SSH Key Login Rejected on RHEL 9

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

SSH prompts for password or denies access even though the correct key is present.

Environment & Reproduction

Inspect permissions on ~/.ssh and authorized_keys, and validate sshd_config PubkeyAuthentication settings.

Root Cause Analysis

File modes, ownership, SELinux labels, or key algorithm policy mismatch blocks key usage.

Quick Triage

Set strict permissions, restore SELinux contexts, and restart sshd after config updates.

Step-by-Step Diagnosis

Capture ssh -vvv client logs and sshd journal entries for rejected key diagnostics.

Solution – Primary Fix

SSH session authenticates with public key and no password fallback is required.

Solution – Alternative Approaches

Run ssh with explicit identity file and confirm successful non-interactive login.

Verification & Acceptance Criteria

Apply standardized SSH hardening baseline and key deployment process.

Rollback Plan

Restore prior sshd_config if recent hardening change blocked approved key algorithms.

Prevention & Hardening

Use automation to manage authorized keys, permissions, and sshd policy idempotently.

Related Errors & Cross-Refs

journalctl -u sshd and audit logs show authentication and policy denial details.

Related tutorial: View the step-by-step tutorial for rhel-9.

View all rhel-9 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Provide sanitized ssh -vvv output, sshd config, and relevant SELinux audit entries.