Computer Security: Principles and Practice, 1/e



Download 7,14 Mb.
bet3/7
Sana10.11.2022
Hajmi7,14 Mb.
#862889
1   2   3   4   5   6   7
Bog'liq
04-AccessControl

Directories are structured in a hierarchical tree

UNIX File Access Control

  • Unique user identification number (user ID)
  • Member of a primary group identified by a group ID
  • Belongs to a specific group
  • 12 protection bits
        • 9 of the protection bits specify read, write, and execute permission for the owner of the file, members of the group and all other users
      • The owner ID, group ID, and protection bits are part of the file’s inode

Traditional UNIX File Access Control

  • “Set user ID”(SetUID)
    • Any program that is owned by, and SetUID to, the “superuser” potentially granted unrestricted access to the system to any user executing that program
  • “Set group ID”(SetGID)
    • System temporarily uses rights of the file owner/group in addition to the real user’s rights when making access control decisions
    • Enables privileged programs to access files/resources not generally accessible
  • Sticky bit
    • When applied to a directory it specifies that only the owner of the file in the directory can rename, move, or delete that file
  • Superuser (root)
    • Is exempt from usual access control restrictions
    • Has system-wide access

When a process requests access to a file:
  • Step 1 selects the ACL entry that most closely matches the requesting process. ACL entries are looked at the order: owner, named users, groups, & others. Only a single entry determines access.
  • Step 2 checks if the matching entry contains sufficient permissions. A process can be a member of more than one group; so more than one group entry can match. If any of these matching group entries contain the requested permissions, one that contains the requested permissions is picked (the result is the same no matter which entry is picked). If none of the matching group entries contains the requested permissions, access will be denied no matter which entry is picked.

Download 7,14 Mb.

Do'stlaringiz bilan baham:
1   2   3   4   5   6   7




Ma'lumotlar bazasi mualliflik huquqi bilan himoyalangan ©hozir.org 2024
ma'muriyatiga murojaat qiling

kiriting | ro'yxatdan o'tish
    Bosh sahifa
юртда тантана
Боғда битган
Бугун юртда
Эшитганлар жилманглар
Эшитмадим деманглар
битган бодомлар
Yangiariq tumani
qitish marakazi
Raqamli texnologiyalar
ilishida muhokamadan
tasdiqqa tavsiya
tavsiya etilgan
iqtisodiyot kafedrasi
steiermarkischen landesregierung
asarlaringizni yuboring
o'zingizning asarlaringizni
Iltimos faqat
faqat o'zingizning
steierm rkischen
landesregierung fachabteilung
rkischen landesregierung
hamshira loyihasi
loyihasi mavsum
faolyatining oqibatlari
asosiy adabiyotlar
fakulteti ahborot
ahborot havfsizligi
havfsizligi kafedrasi
fanidan bo’yicha
fakulteti iqtisodiyot
boshqaruv fakulteti
chiqarishda boshqaruv
ishlab chiqarishda
iqtisodiyot fakultet
multiservis tarmoqlari
fanidan asosiy
Uzbek fanidan
mavzulari potok
asosidagi multiservis
'aliyyil a'ziym
billahil 'aliyyil
illaa billahil
quvvata illaa
falah' deganida
Kompyuter savodxonligi
bo’yicha mustaqil
'alal falah'
Hayya 'alal
'alas soloh
Hayya 'alas
mavsum boyicha


yuklab olish