Refactor: Secure literal search and defensive scope handling (#4492)

* Refactor: Secure literal search and defensive scope handling

* Refactor: Secure literal search for Tweaks Tab

* Merge branch 'ChrisTitusTech:main' into fix-search-security

functions/private/Find-AppsByNameOrDescription.ps1

@@ -3,13 +3,41 @@ function Find-AppsByNameOrDescription {
         .SYNOPSIS
             Searches through the Apps on the Install Tab and hides all entries that do not match the string
 
+        .DESCRIPTION
+            Filters application entries by name or description using literal string matching.
+            Respects collapsed category state and handles null $sync gracefully.
+
         .PARAMETER SearchString
-            The string to be searched for
+            The string to be searched for. Wildcards are treated as literal characters.
+
+        .NOTES
+            - Uses module-scope $sync (no parameter needed; inherits from caller's scope)
+            - Performs literal matching (no wildcard expansion)
+            - Safely handles missing hashtable keys and null UI elements
+            - Protected by try/catch to prevent UI thread crashes
     #>
     param(
-        [Parameter(Mandatory=$false)]
+        [Parameter(Mandatory = $false)]
         [string]$SearchString = ""
     )
+
+    # Validate that $sync exists and has required structure
+    if ($null -eq $sync) {
+        Write-Warning "Find-AppsByNameOrDescription: Global `$sync not found. Aborting search."
+        return
+    }
+
+    if ($null -eq $sync.ItemsControl) {
+        Write-Warning "Find-AppsByNameOrDescription: `$sync.ItemsControl not initialized. Aborting search."
+        return
+    }
+
+    if ($null -eq $sync.configs -or $null -eq $sync.configs.applicationsHashtable) {
+        Write-Warning "Find-AppsByNameOrDescription: `$sync.configs.applicationsHashtable not initialized. Aborting search."
+        return
+    }
+
+    try {
         # Reset the visibility if the search string is empty or the search is cleared
         if ([string]::IsNullOrWhiteSpace($SearchString)) {
             $sync.ItemsControl.Items | ForEach-Object {
@@ -26,7 +54,8 @@ function Find-AppsByNameOrDescription {
                     # Respect the collapsed state of categories (indicated by + prefix)
                     if ($categoryLabel.Content -like "+*") {
                         $wrapPanel.Visibility = [Windows.Visibility]::Collapsed
-                } else {
+                    }
+                    else {
                         $wrapPanel.Visibility = [Windows.Visibility]::Visible
                     }
 
@@ -39,6 +68,9 @@ function Find-AppsByNameOrDescription {
             return
         }
 
+        # Escape wildcard characters for literal matching
+        $escapedSearchString = [System.Management.Automation.WildcardPattern]::Escape($SearchString)
+
         # Perform search
         $sync.ItemsControl.Items | ForEach-Object {
             # Each item is a StackPanel container with Children[0] = label, Children[1] = WrapPanel
@@ -52,8 +84,20 @@ function Find-AppsByNameOrDescription {
 
                 # Search through apps in this category
                 $wrapPanel.Children | ForEach-Object {
-                $appEntry = $sync.configs.applicationsHashtable.$($_.Tag)
+                    # Safely retrieve app entry from hashtable
-                if ($appEntry.Content -like "*$SearchString*" -or $appEntry.Description -like "*$SearchString*") {
+                    $appTag = $_.Tag
+                    $appEntry = $null
+
+                    if (-not [string]::IsNullOrWhiteSpace($appTag) -and $sync.configs.applicationsHashtable.ContainsKey($appTag)) {
+                        $appEntry = $sync.configs.applicationsHashtable[$appTag]
+                    }
+
+                    # Check if app matches search criteria
+                    if ($null -ne $appEntry) {
+                        $contentMatch = $appEntry.Content -like "*$escapedSearchString*"
+                        $descriptionMatch = $appEntry.Description -like "*$escapedSearchString*"
+
+                        if ($contentMatch -or $descriptionMatch) {
                             # Show the App and mark that this category has a match
                             $_.Visibility = [Windows.Visibility]::Visible
                             $categoryHasMatch = $true
@@ -62,6 +106,11 @@ function Find-AppsByNameOrDescription {
                             $_.Visibility = [Windows.Visibility]::Collapsed
                         }
                     }
+                    else {
+                        # Hide app if no entry found (data integrity issue)
+                        $_.Visibility = [Windows.Visibility]::Collapsed
+                    }
+                }
 
                 # If category has matches, show the WrapPanel and update the category label to expanded state
                 if ($categoryHasMatch) {
@@ -71,10 +120,17 @@ function Find-AppsByNameOrDescription {
                     if ($categoryLabel.Content -like "+*") {
                         $categoryLabel.Content = $categoryLabel.Content -replace "^\+ ", "- "
                     }
-            } else {
+                }
+                else {
                     # Hide the entire category container if no matches
                     $_.Visibility = [Windows.Visibility]::Collapsed
                 }
             }
         }
+    }
+    catch {
+        Write-Warning "Find-AppsByNameOrDescription: An error occurred during search: $_"
+        # Fail gracefully - do not crash the UI thread
+        return
+    }
 }

functions/private/Find-TweaksByNameOrDescription.ps1

@@ -3,98 +3,300 @@ function Find-TweaksByNameOrDescription {
         .SYNOPSIS
             Searches through the Tweaks on the Tweaks Tab and hides all entries that do not match the search string
 
+        .DESCRIPTION
+            Filters tweak entries by name or description using literal string matching (no wildcard expansion).
+            Respects collapsed category state and handles null $sync gracefully.
+            Safe for rapid keystroke events; no terminal spam on error conditions.
+
         .PARAMETER SearchString
-            The string to be searched for
+            The string to be searched for. Wildcards are treated as literal characters.
+
+        .NOTES
+            - Uses module-scope $sync (resolved via global/script fallback if needed)
+            - Performs literal matching (no wildcard expansion)
+            - Safely handles missing UI elements and null properties
+            - Protected by try/catch to prevent UI thread crashes
+            - PowerShell 5.1 compatible (no ternary operators, no advanced language features)
     #>
     param(
-        [Parameter(Mandatory=$false)]
+        [Parameter(Mandatory = $false)]
         [string]$SearchString = ""
     )
 
-    # Reset the visibility if the search string is empty or the search is cleared
+    # ──────────────────────────────────────────────────────────────────────────────
-    if ([string]::IsNullOrWhiteSpace($SearchString)) {
+    # 1. RESOLVE $SYNC WITH MULTI-LEVEL FALLBACK
-        # Show all categories
+    # ──────────────────────────────────────────────────────────────────────────────
-        $tweakspanel = $sync.Form.FindName("tweakspanel")
-        $tweakspanel.Children | ForEach-Object {
-            $_.Visibility = [Windows.Visibility]::Visible
 
-            # Foreach category section, show all items
+    if ($null -eq $Sync) {
-            if ($_ -is [Windows.Controls.Border]) {
+        $Sync = $global:sync
-                $_.Visibility = [Windows.Visibility]::Visible
+        if ($null -eq $Sync) {
+            $Sync = $script:sync
+        }
+    }
 
-                # Find ItemsControl
+    # Validate that $Sync exists and has required structure
-                $dockPanel = $_.Child
+    if ($null -eq $Sync) {
-                if ($dockPanel -is [Windows.Controls.DockPanel]) {
+        # Silent return - function called on every keystroke; no warning spam
-                    $itemsControl = $dockPanel.Children | Where-Object { $_ -is [Windows.Controls.ItemsControl] }
-                    if ($itemsControl) {
-                        # Show items in the category
-                        foreach ($item in $itemsControl.Items) {
-                            if ($item -is [Windows.Controls.Label]) {
-                                $item.Visibility = [Windows.Visibility]::Visible
-                            } elseif ($item -is [Windows.Controls.DockPanel] -or
-                                      $item -is [Windows.Controls.StackPanel]) {
-                                $item.Visibility = [Windows.Visibility]::Visible
-                            }
-                        }
-                    }
-                }
-            }
-        }
         return
     }
 
-    # Search for matching tweaks when search string is not null
+    if ($null -eq $Sync.Form) {
-    $tweakspanel = $sync.Form.FindName("tweakspanel")
+        # Silent return - form not yet initialized
+        return
+    }
 
-    $tweakspanel.Children | ForEach-Object {
+    # ──────────────────────────────────────────────────────────────────────────────
+    # 2. GET REFERENCE TO TWEAKS PANEL
+    # ──────────────────────────────────────────────────────────────────────────────
+
+    $tweaksPanel = $null
+    try {
+        $tweaksPanel = $Sync.Form.FindName("tweakspanel")
+    }
+    catch {
+        # Silent return - panel not found or disposed
+        return
+    }
+
+    if ($null -eq $tweaksPanel) {
+        # Silent return - panel doesn't exist
+        return
+    }
+
+    # ──────────────────────────────────────────────────────────────────────────────
+    # 3. HANDLE EMPTY/WHITESPACE SEARCH STRING - RESET TO DEFAULT STATE
+    # ──────────────────────────────────────────────────────────────────────────────
+
+    if ([string]::IsNullOrWhiteSpace($SearchString)) {
+        try {
+            $tweaksPanel.Children | ForEach-Object {
                 $categoryBorder = $_
-        $categoryVisible = $false
 
-        if ($_ -is [Windows.Controls.Border]) {
+                # Safely set visibility
-            # Find the ItemsControl
+                if ($null -ne $categoryBorder) {
-            $dockPanel = $_.Child
+                    $categoryBorder.Visibility = [Windows.Visibility]::Visible
+                }
+
+                # Process each category
+                if ($categoryBorder -is [Windows.Controls.Border]) {
+                    $dockPanel = $null
+                    if ($null -ne $categoryBorder.Child) {
+                        $dockPanel = $categoryBorder.Child
+                    }
+
                     if ($dockPanel -is [Windows.Controls.DockPanel]) {
-                $itemsControl = $dockPanel.Children | Where-Object { $_ -is [Windows.Controls.ItemsControl] }
+                        $itemsControl = $null
-                if ($itemsControl) {
+                        $itemsControl = $dockPanel.Children | Where-Object { $_ -is [Windows.Controls.ItemsControl] } | Select-Object -First 1
+
+                        if ($null -ne $itemsControl) {
+                            # Show all items in the category
+                            foreach ($item in $itemsControl.Items) {
+                                if ($null -ne $item) {
+                                    # Check if it's a category label (first Label in the ItemsControl)
+                                    if ($item -is [Windows.Controls.Label]) {
+                                        $item.Visibility = [Windows.Visibility]::Visible
+                                    }
+                                    elseif ($item -is [Windows.Controls.DockPanel] -or $item -is [Windows.Controls.StackPanel]) {
+                                        # Show all checkbox containers
+                                        $item.Visibility = [Windows.Visibility]::Visible
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        catch {
+            # Silent catch - UI element may be disposed
+        }
+
+        return
+    }
+
+    # ──────────────────────────────────────────────────────────────────────────────
+    # 4. PERFORM LITERAL SEARCH (NO WILDCARD EXPANSION)
+    # ──────────────────────────────────────────────────────────────────────────────
+
+    try {
+        # Normalize search term once for the entire operation
+        $searchTerm = $SearchString
+        if ($null -eq $searchTerm) {
+            $searchTerm = ""
+        }
+
+        # Iterate through all categories
+        $tweaksPanel.Children | ForEach-Object {
+            $categoryBorder = $_
+            $categoryHasMatch = $false
+
+            if ($categoryBorder -is [Windows.Controls.Border]) {
+                $dockPanel = $null
+                if ($null -ne $categoryBorder.Child) {
+                    $dockPanel = $categoryBorder.Child
+                }
+
+                if ($dockPanel -is [Windows.Controls.DockPanel]) {
+                    $itemsControl = $null
+                    $itemsControl = $dockPanel.Children | Where-Object { $_ -is [Windows.Controls.ItemsControl] } | Select-Object -First 1
+
+                    if ($null -ne $itemsControl) {
                         $categoryLabel = $null
 
-                    # Process all items in the ItemsControl
+                        # Process all items (checkboxes, labels, panels) in the ItemsControl
                         for ($i = 0; $i -lt $itemsControl.Items.Count; $i++) {
                             $item = $itemsControl.Items[$i]
 
+                            if ($null -eq $item) {
+                                continue
+                            }
+
+                            # ────────────────────────────────────────────────────────────
+                            # Check if this is a category label (usually first Label)
+                            # ────────────────────────────────────────────────────────────
+
                             if ($item -is [Windows.Controls.Label]) {
                                 $categoryLabel = $item
+                                # Initially hide category label; show it only if matches found
                                 $item.Visibility = [Windows.Visibility]::Collapsed
-                        } elseif ($item -is [Windows.Controls.DockPanel]) {
+                            }
+
+                            # ────────────────────────────────────────────────────────────
+                            # Check if this is a DockPanel containing a tweak checkbox
+                            # ────────────────────────────────────────────────────────────
+
+                            elseif ($item -is [Windows.Controls.DockPanel]) {
+                                $checkbox = $null
+                                $label = $null
+
+                                # Safely extract checkbox and label
                                 $checkbox = $item.Children | Where-Object { $_ -is [Windows.Controls.CheckBox] } | Select-Object -First 1
                                 $label = $item.Children | Where-Object { $_ -is [Windows.Controls.Label] } | Select-Object -First 1
 
-                            if ($label -and ($label.Content -like "*$SearchString*" -or $label.ToolTip -like "*$SearchString*")) {
+                                # Check if tweak matches search criteria
+                                $itemMatches = $false
+
+                                if ($null -ne $label) {
+                                    $labelContent = $label.Content
+                                    $labelToolTip = $label.ToolTip
+
+                                    # Safely null-check properties
+                                    if ($null -eq $labelContent) {
+                                        $labelContent = ""
+                                    }
+                                    if ($null -eq $labelToolTip) {
+                                        $labelToolTip = ""
+                                    }
+
+                                    # Convert to string and perform LITERAL matching
+                                    $labelContentStr = [string]$labelContent
+                                    $labelToolTipStr = [string]$labelToolTip
+
+                                    # Use IndexOf for literal matching (no wildcard interpretation)
+                                    $contentMatch = $labelContentStr.IndexOf($searchTerm, [System.StringComparison]::OrdinalIgnoreCase) -ge 0
+                                    $toolTipMatch = $labelToolTipStr.IndexOf($searchTerm, [System.StringComparison]::OrdinalIgnoreCase) -ge 0
+
+                                    if ($contentMatch -or $toolTipMatch) {
+                                        $itemMatches = $true
+                                    }
+                                }
+
+                                # Set visibility based on match result
+                                if ($itemMatches) {
                                     $item.Visibility = [Windows.Visibility]::Visible
-                                if ($categoryLabel) { $categoryLabel.Visibility = [Windows.Visibility]::Visible }
+                                    $categoryHasMatch = $true
-                                $categoryVisible = $true
+                                }
-                            } else {
+                                else {
                                     $item.Visibility = [Windows.Visibility]::Collapsed
                                 }
-                        } elseif ($item -is [Windows.Controls.StackPanel]) {
+                            }
-                            # StackPanel which contain checkboxes or other elements
+
+                            # ────────────────────────────────────────────────────────────
+                            # Check if this is a StackPanel containing a tweak checkbox
+                            # ────────────────────────────────────────────────────────────
+
+                            elseif ($item -is [Windows.Controls.StackPanel]) {
+                                $checkbox = $null
                                 $checkbox = $item.Children | Where-Object { $_ -is [Windows.Controls.CheckBox] } | Select-Object -First 1
 
-                            if ($checkbox -and ($checkbox.Content -like "*$SearchString*" -or $checkbox.ToolTip -like "*$SearchString*")) {
+                                $itemMatches = $false
+
+                                if ($null -ne $checkbox) {
+                                    $checkboxContent = $checkbox.Content
+                                    $checkboxToolTip = $checkbox.ToolTip
+
+                                    # Safely null-check properties
+                                    if ($null -eq $checkboxContent) {
+                                        $checkboxContent = ""
+                                    }
+                                    if ($null -eq $checkboxToolTip) {
+                                        $checkboxToolTip = ""
+                                    }
+
+                                    # Convert to string and perform LITERAL matching
+                                    $checkboxContentStr = [string]$checkboxContent
+                                    $checkboxToolTipStr = [string]$checkboxToolTip
+
+                                    # Use IndexOf for literal matching (no wildcard interpretation)
+                                    $contentMatch = $checkboxContentStr.IndexOf($searchTerm, [System.StringComparison]::OrdinalIgnoreCase) -ge 0
+                                    $toolTipMatch = $checkboxToolTipStr.IndexOf($searchTerm, [System.StringComparison]::OrdinalIgnoreCase) -ge 0
+
+                                    if ($contentMatch -or $toolTipMatch) {
+                                        $itemMatches = $true
+                                    }
+                                }
+
+                                # Set visibility based on match result
+                                if ($itemMatches) {
                                     $item.Visibility = [Windows.Visibility]::Visible
-                                if ($categoryLabel) { $categoryLabel.Visibility = [Windows.Visibility]::Visible }
+                                    $categoryHasMatch = $true
-                                $categoryVisible = $true
+                                }
-                            } else {
+                                else {
                                     $item.Visibility = [Windows.Visibility]::Collapsed
                                 }
                             }
                         }
+
+                        # ────────────────────────────────────────────────────────────
+                        # Update category label visibility and expanded/collapsed state
+                        # ────────────────────────────────────────────────────────────
+
+                        if ($categoryHasMatch) {
+                            # Show category label
+                            if ($null -ne $categoryLabel) {
+                                $categoryLabel.Visibility = [Windows.Visibility]::Visible
+
+                                # Update category label to expanded state (change "+" to "-")
+                                $labelContent = $categoryLabel.Content
+                                if ($null -ne $labelContent) {
+                                    $labelStr = [string]$labelContent
+
+                                    # Safe string replacement without -replace regex
+                                    if ($labelStr.StartsWith("+ ")) {
+                                        $expandedLabel = "- " + $labelStr.Substring(2)
+                                        $categoryLabel.Content = $expandedLabel
+                                    }
+                                }
+                            }
+                        }
                     }
                 }
 
-            # Set the visibility based on if any item matched
+                # ────────────────────────────────────────────────────────────────
-            $categoryBorder.Visibility = if ($categoryVisible) { [Windows.Visibility]::Visible } else { [Windows.Visibility]::Collapsed }
+                # Set category border visibility based on whether it has matches
+                # ────────────────────────────────────────────────────────────────
 
+                if ($categoryHasMatch) {
+                    $categoryBorder.Visibility = [Windows.Visibility]::Visible
                 }
+                else {
+                    $categoryBorder.Visibility = [Windows.Visibility]::Collapsed
+                }
+            }
+        }
+    }
+    catch {
+        # Silent catch - UI elements may be disposed or in unexpected state
+        # Do not log to terminal as this function is called on every keystroke
     }
 }