P1L5 Flashcards
access control
who is allowed to access what
2 parts of access control
- decide who would have access
2. enforcement
Access control metric (ACM)
- abstract state: rows-users, column-resources
- ACM[U,O] defines what access right user U have on object O
confidentiality
- read related
integrity
- write related
discretionary access control (DAC)
access to a resource is at the discretion of its owner. Since a user can make a copy and share with the third person
ACL (access control list)
handle access to object Oi (column wise)
capability list (C-list)
- handle right of user Ui (row wise)
where are ACL and C-list
in the trusted part of the system
how do we perform access control check
transversal of ACL to see if an ACE (access control entry) exists.
a capability in C-list
- unforgeable reference/handle for a resource
- user catalog of capabilities define defines what a certain user can access.
hydra
store c-list in objs, resources themselves
how sharing happens?
create new ACE, and add access right to that
most OS use ACL or C-list? why?
ACL, which is good for accountability and revocation. C-list is only good for efficiency
a movie ticket is a capability or access control entry?
capability (holder get access)