iOS 和 SSL：无法验证自签名服务器证书

Question

我对使用 SSL 通道使用网络服务还很陌生。 经过相当不错的搜索，我找到了一种使用 NSURLConnection 委托 API 执行 SSL/HTTPS 身份验证的方法。 以下是执行实际身份验证的代码片段：

- (void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge {
[self printLogToConsole:@"Authenticating...."];
[self printLogToConsole:[NSString stringWithFormat:@"\n%@\n", [challenge description]]];
NSLog(@"\n\nserverTrust: %@\n", [[challenge protectionSpace] serverTrust]);

/* Extract the server certificate for trust validation
 */
NSURLProtectionSpace *protectionSpace = [challenge protectionSpace];
assert(protectionSpace);
SecTrustRef trust = [protectionSpace serverTrust];    
assert(trust);
CFRetain(trust); // Make sure this thing stays around until we're done with it
NSURLCredential *credential = [NSURLCredential credentialForTrust:trust];


/* On iOS 
 * we need to convert it to 'der' certificate. It can be done easily through Terminal as follows:
 * $ openssl x509 -in certificate.pem -outform der -out rootcert.der
 */
NSString *path = [[NSBundle mainBundle] pathForResource:@"rootcert" ofType:@"der"];
assert(path);
NSData *data = [NSData dataWithContentsOfFile:path];
assert(data);

/* Set up the array of certificates, we will authenticate against and create credentials */
SecCertificateRef rtCertificate = SecCertificateCreateWithData(NULL, CFBridgingRetain(data));
const void *array[1] = { rtCertificate };
trustedCerts = CFArrayCreate(NULL, array, 1, &kCFTypeArrayCallBacks);
CFRelease(rtCertificate); // for completeness, really does not matter

/* Build up the trust anchor using our root cert */
int err;
SecTrustResultType trustResult = 0;
err = SecTrustSetAnchorCertificates(trust, trustedCerts);
if (err == noErr) {
    err = SecTrustEvaluate(trust, &trustResult);
}
CFRelease(trust); // OK, now we're done with it

[self printLogToConsole:[NSString stringWithFormat:@"trustResult: %d\n", trustResult]];

/* http://developer.apple.com/library/mac/#qa/qa1360/_index.html
 */
BOOL trusted = (err == noErr) && ((trustResult == kSecTrustResultProceed) || (trustResult == kSecTrustResultConfirm) || (trustResult == kSecTrustResultUnspecified));

// Return based on whether we decided to trust or not
if (trusted) {
    [[challenge sender] useCredential:credential forAuthenticationChallenge:challenge];
    [self printLogToConsole:@"Success! Trust validation successful."];
} else {
    [self printLogToConsole:@"Failed! Trust evaluation failed for service root certificate.\n"];
    [[challenge sender] cancelAuthenticationChallenge:challenge];
}

}

但我收到以下错误：

2012-06-11 17:10:12.541 SecureLogin[3424:f803] Error during connection: Error Domain=NSURLErrorDomain Code=-1012 "The operation couldn’t be completed. (NSURLErrorDomain error -1012.)" UserInfo=0x682c790 {NSErrorFailingURLKey=https://staging.esecure.url/authentication/signin/merchants, NSErrorFailingURLStringKey=https://staging.esecure.url/authentication/signin/merchants}

我正在使用从服务器获得的相同证书并将其转换为“der”格式。 我正在为 iOS 5.x 构建应用程序。 我不确定我是否错过了什么。 让我知道你的建议。

谢谢。

编辑在此处检查证书后输出的外观：

如果有什么问题，请告诉我。

谢谢。

Answer 1

我不知道，如果你的代码是有效还是无效，因为我用RestKit为使用REST接口，但最常见的问题，导致NSURLErrorDomain Code=-1012是自签名的证书不具有subject alternative name扩展指向网络服务，如果地址。

要检查您的证书，请下载Portecle 应用程序，如果您需要查看 ssl 证书，该应用程序非常有用。 运行它并从菜单中选择“检查”->“检查证书”并导航到您的证书。 您将看到有关您的证书的基本信息，现在按检查按钮，然后按主题备用名称，并确保您的网络服务的正确 IP 地址在那里。 如果没有，您需要使用此信息再次创建证书。

Answer 2

我确实想出了如何解决这个问题。

我最终逐字节比较了客户端和服务器信任证书。 虽然可能有另一种方法来解决自签名证书的此类问题，但对于此解决方案确实有效。 这是我如何使用它们的 CFData 对象逐字节比较客户端和服务器证书（您也可以参考 Apple 提供的“AdvancedURLConnections”示例代码）：

success = NO;
        pServerCert = SecTrustGetLeafCertificate(trust);
        if (clientCert != NULL) {
            CFDataRef       clientCertData;
            CFDataRef       serverCertData;

            clientCertData = SecCertificateCopyData(clientCert);
            serverCertData   = SecCertificateCopyData(pServerCert);

            assert(clientCertData != NULL);
            assert(serverCertData   != NULL);

            success = CFEqual(clientCertData, serverCertData);

            CFRelease(clientCertData);
            CFRelease(serverCertData);
        }
        if (success) {
            [[challenge sender] useCredential:credential forAuthenticationChallenge:challenge];
            [self printLogToConsole:@"Success! Trust validation successful."];
        } else {
            [self printLogToConsole:@"Failed! Trust evaluation failed for service root certificate.\n"];
            [[challenge sender] cancelAuthenticationChallenge:challenge];
        }

希望这会帮助正在寻找类似问题解决方案的人，

谢谢。