janus-sec

A terminal-first credential exposure auditor.

Your SSH keys, AWS credentials, and kube config are only as safe as their file permissions. A chmod 644 typo, a bad tarball extraction, or a cloud sync tool can quietly leave a private key readable by every user on your machine — and there's usually no warning until something goes wrong.

janus-sec scans the credential files you already have, tells you exactly what's wrong and why it matters, and fixes it with one confirmed keystroke. Nothing leaves your machine — no network calls, no file content is ever read, no sudo.

$ janus-sec
Scanned 4 file(s), 8 not present.

[HIGH] /home/user/.ssh/id_rsa
    Issue:  world_readable (mode 644)
    Why:    This file is readable by any local user on this machine.
            Credential files should only be readable by their owner.
    Fix:    chmod 600 /home/user/.ssh/id_rsa

[MEDIUM] /home/user/.aws/credentials
    Issue:  group_readable (mode 640)
    Why:    This file is readable by group 'docker', which is not one of
            your groups. Other accounts in that group can read this file.
    Fix:    chmod 600 /home/user/.aws/credentials

2 finding(s) total, 1 HIGH risk.

Why this exists

The underlying check here is genuinely simple — find ~/.ssh -perm /077 does most of the mechanical work in one line. That's not the point. The gap janus-sec closes isn't "how do I check this," it's "I never thought to check this, and if I did, I wouldn't trust a one-off command to tell me what to do about it or keep a record that I did it."

Concretely, what a one-liner doesn't give you:

• An explanation. -rw-r--r-- means nothing to most people at a glance. "This private key is readable by any local user on this machine" changes behavior.
• The right fix for each file type. SSH keys, known_hosts, AWS credentials, and kube configs don't all want the same target mode.
• A safe way to apply it. Confirmation by default, --dry-run to preview, and a re-check immediately before writing (the file you looked at when scanning might not be the file you're about to change).
• A record. An append-only audit log of every fix, so "what did I change and when" has a real answer.
• A CI gate. --ci exits non-zero on any HIGH-risk finding, so this can fail a pipeline, not just print a warning nobody reads.

What it checks

Check	Risk	Auto-fix?
World-readable / world-writable	HIGH	Yes
Owned by a different user	HIGH	No — would require sudo, out of scope
Group-readable (by a group you're not in)	MEDIUM	Yes
Symlink pointing outside its expected directory	MEDIUM	No — target choice is a judgment call

Scans by default: ~/.ssh/*, ~/.aws/*, ~/.kube/config, ~/.npmrc, ~/.git-credentials, ~/.docker/config.json. Missing files are silently skipped, not errors — most people won't have all of these.

Safety properties

• No network access, ever.
• Never reads file contents — only metadata (permissions, ownership). It can't tell you if a secret has leaked; it tells you if the file is more exposed than it should be.
• Never elevates privileges. No sudo, no chown. If a fix would require that, janus-sec reports the problem and stops — it doesn't attempt it.
• Every fix requires confirmation (or an explicit --yes for scripted use), and --dry-run previews changes with zero side effects.
• Append-only audit log of every fix applied, at ~/.local/state/janus-sec/audit.log.

Found a security issue? See SECURITY.md for how to report it.

Install

pip install janus-sec

Or from source, for development:

git clone https://github.com/A-S-Manoj/janus-sec.git
cd janus-sec
python3 -m venv .venv && source .venv/bin/activate
pip install -e .

Usage

# Scan (also the default with no arguments - read-only, safe to run any time)
janus-sec
janus-sec scan

# Detailed per-target status (every scanned location, including missing ones)
janus-sec scan -v

# Interactive TUI
janus-sec tui

# Machine-readable output
janus-sec scan --format json

# CI mode: exit 1 if any HIGH-risk finding exists
janus-sec scan --ci

# Fix everything fixable, with confirmation
janus-sec fix

# Fix one specific file
janus-sec fix ~/.ssh/id_rsa

# Preview fixes without changing anything
janus-sec fix --dry-run
janus-sec fix -d

# Skip the confirmation prompt (for scripts)
janus-sec fix --yes
janus-sec fix -y

Configuration

~/.config/janus-sec/config.toml (optional — everything works with no config file at all):

# Suppress a specific check on a specific file - not the whole file,
# just that one issue, so other real problems on it still get caught.
[[ignore]]
path = "/home/user/.ssh/known_hosts"
check_type = "group_readable"
note = "shared dev box, group access is intentional"

# Treat a group as known-safe, machine-wide.
[[allowlist]]
group = "wheel"
action = "suppress"   # or "downgrade_to_low"
note = "trusted admin group on my machines"

Development

Same setup as above, plus test dependencies:

pip install pytest pytest-asyncio
pytest -v

License

MIT