****************************** * Change Password plugin API * ****************************** Document should explain how to create change_password plugin backends and provide details about plugin structure. Plugin uses standard SquirrelMail plugin architecture and implements backends with two hooks. change_password_init hook ------------------------- change_password_init hook is used to execute some code before displaying change password form. Plugin can use this hook to check if install has all required components, or to check if backend is configured correctly, or display some messages to end user. Maybe some background information about password security and how to choose good password. If backend detects some configuration errors that make backend unusable, it can stop execution of the script with PHP exit() call. change_password_dochange hook ----------------------------- change_password_dochange hook is used when user submits old and new passwords. Plugin checks if old password matches current session password and checks new password satisfies requirements set in plugin's configuration. All data is provided in array submitted via hook. 'username' key contains user's login name, 'curpw' contains current session password, 'newpw' contains new password. Function that is attached to plugin should return empty array or array filled with error messages. If array is empty - plugin assumes that password was changed and updates current session password. common strings -------------- Backends can use constants for some error messages. CPW_CURRENT_NOMATCH constant sets 'Your current password is not correct.' error. CPW_INVALID_PW constant sets 'Your new password contains invalid characters.' error. Recommendations --------------- Backend should check, if current password matches stored password. Internal plugin functions only check if password matches the one that was used to login into SquirrelMail. Password is validated against IMAP server and not against used backend. Backend should store only default configuration variables that don't have any information specific to developer's server or these variables should be set to sane default values. Backend's configuration should be controlled with configuration overrides that are set config.php. It is recommended to use array with configuration overrides and make sure that array is set to empty value before loading plugin's configuration file. Backend should not use generic function names. It is recommended to use 'cpw_' prefix. If backend must load other SquirrelMail functions, it must use SM_PATH constant in include_once() calls and make sure that SM_PATH is defined in any case when backend file is loaded. In most cases constant is already defined, but some unusual use of php files might cause php warnings, if constant is used inside backend functions and not defined in backend file. Overrides used by backend and backend requirements must be documented in README file.