16 OS Security Issues

8/9/2019 16 OS Security Issues

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2008Chapter-8 L24: "Embedded Systems - Architecture,

Programming and Design" , Raj Kamal, Publs.: McGraw-Hill,Inc.

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REAL TIME OPERATING SYSTEMS

Lesson-24:

OS SECURITY ISSUESOS SECURITY ISSUES


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1. Important Security Functions1. Important Security Functions


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Protection MechanismProtection Mechanism

OS should provide protection mechanisms

and implement a system administrator (s)

defined security


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Flexibility to of changeFlexibility to of change

when needed to fulfill the need

requirements of all the processes.

For example, a process has control of 32

memory blocks at an instance and the OS

configured the system accordingly. t

Later when more processes are created, this

can be reconfigured.


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Controlled resource sharingControlled resource sharing

Controlling read and write of the resources

and parameters by user processes.

For example, some resources write only for

a process and some read only for a set of

processes

Another example, memory buffer to which

one process writes at an instant till thatbuffer is emptied by other process


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Confinement MechanismConfinement Mechanism

Mechanism that restricts sharing of

parameters to a set of processes only .


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Security Policy (Strategy)Security Policy (Strategy)

Rules for authorizing access to the OS,

system and information.

A policy example is that a communication

system may having a policy of peer-to-

peer communication (connection

establishment preceding the data packets

flow).


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Programming and Design" , Raj Kamal, Publs.: McGraw-Hill,

Inc.

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Authentication MechanismAuthentication Mechanism

External authentication mechanism for the userand a mechanism meant to prevent an

application run unless the user registers and the

system administrator (software) authorizes

Internal authentication for the process, and theprocess should not appear (impersonate) as some

like other processes.

User authentication can become difficult if the

user disseminates password passwords or otherauthentication methods


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AAuthorizationuthorization

User or process (s) allowed to use the

system resources as per the security policy


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EncryptionEncryption

A tool to change information to make it

unusable by any other user or process unless

without the appropriate key is used for

deciphering it.


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SummarySummary


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We learntWe learnt

OS security issues are importantconsiderations.

Protection of memory and resources from

any unauthorized and without explicitauthorization write into the PCB or

resource, or mix up of accesses of one by

another, becomes imperative from an OS

security and protection mechanism


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End of Lesson 24 of Chapter 8End of Lesson 24 of Chapter 8

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16 OS Security Issues