两者的答案都是“是”。
我是一名 Java 人员，所以两周前被问到：
- 学习 Objective-C
- 编写一个原生 iPhone 应用程序
- 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，促使我分享我的经验。
以下是概述，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：
- 使用 Cocoa 中的 URL API 提交对相关资源的 HTTP 请求。
- 为请求实现委托类：
- 响应 SP 重定向至 IdP（Cocoa 自动提供）
- 响应服务器证书信任挑战
- 响应用户凭据挑战
- 响应错误（如果需要）
- 接收经过身份验证的用户的 IdP“绑定模板”，这是一个 HTML 表单，可使用两个参数将用户重定向回 SP
- 以编程方式将两个参数从 IdP HTTP POST 回 SP。
- Cookie 会自动存储并再次由 Cocoa 提供转发
- 实现第二个 URL 请求委托来接收原始请求数据。
以下是 Apple 和 Shibboleth 的一些有用参考：
- 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
