6

这是我使用自签名证书进行身份验证的标准 NSURLConnection 回调：

- (SecCertificateRef)certRefFromDerNamed:(NSString*)derFileName resultingDataRef:(CFDataRef*)dataRefPtr{
    NSString *thePath = [[NSBundle mainBundle] pathForResource:derFileName ofType:@"der"];
    NSData *certData = [[NSData alloc] initWithContentsOfFile:thePath];
    CFDataRef certDataRef = (__bridge_retained CFDataRef)certData;
    SecCertificateRef cert = SecCertificateCreateWithData(NULL, certDataRef);
    *dataRefPtr = certDataRef;
    return cert;
}

- (void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge {

if (connection == self.connection) {

    BOOL trusted = NO;
     if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) {

        SecPolicyRef policyRef = SecPolicyCreateBasicX509();

        SecCertificateRef cert1;
        CFDataRef certData1;

        cert1 = [self certRefFromDerNamed:@"some3rdpartycacert" resultingDataRef:&certData1];

        SecCertificateRef certArray[1] = { cert1 };
        CFArrayRef certArrayRef = CFArrayCreate(NULL, (void *)certArray, 1, NULL);

        SecTrustRef serverTrust = challenge.protectionSpace.serverTrust;
        SecTrustSetAnchorCertificates(serverTrust, certArrayRef);
        SecTrustResultType trustResult;

        SecTrustEvaluate(serverTrust, &trustResult);

        trusted = (trustResult == kSecTrustResultUnspecified);

        CFRelease(certArrayRef);
        CFRelease(policyRef);
        CFRelease(cert1);
        CFRelease(certData1);
    }
    if (trusted) {
        [challenge.sender useCredential:[NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust] forAuthenticationChallenge:challenge];
    } else {
        [challenge.sender performDefaultHandlingForAuthenticationChallenge:challenge];
    }
}
}

而且trustResult总是kSecTrustResultRecoverableTrustFailure。

证书本身有点问题。根据服务器上的 curl 证书主题名称与我连接的 url 不匹配。我已经联系了那家第 3 方公司，他们告诉我我需要在我的代码中接受这个 url 不匹配。问题是我不知道如何在 iOS 上执行此操作。我可以完全绕过证书检查（通过简单地假设trusted=YES和调用useCredential）或完全失败。从安全角度来看，第一种解决方案显然是错误的，并且容易受到 MITM 攻击。

这是 CURL 输出（我在这里使用了 PEM 版本的相同证书）：

ukaszs-iMac:Preferences lukasz$  curl --verbose --cacert ~/Desktop/some3rdpartycacert.txt  https://dev-service.some3rdparty.com:50101/
* About to connect() to dev-service.some3rdparty.com port 50101 (#0)
*   Trying XXX.XXX.XXX.XXX...
* connected
* Connected to dev-service.some3rdparty.com (XXX.XXX.XXX.XXX) port 50101 (#0)
* successfully set certificate verify locations:
*   CAfile: /Users/lukasz/Desktop/some3rdpartycacert.txt
  CApath: none
* SSLv3, TLS handshake, Client hello (1):
* SSLv3, TLS handshake, Server hello (2):
* SSLv3, TLS handshake, CERT (11):
* SSLv3, TLS handshake, Request CERT (13):
* SSLv3, TLS handshake, Server finished (14):
* SSLv3, TLS handshake, CERT (11):
* SSLv3, TLS handshake, Client key exchange (16):
* SSLv3, TLS change cipher, Client hello (1):
* SSLv3, TLS handshake, Finished (20):
* SSLv3, TLS change cipher, Client hello (1):
* SSLv3, TLS handshake, Finished (20):
* SSL connection using AES256-SHA
* Server certificate:
*    subject: C=CA; ST=Ontario; O=Some 3rdParty Corporation; CN=otherpage.some3rdparty.com; emailAddress=noc@some3rdparty.com
*    start date: 2013-10-30 16:52:14 GMT
*    expire date: 2013-10-30 16:52:14 GMT
* SSL: certificate subject name 'otherpage.some3rdparty.com' does not match target host name 'dev-service.some3rdparty.com'
* Closing connection #0
* SSLv3, TLS alert, Client hello (1):
curl: (51) SSL: certificate subject name 'otherpage.some3rdparty.com' does not match target host name 'dev-service.some3rdparty.com'

那么，如何忽略 iOS 上的这个特定错误呢？

4

2 回答 2

11

您需要使用实际主机名创建一个特殊策略，然后serverTrust从中创建和评估。大致：

SecPolicyRef policyRef = SecPolicyCreateSSL(true, CFSTR("otherpage.some3rdparty.com"));

OSStatus    status;
SecTrustRef serverTrust;
status = SecTrustCreateWithCertificates(certificatesFromOriginalServerTrust, policyRef, & serverTrust);
// noErr == status?

status = SecTrustSetAnchorCertificates(serverTrust, certArrayRef);
// noErr == status?

SecTrustResultType trustResult;
status = SecTrustEvaluate(serverTrust, &trustResult);
// noErr == status?

if(kSecTrustResultProceed == trustResult || kSecTrustResultUnspecified == trustResult) {
    // all good
}

ps 你没有使用你创建的策略。

我刚刚在这里找到了更完整的解释。

于 2014-02-14T01:48:14.897 回答
1

对于这个特定的问题，你需要阅读《iOS 5 Programming Pushing the Limits: Developing Extraordinary Mobile Apps for Apple iPhone, iPad, and iPod Touch》一书。（作者：罗布·纳皮尔，穆根斯·库马尔）

在这本书的第 219 页底部，它说： “如果您对通过的名称感到满意，您可以将证书重新评估为简单的 X.509 证书，而不是 SSL 握手的一部分（也就是说，您在忽略主机名的情况下对其进行评估）”

然后它有一个特殊的RNSecTrustEvaluateAsX509功能。因此，实际上使用该功能您可以忽略主机名部分并将该部分设置为“受信任”来评估证书。请参阅http://bit.ly/1g1RzdF（转到第 219 页）

书中的代码可以在这里找到： https ://github.com/iosptl/ios5ptl/blob/master/ch11/Connection/Connection/ConnectionViewController.m

于 2014-02-13T17:12:21.960 回答