Nonlinearsound/windows-credential-manager.md

## windows-credential-manager.md

      
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              windows-credential-manager.md
            
          
    Storing and retreiving Windows Credential Manager info in C# and Go

Lately I had the need for storing SMTP credentials somewhere on the system to be used for a small Go application that would automatically send mails to administrators in case, a certain ETW event would have fired.
The solution on Windows is to use the windows Credential Manager. On Linux you could use pass.
I needed both solutions for Go and C#.
Go

In Go it's pretty simple as Daniel Joos already wrote a nice package for exactly that purpose. You can get it here:
github.com/danieljoos/wincred

So we go get the package after initialising our go mod in the folder, we created.
mkdir winpwdmanager
cd winpwdmanager
go mod init someurl.org/winpwdmanager
go get github.com/danieljoos/wincred
New-Item main.go
vscode .
The code for storing and reading our password looks like this:
package main

import (
	"fmt"

	"github.com/danieljoos/wincred"
)

func main() {
	cred := wincred.NewGenericCredential("myGoApplication")
	cred.CredentialBlob = []byte("my secret")
	err := cred.Write()

	if err != nil {
		fmt.Println(err)
	}

	_cred, err := wincred.GetGenericCredential("myGoApplication")
	if err == nil {
		fmt.Println(string(_cred.CredentialBlob))
	}

}
It will output
my secret

C-Sharp

For his we open Visual Studio and create a new console application project for the .Net Framework (I chose 4.7.2 as the minimum)
Then we get the Nuget package https://www.nuget.org/packages/CredentialManagement/
After that we get the namespace CredentialManagement tht we can use.´in our code.
Here is the complete code for storing and reading a username and password for a selected target.
using CredentialManagement;
using System;

namespace CredentialsTest
{
    internal class Program
    {
        static void Main(string[] args)
        {
            string user = System.Security.Principal.WindowsIdentity.GetCurrent().Name;

            bool success = new Credential
            {
                Target = "csharpcredentialstest",
                Username = "myusername",
                Password = "supersecretpassword",
                PersistanceType = PersistanceType.LocalComputer
            }.Save();

            if (success)
            {
                var cm = new Credential { Target = "csharpcredentialstest" };
                if (!cm.Load())
                {
                    Console.WriteLine("Error in retreiving credentials for csharpcredentialstest}");
                }
                else
                {
                    Console.WriteLine("Username:{0} Password:{1}", cm.Username, cm.Password);
                }
            }

            Console.ReadLine();
        }
    }
}
The application should output the following:
Username:myusername Password:supersecretpassword