Swift - WebView HTTP Auth - Cleanest solution - ios

I have been trying to set up a web view wrapper app that will load the content of a website (still to be launched). Currently, the website is in development mode, and the only endpoints for the website are protected behind a http authentication.
I have been looking at this solution: Swift webview xcode post data
However, I do not want to make a POST request each time, but I'd rather want to authenticate against the website once and keep the connection.
What I'm looking is for a clean and stable solution, one that would allow me to be able to have control of edge cases such as bad credentials provided.
I am not comfortable with using the NSURLConnection because that solution is deprecated in iOS9. I need a solution with NSURLSession.
Let me know if I'm missing something within the above linked solution. I am sure someone had this issue as well. Additionally, the website has SSL protection.
Kind regards

I'm not entirely sure this fulfils your demands in the best way, but if you can use a WKWebView, maybe you can simply rely on the authentication challenge delegate method? See my answer here as well, the relevant code snippet would be:
func webView(webView: WKWebView, didReceiveAuthenticationChallenge
challenge: NSURLAuthenticationChallenge,
completionHandler: (NSURLSessionAuthChallengeDisposition, NSURLCredential?) -> Void) {
let creds = NSURLCredential(user:"username", password:"password", persistence: NSURLCredentialPersistence.ForSession)
completionHandler(NSURLSessionAuthChallengeDisposition.UseCredential, creds)
}
I haven't tried it yet myself, but the documentation says the credentials should be used for the session, so additional requests resulting from links should work. Even if not, that just results for the method to be called again and you can provide the credentials once more.
This is just a rump, you'd have to get name and password from an alert or the like (also you can store the credentials more elegantly to make subsequent calls to the delegate method more elegant).
You also wrote you're using SSL, so I take it you're familiar with the App Transport Security flags (since the question title just has "HTTP" in it and not "HTTPS", which you probably want for it to work smoothly, otherwise see the question I linked).

Okay here is the Swift 3 code.
extension MyController: WKNavigationDelegate {
func webView(_ webView: WKWebView, didReceive challenge: URLAuthenticationChallenge, completionHandler: #escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
guard let u = self.webuser, let p = self.webp else {
completionHandler(.cancelAuthenticationChallenge, nil)
return
}
let creds = URLCredential.init(user: u, password: p, persistence: .forSession)
completionHandler(.useCredential, creds)
}
}

You shouldn't need to use POST or a connection or session. You should just create a mutable URL request and set an auth header. Then ask the web view to load the request.
Auth header details from Wikipedia:
The username and password are combined with a single colon.
The resulting string is encoded using the RFC2045-MIME variant of Base64, except not limited to 76 char/line.
The authorization method and a space i.e. "Basic " is then put before the encoded string.
For example, if the user agent uses Aladdin as the username and OpenSesame as the password then the field is formed as follows:
Authorization: Basic QWxhZGRpbjpPcGVuU2VzYW1l

Related

How do you handle Apple Sign In with WKWebView for platform less than iOS 13?

I'm working on an app that must support Apple Sign In with iOS 10.0+. For the latest iOS I can use AuthenticationServices native library. That's fine, however, for iOS 10-12 we would like to use WKWebView to handle the authentication embedded in app to get the token and email (when possible) after the auth is complete.
I'm following their official guide from apple:
https://developer.apple.com/documentation/sign_in_with_apple/sign_in_with_apple_js/incorporating_sign_in_with_apple_into_other_platforms
The problem now is that when I configure the redirect_uri, how do I get token back from the WKWebView after auth completes successfully? I have "tried" to intercept the response and get the token via the WKWebKit's WKNavigationDelegate navigationResponse response body but to no avail. I'm missing a key information.
public func webView(_ webView: WKWebView,
decidePolicyFor navigationAction: WKNavigationAction,
decisionHandler: #escaping (WKNavigationActionPolicy) -> Void) {
decisionHandler(.allow)
}
private func signInUsingWebAuthenticationSession() {
let queryItems = [
URLQueryItem(name: "client_id", value: "com.devapp.app"),
URLQueryItem(name: "redirect_uri", value: "https://dev.devapp.com/redirect"),
URLQueryItem(name: "response_type", value: "code id_token"), // Or code
URLQueryItem(name: "scope", value: "name email"), // Retrieve name and email
URLQueryItem(name: "response_mode", value: "form_post")
]
var urlComps = URLComponents(string: "https://appleid.apple.com/auth/authorize")!
urlComps.queryItems = queryItems
guard let authURL = urlComps.url else {
return
}
/// ... Load this url in WKWebView
}
I hope there are some smart developers out there who has encountered/solved this issue before and are happy to share their knowledge.
Cheers!
P.S If there are other solution that would work, feel free to comment
Your app will not be approved if you support iOS versions less than 13. If you are required to implement sign in with Apple ID you have to their JS solution as you have already guessed for older versions. I am too still trying to find out how
I've now completed the Apple SignIn support for iOS9 - iOS12 and would like to post the solution if other devs needed help with this. It turns out the answer is in the documentation already (link below), but some words just needs a little more explanation.
https://developer.apple.com/documentation/sign_in_with_apple/sign_in_with_apple_js/incorporating_sign_in_with_apple_into_other_platforms
Solution:
Firstly, the 'redirect_uri' you send to Apple Auth REST API cannot be a custom scheme as only http/https is supported. To redirect auth data (incl id_token data) to your app, you need to have access to your own server, parse the response (or other logic) and perform the redirect yourself AFTER the API returns to the 'redirect_uri' you specified above. How you send the auth data to your app securely is up to you. Options are custom scheme, or redirected URL (with auth data "attached") from your server and parse the id_token out of it. I've used WKWebView and WKNavigationDelegate's decidePolicyFor delegate to capture the url info.
Once the auth data is captured in your app, you can dismiss the WKWebView. The Auth Data contains JWT. If you need the user data and email (if you requested it in the scope) etc you need to decode the JWT and look at the 'sub' and 'email'. I used JWTDecode library for decoding https://github.com/auth0/JWTDecode.swift
For iOS13+ just use the built in AuthenticationServices's ASAuthorizationController.
Cheers!

SFAuthenticationSession completion handler not called

I am trying to implement an approach to exchange cookies from Safari and App. I am using SFAuthenticationSession since the cookies sharing was disabled. I read through the topic and it seems this is the best solution to achieve this. There are not too many blogs or repos to use as an example.
I have implemented the changes redirect in the server side as following.
First I store the cookie as https://example.com/?cookie=12345. Then from the app I start an Authentication Session pointing to https://example.com/getcookie which redirects to customapp://dummy/cookies?cookie=12345
Once stated this. The swift implementation is the following (thanks to this):
let callbackUrl = "customapp://dummy/cookies"
let authURL = "https://example.com/getcookie"
self.authSession = SFAuthenticationSession(url: URL(string: authURL)!, callbackURLScheme: callbackUrl, completionHandler: { (callBack:URL?, error:Error? ) in
guard error == nil, let successURL = callBack else {
return
}
let cookie = self.parseQuery(url: (successURL.absoluteString), param: "cookie")
print(cookie!)
})
self.authSession?.start()
You may notice I am not interested on signing in but getting a cookie stored previously.
Can anyone please advice? My problem is that although the site is redirecting, the completion handler is not called, so I can't parse the callback url.
UPDATE
I found out I was missing the protocol in the Info.plist. After adding the custom protocol to it, the handler was called. Nevertheless, the handler was only called the second time I engaged the Authentication Session.
Any clue?

WKWebView, get all cookies

I want obtain all cookies from WKWebView. Why? I have been started a project that use web-based auth. As result, I should intercept cookies to be sure that user is logged in and for some other purposes. Another case - imagine if user logged in, and than he "kill" the app - due to some delay in storing this cookie session will be lost :(.
The problem seems to be that the cookies are cached and not saved out
to a file immediately.
(#Kemenaran from here - p.5 below)
The point where I try to catch them -
webView:decidePolicyForNavigationResponse:decisionHandler:,
func webView(webView: WKWebView, decidePolicyForNavigationResponse navigationResponse: WKNavigationResponse, decisionHandler: (WKNavigationResponsePolicy) -> Void) {
if let httpResponse = navigationResponse.response as? NSHTTPURLResponse {
if let headers = httpResponse.allHeaderFields as? [String: String], url = httpResponse.URL {
let cookies = NSHTTPCookie.cookiesWithResponseHeaderFields(headers, forURL: url {
for cookie in cookies {
NSHTTPCookieStorage.shared.set(cookie)
}
}
}
}
but not all request are navigation, so one cookie (in my case) is skipped, see details below
Few words about other option I tried...
Yes, i Know that starting from iOS 11, we can use WKHTTPCookieStore as mention here. But my project should support iOS 9+
I for 100% sure, that after 5-10 sec from login, required cookie will be saved to NSHttpCookieStorage (at least all my tests during few days confirm that)
I try to use provided observer NSHTTPCookieManagerCookiesChangedNotification, but it provide me callback only for cookies that comes within webView:decidePolicyForNavigationResponse:decisionHandler
I also try to get cookies using some JS like mentioned here and also test all suggestion from here - really great article by the way. Result - negative
I also found this radar bug, and this SO question, and Sample project, but I want to prevent even this case. (described in this post applicable not only for remove but and for save) Also this situation true and when user kill the app, so case when user login, kill app and relaunch, may be present. And preventing this (simply by checking NSHttpCookieStorage for required cookies are also not good idea, because exactly after login required cookie can be stored with some delay, so this approach requires some bool-powered solution, that looks like weird..
I also read few more SO post for some related problem, and the most usefull are
This one
Another one
One more
But still without good solution...
So, is any way exist to obtain or at least force to immediately store cookies?
I ended with simple "force-like" saving Cookie from webpage.
To get all cookie i use
stringByEvaluatingJavaScriptFromString
with JS string like document.cookie();. As result i able to receive all cookies as a string with ; separator. All i need to do - parse string, create cookie and set it to NSHttpSharedStorage

Intercept request with WKWebView

Now i'm using UIWebView and with canInitWithRequest: of NSURLProtocol i can intercept all requests and do with it what I want.
In the new WKWebView this method there isn't, and i not found something similar.
Has someone resolved this problem?
I see that after 5 years this question still generates curiosity, so I describe how I solved it and about some main problems I faced up.
As many who answered here, I have implemented WKURLSchemeHandler and used new schemes.
First of all the URL that wkwebview launches must not be HTTP (or HTTPS) but one of yours new schemes.
Example
mynewscheme://your-server-application.com
In you WKWebViewConfiguration conf, I set the handler:
[conf setURLSchemeHandler:[CustomSchemeHandler new] forURLScheme:#"mynewscheme"];
[conf setURLSchemeHandler:[CustomSchemeHandler new] forURLScheme:#"mynewschemesecure"];
In CustomSchemeHandler I have implemented webView:startURLSchemeTask: and webView:stopURLSchemeTask:.
In my case I check if the request is for a file that I just saved locally, otherwise I change actual protocol ("mynewscheme or "mynewschemesecure") with http (or https) and I make request by myself.
At this point I solved the "interception problem".
In this new way we have the webview "location" (location.href via javascript) with my new scheme and with it new problems started.
First problem is that my applications work mainly with javascript,
and document.cookie has stopped working. I'm using Cordova
framework, so I've develeped a plugin to set and get cookie to
replace document.cookie (I had to do this, because, obviously, I
have also http header set-cookie).
Second problem is that I've got a lot of "cross-origin" problems, then
I changed all my urls in relative url (or with new schemes)
Third problem is that browser automatically handle server port 80
and 443, omitting them, but has now stopped (maybe because of "not
http location"). In my server code I had to handle this.
Writing down these few rows I admit that it seems to was an easy problem to solve, but I ensure that find out a workaround, how to solve it and integrate with the infinite amount of code has been hard. Every step towards the solution corresponded to a new problem.
You can intercept requests on WKWebView since iOS 8.0 by implementing the decidePolicyFor: navigationAction: method for the WKNavigationDelegate
func webView(_ webView: WKWebView, decidePolicyFor
navigationAction: WKNavigationAction,
decisionHandler: #escaping (WKNavigationActionPolicy) -> Swift.Void) {
//link to intercept www.example.com
// navigation types: linkActivated, formSubmitted,
// backForward, reload, formResubmitted, other
if navigationAction.navigationType == .linkActivated {
if navigationAction.request.url!.absoluteString == "http://www.example.com" {
//do stuff
//this tells the webview to cancel the request
decisionHandler(.cancel)
return
}
}
//this tells the webview to allow the request
decisionHandler(.allow)
}
there are many ways to implement intercepter request.
setup a local proxy, use WKNavigationDelegate
-[ViewController webView:decidePolicyForNavigationAction:decisionHandler:]
load new request and forward to local server, and at the local server side you can do something(eg. cache).
private api. use WKBrowsingContextController and custom URLProtocol
Class cls = NSClassFromString(#"WKBrowsingContextController");
SEL sel = NSSelectorFromString(#"registerSchemeForCustomProtocol:");
if ([(id)cls respondsToSelector:sel]) {
// 把 http 和 https 请求交给 NSURLProtocol 处理
[(id)cls performSelector:sel withObject:#"http"];
[(id)cls performSelector:sel withObject:#"https"];
}
use KVO to get system http/https handler.(ios 11, *)
WKWebViewConfiguration *configuration = [[WKWebViewConfiguration alloc] init];
URLSchemeHandler *schemeHandler = [[URLSchemeHandler alloc] init];
[configuration setURLSchemeHandler:schemeHandler forURLScheme:#"test"];
NSMutableDictionary *handlers = [configuration valueForKey:#"_urlSchemeHandlers"];
handlers[#"http"] = schemeHandler;
handlers[#"https"] = schemeHandler;
all the three ways you probably need handle CORS & post bodies to be stripped,you overwrite change browser`s option request(
Preflighted_requests),you can custom http header to replace http body for post bodies to be stripped.
in iOS 11 WKWebView has come up with Custom Scheme Handler called WKURLSchemeHandler, which you can use to intercept the custom events.
for more info check out this project.
https://github.com/BKRApps/KRWebView
I know I am late but I am able to solve this problem. I can intercept each and every request even your http/https call using below trick. I can also trace the call made from html to server calls. I can also use this to render html with offline content.
Download the html of the website that we want to render in offline or online to intercept the request.
Either place the html in document directory of the user or place it inside the archive. But we should know the path of the html file.
Place all your js, cs, woff, font of our website at the same level as our base html. We need to given permission while loading the web view.
Then we have to register our own custom handler scheme with WKWebView. When wkwebview see the pattern "myhandler-webview" then it will give you control and you will get the callback to 'func webView(_ webView: WKWebView, start urlSchemeTask: WKURLSchemeTask)' delegate implementation. You can play around with url in this delegate like mentioned in point 6.
let configuration = WKWebViewConfiguration();
configuration.setURLSchemeHandler(self, forURLScheme: "myhandler-webview");
webView = WKWebView(frame: view.bounds, configuration: configuration);
Convert file scheme to the custom scheme (myhandler-webview) then load it with WKWebView
let htmlPath = Bundle.main.path(forResource: "index", ofType: "html")
var htmlURL = URL(fileURLWithPath: htmlPath!, isDirectory: false)
htmlURL = self.changeURLScheme(newScheme: "myhandler-webview", forURL: htmlURL)
self.webView.load(URLRequest(url: htmlURL))
Implement below methods of WKURLSchemeHandler protocol and handle didReceiveResponse, didReceiveData, didFinish delegate methods of WKURLSchemeTask.
func webView(_ webView: WKWebView, start urlSchemeTask: WKURLSchemeTask) {
print("Function: \(#function), line: \(#line)")
print("==> \(urlSchemeTask.request.url?.absoluteString ?? "")\n")
// You can find the url pattern by using urlSchemeTask.request.url. and create NSData from your local resource and send the data using 3 delegate method like done below.
// You can also call server api from this native code and return the data to the task.
// You can also cache the data coming from server and use it during offline access of this html.
// When you are returning html the the mime type should be 'text/html'. When you are trying to return Json data then we should change the mime type to 'application/json'.
// For returning json data you need to return NSHTTPURLResponse which has base classs of NSURLResponse with status code 200.
// Handle WKURLSchemeTask delegate methods
let url = changeURLScheme(newScheme: "file", forURL: urlSchemeTask.request.url!)
do {
let data = try Data(contentsOf: url)
urlSchemeTask.didReceive(URLResponse(url: urlSchemeTask.request.url!, mimeType: "text/html", expectedContentLength: data.count, textEncodingName: nil))
urlSchemeTask.didReceive(data)
urlSchemeTask.didFinish()
} catch {
print("Unexpected error when get data from URL: \(url)")
}
}
func webView(_ webView: WKWebView, stop urlSchemeTask: WKURLSchemeTask) {
print("Function: \(#function), line: \(#line)")
print("==> \(urlSchemeTask.request.url?.absoluteString ?? "")\n")
}
Let me know if this explanation is not enough.
Objective c example mentioned below
intercepting request with wkwebview
One can use WKURLSchemeHandler to intercept each and every request to be loaded in WKWebView,
Only disadvantage is that you cannot register http or https scheme for interception,
Solution over that is,
Replace your http/https scheme of url with custom scheme url like xyz://
for e.g. https://google.com can be loaded like xyz://google.com
Now you will get a callback in WKURLSchemeHandler there you again replace it back to https and load data programmatically and call urlSchemeTask.didReceive(response)
This way each and every https request will come to your handler.
I am blindly taking guesses since I only have my windows computer with me. By reading the Apple Developer documentation here is information I gathered that might lead to some ideas on how to solve the question.
Based on WKWebView,
Set the delegate property to an object conforming to the WKUIDelegate protocol to track the loading of web content.
Also, I see we can set our navigationDelegate with the,
weak var navigationDelegate: WKNavigationDelegate? { get set }
The methods of the WKNavigationDelegate protocol help you implement custom behaviors that are triggered during a web view's process of accepting, loading, and completing a navigation request.
Then after we create and set our custom WKNavigationDelegate, we would override some methods to intercept something we might be looking for. I found the Responding to Server Actions section of some interest since they receive a WKNavigation as parameter. Moreover, you might want to skim through WKNavigationAction and WKNavigationResponse see if there is perhaps something which might help us achieve our goal.
BTW, I am just giving some ideas on what to try so that we can solve this question, ideas which might be 100% wrong cause I have not tried them myself.

Authenticating a user with Instagram on iOS: specifying redirect_uri

I am developing an iOS app (using Swift) that allows the user to authenticate through Instagram using OAuth 2.0
In the past, everything was working fine as I was able to specify the authorization URL as such:
https://api.instagram.com/oauth/authorize/?client_id=xxx&redirect_uri=myiosapp://authorize&response_type=code
The key point here being the redirect_uri myiosapp://authorize
My problem is that I am no longer able to register a custom url scheme with Instagram thereby making it impossible(?) to handle the redirect exclusively through my app. If I do try to add such a URI in the "Valid redirect URIs:" field, I get the following error:
You must enter an absolute URI that starts with http:// or https://
What is the recommended way to handle authentication with Instagram exclusively thrugh an iOS native application?
After figuring it out, I thought I'd post my solution for anyone who comes across the same problem.
First of all, I'll just accept that Instagram no longer allows custom schemas in the "Security" -> "Valid redirect URIs" field. Instead, I will enter an arbitrary but valid URI that I can uniquely identify. For example: http://www.mywebsite.com/instagram_auth_ios
Now, when attempting to authorize with Instagram, I'll use that as the redirect URI - even though no webpage actually exists at that URI.
Example: https://api.instagram.com/oauth/authorize/?client_id=xxx&redirect_uri=http://www.mywebsite.com/instagram_auth_ios&response_type=code
Finally, I'll use the UIWebViewDelegate's shouldStartLoadWithRequest method to intercept the redirect request before it runs, and instead call my original custom uri (that way I don't have to rewrite anything). Here's how I wrote that method:
func webView(webView: UIWebView, shouldStartLoadWithRequest request: NSURLRequest, navigationType: UIWebViewNavigationType) -> Bool {
guard let url = request.URL where url.host == "www.mywebsite.com" && url.path == "/instagram_auth_ios" else { return true }
guard let authUrl = NSURLComponents(URL: url, resolvingAgainstBaseURL: false) else { return true }
// Customize the scheme/host/path, etc. as desired for your app
authUrl.scheme = "myappschema"
authUrl.host = "instagram"
authUrl.path = ""
UIApplication.sharedApplication().openURL(authUrl.URL!)
return false
}
There's one small caveat with returning false in the shouldStartLoadWithRequest method in that it will always complain with a "Frame Load Interrupted" error. This doesn't seem to adversely affect anything and can (probably) be safely ignored.

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