IPhone app with SSL client certs

Question

I\'m building an iphone app that needs to access a web service over https using client certificates. If I put the client cert (in pkcs12 format) in the app bundle, I\'m able to

Answer 1

Apple does restrict the use of device-wide keys/certificates to it's own applications/services, such as WiFi, VPN, Mail, etc. Third-party applications are not able to use any of these keys/certs (without jailbreaking). However, applications are able to import, store, and use keys and certificates in a in-app keychain. In addition, you can share keys/certs across multiple applications with the keychain-access-group feature in iOS.

I recently published a blog post titled In-App Mobile Certificates Made Easy with mCMS, which may have helped you out. Our company is developing an API that makes it easy to support in-app certificates, obtained directly from your Microsoft-based PKI. Our solution also offers on-device key generation, instead of generating a P12 on another machine and trying to import it into your app.

Answer 2

Oh man, this brings up painful memories from October/November 2009. I was able to successfully get client-side certs to work but I had to port libcurl to the iPhone (which wasn't easy since the NDA was still in effect at the time).

I haven't done iPhone app development in over a year so I don't know how much is changed, but if I were you I'd first try to get by without client-side certs and if you absolutely must have them you can use libcurl with PEM formatted certs.

Answer 3

If you're using AirWatch for app distribution, their SDK provides the ability to provision certificates from your Certificate Authority to your registered devices. This allows you to provision your certs, and then access them from your app's code.

Answer 4

Does the code suggested in Finding a Certificate In the Keychain work for you?

Answer 5

I've done this for a recent app by making the documents folder for the app accessible via itunes. Our users are then instructed to drag their generated key (in a p12 format file) into the documents panel for our app in iTunes. When the app is started, it checks for the existence of the p12 file and, if it exists, imports the file into the keychain.

It's not the simplest procedure, but it is the most secure because you don't have a private key file being sent around via email.

Answer 6

I've tried with this:

NSString *thePath = [[NSBundle mainBundle] pathForResource:@"certificate" ofType:@"p12"]; 
NSData *PKCS12Data = [[NSData alloc] initWithContentsOfFile:thePath]; 
CFDataRef inPKCS12Data = (CFDataRef)PKCS12Data; 
CFStringRef password = CFSTR("pass"); 
const void *keys[] = { kSecImportExportPassphrase }; 
const void *values[] = { password }; 
CFDictionaryRef optionsDictionary = CFDictionaryCreate(NULL, keys, values, 1, NULL, NULL); 
CFArrayRef items = CFArrayCreate(NULL, 0, 0, NULL); 
SecPKCS12Import(inPKCS12Data, optionsDictionary, &items); 

inPKCS12Data is correct but items is empty. What is happening?