SMJobBless - documentation on when it asks for admin password

Question

I cannot seem to locate any documentation on this, so hopefully someone can confirm the behavior I am seeing with Apple's sample SMJobBless code.

I was under the impression that it would only ask for an admin password if it detected a that a new version of the helper tool needed to be installed.

However, this impression is apparently incorrect.

The behavior I am seeing under 10.6 is that if I launch the app for the first time, it will ask for the password. If I launch almost immediately, it won't. However, if I wait a long enough time, it will ask for the password again. During all of this, the helper tool does not change.

Can anyone point to documentation that defines this as the correct behavior?

Answer 1

If anyone is interested, this (probably) turned out to be a bug and one has been filed. rdar://10280469

The way the system currently works is that it will ask for an admin password every time regardless of whether or not the SMJobBless function needs to install the helper tool or not. The bug is (probably) that a admin password request should not be made if the helper tool does not need to be installed (for example, it is already installed and has the same version as the one in the app bundle).

So, what this means is that the determination of whether or not the helper tool needs to be installed needs to be made before a call to SMJobBless and SMJobBless should only be called if it is already known the helper tool needs to be installed.

In my case, I only need to check whether the tool is installed (SMJobCopyDictionary handles this) and, if the tool is installed, whether or not it's version is older then the version of the tool in my app bundle.

Some (incomplete) code to check whether the tool is installed and what the versions are is below.

There is another alternative to do a version check of the helper tool which is for the helper tool to receive a request for it's version and for it to send a version reply back. Personally, I like the method below, but wanted to mention this alternative as it may be the best path in some situations.

NSDictionary* installedHelperJobData;

installedHelperJobData  = (NSDictionary*)SMJobCopyDictionary( kSMDomainSystemLaunchd, (CFStringRef)@"com.apple.bsd.SMJobBlessHelper" );

NSString*       installedPath           = [[installedHelperJobData objectForKey:@"ProgramArguments"] objectAtIndex:0];
NSURL*          installedPathURL        = [NSURL fileURLWithPath:installedPath];

NSDictionary*   installedInfoPlist      = (NSDictionary*)CFBundleCopyInfoDictionaryForURL( (CFURLRef)installedPathURL );
NSString*       installedBundleVersion  = [installedInfoPlist objectForKey:@"CFBundleVersion"];
NSInteger       installedVersion        = [installedBundleVersion integerValue];

NSLog( @"installedVersion: %ld", (long)installedVersion );

NSBundle*       appBundle       = [NSBundle mainBundle];
NSURL*          appBundleURL    = [appBundle bundleURL];

NSURL*          currentHelperToolURL    = [appBundleURL URLByAppendingPathComponent:@"Contents/Library/LaunchServices/com.apple.bsd.SMJobBlessHelper"];
NSDictionary*   currentInfoPlist        = (NSDictionary*)CFBundleCopyInfoDictionaryForURL( (CFURLRef)currentHelperToolURL );
NSString*       currentBundleVersion    = [currentInfoPlist objectForKey:@"CFBundleVersion"];
NSInteger       currentVersion          = [currentBundleVersion integerValue];

NSLog( @"currentVersion: %ld", (long)currentVersion );