# Configure a Windows host for remote management with Ansible
# -----------------------------------------------------------
#
# This script checks the current WinRM/PSRemoting configuration and makes the
# necessary changes to allow Ansible to connect, authenticate and execute
# PowerShell commands.
#
# Written by Trond Hindenes <trond@hindenes.com>
# Updated by Chris Church <cchurch@ansible.com>
# Updated by Kurt Griffiths <kurt.griffiths@rackspace.com>
#

Param (
    [string]$SubjectName = $env:COMPUTERNAME,
    $CreateSelfSignedCert = $true
)


Function New-LegacySelfSignedCert
{
    Param (
        [string]$SubjectName
    )

    # New-SelfSignedCertificate is hard-coded for 1 year, so follow suit
    $ValidDays = 365

    $name = New-Object -COM "X509Enrollment.CX500DistinguishedName.1"
    $name.Encode("CN=$SubjectName", 0)

    $key = New-Object -COM "X509Enrollment.CX509PrivateKey.1"
    $key.ProviderName = "Microsoft RSA SChannel Cryptographic Provider"
    $key.KeySpec = 1
    $key.Length = 1024
    $key.SecurityDescriptor = "D:PAI(A;;0xd01f01ff;;;SY)(A;;0xd01f01ff;;;BA)(A;;0x80120089;;;NS)"
    $key.MachineContext = 1
    $key.Create()

    $serverauthoid = New-Object -COM "X509Enrollment.CObjectId.1"
    $serverauthoid.InitializeFromValue("1.3.6.1.5.5.7.3.1")
    $ekuoids = New-Object -COM "X509Enrollment.CObjectIds.1"
    $ekuoids.Add($serverauthoid)
    $ekuext = New-Object -COM "X509Enrollment.CX509ExtensionEnhancedKeyUsage.1"
    $ekuext.InitializeEncode($ekuoids)

    $cert = New-Object -COM "X509Enrollment.CX509CertificateRequestCertificate.1"
    $cert.InitializeFromPrivateKey(2, $key, "")
    $cert.Subject = $name
    $cert.Issuer = $cert.Subject
    $cert.NotBefore = (Get-Date).AddDays(-1)
    $cert.NotAfter = $cert.NotBefore.AddDays($ValidDays)
    $cert.X509Extensions.Add($ekuext)
    $cert.Encode()

    $enrollment = New-Object -COM "X509Enrollment.CX509Enrollment.1"
    $enrollment.InitializeFromRequest($cert)
    $certdata = $enrollment.CreateRequest(0)
    $enrollment.InstallResponse(2, $certdata, 0, "")

    # Return the thumbprint of the last installed cert.
    Get-ChildItem "Cert:\LocalMachine\my"| Sort-Object NotBefore -Descending | Select -First 1 | Select -Expand Thumbprint
}


# Setup error handling.
Trap
{
    $_
    Exit 1
}
$ErrorActionPreference = "Stop"


# Find and start the WinRM service.
Write "Verifying WinRM service."
If (!(Get-Service "WinRM"))
{
    Throw "Unable to find the WinRM service."
}
ElseIf ((Get-Service "WinRM").Status -ne "Running")
{
    Write "Starting WinRM service."
    Start-Service -Name "WinRM" -ErrorAction Stop
}
Else
{
    Write "WinRM service is running."
}


# WinRM should be running; check that we have a PS session config.
If (!(Get-PSSessionConfiguration -Verbose:$false) -or (!(Get-ChildItem WSMan:\localhost\Listener)))
{
    Write "Enabling PS Remoting."
    Enable-PSRemoting -Force -ErrorAction Stop
}
Else
{
    Write "PS Remoting is already enabled."
}


# Make sure there is an SSL listener.
$listeners = Get-ChildItem WSMan:\localhost\Listener
If (!($listeners | Where {$_.Keys -like "TRANSPORT=HTTPS"}))
{
    If (!$CreateSelfSignedCert)
    {
        Throw "SSL listener is not enabled. Manually enable the SSL listener and re-run this script."
    }

    # HTTPS-based endpoint does not exist.
    If (Get-Command "New-SelfSignedCertificate" -ErrorAction SilentlyContinue)
    {
        $cert = New-SelfSignedCertificate -DnsName $SubjectName -CertStoreLocation "Cert:\LocalMachine\My"
        $thumbprint = $cert.Thumbprint
    }
    Else
    {
        # w2k8 may not have New-SelfSignedCertificate so we have to roll our own
        $thumbprint = New-LegacySelfSignedCert -SubjectName $SubjectName
    }

    # Create the hashtables of settings to be used.
    $valueset = @{}
    $valueset.Add('Hostname', $SubjectName)
    $valueset.Add('CertificateThumbprint', $thumbprint)

    $selectorset = @{}
    $selectorset.Add('Transport', 'HTTPS')
    $selectorset.Add('Address', '*')

    Write "Enabling SSL listener."
    New-WSManInstance -ResourceURI 'winrm/config/Listener' -SelectorSet $selectorset -ValueSet $valueset
}
Else
{
    Write "SSL listener is already active."
}

If (($listeners | Where {$_.Keys -like "TRANSPORT=HTTP"}))
{
    Write "Warning: HTTP listener is enabled. Do not use basic auth on port 5985."

    # Write "Disabling plaintext listener before enabling basic auth to avoid opening an attack vector."

    # $selectorset = @{}
    # $selectorset.Add('Transport', 'HTTP')
    # $selectorset.Add('Address', '*')

    # Remove-WSManInstance -ResourceURI 'winrm/config/Listener' -SelectorSet $selectorset
}

# Check for basic authentication.
$basicAuthSetting = Get-ChildItem WSMan:\localhost\Service\Auth | Where {$_.Name -eq "Basic"}
If (($basicAuthSetting.Value) -eq $false)
{
    Write "Enabling basic auth support."
    Set-Item -Path "WSMan:\localhost\Service\Auth\Basic" -Value $true
}
Else
{
    Write "Basic auth is already enabled."
}


# Test a remoting connection to localhost, which should work.
$httpsOptions = New-PSSessionOption -SkipCACheck -SkipCNCheck -SkipRevocationCheck
$httpsResult = New-PSSession -UseSSL -ComputerName "localhost" -SessionOption $httpsOptions -ErrorVariable httpsError -ErrorAction SilentlyContinue

If ($httpsResult)
{
    Write "HTTPS sessions are enabled."
}
Else
{
    Throw "Unable to establish an HTTP or HTTPS remoting session."
}


# Configure firewall to allow WinRM HTTPS connections. We have to use netsh because
# New-NetFirewallRule may not be available on w2k8.
$rule_name = "Windows Remote Management (HTTPS-In)"

$fwtest1 = netsh advfirewall firewall show rule name=$rule_name
$fwtest2 = netsh advfirewall firewall show rule name=$rule_name profile=any
If ($fwtest1.count -lt 5)
{
    Write "Adding firewall rule to allow WinRM HTTPS."
    netsh advfirewall firewall add rule profile=any name=$rule_name dir=in localport=5986 protocol=TCP action=allow
}
ElseIf (($fwtest1.count -ge 5) -and ($fwtest2.count -lt 5))
{
    Write "Updating firewall rule to allow WinRM HTTPS for any profile."
    netsh advfirewall firewall set rule name=$rule_name new profile=any
}
Else
{
    Write "Enabling existing firewall rule to allow WinRM HTTPS."
    netsh advfirewall firewall set rule name=$rule_name new enable=yes
}

Write "WinRM service has been successfully configured."