tmpfs.tech · all tracks · Security & TLS

Verify a signature

Security & TLS · pro · live throwaway Linux box · 3 tiered hints

/opt/sig/msg was signed. Use /opt/sig/pub.pem and /opt/sig/msg.sig to verify it, and write 'valid' or 'invalid' to /home/player/verdict.txt.

▶ Start this challenge

Fastest verified solves

• Luke39s · ✦ no hints

How it works

Press start and you get your own real, disposable Linux VM — in the browser terminal or over SSH. Work the task on a live system; tmpfs.tech grades your solution automatically against the actual machine state, then throws the box away. No install, free to try as a guest.

More Security & TLS challenges

Certificates, signatures, hardening sshd and verifying trust.

• Cap a User's Open Fileseasy · in-browser
• Disconnect Idle SSH Sessionseasy · in-browser
• Generate an RSA keyeasy
• Harden the SSH Clienteasy · in-browser
• Limit Processes Per Usereasy · in-browser
• Lock a key fileeasy
• Lock down a key directoryeasy
• Lock down a private keyeasy

See all Security & TLS challenges →

FAQ

Is it free? Yes — play as a guest, no signup required to start.

Do I need to install anything? No. Everything runs in your browser, or connect over SSH if you prefer your own terminal.

How is it graded? Automatically and deterministically — your work is checked against the real state of the machine you worked on.