Host and Application Security Lesson 5: The Role of an OS.
10
Host and Application Security Lesson 5: The Role of an OS
-
Upload
eric-newman -
Category
Documents
-
view
216 -
download
1
Transcript of Host and Application Security Lesson 5: The Role of an OS.
Host and Application SecurityLesson 5: The Role of an OS
Environment What is the output of a program?
Right… it’s all about the Environment What is an operating system? How did Oses come about? Some examples and the security implications
of them
Historically Batched systems Multiprogrammed Systems Time sharing Real-time systems
Services Provided Essentially, a “resource allocator”
CPU time Memory space File storage space IO…
Provides abstraction What’s in there?
Everything the vendor ships “the one program running at all times on the computer”
(Silberschatz)
Pictorially…
User Application Operating System Hardware
OS Architecture Monolothic
Things are loaded into the operating system, and run with the privileges of the OS
Example: Linux Microkernel
Take everything that you don’t need out and put it user mode Example: Symbian
“Hybrid” Kernel Some blending of the above Example: Windows
Windows 7 DOS: One program ruled all Windows 3.1: Some kind of multitasking Windows NT: A protected environment Windows 95, 98, ME: Better separation, better
multitasking, still based on DOS Windows 2000: Based on NT 4 codebase Windows XP: Possibly “most successful” Windows OS Windows Vista: Added UAC, amongst other things Windows 7: Lots of security enhancements
Unix
Source: Wikipedia
Questions?
