在 Swift 2.0 中加载自己的 ca 证书时EXC_BAD_ACCESS SecTrustEvaluate 调用

Question

我正在加载自己的根证书作为我的应用程序的锚证书，但我总是在SecTrustEvaluate(trust!, &trustResult)行上得到一个EXC_BAD_ACCESS。谁能看出我做错了什么？

我已经在 SecTrustAssessment 上查看了 Always EXC_BAD_ACCESS，但它并没有解决我的问题，因为我认为我的问题可能是特定于 Swift 的问题。

public func URLSession(session: NSURLSession, didReceiveChallenge challenge: NSURLAuthenticationChallenge, completionHandler: (NSURLSessionAuthChallengeDisposition, NSURLCredential?) -> Void) {
    if challenge.protectionSpace.authenticationMethod == NSURLAuthenticationMethodServerTrust {
        // First load our extra root-CA to be trusted from the app bundle.
        let trust = challenge.protectionSpace.serverTrust
        let rootCa = "SSLcomDVCA_2_DER"
        if let rootCaPath = NSBundle.mainBundle().pathForResource(rootCa, ofType: "cer") {
            if let rootCaData = NSData(contentsOfFile: rootCaPath) {
                let cfData = CFDataCreate(kCFAllocatorDefault, UnsafePointer<UInt8>(rootCaData.bytes), rootCaData.length)
                let rootCert = SecCertificateCreateWithData(nil, cfData)
                let certs: [CFTypeRef] = [rootCert!]
                let certPointer = UnsafeMutablePointer<UnsafePointer<Void>>(certs)
                let certArrayRef = CFArrayCreate(nil, certPointer
                    , certs.count, nil)
                SecTrustSetAnchorCertificates(trust!, certArrayRef)
                SecTrustSetAnchorCertificatesOnly(trust!, false) // also allow regular CAs.
            }
        }
        var trustResult: SecTrustResultType = 0
        SecTrustEvaluate(trust!, &trustResult)
        if (Int(trustResult) == kSecTrustResultUnspecified ||
            Int(trustResult) == kSecTrustResultProceed) {
                // Trust certificate.
                let credential = NSURLCredential(forTrust: challenge.protectionSpace.serverTrust!)
                challenge.sender!.useCredential(credential, forAuthenticationChallenge: challenge)
        } else {
            NSLog("Invalid server certificate.")
            challenge.sender!.cancelAuthenticationChallenge(challenge)
        }
    } else {
        NSLog("Got unexpected authentication method (challenge.protectionSpace.authenticationMethod)");
        challenge.sender!.cancelAuthenticationChallenge(challenge)
    }
}

Answer 1

使用证书和公钥固定作为指导，我想出了这个作为 Swift 中的证书固定实现。它与您的方法不同，但它在我的测试中有效。

可以使用

Firefox 下载 .der 格式的证书，方法是转到网站，单击地址栏中的挂锁> 更多信息> 查看证书>详细信息选项卡>导出（从格式列表中选择 DER）。

func URLSession(session: NSURLSession, didReceiveChallenge challenge: NSURLAuthenticationChallenge, completionHandler: (NSURLSessionAuthChallengeDisposition, NSURLCredential?) -> Void) {
    if challenge.protectionSpace.authenticationMethod == NSURLAuthenticationMethodServerTrust {
        guard let serverTrust = challenge.protectionSpace.serverTrust else {
            print("serverTrust is nil")
            return
        }
        guard errSecSuccess == SecTrustEvaluate(serverTrust, nil) else {
            print("SecTrustEvaluate is not errSecSuccess")
            return
        }
        guard let serverCertificate = SecTrustGetCertificateAtIndex(serverTrust, 0) else {
            print("serverCertificate is nil")
            return
        }
        let serverCertificateData = SecCertificateCopyData(serverCertificate)
        let data = CFDataGetBytePtr(serverCertificateData)
        let size = CFDataGetLength(serverCertificateData)
        let dataPtr = unsafeBitCast(data, UnsafeMutablePointer<Void>.self)
        let cert1 = NSData(bytes: dataPtr, length: size)
        guard let file = NSBundle.mainBundle().pathForResource("facebook.com", ofType: "der"), cert2 = NSData(contentsOfFile: file) else {
            print("Failed to open .der file")
            return
        }
        guard cert1 == cert2 else {
            print("Certificate pinning failed, certs unequal")
            return
        }
        // Good exit point. 
        print("PASSED Cert Pinning")
        return challenge.sender!.useCredential(NSURLCredential(forTrust: serverTrust), forAuthenticationChallenge: challenge)
    }
    print("FAILED Cert Pinning, authenticationMethod not ServerTrust")
}

Answer 2

最终解决方案如下。我初始代码的问题在于我尝试创建 CFArray 的方式。在代码中的某个地方：

let certs: [CFTypeRef] = [rootCert!]
let certPointer = UnsafeMutablePointer<UnsafePointer<Void>>(certs)
let certArrayRef = CFArrayCreate(nil, certPointer, certs.count, nil)

，我丢失了对证书的引用。通过将代码更改为：

let certs: [CFTypeRef] = [rootCert as! CFTypeRef]  
let certArrayRef : CFArrayRef = CFBridgingRetain(certs as NSArray) as! CFArrayRef

，问题已解决。

func URLSession(session: NSURLSession, didReceiveChallenge challenge: NSURLAuthenticationChallenge, completionHandler: (NSURLSessionAuthChallengeDisposition, NSURLCredential?) -> Void) {
    if challenge.protectionSpace.authenticationMethod == NSURLAuthenticationMethodServerTrust {
        let trust = challenge.protectionSpace.serverTrust
        let rootCa = "SSLcomDVCA_2_DER2"
        if let rootCaPath = NSBundle.mainBundle().pathForResource(rootCa, ofType: "der") {
            if let rootCaData: NSData = NSData(contentsOfFile: rootCaPath) {
                let cfData = CFDataCreate(kCFAllocatorDefault, UnsafePointer<UInt8>(rootCaData.bytes), rootCaData.length)
                let rootCert = SecCertificateCreateWithData(kCFAllocatorDefault, cfData)
                let certs: [CFTypeRef] = [rootCert as! CFTypeRef]
                let certArrayRef : CFArrayRef = CFBridgingRetain(certs as NSArray) as! CFArrayRef
                SecTrustSetAnchorCertificates(trust!, certArrayRef)
                SecTrustSetAnchorCertificatesOnly(trust!, false) // also allow regular CAs.
            }
        }
        var trustResult: SecTrustResultType = 0
        SecTrustEvaluate(trust!, &trustResult)
        if (Int(trustResult) == kSecTrustResultUnspecified ||
            Int(trustResult) == kSecTrustResultProceed) {
                // Trust certificate.
                let credential = NSURLCredential(forTrust: challenge.protectionSpace.serverTrust!)
                challenge.sender!.useCredential(credential, forAuthenticationChallenge: challenge)
        } else {
            NSLog("Invalid server certificate.")
            challenge.sender!.cancelAuthenticationChallenge(challenge)
        }
    } else {
        NSLog("Got unexpected authentication method (challenge.protectionSpace.authenticationMethod)");
        challenge.sender!.cancelAuthenticationChallenge(challenge)
    }