Where is the KeyChain data stored?

问题

Several points about the keychain in iOS:

1. Save user name and password securely;
2. Multiples apps can share data if they share same code signing provision and bundle seed id

My questions would be:

1. Where is the keychain data stored, definitely outside the app sandbox, could we handle them ?
2. What else usage of keychain in iOS apps ?

回答1:

1) The keychain is stored outside the sandbox in an iOS defined location. This is to prevent jailbroken devices from getting access to it. It is not visible through the filesystem. The keychain is the same as Mac OS X, except Apple felt that it wasn't necessary to give end users access to it. You cannot interact with it except through the defined APIs. I should note that it doesn't seem to be accomplishing the goal of preventing access even with jailbroken devices.

2) I don't really know about practical usage of the keychain outside of storing usernames and passwords.

来源：https://stackoverflow.com/questions/9900384/where-is-the-keychain-data-stored