fix folder permissions for programdata\ssh during server install (#549)

contrib/win32/openssh/OpenSSHUtils.psm1

@@ -43,6 +43,8 @@ $everyoneSid = Get-UserSID -WellKnownSidType ([System.Security.Principal.WellKno
 
 $currentUserSid = Get-UserSID -User "$($env:USERDOMAIN)\$($env:USERNAME)"
 
+$authenticatedUserSid = Get-UserSID -WellKnownSidType ([System.Security.Principal.WellKnownSidType]::AuthenticatedUserSid)
+
 #Taken from P/Invoke.NET with minor adjustments.
  $definition = @'
 using System;
@@ -268,6 +270,33 @@ function Repair-UserSshConfigPermission
         Repair-FilePermission -Owners $UserSid,$adminsSid,$systemSid -AnyAccessOK $UserSid @psBoundParameters
 }
 
+<#
+    .Synopsis
+    Repair-SSHFolderPermission
+    Repair the file owner and permission of ssh folder & any files inside it
+#>
+function Repair-SSHFolderPermission
+{
+    [CmdletBinding(SupportsShouldProcess=$true, ConfirmImpact="High")]
+    param (
+        [parameter(Mandatory=$true)]
+        [ValidateNotNullOrEmpty()]        
+        [string]$sshProgDataPath)
+
+    # SSH Folder - owner: System or Admins; full access: System, Admins; read or readandexecute/synchronize permissible: Authenticated Users
+    Repair-FilePermission -FilePath $sshProgDataPath -Owners $adminsSid, $systemSid -FullAccessNeeded $adminsSid,$systemSid -ReadAndExecuteAccessOK $authenticatedUserSid
+    # Files in SSH Folder (excluding private key files) 
+    # owner: System or Admins; full access: System, Admins; read/readandexecute/synchronize permissable: Authenticated Users
+    $privateKeyFiles = @("ssh_host_dsa_key", "ssh_host_ecdsa_key", "ssh_host_ed25519_key", "ssh_host_rsa_key")
+    Get-ChildItem -Path (Join-Path $sshProgDataPath '*') -Recurse -Exclude ($privateKeyFiles) -Force | ForEach-Object {
+        Repair-FilePermission -FilePath $_.FullName -Owners $adminsSid, $systemSid -FullAccessNeeded $adminsSid, $systemSid -ReadAndExecuteAccessOK $authenticatedUserSid
+    } 
+    # Private key files - owner: System or Admins; full access: System, Admins
+    Get-ChildItem -Path (Join-Path $sshProgDataPath '*') -Recurse -Include $privateKeyFiles -Force | ForEach-Object {
+        Repair-FilePermission -FilePath $_.FullName -Owners $adminsSid, $systemSid -FullAccessNeeded $systemSid, $adminsSid
+    }
+}
+
 <#
     .Synopsis
     Repair-FilePermissionInternal
@@ -285,10 +314,11 @@ function Repair-FilePermission
         [System.Security.Principal.SecurityIdentifier[]] $AnyAccessOK = $null,
         [System.Security.Principal.SecurityIdentifier[]] $FullAccessNeeded = $null,
         [System.Security.Principal.SecurityIdentifier[]] $ReadAccessOK = $null,
-        [System.Security.Principal.SecurityIdentifier[]] $ReadAccessNeeded = $null
+        [System.Security.Principal.SecurityIdentifier[]] $ReadAccessNeeded = $null,
+        [System.Security.Principal.SecurityIdentifier[]] $ReadAndExecuteAccessOK = $null
     )
 
-    if(-not (Test-Path $FilePath -PathType Leaf))
+    if(-not (Test-Path $FilePath))
     {
         Write-host "$FilePath not found" -ForegroundColor Yellow
         return
@@ -319,7 +349,8 @@ function Repair-FilePermissionInternal {
         [System.Security.Principal.SecurityIdentifier[]] $AnyAccessOK = $null,
         [System.Security.Principal.SecurityIdentifier[]] $FullAccessNeeded = $null,
         [System.Security.Principal.SecurityIdentifier[]] $ReadAccessOK = $null,
-        [System.Security.Principal.SecurityIdentifier[]] $ReadAccessNeeded = $null
+        [System.Security.Principal.SecurityIdentifier[]] $ReadAccessNeeded = $null,
+        [System.Security.Principal.SecurityIdentifier[]] $ReadAndExecuteAccessOK = $null
     )
 
     $acl = Get-Acl $FilePath
@@ -353,6 +384,7 @@ function Repair-FilePermissionInternal {
 
     $ReadAccessPerm = ([System.UInt32] [System.Security.AccessControl.FileSystemRights]::Read.value__) -bor `
                     ([System.UInt32] [System.Security.AccessControl.FileSystemRights]::Synchronize.value__)
+    $ReadAndExecuteAccessPerm = $ReadAccessPerm -bor ([System.UInt32] [System.Security.AccessControl.FileSystemRights]::ReadAndExecute.value__)
     $FullControlPerm = [System.UInt32] [System.Security.AccessControl.FileSystemRights]::FullControl.value__
 
     #system and admin groups can have any access to the file; plus the account in the AnyAccessOK list
@@ -455,6 +487,48 @@ function Repair-FilePermissionInternal {
             #ignore those accounts listed in the AnyAccessOK list.
             continue;
         }
+        # Handle ReadAndExecuteAccessOK list and make sure they are only granted Read or ReadAndExecute & Synchronize access
+        elseif($ReadAndExecuteAccessOK -contains $IdentityReferenceSid)
+        {
+            # checks if user access is already either: Read or ReadAndExecute & Synchronize
+            if (-not ($a.AccessControlType.Equals([System.Security.AccessControl.AccessControlType]::Allow)) -or `
+            (-not (([System.UInt32]$a.FileSystemRights.value__) -band (-bnot $ReadAndExecuteAccessPerm))))
+            {
+                continue;
+            }
+            
+            if($a.IsInherited)
+            {
+                if($needChange)    
+                {
+                    Enable-Privilege SeRestorePrivilege | out-null
+                    Set-Acl -Path $FilePath -AclObject $acl -Confirm:$false
+                }
+                
+                return Remove-RuleProtection @paras
+            }
+            $caption = "'$($a.IdentityReference)' has the following access to '$FilePath': '$($a.FileSystemRights)'."
+            $prompt = "Shall I make it ReadAndExecute, and Synchronize only?"
+            $description = "Set'$($a.IdentityReference)' Read access only to '$FilePath'. "
+
+            if($pscmdlet.ShouldProcess($description, $prompt, $caption))
+            {
+                $needChange = $true
+                $ace = New-Object System.Security.AccessControl.FileSystemAccessRule `
+                    ($IdentityReferenceSid, "ReadAndExecute, Synchronize", "None", "None", "Allow")
+                          
+                $acl.SetAccessRule($ace)
+                Write-Host "'$($a.IdentityReference)' now has ReadAndExecute, Synchronize access to '$FilePath'. " -ForegroundColor Green
+            }
+            else
+            {
+                $health = $false
+                if(-not $PSBoundParameters.ContainsKey("WhatIf"))
+                {
+                    Write-Host "'$($a.IdentityReference)' still has these access to '$FilePath': '$($a.FileSystemRights)'." -ForegroundColor Yellow
+                }
+            }
+        }
         #If everyone is in the ReadAccessOK list, any user can have read access;
         # below block make sure they are granted Read access only
         elseif(($realReadAcessOKList -contains $everyoneSid) -or ($realReadAcessOKList -contains $IdentityReferenceSid))
@@ -649,7 +723,7 @@ function Remove-RuleProtection
         [string]$FilePath
     )
     $message = "Need to remove the inheritance before repair the rules."
-    $prompt = "Shall I remove the inheritace?"
+    $prompt = "Shall I remove the inheritance?"
     $description = "Remove inheritance of '$FilePath'."
 
     if($pscmdlet.ShouldProcess($description, $prompt, $message))
@@ -734,4 +808,4 @@ function Enable-Privilege {
     $type[0]::EnablePrivilege($Privilege, $Disable)
 }
 
-Export-ModuleMember -Function Repair-FilePermission, Repair-SshdConfigPermission, Repair-SshdHostKeyPermission, Repair-AuthorizedKeyPermission, Repair-UserKeyPermission, Repair-UserSshConfigPermission, Enable-Privilege, Get-UserAccount, Get-UserSID, Repair-AdministratorsAuthorizedKeysPermission, Repair-ModuliFilePermission
+Export-ModuleMember -Function Repair-FilePermission, Repair-SshdConfigPermission, Repair-SshdHostKeyPermission, Repair-AuthorizedKeyPermission, Repair-UserKeyPermission, Repair-UserSshConfigPermission, Enable-Privilege, Get-UserAccount, Get-UserSID, Repair-AdministratorsAuthorizedKeysPermission, Repair-ModuliFilePermission, Repair-SSHFolderPermission

contrib/win32/openssh/install-sshd.ps1

@@ -2,6 +2,7 @@
 # @friism - Fixed issue with invalid SDDL on Set-Acl
 # @manojampalam - removed ntrights.exe dependency
 # @bingbing8 - removed secedit.exe dependency
+# @tessgauthier - added permissions check for %programData%/ssh
 
 $ErrorActionPreference = 'Stop'
 
@@ -84,6 +85,13 @@ if (Test-Path $moduliPath -PathType Leaf)
     Repair-ModuliFilePermission -FilePath $moduliPath @psBoundParameters -confirm:$false
 }
 
+# If %programData%/ssh folder already exists, verify and, if necessary and approved by user, fix permissions 
+$sshProgDataPath = Join-Path $env:ProgramData "ssh"
+if (Test-Path $sshProgDataPath)
+{
+    Repair-SSHFolderPermission -sshProgDataPath $sshProgDataPath
+}
+
 #register etw provider
 wevtutil im `"$etwman`"