to query if the data needs to be unencrypted at a later time. But then again the user could be anyone and not the one it was intended for.
What if I generated the key and then passed it through the URL query string in order to verify that it is the user submitting the form? And then store the key in the database to match key and user.

I am thinking outloud here, but maybe the second option would be the better one? I really don't know since I am new to this part of programming. I have done MD5 encrypting so I understand the concept of the encryption. But can't use MD5 because it is one-way encryption.

What do you think?

~Candi

led mike18-Jul-08 8:12

18-Jul-08 8:12

stormcandi wrote:
The articles I have read have all pretty much agreed that the RSA and DES encryption are how digital signatures are done.

Yes, sorry I didn't make my point clearly. I meant a solution that does not involve digital signatures being supplied by users.

stormcandi wrote:
I really don't know since I am new to this part of programming.

You mean security? Well if you are going to do some work with it I can't stress enough that you take the time to study it and really get a secure Big Grin | :-D

grasp of it. I have worked with people that think they know security because they understand encryption. You don't want to be one of those people. Security has some logical reality based aspects where when it finally sinks in you are like, oh yeah duh. But until it does sink in for us we are just really dangerous.

led mike

stormcandi18-Jul-08 8:20

18-Jul-08 8:20

Well I guess I need to find some good books that will help me out. Laugh | :laugh:

Thanks for your help and suggestion. I will definately follow it!

~Candi

led mike18-Jul-08 8:47

18-Jul-08 8:47

stormcandi wrote:
Well I guess I need to find some good books that will help me out.

You might start with wikipedia[^]. There are several book references as well as others links for further reading.

led mike

stormcandi18-Jul-08 8:50

18-Jul-08 8:50

Thanks for getting me started!

~Candi

XML Reorder

H@is@here18-Jul-08 5:56

H@is@here

18-Jul-08 5:56

Hello everyone,

I would like to know if someone has experienced this problem:

I have a xml file:

<?xml version="1.0" standalone="yes"?>
<requests>
  <request>
    <idRequest>123</idRequest>
    <requestType>001AA</requestType>
    <subRequest>
      <name>Some Name</name>
      <birthDate>12-12-2007</birthDate>
      <isbirthDateComplete>true</isbirthDateComplete>
    </subRequest>
    <observations>Some Observations...</observations>
    <recordType>Insert</recordType>
  </resquest>
</requests>

If I read the xml:

 DataSet dsTest = new DataSet();
dsTeste.ReadXml(Application.StartupPath + "\\Test.xml");

and then write it back:

dsTest.WriteXml(Application.StartupPath + "\\Test1.xml");

it gives me:

<?xml version="1.0" standalone="yes"?>
<requests>
  <request>
    <idRequest>123</idRequest>
    <requestType>001AA</requestType>
    <observations>Some Observations...</observations>
    <recordType>Insert</recordType>
    <subRequest>
      <name>Some Name</name>
      <birthDate>12-12-2007</birthDate>
      <isbirthDateComplete>true</isbirthDateComplete>
    </subRequest>
  </resquest>
</requests>

It simply change the order of the nodes. Is there any reason for this?

Thanks in advance.

led mike18-Jul-08 6:46

18-Jul-08 6:46

H@is@here wrote:
Is there any reason for this?

Yes and no. I'm pretty sure default Serialization does not guarantee order of nodes because in the XML standard order is not supported. Sorting is but not original order. Again, I'm not 100% sure but pretty confident.

led mike

H@is@here18-Jul-08 7:05

H@is@here

18-Jul-08 7:05

Hello and thank you for your answer.

And what is more interesting is that I have a xsd file with this xml and it still reorder the xml.

Dead | X|

Humm!

Mbah Dhaim18-Jul-08 7:05

Mbah Dhaim

18-Jul-08 7:05

because the dataset you create based on that xml will order xml contents as 2 datatable, 'request' and 'subrequest' where those datatable have hidden relation try dsTest.WriteXmlSchema(filename) to know its structure

dhaim
program is hobby that make some money as side effect Smile | :)