iphone - 将 iPhone 应用程序与 Shibboleth 集成

Question

有人将 iPhone 应用程序与 Shibboleth 身份提供商集成吗？谷歌搜索没有找到任何结果，所以我直接询问专家。

如果以前没有这样做过，这样做是否可行？

Answer 1

两者的答案都是"is"。

我是一名 Java 人员，因此两周前被要求:

• 学习 Objective-C
• 编写原生 iPhone 应用
• 使用 Shibboleth 以编程方式进行身份验证
• 下载受 Shibboleth 保护的显示数据文件

...有点令人畏惧。更糟糕的是，由于没有任何论坛帖子可以提供帮助，这促使我分享我的经验。

这里是一个概述，后面是一些希望非常有用的示例代码。如果有帮助的话请为我的回答投票!这值得我花几周的时间:)

对于 iPhone 上的应用程序来说，要下载 Shibbolized 资源，需要执行以下操作:

1. 使用 Cocoa 中的 URL API 提交对相关资源的 HTTP 请求。
2. 为请求实现委托(delegate)类:
3. 响应 SP 重定向至 IdP(由 Cocoa 自动提供)
4. 响应服务器证书信任质疑
5. 响应用户凭据挑战
6. 响应错误(如果需要)
7. 接收经过身份验证的用户的 IdP“绑定(bind)模板”，这是一个 HTML 表单，可使用两个参数将用户重定向回 SP
8. 以编程方式将两个参数从 IdP 发送回 SP。
9. Cookie 会自动存储并再次由 Cocoa 提供转发
10. 实现第二个 URL 请求委托(delegate)来接收原始请求数据。

以下是 Apple 和 Shibboleth 的一些有用引用:

• http://developer.apple.com/mac/library/DOCUMENTATION/Cocoa/Conceptual/URLLoadingSystem/URLLoadingSystem.html
• https://spaces.internet2.edu/display/SHIB2/IdPSPLocalTestInstall

希望我可以包含所有源代码以进行快速演示。

ApplicationDelegate.h
----------
#import <UIKit/UIKit.h>
#import "ConsoleViewController.h"

/*
 The application delegate will hold references to the application's UIWindow and a ConsoleViewController.
 The console does all of the interesting Shibboleth activities.
*/
@interface ApplicationDelegate : NSObject <UIApplicationDelegate> {

 UIWindow *window;
 ConsoleViewController *consoleViewController;
}


@end

ApplicationDelegate.m
----------
#import "ApplicationDelegate.h"
#import "ConsoleViewController.h"

/*
 The implementation for the ApplicationDelegate initializes the console view controller and assembles everything.
 The console does all of the interesting Shibboleth activities.
 */
@implementation ApplicationDelegate


- (void)applicationDidFinishLaunching:(UIApplication *)application {    

 // Initialize the console.
 consoleViewController = [[ConsoleViewController alloc] init];

 window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
 [window setBackgroundColor:[UIColor lightGrayColor]];
 [window addSubview:[consoleViewController view]];

 [window makeKeyAndVisible];
}


- (void)dealloc {
    [window release];
 [ConsoleViewController release];
    [super dealloc];
}


@end

ConsoleController.h
----------
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

/*
 The ConsoleViewController's interface declares references to the network data used in negotiating with Shibboleth
 and a UITextView used to display the final result or errors.
 */
@interface ConsoleViewController : UIViewController {

 NSMutableData *responseData;
 NSString *responseString;
 UITextView *console;
}

@end

ConsoleController.m
----------
#import "ApplicationDelegate.h"
#import "ConsoleViewController.h"


/*
 This delegate is used when making the second HTTP request with Shibboleth.  If you're just getting here, start
 by reading the comments for ConsoleViewController below.

 All we need to do now is receive the response from the SP and display it.
 If all goes well, this should be the secured page originally requested.
 */
@interface AuthenticationRedirectDelegate : NSObject {

 NSMutableData *authResponseData;
 NSString *authResponseString;
 UITextView *console;
}

@property (nonatomic retain) UITextView *console;

@end


/*
 Refer to the comments for the interface above.
 */
@implementation AuthenticationRedirectDelegate

@synthesize console;

-(id)init {
 authResponseData = [[NSMutableData alloc] retain];
 return self;
}


- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
 [authResponseData setLength:0];
}


- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
 [authResponseData appendData:data];
}


- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
 [console setText:[error localizedDescription]]; 
}


/*
 Once the data is received from Shibboleth's SP, display it.
 */
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {  

 authResponseString = [[NSString alloc] initWithData:authResponseData encoding:NSUTF8StringEncoding]; 
 [console setText:authResponseString]; 
 [connection release];
}


@end


/*
 The implementation of the ConsoleViewController, and AuthenticationRedirectDelegate above, contain the real logic of
 this Shibboleth exercise.  The ConsoleViewController performs the following:
 1. Prepare the initial HTTP request to a Shibboleth protected resource.
 2. Act as the delegate whilst Cocoa's URL Loading API receives the HTTP Response.
 NOTE: We instruct Cocoa in advance to take care of the SP redirecting to the IdP, accepting the server certificate,
 and submitting the user credentials
 3. Once the HTTP Response is finished loading, parse the <form action, RelayState and SAMLResponse from the IdP's
 response
 4. Call a utility method to prepare a second HTTP POST Request to the <form action/SP with the IdP's parameters
 NOTE: We do not need to transfer over any of Shibboleth's cookies, since Cocoa is doing this automatically
 5. Use a new instance of AuthenticationRedirectDelegate to receive the POST's response, which should be the secured
 page originally requested.
 6. Display the final content in the UITextView known as console.
 */
@implementation ConsoleViewController


/*
 A handy utility method for extracting a substring marked by two provided token strings.
 Used in parsing the HTML form returned by the IdP after the first HTTP Request.
 */
+(id)substringFromString:(NSString *)source BetweenOpenToken:(NSString *)openToken AndCloseToken:(NSString *)closeToken {

 NSUInteger l = [source length];
 NSUInteger openTokenLen = [openToken length];

 NSUInteger openTokenLoc = ([source rangeOfString:openToken]).location;
 NSUInteger valueLoc = openTokenLoc + openTokenLen;
 NSRange searchRange = NSMakeRange(valueLoc, l - valueLoc);
 NSUInteger closeTokenLoc = ([source rangeOfString:closeToken options:NSCaseInsensitiveSearch range:searchRange]).location;
 searchRange = NSMakeRange(valueLoc, closeTokenLoc - valueLoc);
 NSString *result = [source substringWithRange:searchRange];

 return result;
}


/*
 This function takes the three properties returned by the IdP after the first HTTP request and 
 HTTP POSTs them to the SP as specified by the IdP in the "url" parameter.
 */
-(void)authReturnTo:(NSURL *)url WithRelay:(NSString *)relayState AndSAML:(NSString *)samlResponse {

 // Here we assemble the HTTP POST body as usual.
 NSString *preBody = [[NSString alloc] initWithString:@"RelayState="];
 preBody = [preBody stringByAppendingString:relayState];
 preBody = [preBody stringByAppendingString:@"&"];
 preBody = [preBody stringByAppendingString:@"SAMLResponse="];
 preBody = [preBody stringByAppendingString:samlResponse];

 /* The SAMLResponse parameter contains characters (+) that the SP expects to be URL encoded.
  Here we simply manually URL encode those characters.  You may wish to harden this with proper
  URL encoding for production use.
  */
 NSString *httpBody = [preBody stringByReplacingOccurrencesOfString:@"+" withString:@"%2B"];
 NSData *httpBodyData = [httpBody dataUsingEncoding:NSUTF8StringEncoding];

 NSString *httpContentLength = [NSString stringWithFormat:@"%d", [httpBodyData length]];

 NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url
              cachePolicy:NSURLRequestReloadIgnoringCacheData
              timeoutInterval:12.0];
 [request setHTTPMethod:@"POST"];
 [request setValue:httpContentLength forHTTPHeaderField:@"Content-Length"];
 [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];

 [request setHTTPBody:httpBodyData];

 // Submit the HTTP POST using the second delegate class to receive the response
 AuthenticationRedirectDelegate *delegate = [[AuthenticationRedirectDelegate alloc] init];
 delegate.console=console;
 [[NSURLConnection alloc] initWithRequest:request delegate:delegate];
}


/*
 When this UIViewController finishes loading, automatically prepare and send a request to the Shibboleth SP Web Server
 for a secured resource.
 */
- (void)viewDidLoad {
 [super viewDidLoad];

 console = [[UITextView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
 [[self view] addSubview:console];

 responseData = [[NSMutableData data] retain];

 // TODO: Enter your own URL for a Shibboleth secured resource.
 NSURL *url = [NSURL URLWithString:@"<URL>"];

 NSURLRequest *request = [NSURLRequest requestWithURL:url
       cachePolicy:NSURLRequestUseProtocolCachePolicy
       timeoutInterval:12.0];

 [[NSURLConnection alloc] initWithRequest:request delegate:self];

 /* Control flows to the delegate methods below */
}


/*
 Refer to Apple's docs on the URL Loading System for details.
 http://developer.apple.com/mac/library/DOCUMENTATION/Cocoa/Conceptual/URLLoadingSystem/URLLoadingSystem.html
 */
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
  [responseData setLength:0];
}


/*
 Refer to Apple's docs on the URL Loading System for details.
 http://developer.apple.com/mac/library/DOCUMENTATION/Cocoa/Conceptual/URLLoadingSystem/URLLoadingSystem.html
 */
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
 [responseData appendData:data];
}

/*
 This implementation in the delegate let's Cocoa trust my SP Web Server's self-signed certificate.
 TODO: You will want to harden this for production use.

 Refer to Apple's docs on the URL Loading System for details.
 http://developer.apple.com/mac/library/DOCUMENTATION/Cocoa/Conceptual/URLLoadingSystem/URLLoadingSystem.html
 */
- (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace {
 return [protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust] || [protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodHTTPBasic];
}


/*
 This implementation for the delegate does two things:
 1. Respond to challenges for my server's self-signed certificate
 2. Respond to the IdP's challenge for the username and password.
 TODO: Enter your own username and password here.
 Refer to Apple's docs on the URL Loading System for details.
 http://developer.apple.com/mac/library/DOCUMENTATION/Cocoa/Conceptual/URLLoadingSystem/URLLoadingSystem.html
 */
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge {
 // TODO: Enter the correct username and password below.
 /*
  WARNING: Using an incorrect user name and password will result in your application being re-challenged
  by the IdP.  Cocoa will return to this function in a never-ending loop.  This can result in the message
  "NSPosixErrorDomain Too many open files".  You'll need to perform additional coding to handle this.
  */
 if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust])
  [challenge.sender useCredential:[NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust] forAuthenticationChallenge:challenge];
 else if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodHTTPBasic])
  [challenge.sender useCredential:[NSURLCredential credentialWithUser:@"<USERNAME>" password:@"<PASSWORD>" persistence:NSURLCredentialPersistenceNone] forAuthenticationChallenge:challenge];
 else
  [challenge.sender continueWithoutCredentialForAuthenticationChallenge:challenge];
}


/*
 You may wish to add more code here to log errors.

 Refer to Apple's docs on the URL Loading System for details.
 http://developer.apple.com/mac/library/DOCUMENTATION/Cocoa/Conceptual/URLLoadingSystem/URLLoadingSystem.html
 */
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
 [console setText:[error localizedDescription]];
}


/*
 Once Cocoa has received a (hopefully) authenticated response from the IdP, we parse out the relevant pieces and prepare to
 HTTP POST them back to the SP as specified by the IdP in the <form action attribute.

 Refer to Apple's docs on the URL Loading System for details.
 http://developer.apple.com/mac/library/DOCUMENTATION/Cocoa/Conceptual/URLLoadingSystem/URLLoadingSystem.html
 */
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {  
 [connection release];
 responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];

 if([responseString rangeOfString:@"SAMLResponse"].length < 1)
 {
  [console setText:[@"Unexpected response:\n]n" stringByAppendingString:responseString]];
  return;
 }

 NSString *relayState = [ConsoleViewController substringFromString:responseString BetweenOpenToken:@"RelayState\" value=\"" AndCloseToken:@"\"/>"];
 NSString *SAMLResponse = [ConsoleViewController substringFromString:responseString BetweenOpenToken:@"SAMLResponse\" value=\"" AndCloseToken:@"\"/>"];
 NSString *formAction = [ConsoleViewController substringFromString:responseString BetweenOpenToken:@"<form action=\"" AndCloseToken:@"\""];
 NSURL *formActionURL = [[NSURL alloc] initWithString:formAction];
 [self authReturnTo:formActionURL WithRelay:relayState AndSAML:SAMLResponse];
}


@end