Hermes Security Hardening

IDENTITY: Hardener.Sysadmin. Execute security hardening — fix file permissions, install secret-scanning hooks, migrate to macOS Keychain, create security policy, and set up automated prevention. Action-first, report-after. Law: AlwaysUseAbsolutePaths — macOS terminal tool's ~ resolution is unreliable for file operations. WHENUSE: InitialSetup|AfterExposedSecretsFound|PeriodicHardening{weekly,monthly}|ComplianceRequirement. ESPECIALLY:WorldReadableEnvFiles|NoSecretScanningOnCommit|PlaintextKeysInDotEnv. NoSkip:PostChangeVerification{statPermissions,gitleaksScan,npmAudit}. REDFLAGS: cp~pathFailsSilently->Use/$USER/absPath|hermesConfigGetReturnsEmpty->grepConfigDirectly|Gitleaks--pipeFlagFails->Use--no-gitWith--source|PreCommitHookNotFiring->CheckExecutable+core.hooksPath|KeychainSecretsNotLoading->CheckAccountName+ReAdd. RATIONALIZATIONS: BashVsPython->BashFasterNoFstringIssues|GitleaksVsTruffleHog->GitleaksFasterBetterTOML|NoAutomaticKeyRotation->UserWantsMonitoringFirst. QUICKREF: Map{ActiveEnvFiles{findNotArchive}->WhichEnvLoaded{hermes config}}->Audit{Permissions,SecretsExposed,NetworkExposure,ConfigPrivacy{redact_secrets,redact_pii,approvals.mode}}->Create{SecDir{scripts+gitleaks+precommit+policy+keychainLoader}}->Apply{chmod600,gitleaks,precommit,keychain}->Verify{Stats,gitleaksScan,banditScan,npmAudit,KeychainLoad,PreCommitTest}.

Overview

This skill automates comprehensive security hardening for a Hermes installation. It addresses the three critical areas:

1. File Permissions — .env files to 600, .git directories to remove world access
2. Secret Management — migrates from plaintext .env to macOS Keychain, provides loader script
3. Prevention — installs gitleaks pre-commit hooks, creates security policy, builds automated remediation

When to Use

• Initial Hermes installation security setup
• After discovering exposed secrets or weak permissions
• Periodic security hardening (weekly/monthly)
• Auditing a Hermes installation for compliance

Prerequisites

• macOS (uses security CLI for Keychain)
• Hermes installed in standard locations: ~/.hermes/, ~/hermes-webui/, ~/hermes-workspace/
• User has write permissions to all Hermes directories
• Shell: zsh or bash

What This Skill Creates

~/.hermes/security/
├── harden-hermes.sh              (primary — bash, idempotent)
├── harden-hermes-security.py     (fallback — Python)
├── install-all.sh                (one-command fresh install)
├── pre-commit.template           (gitleaks hook source)
├── .gitleaks.toml.template       (gitleaks config)
├── SECURITY_POLICY.md            (full security policy)
├── README.md                     (quick reference)
└── HARDENING_SUMMARY.md          (run summary)

~/.hermes/load-keychain-secrets.sh   (keychain loader — source in shell)
~/hermes-webui/.gitleaks.toml         (active gitleaks config)
~/hermes-webui/.git/hooks/pre-commit  (active pre-commit hook)

Execution Approach

This user prefers action-first, explanation-after. Do not list options or ask "which do you want to do?" — instead, execute the full set of changes, then deliver a structured report explaining what changed and how each control works. Verify each change after applying it and include the verification result in the report. This preference applies to all security-hardening sessions unless the user explicitly asks for a plan first.

Step-by-Step Process

Step 0: Map the Active .env Files

Before hardening, identify which .env files actually carry active credentials. The skill's template references archive/.env but that's a state-snapshot directory — not active config.

# Find all active .env files (exclude archive and home/ subdirectories)
find ~/.hermes -name ".env" -not -path "*/home/*" -not -path "*/state-snapshots/*" -not -path "*/archive/*"

# Check which .env is loaded by the current profile
hermes config | grep "Secrets:"

Likely targets:

• ~/.hermes/.env — root, shared across profiles (often the primary threat)
• ~/.hermes/profiles/<name>/.env — profile-specific overrides

Step 1: Audit Current State

Scan to identify issues before fixing:

# Check .env file permissions (use ABSOLUTE paths — macOS ~ resolution bug)
ls -la /Users/$USER/.hermes/.env /Users/$USER/.hermes/profiles/senna/.env
stat -f "%A %N" /Users/$USER/.hermes/.env /Users/$USER/.hermes/profiles/senna/.env

# Check git directory world-access
namei -l /Users/$USER/hermes-webui/.git /Users/$USER/hermes-workspace/.git 2>/dev/null

# Check for exposed secrets in files
grep -r "api_key\|token\|password\|HERMES.*KEY\|OPENROUTER\|ANTHROPIC\|DEEPSEEK\|GITHUB" ~/.hermes/.env ~/.hermes/profiles/senna/.env 2>/dev/null

# Check network exposure
lsof -i -n -P | grep -E '8787|8642'

# Check current config values for privacy/security toggles
grep -n "redact_secrets\|redact_pii\|approvals.mode\|mode:" /Users/$USER/.hermes/profiles/senna/config.yaml | head -10

Expected findings before fix:

• .env files: -rw-r--r-- (644) — world-readable ❌
• .git dirs: drwxr-xr-x (755) — world-traversable ❌
• Secrets in plaintext ❌
• redact_pii: false — PII exposed in gateway context ❌
• approvals.mode: manual — prompts on every flagged command ❌

Step 2: Create Security Directory Structure

mkdir -p ~/.hermes/security

All artifacts live here for version control and backup.

Step 3: Build the Hardening Script (Bash — Recommended)

Create ~/.hermes/security/harden-hermes.sh:

#!/usr/bin/env bash
set -e

echo "🔐 Hermes Security Hardening"
echo "============================"

# 1. Fix .env perms (root + active profile — NOT archive/ which is state snapshots)
chmod 600 ~/.hermes/.env 2>/dev/null && echo "✓ ~/.hermes/.env" || echo "- not found"
chmod 600 ~/.hermes/profiles/senna/.env 2>/dev/null && echo "✓ profile .env" || echo "- not found"

# 2. Fix git dirs (remove world access — all repos that contain Hermes code)
chmod -R o-rwx ~/hermes-webui/.git 2>/dev/null && echo "✓ ~/hermes-webui/.git" || echo "- not found"
chmod -R o-rwx ~/hermes-workspace/.git 2>/dev/null && echo "✓ ~/hermes-workspace/.git" || echo "- not found"

# 3. Install tools
brew install gitleaks 2>/dev/null && echo "✓ gitleaks" || echo "⚠ gitleaks may already be installed"
pip install bandit safety 2>/dev/null && echo "✓ bandit, safety" || echo "⚠ pip install failed"

# 4. Configure gitleaks (if missing)
if [ ! -f ~/hermes-webui/.gitleaks.toml ]; then
    cp ~/.hermes/security/.gitleaks.toml.template ~/hermes-webui/.gitleaks.toml 2>/dev/null || true
fi

# 5. Install pre-commit hooks in ALL Hermes repos
for repo in ~/hermes-webui ~/hermes-workspace; do
    if [ -d "$repo/.git" ]; then
        cp ~/.hermes/security/pre-commit.template "$repo/.git/hooks/pre-commit" 2>/dev/null || true
        chmod +x "$repo/.git/hooks/pre-commit" 2>/dev/null || true
        echo "✓ pre-commit hook installed: $repo"
    fi
done

echo "✅ Done!"

Rationale for bash over Python: Bash avoids f-string formatting issues (experienced), uses native chmod, simpler error handling with ||, and runs faster without interpreter overhead. Keep Python version as fallback for complex logic extensions.

Make it executable:

chmod +x ~/.hermes/security/harden-hermes.sh

Step 4: Create the Pre-commit Hook

Hook file: ~/.hermes/security/pre-commit.template

#!/usr/bin/env bash
# Hermes Pre-commit Hook — blocks secret leakage

if command -v gitleaks &>/dev/null; then
    echo "🔍 Scanning for secrets with gitleaks..."
    if ! gitleaks detect --source="$(git rev-parse --show-toplevel)" --no-git -v 2>/dev/null; then
        echo "❌ Commit blocked: secrets detected!"
        exit 1
    fi
fi

# Optional: bandit for Python files
if command -v bandit &>/dev/null; then
    STAGED_PY=$(git diff --cached --name-only --diff-filter=ACM | grep '\.py$')
    if [ -n "$STAGED_PY" ]; then
        echo "🔍 Scanning Python files with bandit..."
        echo "$STAGED_PY" | xargs bandit -r 2>/dev/null || true
    fi
fi

exit 0

Install pre-commit hooks to BOTH repos (workspace AND webui):

# Use ABSOLUTE paths — macOS terminal tool may not resolve ~ correctly for cp
cp /Users/$USER/.hermes/security/pre-commit.template /Users/$USER/hermes-webui/.git/hooks/pre-commit
cp /Users/$USER/.hermes/security/pre-commit.template /Users/$USER/hermes-workspace/.git/hooks/pre-commit
chmod +x /Users/$USER/hermes-webui/.git/hooks/pre-commit /Users/$USER/hermes-workspace/.git/hooks/pre-commit

Note: Pre-commit hooks are per-repo, not global. You must install in each Hermes component repo separately. Don't forget hermes-workspace — the skill's original examples only show hermes-webui. Document this in policy.

Step 5: Configure Gitleaks

Create ~/.hermes/security/.gitleaks.toml.template:

[extend]
useDefault = true

[allowlist]
description = "Allowlist for Hermes codebase"
regexTarget = "line"
regexes = [
    # HERMES_WEBUI_PORT=8787 — allowed
    'HERMES_WEBUI_PORT=\d+',
    # HERMES_WEBUI_HOST=127.0.0.1 — allowed
    'HERMES_WEBUI_HOST=',
    # OBSIDIAN_VAULT_PATH — allowed
    'OBSIDIAN_VAULT_PATH=',
]

# Custom rules for your secret patterns
[[rules]]
id = "hermes-exposed-api-key"
description = "Detect exposed API keys in .env files"
regex = '''(?i)(api[_-]?key|token|secret|password)\s*=\s*["']?[A-Za-z0-9_\-]{20,}["']?'''
tags = ["key", "secret"]

Copy to active repo:

cp ~/.hermes/security/.gitleaks.toml.template ~/hermes-webui/.gitleaks.toml

Step 6: Create Keychain Loader

File: ~/.hermes/load-keychain-secrets.sh

#!/usr/bin/env bash
# Load Hermes secrets from macOS Keychain into environment variables
# Source this in your shell: source ~/.hermes/load-keychain-secrets.sh

KEYCHAIN_SERVICE="hermes-secrets"

# Function to load a secret by account name
_load_secret() {
    local account="$1"
    local varname="$2"
    local secret
    secret=$(security find-generic-password -s "$KEYCHAIN_SERVICE" -a "$account" -w 2>/dev/null)
    if [ -n "$secret" ]; then
        export "$varname=$secret"
        echo "✓ Loaded $account → $varname"
    else
        echo "⚠ $account not found in keychain"
    fi
}

# Load all Hermes secrets
_load_secret "openrouter-api-key" "OPENROUTER_API_KEY"
_load_secret "github-token" "GITHUB_TOKEN"

# Unset helper function
unset -f _load_secret

Make executable:

chmod +x ~/.hermes/load-keychain-secrets.sh

Add to shell profile:

echo 'source ~/.hermes/load-keychain-secrets.sh' >> ~/.zshrc
source ~/.zshrc

Step 7: Create Security Policy

File: ~/.hermes/security/SECURITY_POLICY.md

Structure:

• Section 1 — Overview: Security principles (least privilege, defense in depth)
• Section 2 — Secrets Management: Mandatory Keychain storage, .env only for non-secrets
• Section 3 — File Permissions: Matrix of required modes (.env=600, .git=700)
• Section 4 — Network Security: Binding policy (127.0.0.1 default, external needs approval)
• Section 5 — Code Security: Prohibited patterns (exec(), pickle.load(), shell=True)
• Section 6 — Access Control: Non-root execution, user isolation
• Section 7 — Monitoring & Incident Response: Log review schedule, key monitoring
• Section 8 — Regular Maintenance: Weekly/monthly/quarterly checklists
• Section 9 — Security Checklist: New install verification
• Section 10 — Compliance & Exceptions: How to document deviations
• Section 11 — Contact & Resources: Tool references
• Section 12 — Quick Reference Commands: One-liners

Key policy decisions to document:

• External API binding (0.0.0.0) is allowed but requires firewall justification
• Secrets: Keychain only, never plaintext .env
• No TLS for localhost (acceptable risk for single-user)
• Key rotation: OpenRouter 90d, GitHub 180d (monitor instead, user discretion)

Step 8: Add Secrets to Keychain

User executes (manual — cannot automate secret entry):

security add-generic-password -a openrouter-api-key -s hermes-secrets -w "sk-or-actual-key-here"
security add-generic-password -a github-token -s hermes-secrets -w "ghp_actual-token-here"

Verify (values hidden):

security find-generic-password -s hermes-secrets -g

Important: The security CLI prompts for keychain access on first use. User must allow.

Step 9: Verify Everything

Run comprehensive checks:

# 1. Permissions — check ACTIVE .env files, not archive/ snapshots
stat -f "%A %N" ~/.hermes/.env ~/.hermes/profiles/senna/.env 2>/dev/null     # → 600
ls -ld ~/hermes-webui/.git             # → drwx------ (no world bits)

# 2. Secret scanning
gitleaks detect --source=~/hermes-webui
gitleaks detect --source=~/hermes-workspace

# 3. Python security scan
bandit -r ~/hermes-webui/api

# 4. Dependency check
cd ~/hermes-workspace && npm audit --audit-level=moderate

# 5. Keychain loading
source ~/.hermes/load-keychain-secrets.sh
echo $OPENROUTER_API_KEY  # should show (if added)

# 6. Pre-commit test
cd ~/hermes-webui
git add -A  # should run gitleaks and pass if no secrets

Step 10: Set Up Weekly Automation (Optional)

Cron job to re-harden weekly:

crontab -e
# Add:
0 3 * * 0 ~/.hermes/security/harden-hermes.sh >/dev/null 2>&1

Or use Hermes's built-in cron (if available):

# In hermes config
cronjob(action='create', schedule='0 3 * * 0', prompt='Run Hermes security hardening', skills=['hermes-security-hardening'])

Pitfalls & Solutions

Problem: macOS '~' path resolution in terminal tool

Symptom: cp ~/.hermes/security/pre-commit.sh … fails silently or copies to a wrong location, even though other commands (like ls -la) work fine with tilde paths. The file "exists at abs path" when checked with /Users/$USER/... but cp ~/... errors with "No such file or directory."

Cause: The Hermes terminal tool runs without a full shell environment, so ~ may resolve differently (or to a subdirectory like ~/.hermes/profiles/senna/home/.hermes/) than in an interactive terminal.

Fix: Always use absolute paths (/Users/$USER/...) for file operations — especially cp, mv, chmod, and stat:

# DO — use absolute paths
cp /Users/$USER/.hermes/security/pre-commit.sh /Users/$USER/hermes-webui/.git/hooks/pre-commit

# DON'T — may fail or resolve to wrong directory
cp ~/.hermes/security/pre-commit.sh ~/hermes-webui/.git/hooks/pre-commit

For read-only commands (ls, grep, cat), tilde often works fine. For destructive/copy operations, always resolve the full path.

Problem: Config change not verifiable via hermes config get

Symptom: hermes config get approvals.mode returns empty output or exit code 2, even though the value is set in config.yaml.

Cause: hermes config get only recognizes a subset of config keys. Privacy/security sub-keys (under privacy:, security:, approvals:) may not be exposed via this interface.

Fix: Use grep directly on the config file:

grep -n "redact_secrets\|redact_pii\|approvals.mode\|mode:" /Users/$USER/.hermes/profiles/senna/config.yaml

This is more reliable than hermes config get for nested config sections.

Problem: Gitleaks --pipe flag (v8.x)

Symptom: Running gitleaks detect --no-git --pipe fails with "unknown shorthand flag" or hangs scanning large directories.

Cause: Gitleaks v8.x changed its stdin handling. The --pipe flag is for reading from stdin (e.g., cat file | gitleaks detect --pipe). The --no-git flag treats the source as a regular directory. In a pre-commit hook context, use --no-git with a --source pointing to the repo root — don't pipe into it.

Fix in pre-commit hooks: The hook should use --no-git with --source set to $(git rev-parse --show-toplevel):

gitleaks detect --source="$(git rev-parse --show-toplevel)" --no-git -v

Symptom: SyntaxError: f-string: missing '}' or similar when running Python hardening script.

Cause: In Python 3.11 and earlier, f-strings cannot contain backslash-escaped expressions that span lines. The original script had f" ✓ {f} -> {oct(expected_perm)}" on a single line but the {f} variable came from a loop that used path objects with backslashes in string formatting.

Solution: Switch to bash for the primary hardening script (simpler, no f-string issues). If Python is required, replace f-strings with concatenation:

log("  ✓ " + str(f) + " -> " + oct(expected_perm), "OK")

Or use .format():

log("  ✓ {} -> {}".format(f, oct(expected_perm)), "OK")

Decision: Bash is better for this task — fewer dependencies, runs faster, fewer syntax traps.

Problem: Pre-commit hook not firing

Symptom: git commit doesn't run gitleaks scan.

Cause: Hook not executable, or installed in wrong repo, or git config core.hooksPath overrides.

Solution:

chmod +x ~/hermes-webui/.git/hooks/pre-commit
git config core.hooksPath  # if set, adjust accordingly
ls -l ~/hermes-webui/.git/hooks/pre-commit  # should show -rwxr-xr-x

Problem: Keychain secrets not loading

Symptom: echo $OPENROUTER_API_KEY shows empty after source.

Cause: Secret not in keychain, wrong account name, or keychain access denied.

Diagnosis:

security find-generic-password -s hermes-secrets -a openrouter-api-key -w
# Returns secret if found, or prompts for keychain access

Fix: Re-add with exact account name:

security add-generic-password -a openrouter-api-key -s hermes-secrets -w "actual-key"

Problem: Gitleaks false positives

Symptom: Hook blocks commit on allowed patterns (e.g., HERMES_WEBUI_PORT=8787).

Cause: Default gitleaks rules are overzealous.

Fix: Add regex allowlist entries in ~/hermes-webui/.gitleaks.toml:

[allowlist]
regexes = [
    'HERMES_WEBUI_PORT=\d+',
    'HERMES_WEBUI_HOST=',
]

Problem: Permissions revert after reboots

Symptom: .env files become 644 again after system restart.

Cause: Some backup/restore process or synced folder resetting permissions. Unlikely on local macOS.

Fix: Ensure no cloud sync (Dropbox, iCloud) is resetting. Add cron weekly check:

0 3 * * 0 ~/.hermes/security/harden-hermes.sh

Decision Log

Output

After running this skill, you will have:

1. All file permissions corrected — verified with ls -l
2. Active secret scanning — git commit triggers gitleaks
3. Keychain integration — source ~/.hermes/load-keychain-secrets.sh populates env vars
4. Security policy — documented standards in SECURITY_POLICY.md
5. Automation — one-command harden-hermes.sh for future runs
6. Audit trail — all changes logged, reversible

Verification Checklist

• stat -f "%A %N" ~/.hermes/.env shows 600 (owner-only)
• stat -f "%A %N" ~/.hermes/profiles/senna/.env shows 600
• ls -ld ~/hermes-webui/.git shows no world-bits (drwx------)
• ls -ld ~/hermes-workspace/.git shows no world-bits
• grep "redact_secrets" ~/.hermes/profiles/senna/config.yaml shows true
• grep "redact_pii" ~/.hermes/profiles/senna/config.yaml shows true
• grep "approvals.mode" ~/.hermes/profiles/senna/config.yaml shows smart
• lsof -nP -iTCP:8642 -sTCP:LISTEN shows 127.0.0.1:8642 (localhost-only)
• gitleaks version returns a version number (v8+)
• ls -la ~/hermes-webui/.git/hooks/pre-commit exists and is executable
• ls -la ~/hermes-workspace/.git/hooks/pre-commit exists and is executable
• cat ~/.hermes/security/SECURITY_POLICY.md exists and is readable

Config verification: hermes config get <key> may not return all values. Always fall back to grepping the config file directly for nested keys under privacy:, security:, and approvals:.

Runtime Security Plugin

This skill hardens the pre-deploy layer (permissions, secrets, pre-commit hooks). To add runtime security that fires automatically on every tool call (command scanning, output filtering, audit trail, injection defense), see hermes-runtime-security. It builds a Hermes plugin using the pre_tool_call / post_tool_call / pre_gateway_dispatch hooks — once installed, it runs without manual invocation.

The two approaches are complementary layers in a defense-in-depth strategy:

• This skill = static hardening (permissions, keychain, gitleaks)
• hermes-runtime-security = dynamic middleware (live scanning at execution time)

Related Skills

• hermes-directory-cleanup — cleanup old archives (complementary)
• gitleaks — standalone secret scanning (used internally)
• system-hardening — broader OS-level security (future)

VPS Security Hardening (Linux Cloud Servers)

When deploying Hermes on a VPS (Oracle Cloud, Hetzner, DigitalOcean, etc.), apply security hardening on day 1 before installing Hermes. The VPS has a different threat model than macOS: it's internet-facing, discoverable (especially if you build in public), and attackers scan new IPs within hours.

Full checklist: references/vps-security-hardening.md

Key layers:

1. SSH hardening — key-only auth, no root login, max 3 retries
2. UFW firewall — default deny, only SSH open (Hermes communicates outbound only)
3. Fail2Ban — auto-ban after 3 failed SSH attempts
4. Unattended security updates — auto-patch CVEs
5. Audit logging — track config/user/cron changes
6. Non-root user — never run Hermes as root

VPS provider comparison is included in the reference (Oracle Free vs Hetzner CX22/CX32 vs DigitalOcean vs Contabo).

Build-in-Public Security

When your repos are public (build-in-public), the threat model changes:

• Commits are scraped by bots within seconds of push
• Screenshots may leak terminal contents with secrets
• Architecture diagrams shouldn't include internal IPs

What to expose: source code, architecture decisions, commit history, bug stories, performance metrics, revenue numbers, tech stack choices.

What to hide: API keys, .env files, server IPs, DB connection strings, OAuth secrets, SSH keys, personal info in code comments.

The golden rule: If you'd be uncomfortable seeing it on the front page of Hacker News, don't commit it.

Required for public repos:

• .gitignore covering .env, *.key, *.pem, auth.json, credentials.json
• gitleaks pre-commit hook (blocks secret commits before they happen)
• GitHub secret scanning enabled per repo
• Dependabot alerts enabled
• Branch protection on main (require PR reviews, even if solo)
• GitHub PAT with minimal scopes (only repo, not admin:org)

Runtime Security Companion

This skill covers STATIC hardening (permissions, pre-commit hooks, keychain). For RUNTIME security during agent operation (command scanning, injection defense, output scanning), the Katana plugin runs automatically:

• Plugin: ~/.hermes/profiles/senna/plugins/katana/
• Config: ~/.hermes/profiles/senna/plugins/katana/config.yaml
• Audit: ~/.hermes/logs/katana-audit.jsonl
• Development pattern: see hermes-plugin-dev skill

Static (this skill) + Runtime (Katana plugin) = defense in depth.

References

Maintenance

This skill produces artifacts that require periodic updates:

• Weekly: Run ~/.hermes/security/harden-hermes.sh to fix any drift
• Monthly: Update gitleaks rules, review SECURITY_POLICY.md
• Quarterly: Rotate API keys in keychain, run full bandit scan

If you update the policy or hooks manually, consider patching this skill to keep the templates current.