- Install and launch the iPhone Configuration Utility.
- Click on Configuration Profiles in the Library menu on the left.
- Click the New+ button along the top of the window, and on the General tab, fill out the info (Name, Identifier, etc.); there is no need to digitally sign it.
- Next Click on the Passcode tab, and check Require Passcode on Device. Check the various options/restrictions you want to enable.
- When you are all done, click the Share button at the top of the window. An email will open with a configuration profile attached (see sample below). Send the email to your iPhone.
- Open Mail on your iPhone, and open the message with the configuration profile attached. Click on the profile attachment, and then follow the on-screen prompts to install the profile and set your new long passcode.
Below is a sample of the XML generated by the utility. It enforces a minimum six-long alphanumeric passcode. If you save it to a plain text file with the extension .mobileconfig, and email the file to your iPhone, it should enable this passcode feature. Apple documents the DTD in their Enterprise Deployment Guide.

