# Author: Scott Sutherland 2013, NetSPI
# Version: Get-SPN version 1.1
# Requirements: Powershell v.3
# Comments: The technique used to query LDAP was based on the "Get-AuditDSDisabledUserAcount" 
# function found in Carols Perez's PoshSec-Mod project.#


function Get-SPN
{   
    <#
    .SYNOPSIS
       Displays Service Principal Names (SPN) for domain accounts based on SPN service name, domain account, or domain group via LDAP queries.
       
    .DESCRIPTION
       Displays Service Principal Names (SPN) for domain accounts based on SPN service name, domain 
       account, or domain group via LDAP queries. This information can be used to identify systems 
       running specific service and the domain accounts running them.  For example, this script 
       could be used to locate domain systems where SQL Server has been installed.  It can also be 
       used to help find systems where members of the Domain Admins group might be logged in if the 
       accounts where used to run services on the domain (which is very common).  So this should be 
       handy for both system administrators and penetration testers.  The script currentls supports 
       trusted connections and provided credentials.
       
    .EXAMPLE
       Return a list of SQL Servers that have registered SPNs in LDAP on the current user's domain.
       
       PS C:\Get-SPN -type service -search "MSSQLSvc*"     

       Name            : sql admin
       SAMAccount      : sqladmin
       Description     : This account is used to run SQL Server services on the domain.
       UserPrincipal   : sqladmin@demo.com
       DN              : CN=sql admin,CN=Users,DC=demo,DC=com
       Created         : 9/3/2010 9:42:08 PM
       LastModified    : 12/27/2013 6:40:35 PM
       PasswordLastSet : 12/27/2013 12:40:35 PM
       AccountExpires  : <Never>
       LastLogon       : 12/27/2013 8:46:10 PM
       GroupMembership : CN=Domain Admins,CN=Users,DC=demo,DC=com CN=Remote Desktop Users,CN=Builtin,DC=demo,DC=com
       SPN Count       : 1
       
       ServicePrincipalNames (SPN):
       MSSQLSvc/DB1.demo.com:1433
       
    .EXAMPLE
       Return a list of SQL Servers that have registered SPNs in LDAP on the current user's domain in list view.  This output can be piped.
       PS C:\Get-SPN -type service -search "MSSQLSvc*" -List yes | Format-Table -AutoSize
       
       Account       Server       Service
       -------       ------       -------
       sqladmin      DB1.demo.com MSSQLSvc
       
    .EXAMPLE
       Using supplied credentials return a list of SQL Servers that have registered SPNs in LDAP for the default domain of a remote domain controller.
       PS C:\Get-SPN  -type service -search "MSSQLSvc*" -List yes -DomainController 192.168.1.100 -Credential domain\user | Format-Table -AutoSize
           
       Account       Server       Service
       -------       ------       -------
       sqladmin      DB1.demo.com MSSQLSvc
       
    .EXAMPLE
       Using supplied credentials return a list of SQL Servers that have registered SPNs in LDAP for the default domain of a remote domain controller, but select one column.
       PS C:\Get-SPN -type service -search "MSSQLSvc*" -List yes -DomainController 192.168.1.100 -Credential domain\user | Select Server | Format-Table -AutoSize

       Account
       -------
       sqladmin

     .EXAMPLE
       Using supplied credentials to authenticate to a remote domain controller query LDAP to return a list of servers where the supplied user is registered to run services.
       PS C:\Get-SPN -type user -search "*sql*" -List yes -DomainController 192.168.1.100 -Credential domain\user -list yes | Format-Table -AutoSize
       
       Account  Server       Service
       -------  ------       -------
       sqladmin DB1.demo.com MSSQLSvc

     .EXAMPLE
       Using supplied credentials to authenticate to a remote domain controller query LDAP to return a list of servers where the supplied group members are registered to run services.
       PS C:\ Get-SPN -type group -search "Domain Admins" -List yes -DomainController 192.168.1.100 -Credential domain\user
       
       Account       Server        Service
       -------       ------        -------
       Administrator DB1.demo.com  MSSQLSvc
       sqladmin      DB1.demo.com  MSSQLSvc
       svc_PoolAdmin hav3.demo.com www

     .LINK
        http://www.netspi.com
        http://msdn.microsoft.com/en-us/library/windows/desktop/ms677949(v=vs.85).aspx
        http://technet.microsoft.com/en-us/library/cc731241.aspx
        http://technet.microsoft.com/en-us/library/cc978021.aspx    
    #>
    [CmdletBinding()]
    Param(
        [Parameter(Mandatory=$false,
        HelpMessage="Credentials to use when connecting to a Domain Controller.")]
        [System.Management.Automation.PSCredential]
        [System.Management.Automation.Credential()]$Credential = [System.Management.Automation.PSCredential]::Empty,

        [Parameter(Mandatory=$false,
        HelpMessage="Domain controller for Domain and Site that you want to query against.")]
        [string]$DomainController,

        [Parameter(Mandatory=$false,
        HelpMessage="Maximum number of Objects to pull from AD, limit is 1,000 .")]
        [int]$Limit = 1000,

        [Parameter(Mandatory=$false,
        HelpMessage="scope of a search as either a base, one-level, or subtree search, default is subtree.")]
        [ValidateSet("Subtree","OneLevel","Base")]
        [string]$SearchScope = "Subtree",

        [Parameter(Mandatory=$false,
        HelpMessage="Distinguished Name Path to limit search to.")]
        [string]$SearchDN,

        [Parameter(Mandatory=$True,
        HelpMessage="Search by domain user, domain group, or SPN service name to search for.")]
        [string]$Type,

        [Parameter(Mandatory=$True,
        HelpMessage="Define search for user, group, or SPN service name. Wildcards are accepted")]
        [string]$Search,

        [Parameter(Mandatory=$false,
        HelpMessage="View minimal information that includes the accounts,affected systems,and registered services.  Nice for getting quick list of DAs.")]
        [string]$List
    )

    Begin
    {        
        # Setup domain user and domain controller (if provided)
        if ($DomainController -and $Credential.GetNetworkCredential().Password)
        {
            $ObjDomain = New-Object System.DirectoryServices.DirectoryEntry "LDAP://$($DomainController)", $Credential.UserName,$Credential.GetNetworkCredential().Password
            $ObjSearcher = New-Object System.DirectoryServices.DirectorySearcher $ObjDomain
        }
        else
        {
            $ObjDomain = [ADSI]""  
            $ObjSearcher = New-Object System.DirectoryServices.DirectorySearcher $ObjDomain
        }
    }

    Process
    {   
        # Setup LDAP queries
        $CurrentDomain = $ObjDomain.distinguishedName
        $QueryGroup = "(&(objectCategory=user)(memberOf=CN=$Search,CN=Users,$CurrentDomain))"
        $QueryUser = "(samaccountname=$Search)"
        $QueryService = "(ServicePrincipalName=$Search)"
        
        # Define the search type 
        if(($Type -eq "group") -or ($Type -eq "user") -or ($Type -eq "service")){

            # Define query based on type
            switch ($Type) 
            { 
                "group" {$MyFilter = $QueryGroup} 
                "user" {$MyFilter = $QueryUser} 
                "service" {$MyFilter = $QueryService} 
                default {"Invalid query type."}
            }
        }
        
        # Define LDAP query options
        $ObjSearcher.PageSize = $Limit
        $ObjSearcher.Filter = $Myfilter
        $ObjSearcher.SearchScope = $SearchScope

        if ($SearchDN)
        {
            $ObjSearcher.SearchDN = New-Object System.DirectoryServices.DirectoryEntry("LDAP://$($SearchDN)")
        }

        # Get a count of the number of accounts that match the LDAP query
        $Records = $ObjSearcher.FindAll()
        $RecordCount = $Records.count

        # Display search results if results exist
        if ($RecordCount -gt 0){
                
            # Create data table to house results
            $DataTable = New-Object System.Data.DataTable 

            # Create and name columns in the data table
            $DataTable.Columns.Add("Account") | Out-Null
            $DataTable.Columns.Add("Server") | Out-Null
            $DataTable.Columns.Add("Service") | Out-Null            

            # Display account records                
            $ObjSearcher.FindAll() | ForEach-Object {

                # Fill hash array with results                    
                $UserProps = @{}
                $UserProps.Add('Name', "$($_.properties.name)")
                $UserProps.Add('SAMAccount', "$($_.properties.samaccountname)")
                $UserProps.Add('Description', "$($_.properties.description)")
                $UserProps.Add('UserPrincipal', "$($_.properties.userprincipalname)")
                $UserProps.Add('DN', "$($_.properties.distinguishedname)")
                $UserProps.Add('Created', [dateTime]"$($_.properties.whencreated)")
                $UserProps.Add('LastModified', [dateTime]"$($_.properties.whenchanged)")
                $UserProps.Add('PasswordLastSet', [dateTime]::FromFileTime("$($_.properties.pwdlastset)"))                    
                $UserProps.Add('AccountExpires',( &{$exval = "$($_.properties.accountexpires)"
                    If (($exval -eq 0) -or ($exval -gt [DateTime]::MaxValue.Ticks))
                    {
                        $AcctExpires = "<Never>"
                        $AcctExpires
                    }Else{
                        $Date = [DateTime]$exval
                        $AcctExpires = $Date.AddYears(1600).ToLocalTime()
                        $AcctExpires
                    }
                }))
                $UserProps.Add('LastLogon', [dateTime]::FromFileTime("$($_.properties.lastlogon)"))
                $UserProps.Add('GroupMembership', "$($_.properties.memberof)")
                $UserProps.Add('SPN Count', "$($_.properties['ServicePrincipalName'].count)")                 

                # Only display line for detailed view
                If (!$list){

                    # Format array as object and display records
                    Write-Verbose " "
                    [pscustomobject]$UserProps 
                }

                # Get number of SPNs for accounts, parse them, and add them to the data table
                $SPN_Count = $_.properties['ServicePrincipalName'].count
                if ($SPN_Count -gt 0)
                {
                        
                    # Only display line for detailed view
                    If (!$list){
                        Write-Output "ServicePrincipalNames (SPN):"
                            $_.properties['ServicePrincipalName']
                    }
                        
                    # Add records to data table
                    foreach ($item in $_.properties['ServicePrincipalName'])
                    {
                        $SpnServer =  $item.split("/")[1].split(":")[0] 
                        $SpnService =  $item.split("/")[0]                                                    
                        $DataTable.Rows.Add($($_.properties.samaccountname), $SpnServer, $SpnService) | Out-Null  
                    }
                }            
                    
                # Only display line for detailed view
                If (!$list){
                    Write-Verbose " "
                    Write-Verbose "-------------------------------------------------------------"
                }
            } 

            # Only display lines for detailed view
            If (!$list){

                # Display number of accounts found
                Write-Verbose "Found $RecordCount accounts that matched your search."   
                Write-Verbose "-------------------------------------------------------------"
                Write-Verbose " "                                    
            }else{

                # Display results in list view that can feed into the pipeline
                $DataTable |  Sort-Object Account,Server,Service | select account,server,service -Unique
            }
        }else{

            # Display fail
            Write-Verbose " " 
            Write-Verbose "No records were found that match your search."
            Write-Verbose ""
        }        
    }
}