If you plan on only storing your user's login and password, I think you should first try using only one identifier in:
KeychainItemWrapper *wrapper = [[KeychainItemWrapper alloc] initWithIdentifier:@"My_Unique_Id" accessGroup:nil];
Then, when you connect your user, you use:
[wrapper setObject:userName forKey:(__bridge id)kSecAttrAccount];
[wrapper setObject:password forKey:(__bridge id)kSecValueData];
And then your method to see if the user has already gotten credentials becomes:
- (BOOL)isUserLogged
{
KeychainItemWrapper *wrapper = [[KeychainItemWrapper alloc] initWithIdentifier:@"My_Unique_Id" accessGroup:nil];
NSString *username = [wrapper objectForKey:(__bridge id)kSecAttrAccount];
NSString *password = [wrapper objectForKey:(__bridge id)kSecValueData];
BOOL isLogged = ([username length] > 0 && [password length] > 0);
return isLogged;
}
Try that at first and see if it works...