VaultServer

0.8.4

Public/Sign-SSHHostPublicKey.ps1

                                <#

    .SYNOPSIS

        This function (via teh Vault Server REST API) asks the Vault Server to sign the Local Host's

        SSH Host Key (i.e. 'C:\ProgramData\ssh\ssh_host_rsa_key.pub', resulting in output

        'C:\ProgramData\ssh\ssh_host_rsa_key-cert.pub').

    .DESCRIPTION

        See .SYNOPSIS

    .NOTES

    .PARAMETER VaultSSHHostSigningUrl

        This parameter is MANDATORY.

        This parameter takes a string that represents the Vault Server REST API endpoint responsible

        for signing Host/Machine SSH Keys. The Url should be something like:

            https://vaultserver.zero.lab:8200/v1/ssh-host-signer/sign/hostrole

    .PARAMETER VaultAuthToken

        This parameter is MANDATORY.

        This parameter takes a string that represents a Vault Authentication Token that has

        permission to request SSH Host Key Signing via the Vault Server REST API.

    .EXAMPLE

        # Open an elevated PowerShell Session, import the module, and -

        PS C:\Users\zeroadmin> Sign-SSHHostPublicKey -VaultSSHHostSigningUrl $VaultSSHHostSigningUrl -VaultAuthToken $ZeroAdminToken

#>

function Sign-SSHHostPublicKey {

    [CmdletBinding()]

    Param(

        [Parameter(Mandatory=$True)]

        [string]$VaultSSHHostSigningUrl, # Should be something like "http://192.168.2.12:8200/v1/ssh-host-signer/sign/hostrole"

        [Parameter(Mandatory=$True)]

        [string]$VaultAuthToken # Should be something like 'myroot' or '434f37ca-89ae-9073-8783-087c268fd46f'

    )

    # Make sure sshd service is installed and running. If it is, we shouldn't need to use

    # the New-SSHD server function

    if (![bool]$(Get-Service sshd -ErrorAction SilentlyContinue)) {

        if (![bool]$(Get-Service ssh-agent -ErrorAction SilentlyContinue)) {

            $InstallWinSSHSplatParams = @{

                GiveWinSSHBinariesPathPriority  = $True

                ConfigureSSHDOnLocalHost        = $True

                DefaultShell                    = "powershell"

                GitHubInstall                   = $True

                ErrorAction                     = "SilentlyContinue"

                ErrorVariable                   = "IWSErr"

            }

            try {

                $InstallWinSSHResults = Install-WinSSH @InstallWinSSHSplatParams -ErrorAction Stop

                if (!$InstallWinSSHResults) {throw "There was a problem with the Install-WinSSH function! Halting!"}

            }

            catch {

                Write-Error $_

                Write-Host "Errors for the Install-WinSSH function are as follows:"

                Write-Error $($IWSErr | Out-String)

                $global:FunctionResult = "1"

                return

            }

        }

        else {

            $NewSSHDServerSplatParams = @{

                ErrorAction         = "SilentlyContinue"

                ErrorVariable       = "SSHDErr"

                DefaultShell        = "powershell"

            }

            try {

                $NewSSHDServerResult = New-SSHDServer @NewSSHDServerSplatParams

                if (!$NewSSHDServerResult) {throw "There was a problem with the New-SSHDServer function! Halting!"}

            }

            catch {

                Write-Error $_

                Write-Host "Errors for the New-SSHDServer function are as follows:"

                Write-Error $($SSHDErr | Out-String)

                $global:FunctionResult = "1"

                return

            }

        }

    }

    if (Test-Path "$env:ProgramData\ssh") {

        $sshdir = "$env:ProgramData\ssh"

    }

    elseif (Test-Path "$env:ProgramFiles\OpenSSH-Win64") {

        $sshdir = "$env:ProgramFiles\OpenSSH-Win64"

    }

    if (!$sshdir) {

        Write-Error "Unable to find ssh directory at '$env:ProgramData\ssh' or '$env:ProgramFiles\OpenSSH-Win64'! Halting!"

        $global:FunctionResult = "1"

        return

    }

    $PathToSSHHostPublicKeyFile = "$sshdir\ssh_host_rsa_key.pub"

    if (!$(Test-Path $PathToSSHHostPublicKeyFile)) {

        Write-Error "Unable to find the SSH RSA Host Key for $env:ComputerName at path '$sshdir\ssh_host_rsa_key.pub'! Halting!"

        $global:FunctionResult = "1"

        return

    }

    $SignedPubKeyCertFilePath = $PathToSSHHostPublicKeyFile -replace "\.pub","-cert.pub"

    # Make sure $VaultSSHHostSigningUrl is a valid Url

    try {

        $UriObject = [uri]$VaultSSHHostSigningUrl

    }

    catch {

        Write-Error $_

        $global:FunctionResult = "1"

        return

    }

    if (![bool]$($UriObject.Scheme -match "http")) {

        Write-Error "'$VaultSSHHostSigningUrl' does not appear to be a URL! Halting!"

        $global:FunctionResult = "1"

        return

    }

    # If $VaultSSHHostSigningUrl ends in '/', remove it

    if ($VaultSSHHostSigningUrl[-1] -eq "/") {

        $VaultSSHHostSigningUrl = $VaultSSHHostSigningUrl.Substring(0,$VaultSSHHostSigningUrl.Length-1)

    }

    ##### BEGIN Main Body #####

    # HTTP API Request

    # The below removes 'comment' text from the Host Public key because sometimes it can cause problems

    # with the below json

    $PubKeyContent = $($(Get-Content $PathToSSHHostPublicKeyFile) -split "[\s]")[0..1] -join " "

    $jsonRequest = @"

{

    "cert_type": "host",

    "extension": {

      "permit-pty": "",

      "permit-agent-forwarding": ""

    },

    "public_key": "$PubKeyContent"

  }

"@

    $JsonRequestAsSingleLineString = $jsonRequest | ConvertFrom-Json | ConvertTo-Json -Compress

    $HeadersParameters = @{

        "X-Vault-Token" = $VaultAuthToken

    }

    $IWRSplatParams = @{

        Uri         = $VaultSSHHostSigningUrl

        Headers     = $HeadersParameters

        Body        = $JsonRequestAsSingleLineString

        Method      = "Post"

    }

    $SignedSSHClientPubKeyCertResponse = Invoke-WebRequest @IWRSplatParams

    Set-Content -Value $($SignedSSHClientPubKeyCertResponse.Content | ConvertFrom-Json).data.signed_key.Trim() -Path $SignedPubKeyCertFilePath

    # Make sure permissions on "$sshdir/ssh_host_rsa_key-cert.pub" are set properly

    if ($PSVersionTable.PSEdition -eq "Core") {

        Invoke-WinCommand -ComputerName localhost -ScriptBlock {

            $SecurityDescriptor = Get-NTFSSecurityDescriptor -Path $args[0]

            $SecurityDescriptor | Disable-NTFSAccessInheritance -RemoveInheritedAccessRules

            $SecurityDescriptor | Clear-NTFSAccess

            $SecurityDescriptor | Add-NTFSAccess -Account "NT AUTHORITY\SYSTEM" -AccessRights "FullControl" -AppliesTo ThisFolderSubfoldersAndFiles

            $SecurityDescriptor | Add-NTFSAccess -Account "Administrators" -AccessRights "FullControl" -AppliesTo ThisFolderSubfoldersAndFiles

            $SecurityDescriptor | Add-NTFSAccess -Account "NT AUTHORITY\Authenticated Users" -AccessRights "ReadAndExecute, Synchronize" -AppliesTo ThisFolderSubfoldersAndFiles

            $SecurityDescriptor | Set-NTFSSecurityDescriptor

        } -ArgumentList $SignedPubKeyCertFilePath

    }

    else {

        $SecurityDescriptor = Get-NTFSSecurityDescriptor -Path $SignedPubKeyCertFilePath

        $SecurityDescriptor | Disable-NTFSAccessInheritance -RemoveInheritedAccessRules

        $SecurityDescriptor | Clear-NTFSAccess

        $SecurityDescriptor | Add-NTFSAccess -Account "NT AUTHORITY\SYSTEM" -AccessRights "FullControl" -AppliesTo ThisFolderSubfoldersAndFiles

        $SecurityDescriptor | Add-NTFSAccess -Account "Administrators" -AccessRights "FullControl" -AppliesTo ThisFolderSubfoldersAndFiles

        $SecurityDescriptor | Add-NTFSAccess -Account "NT AUTHORITY\Authenticated Users" -AccessRights "ReadAndExecute, Synchronize" -AppliesTo ThisFolderSubfoldersAndFiles

        $SecurityDescriptor | Set-NTFSSecurityDescriptor

    }

    # Update sshd_config

    [System.Collections.ArrayList]$sshdContent = Get-Content $sshdConfigPath

    # Determine if sshd_config already has the 'HostCertificate' option active

    $ExistingHostCertificateOption = $sshdContent -match "HostCertificate" | Where-Object {$_ -notmatch "#"}

    $HostCertificatePathWithForwardSlashes = "$sshdir\ssh_host_rsa_key-cert.pub" -replace "\\","/"

    $HostCertificateOptionLine = "HostCertificate $HostCertificatePathWithForwardSlashes"

    if (!$ExistingHostCertificateOption) {

        try {

            $LineNumberToInsertOn = $sshdContent.IndexOf($($sshdContent -match "HostKey __PROGRAMDATA__/ssh/ssh_host_rsa_key")) + 1

            [System.Collections.ArrayList]$sshdContent.Insert($LineNumberToInsertOn, $HostCertificateOptionLine)

            Set-Content -Value $sshdContent -Path $sshdConfigPath

            $SSHDConfigContentChanged = $True

            [System.Collections.ArrayList]$sshdContent = Get-Content $sshdConfigPath

        }

        catch {

            Write-Error $_

            $global:FunctionResult = "1"

            return

        }

    }

    else {

        if ($ExistingHostCertificateOption -ne $HostCertificateOptionLine) {

            $UpdatedSSHDConfig = $sshdContent -replace [regex]::Escape($ExistingHostCertificateOption),"$HostCertificateOptionLine"

            try {

                Set-Content -Value $UpdatedSSHDConfig -Path $sshdConfigPath

                $SSHDConfigContentChanged = $True

                [System.Collections.ArrayList]$sshdContent = Get-Content $sshdConfigPath

            }

            catch {

                Write-Error $_

                $global:FunctionResult = "1"

                return

            }

        }

        else {

            Write-Warning "The specified 'HostCertificate' option is already active in the the sshd_config file. No changes made."

        }

    }

    [pscustomobject]@{

        SignedPubKeyCertFile        = Get-Item $SignedPubKeyCertFilePath

        SSHDConfigContentChanged    = if ($SSHDConfigContentChanged) {$True} else {$False}

        SSHDContentThatWasAdded     = if ($SSHDConfigContentChanged) {$HostCertificateOptionLine}

    }

}

# SIG # Begin signature block

# MIIMiAYJKoZIhvcNAQcCoIIMeTCCDHUCAQExCzAJBgUrDgMCGgUAMGkGCisGAQQB

# gjcCAQSgWzBZMDQGCisGAQQBgjcCAR4wJgIDAQAABBAfzDtgWUsITrck0sYpfvNR

# AgEAAgEAAgEAAgEAAgEAMCEwCQYFKw4DAhoFAAQUZajRlotBSytFUYKyHdZKkD8j

# Eyigggn9MIIEJjCCAw6gAwIBAgITawAAAB/Nnq77QGja+wAAAAAAHzANBgkqhkiG

# 9w0BAQsFADAwMQwwCgYDVQQGEwNMQUIxDTALBgNVBAoTBFpFUk8xETAPBgNVBAMT

# CFplcm9EQzAxMB4XDTE3MDkyMDIxMDM1OFoXDTE5MDkyMDIxMTM1OFowPTETMBEG

# CgmSJomT8ixkARkWA0xBQjEUMBIGCgmSJomT8ixkARkWBFpFUk8xEDAOBgNVBAMT

# B1plcm9TQ0EwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQDCwqv+ROc1

# bpJmKx+8rPUUfT3kPSUYeDxY8GXU2RrWcL5TSZ6AVJsvNpj+7d94OEmPZate7h4d

# gJnhCSyh2/3v0BHBdgPzLcveLpxPiSWpTnqSWlLUW2NMFRRojZRscdA+e+9QotOB

# aZmnLDrlePQe5W7S1CxbVu+W0H5/ukte5h6gsKa0ktNJ6X9nOPiGBMn1LcZV/Ksl

# lUyuTc7KKYydYjbSSv2rQ4qmZCQHqxyNWVub1IiEP7ClqCYqeCdsTtfw4Y3WKxDI

# JaPmWzlHNs0nkEjvnAJhsRdLFbvY5C2KJIenxR0gA79U8Xd6+cZanrBUNbUC8GCN

# wYkYp4A4Jx+9AgMBAAGjggEqMIIBJjASBgkrBgEEAYI3FQEEBQIDAQABMCMGCSsG

# AQQBgjcVAgQWBBQ/0jsn2LS8aZiDw0omqt9+KWpj3DAdBgNVHQ4EFgQUicLX4r2C

# Kn0Zf5NYut8n7bkyhf4wGQYJKwYBBAGCNxQCBAweCgBTAHUAYgBDAEEwDgYDVR0P

# AQH/BAQDAgGGMA8GA1UdEwEB/wQFMAMBAf8wHwYDVR0jBBgwFoAUdpW6phL2RQNF

# 7AZBgQV4tgr7OE0wMQYDVR0fBCowKDAmoCSgIoYgaHR0cDovL3BraS9jZXJ0ZGF0

# YS9aZXJvREMwMS5jcmwwPAYIKwYBBQUHAQEEMDAuMCwGCCsGAQUFBzAChiBodHRw

# Oi8vcGtpL2NlcnRkYXRhL1plcm9EQzAxLmNydDANBgkqhkiG9w0BAQsFAAOCAQEA

# tyX7aHk8vUM2WTQKINtrHKJJi29HaxhPaHrNZ0c32H70YZoFFaryM0GMowEaDbj0

# a3ShBuQWfW7bD7Z4DmNc5Q6cp7JeDKSZHwe5JWFGrl7DlSFSab/+a0GQgtG05dXW

# YVQsrwgfTDRXkmpLQxvSxAbxKiGrnuS+kaYmzRVDYWSZHwHFNgxeZ/La9/8FdCir

# MXdJEAGzG+9TwO9JvJSyoGTzu7n93IQp6QteRlaYVemd5/fYqBhtskk1zDiv9edk

# mHHpRWf9Xo94ZPEy7BqmDuixm4LdmmzIcFWqGGMo51hvzz0EaE8K5HuNvNaUB/hq

# MTOIB5145K8bFOoKHO4LkTCCBc8wggS3oAMCAQICE1gAAAH5oOvjAv3166MAAQAA

# AfkwDQYJKoZIhvcNAQELBQAwPTETMBEGCgmSJomT8ixkARkWA0xBQjEUMBIGCgmS

# JomT8ixkARkWBFpFUk8xEDAOBgNVBAMTB1plcm9TQ0EwHhcNMTcwOTIwMjE0MTIy

# WhcNMTkwOTIwMjExMzU4WjBpMQswCQYDVQQGEwJVUzELMAkGA1UECBMCUEExFTAT

# BgNVBAcTDFBoaWxhZGVscGhpYTEVMBMGA1UEChMMRGlNYWdnaW8gSW5jMQswCQYD

# VQQLEwJJVDESMBAGA1UEAxMJWmVyb0NvZGUyMIIBIjANBgkqhkiG9w0BAQEFAAOC

# AQ8AMIIBCgKCAQEAxX0+4yas6xfiaNVVVZJB2aRK+gS3iEMLx8wMF3kLJYLJyR+l

# rcGF/x3gMxcvkKJQouLuChjh2+i7Ra1aO37ch3X3KDMZIoWrSzbbvqdBlwax7Gsm

# BdLH9HZimSMCVgux0IfkClvnOlrc7Wpv1jqgvseRku5YKnNm1JD+91JDp/hBWRxR

# 3Qg2OR667FJd1Q/5FWwAdrzoQbFUuvAyeVl7TNW0n1XUHRgq9+ZYawb+fxl1ruTj

# 3MoktaLVzFKWqeHPKvgUTTnXvEbLh9RzX1eApZfTJmnUjBcl1tCQbSzLYkfJlJO6

# eRUHZwojUK+TkidfklU2SpgvyJm2DhCtssFWiQIDAQABo4ICmjCCApYwDgYDVR0P

# AQH/BAQDAgeAMBMGA1UdJQQMMAoGCCsGAQUFBwMDMB0GA1UdDgQWBBS5d2bhatXq

# eUDFo9KltQWHthbPKzAfBgNVHSMEGDAWgBSJwtfivYIqfRl/k1i63yftuTKF/jCB

# 6QYDVR0fBIHhMIHeMIHboIHYoIHVhoGubGRhcDovLy9DTj1aZXJvU0NBKDEpLENO

# PVplcm9TQ0EsQ049Q0RQLENOPVB1YmxpYyUyMEtleSUyMFNlcnZpY2VzLENOPVNl

# cnZpY2VzLENOPUNvbmZpZ3VyYXRpb24sREM9emVybyxEQz1sYWI/Y2VydGlmaWNh

# dGVSZXZvY2F0aW9uTGlzdD9iYXNlP29iamVjdENsYXNzPWNSTERpc3RyaWJ1dGlv

# blBvaW50hiJodHRwOi8vcGtpL2NlcnRkYXRhL1plcm9TQ0EoMSkuY3JsMIHmBggr

# BgEFBQcBAQSB2TCB1jCBowYIKwYBBQUHMAKGgZZsZGFwOi8vL0NOPVplcm9TQ0Es

# Q049QUlBLENOPVB1YmxpYyUyMEtleSUyMFNlcnZpY2VzLENOPVNlcnZpY2VzLENO

# PUNvbmZpZ3VyYXRpb24sREM9emVybyxEQz1sYWI/Y0FDZXJ0aWZpY2F0ZT9iYXNl

# P29iamVjdENsYXNzPWNlcnRpZmljYXRpb25BdXRob3JpdHkwLgYIKwYBBQUHMAKG

# Imh0dHA6Ly9wa2kvY2VydGRhdGEvWmVyb1NDQSgxKS5jcnQwPQYJKwYBBAGCNxUH

# BDAwLgYmKwYBBAGCNxUIg7j0P4Sb8nmD8Y84g7C3MobRzXiBJ6HzzB+P2VUCAWQC

# AQUwGwYJKwYBBAGCNxUKBA4wDDAKBggrBgEFBQcDAzANBgkqhkiG9w0BAQsFAAOC

# AQEAszRRF+YTPhd9UbkJZy/pZQIqTjpXLpbhxWzs1ECTwtIbJPiI4dhAVAjrzkGj

# DyXYWmpnNsyk19qE82AX75G9FLESfHbtesUXnrhbnsov4/D/qmXk/1KD9CE0lQHF

# Lu2DvOsdf2mp2pjdeBgKMRuy4cZ0VCc/myO7uy7dq0CvVdXRsQC6Fqtr7yob9NbE

# OdUYDBAGrt5ZAkw5YeL8H9E3JLGXtE7ir3ksT6Ki1mont2epJfHkO5JkmOI6XVtg

# anuOGbo62885BOiXLu5+H2Fg+8ueTP40zFhfLh3e3Kj6Lm/NdovqqTBAsk04tFW9

# Hp4gWfVc0gTDwok3rHOrfIY35TGCAfUwggHxAgEBMFQwPTETMBEGCgmSJomT8ixk

# ARkWA0xBQjEUMBIGCgmSJomT8ixkARkWBFpFUk8xEDAOBgNVBAMTB1plcm9TQ0EC

# E1gAAAH5oOvjAv3166MAAQAAAfkwCQYFKw4DAhoFAKB4MBgGCisGAQQBgjcCAQwx

# CjAIoAKAAKECgAAwGQYJKoZIhvcNAQkDMQwGCisGAQQBgjcCAQQwHAYKKwYBBAGC

# NwIBCzEOMAwGCisGAQQBgjcCARUwIwYJKoZIhvcNAQkEMRYEFPJXGXeplXPfxj1s

# HulIXMRskVoLMA0GCSqGSIb3DQEBAQUABIIBADbKpkcMAQVUy70b/2o8MW+mkG0/

# voanlljkokCHYsi9KGJb4FZ77wFn64OGmJuFZCcXv4emsj2ML3rCJE6pVAyJFw6F

# M63npjGESU7ZcVae2qkvpm5uv1seJXlw1FWfx/yF809GRUAurXXZKPUCTeUzsNHF

# k+0NpZIUNhytvNLa7okSYFI4qKi8gsfkGilFMql2pNGsaWOWvbRAq/yuN85RY5yL

# CdFDJcJAKMCAGQapLIFqwYWzErvprW7JExFoyClKpnTFpZJ835akgF1PNfCV4eZm

# GFIG3cKEMnk6xgbd6AE0RDrFcUEYrSPaHZlbY/y/RF4hpDom0ak+RofL/a8=

# SIG # End signature block