Question

I use the following code to retrieve the login credentials from the iPhone keychain:

KeychainItemWrapper *wrapper = [[KeychainItemWrapper alloc] initWithIdentifier:@"Test" accessGroup:nil];
NSString *username = [wrapper objectForKey:(id)kSecAttrAccount];
NSString *password = [wrapper objectForKey:(id)kSecValueData];
[wrapper release];

I’m under the impression that the first time a user launches the app, neither username nor password could be retrieved from the keychain, so username and password should be equal to nil. I, however, was unable to print out any of these variables using NSLog.

Any suggestions?

Answer 1

Your assumption is wrong- on creation, the “kSecAttrAccount” and “kSecValueData” are NOT set to nil. They are set to an empty string (that is, “”). So, this code will return true:

[username isEqualToString:@""]    // returns true on creation