Keychain (software)

Keychain is password management system in OS X developed by Apple. It was introduced with Mac OS 8.6, and has been included in all subsequent versions of Mac OS, including OS X. A Keychain can contain various types of data: passwords (for websites, FTP servers, SSH accounts, network shares, wireless networks, groupware applications, encrypted disk images), private keys, certificates, and secure notes.

Storage and access

In Mac OS X, keychain files are stored in ~/Library/Keychains/, /Library/Keychains/, and /Network/Library/Keychains/, and the Keychain Access GUI application is located in the Utilities folder in the Applications folder. It is free, open source software released under the terms of the APSL. The command line equivalent of Keychain Access is /usr/bin/security.

The keychain file(s) stores a variety of data fields including a title, URL, notes and password. Only the passwords and Secure Notes are encrypted, with Triple DES.

Locking and unlocking

The default keychain file is the login keychain, typically unlocked on login by the user's login password, although the password for this keychain can instead be different from a user’s login password, adding security at the expense of some convenience. The Keychain Access application does not permit setting an empty password on a keychain.