Get Cached Credentials in PowerShell from Windows 7 Credential Manager

You can use Add-Type cmdlet to easily port it I believe:

$sig = @"[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]public struct NativeCredential{    public UInt32 Flags;    public CRED_TYPE Type;    public IntPtr TargetName;    public IntPtr Comment;    public System.Runtime.InteropServices.ComTypes.FILETIME LastWritten;    public UInt32 CredentialBlobSize;    public IntPtr CredentialBlob;    public UInt32 Persist;    public UInt32 AttributeCount;    public IntPtr Attributes;    public IntPtr TargetAlias;    public IntPtr UserName;    internal static NativeCredential GetNativeCredential(Credential cred)    {        NativeCredential ncred = new NativeCredential();        ncred.AttributeCount = 0;        ncred.Attributes = IntPtr.Zero;        ncred.Comment = IntPtr.Zero;        ncred.TargetAlias = IntPtr.Zero;        ncred.Type = CRED_TYPE.GENERIC;        ncred.Persist = (UInt32)1;        ncred.CredentialBlobSize = (UInt32)cred.CredentialBlobSize;        ncred.TargetName = Marshal.StringToCoTaskMemUni(cred.TargetName);        ncred.CredentialBlob = Marshal.StringToCoTaskMemUni(cred.CredentialBlob);        ncred.UserName = Marshal.StringToCoTaskMemUni(System.Environment.UserName);        return ncred;    }}[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]public struct Credential{    public UInt32 Flags;    public CRED_TYPE Type;    public string TargetName;    public string Comment;    public System.Runtime.InteropServices.ComTypes.FILETIME LastWritten;    public UInt32 CredentialBlobSize;    public string CredentialBlob;    public UInt32 Persist;    public UInt32 AttributeCount;    public IntPtr Attributes;    public string TargetAlias;    public string UserName;}public enum CRED_TYPE : uint    {        GENERIC = 1,        DOMAIN_PASSWORD = 2,        DOMAIN_CERTIFICATE = 3,        DOMAIN_VISIBLE_PASSWORD = 4,        GENERIC_CERTIFICATE = 5,        DOMAIN_EXTENDED = 6,        MAXIMUM = 7,      // Maximum supported cred type        MAXIMUM_EX = (MAXIMUM + 1000),  // Allow new applications to run on old OSes    }public class CriticalCredentialHandle : Microsoft.Win32.SafeHandles.CriticalHandleZeroOrMinusOneIsInvalid{    public CriticalCredentialHandle(IntPtr preexistingHandle)    {        SetHandle(preexistingHandle);    }    public Credential GetCredential()    {        if (!IsInvalid)        {            NativeCredential ncred = (NativeCredential)Marshal.PtrToStructure(handle,                  typeof(NativeCredential));            Credential cred = new Credential();            cred.CredentialBlobSize = ncred.CredentialBlobSize;            cred.CredentialBlob = Marshal.PtrToStringUni(ncred.CredentialBlob,                  (int)ncred.CredentialBlobSize / 2);            cred.UserName = Marshal.PtrToStringUni(ncred.UserName);            cred.TargetName = Marshal.PtrToStringUni(ncred.TargetName);            cred.TargetAlias = Marshal.PtrToStringUni(ncred.TargetAlias);            cred.Type = ncred.Type;            cred.Flags = ncred.Flags;            cred.Persist = ncred.Persist;            return cred;        }        else        {            throw new InvalidOperationException("Invalid CriticalHandle!");        }    }    override protected bool ReleaseHandle()    {        if (!IsInvalid)        {            CredFree(handle);            SetHandleAsInvalid();            return true;        }        return false;    }}[DllImport("Advapi32.dll", EntryPoint = "CredReadW", CharSet = CharSet.Unicode, SetLastError = true)]public static extern bool CredRead(string target, CRED_TYPE type, int reservedFlag, out IntPtr CredentialPtr);[DllImport("Advapi32.dll", EntryPoint = "CredFree", SetLastError = true)]public static extern bool CredFree([In] IntPtr cred);"@Add-Type -MemberDefinition $sig -Namespace "ADVAPI32" -Name 'Util'$targetName = "computer"$nCredPtr= New-Object IntPtr$success = [ADVAPI32.Util]::CredRead($targetName,1,0,[ref] $nCredPtr)if($success){    $critCred = New-Object ADVAPI32.Util+CriticalCredentialHandle $nCredPtr    $cred = $critCred.GetCredential()    $password = $cred.CredentialBlob;    write-host -fore blue $password}

Adapted from here: http://social.technet.microsoft.com/Forums/en-US/ITCG/thread/e91769eb-dbce-4e77-8b61-d3e55690b511/

Based on: http://blogs.msdn.com/b/peerchan/archive/2005/11/01/487834.aspx

This has already been done:

http://gallery.technet.microsoft.com/scriptcenter/PowerShell-Credentials-d44c3cde/view/Discussions

It provides a couple cred-man related methods, and it is already documented.