Encrypt and decrypting connectionstring

Question

0.00/5 (No votes)

See more:

i encrypt my app connectionstring but when i launch the app that decrypt the connection string and connect to my database the connection string maintain in the encrypted format

What I have tried:

i'm training to decrypt my encrypted connection string putted in app.config , so in first i crypt it thani replaced the real one by the crypted chaine and it look

XML

<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <configSections>
    </configSections>
    <connectionStrings>
        <add name="Benificiare.Properties.Settings.LogementConnectionString" connectionString="6uDB/32KxMOEPPO0maQDJ63Adjp7okmRdGd9s67mV5+8v6wiRK8UKWscnJSbQzFZTQCLiHQnZPGC8S6lI5Uw28qgjKLL14bkL8sNaDkwRUZ+bB6GMFelH9OVZpG1p+4T/I1LosmrkHylQKHotPFZg3xq3EwDJOY3rjbgE5mu6ow=" providerName="System.Data.SqlClient"/>
    </connectionStrings>
<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1"/></startup></configuration>

in my code i do the inverse

C#

Configuration configuration = null;
            string connection = null;
           configuration = ConfigurationManager.OpenExeConfiguration(@".\Myapp.exe");
            connection = ConfigurationManager.ConnectionStrings["Benificiare.Properties.Settings.LogementConnectionString"].ConnectionString;
            string ENC = DecryptString(connection, "KEY");    //decrypte the connection string                   
            configuration.ConnectionStrings.ConnectionStrings["Benificiare.Properties.Settings.LogementConnectionString"].ConnectionString = ENC;

when i try to connect i'll have message indecate that the connectionstring is not changed.

Posted 19-May-19 22:46pm

Amar zaidi

Updated 14-Jun-21 0:54am

phil.o

v2

Add a Solution

5 solutions

Solution 1

This line:

C#

connection = ConfigurationManager.ConnectionStrings["Myapp.Properties.Settings.LogementConnectionString"].ConnectionString;

seeks for a connection named Myapp.Properties.Settings.LogementConnectionString.

But this line:

XML

<add name="Benificiare.Properties.Settings.LogementConnectionString" ...

declares the connection under the name Benificiare.Properties.Settings.LogementConnectionString.

Either you misnamed the connection in the XML file, or you misnamed it when you try to fetch it from your C# code. I'm surprised this code does not produce an exception at runtime when you try to access an unexistent connection string.

Your best option here is to start using your debugger^. Debugging is a very funny part of a developer's job, I warmly encourage you to give it a try as you even may find it entertaining.

Put a breakpoint^ on the line you wish to start debugging from, and launch the debug session (see above link for that).

We cannot do that for you, nor do we have all relevant informations. Learning to do it yourself could bring you quite a satisfaction, though.

Posted 19-May-19 23:30pm

phil.o

Comments

Amar zaidi 20-May-19 5:46am

i don't mis any think, the connection is declared correctly, i change only the word benificiare by my MyApp when i was writing the qustion the
real pb is How to change
ConfigurationManager.OpenExeConfiguration(@".\Benificiare.exe").ConnectionStrings.CurrentConfiguration.ConnectionStrings.ConnectionStrings["Benificiare.Properties.Settings.LogementConnectionString"].ConnectionString = ENC;

when i debbug the string ENC become null and it maintaine the encrypted chaine

phil.o 20-May-19 5:52am

Then, this is the DecryptString() method that you have to debug further, since it returns a null value. You did not show its implementation in your code sample. But no big deal: just as you have debugged the portion of the code that you showed, now debug the DecryptString() method, and get why it returns a null value from the encoded string obtained from configuration.
Edit: I corrected your code block so other members are not mislead by a typo.

Amar zaidi 21-May-19 4:43am

i fix it

Solution 2

i debug it and it works correctly,
my idea is divided in two steps
1- i encrypt the connectionstring so i take it from app.config and i encrypt it outsid with an Encrypt() function then string returned i replace it with the app.config connectionstring .
2- in my app and when it loading i have to extract the connectionstring from the app.config
connection =

C#

ConfigurationManager.OpenExeConfiguration(@".\Benificiare.exe").ConnectionStrings.ConnectionStrings["Benificiare.Properties.Settings.LogementConnectionString"].ConnectionString;

then i decrypt it

C#

string ENC = DecryptString(connection, "MyPassPhrase");

then ihave to change my connectionstring

C#

ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None).ConnectionStrings.CurrentConfiguration.ConnectionStrings.ConnectionStrings["Benificiare.Properties.Settings.LogementConnectionString"].ConnectionString = ENC;

my fault was the pb of the run time (file was protected ), so i fix it using OpenExeConfiguration(ConfigurationUserLevel.None) Instead
OpenExeConfiguration(@".\Myapp.exe")

Posted 20-May-19 22:43pm

Amar zaidi

Solution 3

I think you may be over complicating things a bit. Given an app.config file like this

C#

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <connectionStrings>
    <clear />
    <add name="MyConnection"
     providerName="System.Data.ProviderName"
     connectionString="Tie two pieces of string together" />
  </connectionStrings>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
    </startup>
</configuration>

The following app shows a way of managing encryption and decryption. It's based largely on this documentation.

C#

using System;
//may need to add reference to System.Configuration
using System.Configuration;
namespace Scratch
{
    class Program
    {
        static void Main(string[] args)
        {
                                        //path to the exe file
            EnsureConnectionIsEncrypted(@".\Scratch.exe");
            //To do:use a text reader to check .\Scratch.exe.config 
            //now has an encrypted connection
            //Note: The App.config file in solution explorer is not changed
            //To retrieve the decrypted string, simply do this:- 
            var connectionString = ConfigurationManager.ConnectionStrings["MyConnection"].ConnectionString;
            Console.WriteLine(connectionString);
            Console.ReadLine();
        }
        //The encryption must be enacted on the client machine, 
        //as decryption can only be done by the machine 
        //that performed the encryption
        static void EnsureConnectionIsEncrypted(string exeFileName)
        {
                 Configuration config = ConfigurationManager.
                    OpenExeConfiguration(exeFileName);
                ConnectionStringsSection section =
                    config.GetSection("connectionStrings")
                    as ConnectionStringsSection;
                if (!section.SectionInformation.IsProtected)
                {
                    section.SectionInformation.ProtectSection(
                       "DataProtectionConfigurationProvider");
                    config.Save();
                }
        }
    }
}

After encryption, the exe.config file in the output directory will look something like this, the actual CipherValue has been truncated.

C#

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <connectionStrings configProtectionProvider="DataProtectionConfigurationProvider">
    <EncryptedData>
      <CipherData>
        <CipherValue>AQAAANCMnd8BFdERjHoAwE/Cl........................</CipherValue>
      </CipherData>
    </EncryptedData>
  </connectionStrings>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
    </startup>
</configuration>

Posted 21-May-19 20:59pm

George Swan

Comments

Amar zaidi 22-May-19 8:12am

it works but if i try to deploy my app in other machine it doesn't work

George Swan 22-May-19 10:28am

The exe.config file on the client machine must be unencrypted when the app first runs. Only the machine that encrypts the connection string can decrypt it.

Amar zaidi 23-May-19 6:29am

and how that can be happen.
because i thing that your solution is better then mine, i looked at some video talk about exporting and importing keys useing aspnet_regiis but till now i m not applicate it correctly

Solution 5

can u explain the

DecryptString

function?
string ENC = DecryptString(connection, "KEY");

Posted 14-Jun-21 0:54am

Member 15245377

Updated 14-Jun-21 0:56am

v3

Comments

Richard Deeming 14-Jun-21 10:38am

If you want to ask for more information, click the "Have a Question or Comment?" button under the question or solution, and post a comment.

Do not post your comment as a "solution" to the question.

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Amar zaidi · Accepted Answer · 2019-05-22T02:36:00

finally, i have the solution and it works
so as I said before I encrypt my connectionstring elsewhere with an Encrypt() function then I put the encrypted string in Place of my old connectionstring of APP.CONFIG

HTML

<pre><?xml version="1.0" encoding="utf-8"?>
<configuration>
    <configSections>
    </configSections>
    <connectionStrings>
        <add name="Benificiare.Properties.Settings.LogementConnectionString" connectionString="6uDB/32KxMOEPPO0maQDJ63Adjp7okmRdGd9s67mV5+8v6wiRK8UKWscnJSbQzFZTQCLiHQnZPGC8S6lI5Uw28qgjKLL14bkL8sNaDkwRUZ+bB6GMFelH9OVZpG1p+4T/I1LosmrkHylQKHotPFZg3xq3EwDJOY3rjbgE5mu6ow=" providerName="System.Data.SqlClient"/>
    </connectionStrings>
<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1"/></startup></configuration>

THE NAME OF CONNECTION IS

Benificiare.Properties.Settings.LogementConnectionString

and the encrypted chaine is

"Benificiare.Properties.Settings.LogementConnectionString" connectionString="6uDB/32KxMOEPPO0maQDJ63Adjp7okmRdGd9s67mV5+8v6wiRK8UKWscnJSbQzFZTQCLiHQnZPGC8S6lI5Uw28qgjKLL14bkL8sNaDkwRUZ+bB6GMFelH9OVZpG1p+4T/I1LosmrkHylQKHotPFZg3xq3EwDJOY3rjbgE5mu6ow="

when the app is running i have to decrypt this one and use the decrypted as a connectionstringg of my app so what i did is

C#

Configuration  configuration = ConfigurationManager.OpenExeConfiguration(@".\Myapp.exe");
            connection = ConfigurationManager.ConnectionStrings["Benificiare.Properties.Settings.LogementConnectionString"].ConnectionString;
            string ENC = DecryptString(connection, "KEY");    //decrypte the connection string                   
            configuration.ConnectionStrings.ConnectionStrings["Benificiare.Properties.Settings.LogementConnectionString"].ConnectionString = ENC; // change the connectionstring of the app with the decrypted one ****** but this variable was in mode readonly so my pb was in this instruction

so what i have to do, is to change the last instruction with

C#

var settings = ConfigurationManager.ConnectionStrings["Benificiare.Properties.Settings.LogementConnectionString"];
           var field = typeof(ConfigurationElement).GetField( "_bReadOnly", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
           field.SetValue(settings, false);
           settings.ConnectionString = ENC;

and it works pefectly

Encrypt and decrypting connectionstring

5 solutions

Solution 1

Solution 2

Solution 3

Solution 4

Solution 5

Add your solution here

Preview 0

Existing Members

...or Join us