UIWebView to view self signed websites (No private api, not NSURLConnection) - is it possible?
Finally I got it!
What you can do is this:
Initiate your request using UIWebView
as normal. Then - in webView:shouldStartLoadWithRequest
- we reply NO, and instead start an NSURLConnection with the same request.
Using NSURLConnection
, you can communicate with a self-signed server, as we have the ability to control the authentication through the extra delegate methods which are not available to a UIWebView
. So using connection:didReceiveAuthenticationChallenge
we can authenticate against the self signed server.
Then, in connection:didReceiveData
, we cancel the NSURLConnection
request, and start the same request again using UIWebView
- which will work now, because we've already got through the server authentication :)
Here are the relevant code snippets below.
Note: Instance variables you will see are of the following type:
UIWebView *_web
NSURLConnection *_urlConnection
NSURLRequest *_request
(I use an instance var for _request
as in my case it's a POST with lots of login details, but you could change to use the request passed in as arguments to the methods if you needed.)
#pragma mark - Webview delegate
// Note: This method is particularly important. As the server is using a self signed certificate,
// we cannot use just UIWebView - as it doesn't allow for using self-certs. Instead, we stop the
// request in this method below, create an NSURLConnection (which can allow self-certs via the delegate methods
// which UIWebView does not have), authenticate using NSURLConnection, then use another UIWebView to complete
// the loading and viewing of the page. See connection:didReceiveAuthenticationChallenge to see how this works.
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType;
{
NSLog(@"Did start loading: %@ auth:%d", [[request URL] absoluteString], _authenticated);
if (!_authenticated) {
_authenticated = NO;
_urlConnection = [[NSURLConnection alloc] initWithRequest:_request delegate:self];
[_urlConnection start];
return NO;
}
return YES;
}
#pragma mark - NURLConnection delegate
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge;
{
NSLog(@"WebController Got auth challange via NSURLConnection");
if ([challenge previousFailureCount] == 0)
{
_authenticated = YES;
NSURLCredential *credential = [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust];
[challenge.sender useCredential:credential forAuthenticationChallenge:challenge];
} else
{
[[challenge sender] cancelAuthenticationChallenge:challenge];
}
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response;
{
NSLog(@"WebController received response via NSURLConnection");
// remake a webview call now that authentication has passed ok.
_authenticated = YES;
[_web loadRequest:_request];
// Cancel the URL connection otherwise we double up (webview + url connection, same url = no good!)
[_urlConnection cancel];
}
// We use this method is to accept an untrusted site which unfortunately we need to do, as our PVM servers are self signed.
- (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace
{
return [protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust];
}
I hope this helps others with the same issue I was having!
Stretch's answer appears to be a great workaround, but it uses deprecated APIs. So, I thought it might be worthy of an upgrade to the code.
For this code sample, I added the routines to the ViewController which contains my UIWebView. I made my UIViewController a UIWebViewDelegate and a NSURLConnectionDataDelegate. Then I added 2 data members: _Authenticated and _FailedRequest. With that, the code looks like this:
-(BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
BOOL result = _Authenticated;
if (!_Authenticated) {
_FailedRequest = request;
[[NSURLConnection alloc] initWithRequest:request delegate:self];
}
return result;
}
-(void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge {
if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) {
NSURL* baseURL = [_FailedRequest URL];
if ([challenge.protectionSpace.host isEqualToString:baseURL.host]) {
NSLog(@"trusting connection to host %@", challenge.protectionSpace.host);
[challenge.sender useCredential:[NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust] forAuthenticationChallenge:challenge];
} else
NSLog(@"Not trusting connection to host %@", challenge.protectionSpace.host);
}
[challenge.sender continueWithoutCredentialForAuthenticationChallenge:challenge];
}
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)pResponse {
_Authenticated = YES;
[connection cancel];
[_WebView loadRequest:_FailedRequest];
}
I set _Authenticated to NO when I load the view and don't reset it. This seems to allow the UIWebView to make multiple requests to the same site. I did not try switching sites and trying to come back. That may cause the need for resetting _Authenticated. Also, if you are switching sites, you should keep a dictionary (one entry for each host) for _Authenticated instead of a BOOL.
This is the Panacea!
BOOL _Authenticated;
NSURLRequest *_FailedRequest;
#pragma UIWebViewDelegate
-(BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
BOOL result = _Authenticated;
if (!_Authenticated) {
_FailedRequest = request;
NSURLConnection *urlConnection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
[urlConnection start];
}
return result;
}
#pragma NSURLConnectionDelegate
-(void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge {
if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) {
NSURL* baseURL = [NSURL URLWithString:@"your url"];
if ([challenge.protectionSpace.host isEqualToString:baseURL.host]) {
NSLog(@"trusting connection to host %@", challenge.protectionSpace.host);
[challenge.sender useCredential:[NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust] forAuthenticationChallenge:challenge];
} else
NSLog(@"Not trusting connection to host %@", challenge.protectionSpace.host);
}
[challenge.sender continueWithoutCredentialForAuthenticationChallenge:challenge];
}
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)pResponse {
_Authenticated = YES;
[connection cancel];
[self.webView loadRequest:_FailedRequest];
}
- (void)viewDidLoad{
[super viewDidLoad];
NSURL *url = [NSURL URLWithString:@"your url"];
NSURLRequest *requestURL = [NSURLRequest requestWithURL:url];
[self.webView loadRequest:requestURL];
// Do any additional setup after loading the view.
}