If anybody just wants a code snippet so that they can distribute scripts without having to instruct the end users to install modules or include DLL files, this should do the trick.
$code = @"
using System.Text;
using System;
using System.Runtime.InteropServices;
namespace CredManager {
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct CredentialMem
{
public int flags;
public int type;
public string targetName;
public string comment;
public System.Runtime.InteropServices.ComTypes.FILETIME lastWritten;
public int credentialBlobSize;
public IntPtr credentialBlob;
public int persist;
public int attributeCount;
public IntPtr credAttribute;
public string targetAlias;
public string userName;
}
public class Credential {
public string target;
public string username;
public string password;
public Credential(string target, string username, string password) {
this.target = target;
this.username = username;
this.password = password;
}
}
public class Util
{
[DllImport("advapi32.dll", EntryPoint = "CredReadW", CharSet = CharSet.Unicode, SetLastError = true)]
private static extern bool CredRead(string target, int type, int reservedFlag, out IntPtr credentialPtr);
public static Credential GetUserCredential(string target)
{
CredentialMem credMem;
IntPtr credPtr;
if (CredRead(target, 1, 0, out credPtr))
{
credMem = Marshal.PtrToStructure<CredentialMem>(credPtr);
byte[] passwordBytes = new byte[credMem.credentialBlobSize];
Marshal.Copy(credMem.credentialBlob, passwordBytes, 0, credMem.credentialBlobSize);
Credential cred = new Credential(credMem.targetName, credMem.userName, Encoding.Unicode.GetString(passwordBytes));
return cred;
} else {
throw new Exception("Failed to retrieve credentials");
}
}
[DllImport("Advapi32.dll", SetLastError = true, EntryPoint = "CredWriteW", CharSet = CharSet.Unicode)]
private static extern bool CredWrite([In] ref CredentialMem userCredential, [In] int flags);
public static void SetUserCredential(string target, string userName, string password)
{
CredentialMem userCredential = new CredentialMem();
userCredential.targetName = target;
userCredential.type = 1;
userCredential.userName = userName;
userCredential.attributeCount = 0;
userCredential.persist = 3;
byte[] bpassword = Encoding.Unicode.GetBytes(password);
userCredential.credentialBlobSize = (int)bpassword.Length;
userCredential.credentialBlob = Marshal.StringToCoTaskMemUni(password);
if (!CredWrite(ref userCredential, 0))
{
throw new System.ComponentModel.Win32Exception(Marshal.GetLastWin32Error());
}
}
}
}
"@
Add-Type -TypeDefinition $code -Language CSharp
# How to store credentials
[CredManager.Util]::SetUserCredential("Application Name", "Username", "Password")
# How to retrieve credentials
[CredManager.Util]::GetUserCredential("Application Name")
# How to just get the password
[CredManager.Util]::GetUserCredential("Application Name").password
The above code was tested on PowerShell 7 and PowerShell 5, though you may need a somewhat recent version of the .Net framework if you're using the latter.
edit: added missing semicolon to code snippet as noted by @alazyworkaholic
