Fix #8057: Add Download Delegate to handle PassKit blobs (#8588)

Sources/Brave/Frontend/Browser/BrowserViewController.swift

@@ -192,6 +192,8 @@ public class BrowserViewController: UIViewController {
   var downloadToast: DownloadToast?  // A toast that is showing the combined download progress
   var addToPlayListActivityItem: (enabled: Bool, item: PlaylistInfo?)?  // A boolean to determine If AddToListActivity should be added
   var openInPlaylistActivityItem: (enabled: Bool, item: PlaylistInfo?)?  // A boolean to determine if OpenInPlaylistActivity should be shown
+  var shouldDownloadNavigationResponse: Bool = false
+  var pendingDownloads = [WKDownload: PendingDownload]()
 
   var navigationToolbar: ToolbarProtocol {
     return toolbar ?? topToolbar

Sources/Brave/Frontend/Browser/BrowserViewController/BrowserViewController+WKDownloadDelegate.swift

@@ -0,0 +1,71 @@
+// Copyright 2021 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import Foundation
+import WebKit
+import PassKit
+import Shared
+
+extension BrowserViewController: WKDownloadDelegate {
+
+  struct PendingDownload: Hashable, Equatable {
+    let fileURL: URL
+    let response: URLResponse
+    let suggestedFileName: String
+  }
+
+  public func download(_ download: WKDownload, decideDestinationUsing response: URLResponse, suggestedFilename: String) async -> URL? {
+    let temporaryDir = NSTemporaryDirectory()
+    let fileName = temporaryDir + "/" + suggestedFilename
+    let url = URL(fileURLWithPath: fileName)
+    pendingDownloads[download] = PendingDownload(fileURL: url, response: response, suggestedFileName: suggestedFilename)
+    return url
+  }
+
+  public func download(_ download: WKDownload, decidedPolicyForHTTPRedirection response: HTTPURLResponse, newRequest request: URLRequest) async -> WKDownload.RedirectPolicy {
+    return .allow
+  }
+
+  public func download(_ download: WKDownload, respondTo challenge: URLAuthenticationChallenge) async -> (URLSession.AuthChallengeDisposition, URLCredential?) {
+    return (.performDefaultHandling, nil)
+  }
+
+  @MainActor
+  public func downloadDidFinish(_ download: WKDownload) {
+    guard let downloadInfo = pendingDownloads[download] else {
+      return
+    }
+
+    pendingDownloads.removeValue(forKey: download)
+
+    let response = URLResponse(url: downloadInfo.fileURL,
+                               mimeType: downloadInfo.response.mimeType,
+                               expectedContentLength: Int(downloadInfo.response.expectedContentLength),
+                               textEncodingName: downloadInfo.response.textEncodingName)
+
+    if let passbookHelper = OpenPassBookHelper(request: nil, response: response, canShowInWebView: false, forceDownload: false, browserViewController: self) {
+      passbookHelper.open()
+    }
+
+    Task {
+      try FileManager.default.removeItem(at: downloadInfo.fileURL)
+    }
+  }
+
+  @MainActor
+  public func download(_ download: WKDownload, didFailWithError error: Error, resumeData: Data?) {
+    // display an error
+    let alertController = UIAlertController(
+      title: Strings.unableToAddPassErrorTitle,
+      message: Strings.unableToAddPassErrorMessage,
+      preferredStyle: .alert)
+    alertController.addAction(
+      UIAlertAction(title: Strings.unableToAddPassErrorDismiss, style: .cancel) { (action) in
+        // Do nothing.
+      }
+    )
+    present(alertController, animated: true, completion: nil)
+  }
+}

Sources/Brave/Frontend/Browser/BrowserViewController/BrowserViewController+WKNavigationDelegate.swift

@@ -394,6 +394,10 @@ extension BrowserViewController: WKNavigationDelegate {
         self.tabManager.selectedTab?.blockAllAlerts = false
       }
 
+      if navigationAction.shouldPerformDownload {
+        self.shouldDownloadNavigationResponse = true
+      }
+
       return (.allow, preferences)
     }
 
@@ -493,6 +497,14 @@ extension BrowserViewController: WKNavigationDelegate {
     }
 
     // Check if this response should be handed off to Passbook.
+    if shouldDownloadNavigationResponse {
+      shouldDownloadNavigationResponse = false
+
+      if response.mimeType == MIMEType.passbook {
+        return .download
+      }
+    }
+
     if let passbookHelper = OpenPassBookHelper(request: request, response: response, canShowInWebView: canShowInWebView, forceDownload: forceDownload, browserViewController: self) {
       // Open our helper and cancel this response from the webview.
       passbookHelper.open()
@@ -529,11 +541,23 @@ extension BrowserViewController: WKNavigationDelegate {
 
       tab.mimeType = response.mimeType
     }
+
+    if canShowInWebView {
+      return .allow
+    }
 
     // If none of our helpers are responsible for handling this response,
     // just let the webview handle it as normal.
     return .allow
   }
+
+  public func webView(_ webView: WKWebView, navigationAction: WKNavigationAction, didBecome download: WKDownload) {
+    Logger.module.error("ERROR: Should Never download NavigationAction since we never return .download from decidePolicyForAction.")
+  }
+
+  public func webView(_ webView: WKWebView, navigationResponse: WKNavigationResponse, didBecome download: WKDownload) {
+    download.delegate = self
+  }
 
   nonisolated public func webView(_ webView: WKWebView, respondTo challenge: URLAuthenticationChallenge) async -> (URLSession.AuthChallengeDisposition, URLCredential?) {
 

Sources/Brave/Frontend/Browser/TabManagerNavDelegate.swift

@@ -105,6 +105,10 @@ class TabManagerNavDelegate: NSObject, WKNavigationDelegate {
           res = policy
         }
 
+        if policy == .download {
+          res = policy
+        }
+
         pref = preferences
       }
     }
@@ -127,6 +131,10 @@ class TabManagerNavDelegate: NSObject, WKNavigationDelegate {
         if policy == .cancel {
           res = policy
         }
+
+        if policy == .download {
+          res = policy
+        }
       }
     }
 
@@ -137,4 +145,24 @@ class TabManagerNavDelegate: NSObject, WKNavigationDelegate {
 
     return res
   }
+
+  @MainActor
+  public func webView(_ webView: WKWebView, navigationAction: WKNavigationAction, didBecome download: WKDownload) {
+    for delegate in delegates {
+      delegate.webView?(webView, navigationAction: navigationAction, didBecome: download)
+      if download.delegate != nil {
+        return
+      }
+    }
+  }
+
+  @MainActor
+  public func webView(_ webView: WKWebView, navigationResponse: WKNavigationResponse, didBecome download: WKDownload) {
+    for delegate in delegates {
+      delegate.webView?(webView, navigationResponse: navigationResponse, didBecome: download)
+      if download.delegate != nil {
+        return
+      }
+    }
+  }
 }