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scenario medium Understand ssh-perms 2 points

Question 47. CSCD240-E1-C

-rw------- on .ssh and drwx------ on .config — which is typical for an SSH private key and why?

Work the drill

Answer on paper or in a terminal before revealing the ideal answer.

Ideal answer
The 600 (-rw-------) pattern. SSH refuses to use a private key if it is readable by anyone but owner — it enforces the "owner only" permission to prevent credential theft.

Misconception bank

Each row below is a plausible wrong answer, the thinking that produces it, and the remedy that corrects the misconception. These are the foundation of the multiple-choice framing and the targeted feedback a student receives after answering.

0755 pattern
Misconception. World-readable keys are rejected by sshd.
Remedy. Memorize: SSH private keys = 600.

Authority mappings

Hover any chip for the mapping justification; click to open the authority record.

DCWF tasks: T0136
KU outcomes: CO-M9-O2
KU topics: CD-CSP-T16

Course-artifact links

Lectures

  • CSCD240-S26-L05. Permissions part 1: ls -l anatomy, rwx, file types