iOS 中的 NSURLConnection 和基本 HTTP 身份验证

Question

我需要使用基本Authentication 调用初始GET HTTP request。这将是第一次将请求发送到服务器，并且我已经拥有 username & password，因此无需来自服务器的授权挑战。

第一个问题：

1. NSURLConnection 是否必须设置为同步才能进行基本身份验证？根据这个post的回答，如果你选择异步路由，似乎你不能做Basic Auth。

2. 任何人都知道任何一些示例代码来说明GET request 上的基本身份验证，而无需质询响应？ Apple's documentation 显示了一个示例，但仅在服务器向客户端发出质询请求之后。

我对 SDK 的网络部分有点陌生，我不确定我应该使用哪些其他类来使其正常工作。 （我看到了NSURLCredential 类，但它似乎只在客户端向服务器请求授权资源后与NSURLAuthenticationChallenge 一起使用）。

Answer 1

我正在使用与MGTwitterEngine 的异步连接，它在NSMutableURLRequest (theRequest) 中设置授权，如下所示：

NSString *authStr = [NSString stringWithFormat:@"%@:%@", [self username], [self password]];
NSData *authData = [authStr dataUsingEncoding:NSASCIIStringEncoding];
NSString *authValue = [NSString stringWithFormat:@"Basic %@", [authData base64EncodingWithLineLength:80]];
[theRequest setValue:authValue forHTTPHeaderField:@"Authorization"];

我不认为这种方法需要通过挑战循环，但我可能错了

Answer 2

即使问题得到了回答，我也想提出不需要外部库的解决方案，我在另一个线程中找到了：

// Setup NSURLConnection
NSURL *URL = [NSURL URLWithString:url];
NSURLRequest *request = [NSURLRequest requestWithURL:URL
                                         cachePolicy:NSURLRequestUseProtocolCachePolicy
                                     timeoutInterval:30.0];

NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
[connection start];
[connection release];

// NSURLConnection Delegates
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge {
    if ([challenge previousFailureCount] == 0) {
        NSLog(@"received authentication challenge");
        NSURLCredential *newCredential = [NSURLCredential credentialWithUser:@"USER"
                                                                    password:@"PASSWORD"
                                                                 persistence:NSURLCredentialPersistenceForSession];
        NSLog(@"credential created");
        [[challenge sender] useCredential:newCredential forAuthenticationChallenge:challenge];
        NSLog(@"responded to authentication challenge");    
    }
    else {
        NSLog(@"previous authentication failure");
    }
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    ...
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    ...
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    ...
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    ...
}

Answer 3

这是一个不涉及第三者的详细答案：

请看这里：

//username and password value
NSString *username = @“your_username”;
NSString *password = @“your_password”;

//HTTP Basic Authentication
NSString *authenticationString = [NSString stringWithFormat:@"%@:%@", username, password]];
NSData *authenticationData = [authenticationString dataUsingEncoding:NSASCIIStringEncoding];
NSString *authenticationValue = [authenticationData base64Encoding];

//Set up your request
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:@"http://www.your-api.com/“]];

// Set your user login credentials
[request setValue:[NSString stringWithFormat:@"Basic %@", authenticationValue] forHTTPHeaderField:@"Authorization"];

// Send your request asynchronously
[NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *responseCode, NSData *responseData, NSError *responseError) {
      if ([responseData length] > 0 && responseError == nil){
            //logic here
      }else if ([responseData length] == 0 && responseError == nil){
             NSLog(@"data error: %@", responseError);
             UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil message:@"Error accessing the data" delegate:nil cancelButtonTitle:@"Close" otherButtonTitles:nil];
             [alert show];
             [alert release];
      }else if (responseError != nil && responseError.code == NSURLErrorTimedOut){
             NSLog(@"data timeout: %@”, NSURLErrorTimedOut);
             UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil message:@"connection timeout" delegate:nil cancelButtonTitle:@"Close" otherButtonTitles:nil];
             [alert show];
             [alert release];
      }else if (responseError != nil){
             NSLog(@"data download error: %@”,responseError);
             UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil message:@"data download error" delegate:nil cancelButtonTitle:@"Close" otherButtonTitles:nil];
             [alert show];
             [alert release];
      }
}]

请让我知道您对此的反馈。

谢谢

Answer 4

如果您不想导入整个 MGTwitterEngine 并且不执行异步请求 然后你可以使用 http://www.chrisumbel.com/article/basic_authentication_iphone_cocoa_touch

对用户名和密码进行base64编码 所以替换

NSString *authValue = [NSString stringWithFormat:@"Basic %@", [authData base64EncodingWithLineLength:80]];

与

NSString *encodedLoginData = [Base64 encode:[loginString dataUsingEncoding:NSUTF8StringEncoding]];

之后

您需要包含以下文件

static char *alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

@implementation Base64
+(NSString *)encode:(NSData *)plainText {
    int encodedLength = (((([plainText length] % 3) + [plainText length]) / 3) * 4) + 1;
    unsigned char *outputBuffer = malloc(encodedLength);
    unsigned char *inputBuffer = (unsigned char *)[plainText bytes];

    NSInteger i;
    NSInteger j = 0;
    int remain;

    for(i = 0; i < [plainText length]; i += 3) {
        remain = [plainText length] - i;

        outputBuffer[j++] = alphabet[(inputBuffer[i] & 0xFC) >> 2];
        outputBuffer[j++] = alphabet[((inputBuffer[i] & 0x03) << 4) | 
                                     ((remain > 1) ? ((inputBuffer[i + 1] & 0xF0) >> 4): 0)];

        if(remain > 1)
            outputBuffer[j++] = alphabet[((inputBuffer[i + 1] & 0x0F) << 2)
                                         | ((remain > 2) ? ((inputBuffer[i + 2] & 0xC0) >> 6) : 0)];
        else 
            outputBuffer[j++] = '=';

        if(remain > 2)
            outputBuffer[j++] = alphabet[inputBuffer[i + 2] & 0x3F];
        else
            outputBuffer[j++] = '=';            
    }

    outputBuffer[j] = 0;

    NSString *result = [NSString stringWithCString:outputBuffer length:strlen(outputBuffer)];
    free(outputBuffer);

    return result;
}
@end

Answer 5

由于不推荐使用 NSData::dataUsingEncoding (ios 7.0)，您可以使用此解决方案：

// Forming string with credentials 'myusername:mypassword'
NSString *authStr = [NSString stringWithFormat:@"%@:%@", username, password];
// Getting data from it
NSData *authData = [authStr dataUsingEncoding:NSASCIIStringEncoding];
// Encoding data with base64 and converting back to NSString
NSString* authStrData = [[NSString alloc] initWithData:[authData base64EncodedDataWithOptions:NSDataBase64EncodingEndLineWithLineFeed] encoding:NSASCIIStringEncoding];
// Forming Basic Authorization string Header
NSString *authValue = [NSString stringWithFormat:@"Basic %@", authStrData];
// Assigning it to request
[request setValue:authValue forHTTPHeaderField:@"Authorization"];

Answer 6

如果您使用GTMHTTPFetcher 进行连接，则基本身份验证也相当简单。您只需在开始提取之前向提取器提供凭据即可。

NSString * urlString = @"http://www.testurl.com/";
NSURL * url = [NSURL URLWithString:urlString];
NSMutableURLRequest * request = [NSMutableURLRequest requestWithURL:url];

NSURLCredential * credential = [NSURLCredential credentialWithUser:@"username" password:@"password" persistence:NSURLCredentialPersistenceForSession];

GTMHTTPFetcher * gFetcher = [GTMHTTPFetcher fetcherWithRequest:request];
gFetcher.credential = credential;

[gFetcher beginFetchWithDelegate:self didFinishSelector:@selector(fetchCompleted:withData:andError:)];

Answer 7

您能告诉我在您的示例代码中将编码行长度限制为 80 的原因是什么？我认为 HTTP 标头的最大长度约为 4k（或者某些服务器可能不会花费比这更长的时间）。 – Justin Galzic 2009 年 12 月 29 日 17:29

不限于80，它是NSData+Base64.h/m中base64EncodingWithLineLength方法的一个选项，你可以将你的编码字符串分成多行，这对于其他应用程序很有用，例如nntp传输。我相信 twitter 引擎作者选择 80 的长度足以容纳大多数用户/密码编码结果到一行。

Answer 8

您可以使用AFNetworking（它是开源的），这是对我有用的代码。此代码发送带有基本身份验证的文件。只需更改网址、电子邮件和密码。

NSString *serverUrl = [NSString stringWithFormat:@"http://www.yoursite.com/uploadlink", profile.host];
NSMutableURLRequest *request = [[AFHTTPRequestSerializer serializer] requestWithMethod:@"POST" URLString:serverUrl parameters:nil error:nil];


NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
AFURLSessionManager *manager = [[AFURLSessionManager alloc] initWithSessionConfiguration:configuration];

// Forming string with credentials 'myusername:mypassword'
NSString *authStr = [NSString stringWithFormat:@"%@:%@", email, emailPassword];
// Getting data from it
NSData *authData = [authStr dataUsingEncoding:NSASCIIStringEncoding];
// Encoding data with base64 and converting back to NSString
NSString* authStrData = [[NSString alloc] initWithData:[authData base64EncodedDataWithOptions:NSDataBase64EncodingEndLineWithLineFeed] encoding:NSASCIIStringEncoding];
// Forming Basic Authorization string Header
NSString *authValue = [NSString stringWithFormat:@"Basic %@", authStrData];
// Assigning it to request
[request setValue:authValue forHTTPHeaderField:@"Authorization"];

manager.responseSerializer = [AFHTTPResponseSerializer serializer];

NSURL *filePath = [NSURL fileURLWithPath:[url path]];
NSURLSessionUploadTask *uploadTask = [manager uploadTaskWithRequest:request fromFile:filePath progress:^(NSProgress * _Nonnull uploadProgress) {
// This is not called back on the main queue.
// You are responsible for dispatching to the main queue for UI updates
     dispatch_async(dispatch_get_main_queue(), ^{
                //Update the progress view
                LLog(@"progres increase... %@ , fraction: %f", uploadProgress.debugDescription, uploadProgress.fractionCompleted);
            });
        } completionHandler:^(NSURLResponse *response, id responseObject, NSError *error) {
            if (error) {
                NSLog(@"Error: %@", error);
            } else {
                NSLog(@"Success: %@ %@", response, responseObject);
            }
        }];
[uploadTask resume];