6

从安全墙后面的安全 URL 下载图像。像https://foo.com/bar.png这样的 URL

有时我会收到 SSLHandshake 错误。有时错误发生一次，但有时错误是恒定的，我无法下载文件。

DownloadImageApp[2914] <Warning>: CHALLENGE!!! (NSURLAuthenticationMethodServerTrust)
DownloadImageApp[2914] <Warning>:    server = foo.com
DownloadImageApp[2914] <Warning>: CFNetwork SSLHandshake failed (-9810)
DownloadImageApp[2914] <Warning>: CHALLENGE!!! (NSURLAuthenticationMethodServerTrust)
DownloadImageApp[2914] <Warning>:    server = foo.com
DownloadImageApp[2914] <Warning>: CHALLENGE!!! (NSURLAuthenticationMethodNTLM)
DownloadImageApp[2914] <Warning>:    NSURLAuthenticationMethodNTLM

我使用以下代码来处理挑战

- (void)URLSession:(NSURLSession *)session didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition, NSURLCredential *))completionHandler {
    NSLog(@"CHALLENGE!!! (%@)", challenge.protectionSpace.authenticationMethod);

    if (challenge.error)
        NSLog(@"  -- error: %@", challenge.error.description);
    if (challenge.previousFailureCount > 0)
        NSLog(@"  -- previous failure count = %d", challenge.previousFailureCount);
    if (challenge.proposedCredential)
        NSLog(@"  -- proposed credential user: %@", challenge.proposedCredential.user);

    if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) {
        NSLog(@"   server = %@", challenge.protectionSpace.host);
        completionHandler(NSURLSessionAuthChallengeUseCredential, [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust]);
    } else if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodNTLM]) {
        NSLog(@"   NSURLAuthenticationMethodNTLM");
        NSURLCredential *credential = [NSURLCredential credentialWithUser:@"username" password:@"passwordIsSecretShhh" persistence:NSURLCredentialPersistenceForSession];
        completionHandler(NSURLSessionAuthChallengeUseCredential, credential);
    } else {
        NSLog(@"   ????");
    }
}

即使它完全失败并且无法加载，我仍然可以跳到 Safari，输入 URL 并加载它。因此，我正在寻找会导致此问题的想法，而不是糟糕的网络问题或托管 Web 服务器的参差不齐的问题。

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1 回答 1

4

我终于解决了这个问题。它与我的代码无关。

问题是导致安装在服务器中的 Trend SSL 监控软件。一旦软件被禁用，错误就会立即消失。

这不是一个很好的答案，但希望它能对其他人有所帮助。

于 2014-03-13T18:14:11.357 回答