How to determine the installed certificate in ios 11?

Question

iOS

Good morning everyone!
Apple released yesterday for IOS11 developers and in my application the definition of the installed certificate on the device broke. Mb someone has a similar problem and someone managed to solve it?
Thanks in advance for your reply!

- (BOOL)IsMobileConfigInstalled {
    NSString *certPath = [[NSBundle mainBundle] pathForResource:@"cert" ofType:@"der"];
    NSData *certData = [NSData dataWithContentsOfFile:certPath];
    SecCertificateRef cert = NULL;
    if ([certData length]) {
         cert = SecCertificateCreateWithData(NULL, (__bridge CFDataRef) certData);
        if (cert != NULL) {
            CFStringRef certSummary = SecCertificateCopySubjectSummary(cert);
            NSString *summaryString = [[NSString alloc] initWithString:(__bridge NSString *) certSummary];
            CFRelease(certSummary);
        }
    }
    SecPolicyRef policy = SecPolicyCreateBasicX509();
    SecTrustRef trust;
    OSStatus err = SecTrustCreateWithCertificates((__bridge CFArrayRef) @[
            (__bridge id) cert
    ], policy, &trust);
    SecTrustResultType trustResult = (SecTrustResultType) -1;
    err = SecTrustEvaluate(trust, &trustResult);
    CFRelease(trust);
    CFRelease(policy);
    CFRelease(cert);
    return kSecTrustResultUnspecified == trustResult;
}

Answer 1

He asked, he answered.
In general, Apple stupidly changed the response of the trustResult variable, now it is kSecTrustResultProceed.
I am attaching a working code with a fix.

- (BOOL)IsMobileConfigInstalled {
    NSString *certPath = [[NSBundle mainBundle] pathForResource:@"cert" ofType:@"der"];
    NSData *certData = [NSData dataWithContentsOfFile:certPath];
    SecCertificateRef cert = NULL;
    if ([certData length]) {
        cert = SecCertificateCreateWithData(NULL, (__bridge CFDataRef) certData);
        if (cert != NULL) {
            CFStringRef certSummary = SecCertificateCopySubjectSummary(cert);
            NSString *summaryString = [[NSString alloc] initWithString:(__bridge NSString *) certSummary];
            CFRelease(certSummary);
        }
    }
    SecPolicyRef policy = SecPolicyCreateBasicX509();
    SecTrustRef trust;
    OSStatus err = SecTrustCreateWithCertificates((__bridge CFArrayRef) @[
            (__bridge id) cert
    ], policy, &trust);
    SecTrustResultType trustResult = (SecTrustResultType) -1;
    err = SecTrustEvaluate(trust, &trustResult);
    CFRelease(trust);
    CFRelease(policy);
    CFRelease(cert);
    NSString *ver = [[UIDevice currentDevice] systemVersion];
    float ver_float = [ver floatValue];
    if (ver_float >= 11)
        return kSecTrustResultProceed == trustResult;
    return kSecTrustResultUnspecified == trustResult;
}