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iOS - How to add HTTPS support for one's own Certificate Authority
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| #import <Security/Security.h> | |
| #import <CoreFoundation/CoreFoundation.h> | |
| #import <Foundation/Foundation.h> | |
| @interface SSLHelper : NSObject | |
| + (SSLHelper *)sharedInstance; | |
| - (void) addCertToKeychain:(NSData*)certInDer; | |
| - (BOOL) canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace; | |
| - (BOOL) manageAuthorizationForChallenge:(NSURLAuthenticationChallenge*)challenge; | |
| @end | |
| /* | |
| From: | |
| - https://developer.apple.com/library/ios/technotes/tn2232 | |
| - http://stackoverflow.com/questions/5323686/ios-pre-install-ssl-certificate-in-keychain-programmatically/9941559#9941559 | |
| - http://stackoverflow.com/questions/11608847/always-exc-bad-access-on-sectrustevaluate | |
| # New server private key | |
| openssl genrsa 2048 -out server-key.pem | |
| # Create a certificate sign request | |
| openssl req -new -key server-key.pem -out certificate.csr | |
| # Autosign certificate sign request with own server private key | |
| # The result is an autosign certificate that can also be a Certificate Authority | |
| openssl x509 -req -days 65537 -in certificate.csr -signkey server-key.pem -out certificate.crt | |
| # Generate certificate in format compatible with iOS | |
| openssl x509 -in certificate.crt -inform PEM -out certificate.der -outform DER | |
| Usage example, with certificate.der file: | |
| // Load certificate as new Certificate Authority | |
| NSBundle * bundle = [NSBundle bundleForClass:[self class]]; | |
| NSData *trustedCertDerData = [NSData dataWithContentsOfFile:[bundle pathForResource:@"certificate" ofType:@"der"]]; | |
| [[SSLHelper sharedInstance] addCertToKeychain:trustedCertDerData]; | |
| // For NSURLConnection, add hooks to delegate NSURLConnectionDelegate on: | |
| - (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace { | |
| return [[SSLHelper sharedInstance] canAuthenticateAgainstProtectionSpace:protectionSpace]; | |
| } | |
| - (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge { | |
| [[SSLHelper sharedInstance] manageAuthorizationForChallenge:challenge]; | |
| } | |
| */ | |
| @interface SSLHelper () { | |
| NSMutableArray * _certRefsArray; | |
| } | |
| - (BOOL) evaluateWithLocalCertificatesForTrust:(SecTrustRef)trust; | |
| @end | |
| @implementation SSLHelper | |
| + (SSLHelper *)sharedInstance | |
| { | |
| static SSLHelper * sInstance = nil; | |
| static dispatch_once_t once = 0; | |
| dispatch_once(&once, ^{ | |
| sInstance = [[self alloc] init]; | |
| }); | |
| return sInstance; | |
| } | |
| - (id)init | |
| { | |
| self = [super init]; | |
| if (self) { | |
| _certRefsArray = [NSMutableArray new]; | |
| } | |
| return self; | |
| } | |
| - (void)dealloc | |
| { | |
| for (id cert in _certRefsArray) { | |
| CFRelease((__bridge CFTypeRef)(cert)); | |
| } | |
| } | |
| - (void) addCertToKeychain:(NSData*)certInDer | |
| { | |
| CFDataRef certDataRef = (__bridge CFDataRef)(certInDer); | |
| SecCertificateRef caCertRef = SecCertificateCreateWithData(NULL, certDataRef); | |
| assert(caCertRef); | |
| [_certRefsArray addObject:(__bridge id)(caCertRef)]; | |
| } | |
| - (BOOL)canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace | |
| { | |
| return [protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]; | |
| } | |
| - (BOOL) evaluateWithLocalCertificatesForTrust:(SecTrustRef)trust | |
| { | |
| OSStatus err; | |
| SecTrustResultType trustResult; | |
| BOOL trusted; | |
| err = SecTrustSetAnchorCertificates(trust, (__bridge CFArrayRef)_certRefsArray); | |
| if (err == noErr) { | |
| err = SecTrustEvaluate(trust, &trustResult); | |
| trusted = (err == noErr) && ((trustResult == kSecTrustResultProceed) || (trustResult == kSecTrustResultUnspecified)); | |
| } | |
| else { | |
| trusted = false; | |
| } | |
| return trusted; | |
| } | |
| - (BOOL) manageAuthorizationForChallenge:(NSURLAuthenticationChallenge*)challenge | |
| { | |
| // Check if challenge is really for SSL | |
| if (! [challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) { | |
| return NO; | |
| } | |
| OSStatus err; | |
| NSURLProtectionSpace * protectionSpace; | |
| SecTrustRef trust; | |
| SecTrustResultType trustResult; | |
| BOOL trusted; | |
| protectionSpace = [challenge protectionSpace]; | |
| assert(protectionSpace != nil); | |
| // Default trust evaluation | |
| trust = [protectionSpace serverTrust]; | |
| assert(trust != NULL); | |
| err = SecTrustEvaluate(trust, &trustResult); | |
| trusted = (err == noErr) && ((trustResult == kSecTrustResultProceed) || (trustResult == kSecTrustResultUnspecified)); | |
| // If that fails, apply our certificates as anchors and see if that helps | |
| // Note: the certificate will then stay as an anchor certificates, so the following code is applied only once | |
| if ( ! trusted ) { | |
| NSLog(@"Certificate not trusted, trying our CA"); | |
| trusted = [[SSLHelper sharedInstance] evaluateWithLocalCertificatesForTrust:trust]; | |
| } | |
| if(trusted) { | |
| [challenge.sender useCredential:[NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust] forAuthenticationChallenge:challenge]; | |
| return YES; | |
| } | |
| return NO; | |
| } | |
| @end |
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