Dotfiles/setup/modules/FreeipaAnsible/ansible/ansipa-enforce-policies.sh

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#!/usr/bin/env bash
# ansipa-enforce-policies.sh — enforce FreeIPA host-group-driven policies on this client.
#
# Policies are idempotent and reversible: joining a group applies the policy;
# leaving the group removes it on the next run (every 30 min via systemd timer).
#
# Host-group naming conventions:
# policy-block-binary-<name> Block execution of <name> via two layers:
# 1. PATH-priority wrapper in /usr/local/bin/ (catches $PATH calls)
# 2. AppArmor deny profile in /etc/apparmor.d/ (catches absolute paths)
# AppArmor layer is skipped silently if apparmor_parser is not present.
# policy-timeshift-backup Enforce a daily Timeshift snapshot (requires timeshift installed)
# policy-security-scan Enforce daily ClamAV + rkhunter + chkrootkit scans
#
# Notes:
# - Install scan tools first: add the host to ansipa-module-anti-malware.
# - Configure Timeshift (type + target device) before enabling policy-timeshift-backup.
set -euo pipefail
LOG_TAG="ansipa-policies"
STATE_DIR="/var/lib/ansipa-policies"
BLOCK_DIR="/usr/local/bin"
APPARMOR_DIR="/etc/apparmor.d"
CRON_DIR="/etc/cron.d"
log() { echo "[$LOG_TAG] $*"; logger -t "$LOG_TAG" "$*" 2>/dev/null || true; }
warn() { echo "[$LOG_TAG][WARN] $*" >&2; logger -t "$LOG_TAG" "WARN: $*" 2>/dev/null || true; }
HOST_FQDN=$(hostname -f 2>/dev/null || hostname)
if ! command -v ipa &>/dev/null; then
warn "ipa command not found — host not enrolled in FreeIPA. Exiting."
exit 0
fi
kinit -k "host/$HOST_FQDN" &>/dev/null || true
mkdir -p "$STATE_DIR"
# ── Fetch host group membership ───────────────────────────────────────────────
RAW_GROUPS=$(ipa host-show "$HOST_FQDN" --all 2>/dev/null \
| grep -i "Member of host-groups:" | sed 's/.*: //' || true)
# ── Parse active policy groups ────────────────────────────────────────────────
ACTIVE_BLOCK_BINARIES=()
WANT_TIMESHIFT_BACKUP=false
WANT_SECURITY_SCAN=false
if [[ -n "$RAW_GROUPS" ]]; then
while IFS=',' read -ra GRP_ARRAY; do
for g in "${GRP_ARRAY[@]}"; do
g="${g// /}"
case "$g" in
policy-block-binary-*) ACTIVE_BLOCK_BINARIES+=("${g#policy-block-binary-}") ;;
policy-timeshift-backup) WANT_TIMESHIFT_BACKUP=true ;;
policy-security-scan) WANT_SECURITY_SCAN=true ;;
esac
done
done <<< "$RAW_GROUPS"
fi
log "Active policies — block-binary: ${ACTIVE_BLOCK_BINARIES[*]:-none}" \
"| timeshift-backup: $WANT_TIMESHIFT_BACKUP | security-scan: $WANT_SECURITY_SCAN"
# ── Helpers ───────────────────────────────────────────────────────────────────
in_active_list() {
local needle="$1"
for b in "${ACTIVE_BLOCK_BINARIES[@]}"; do
[[ "$b" == "$needle" ]] && return 0
done
return 1
}
# Find the real installed binary, skipping /usr/local/bin where our wrapper lives.
find_real_binary() {
local name="$1"
for dir in /usr/bin /usr/sbin /bin /sbin /usr/local/sbin /opt/bin; do
[[ -x "$dir/$name" ]] && echo "$dir/$name" && return 0
done
return 1
}
aa_profile_file() { echo "$APPARMOR_DIR/ansipa-block-${1}"; }
# Load an AppArmor deny profile for a binary path.
# An empty AppArmor profile denies all access: the binary cannot load shared
# libraries or open any files, so it exits immediately with a permission error.
apply_apparmor_block() {
local bin="$1"
command -v apparmor_parser &>/dev/null || return 0
local bin_path
bin_path=$(find_real_binary "$bin") || {
warn "AppArmor block: real binary '$bin' not found on disk — profile skipped until it is installed."
return 0
}
local profile_file
profile_file=$(aa_profile_file "$bin")
# Write the profile only if it doesn't exist or points to a different path.
if [[ ! -f "$profile_file" ]] || ! grep -qF "$bin_path" "$profile_file" 2>/dev/null; then
log "Writing AppArmor block profile: $profile_file ($bin_path)"
cat > "$profile_file" <<PROFILE
#include <tunables/global>
# ansipa-block-policy: managed by ansipa-enforce-policies — do not edit manually.
# Deny all access so the binary cannot load libraries or run.
# To unblock manually: apparmor_parser -R $profile_file && rm $profile_file
$bin_path {
}
PROFILE
fi
# Load (or reload) the profile in enforce mode.
if ! apparmor_parser -r "$profile_file" 2>/dev/null; then
warn "apparmor_parser failed to load $profile_file — AppArmor block not active"
fi
}
# Remove the AppArmor deny profile for a binary.
remove_apparmor_block() {
local bin="$1"
command -v apparmor_parser &>/dev/null || return 0
local profile_file
profile_file=$(aa_profile_file "$bin")
[[ -f "$profile_file" ]] || return 0
if grep -q "ansipa-block-policy" "$profile_file" 2>/dev/null; then
apparmor_parser -R "$profile_file" 2>/dev/null || true
rm -f "$profile_file"
log "Removed AppArmor block profile: $bin"
fi
}
# ── Binary blocking ───────────────────────────────────────────────────────────
# Layer 1: PATH-priority wrapper in /usr/local/bin/ — blocks $PATH-based calls.
# Layer 2: AppArmor deny profile — blocks absolute-path calls and direct exec().
# Both layers use the "ansipa policy" sentinel to identify managed files.
BLOCK_STATE="$STATE_DIR/blocked-binaries"
[[ -f "$BLOCK_STATE" ]] || touch "$BLOCK_STATE"
for BIN in "${ACTIVE_BLOCK_BINARIES[@]}"; do
WRAPPER="$BLOCK_DIR/$BIN"
if [[ ! -f "$WRAPPER" ]] || ! grep -q "blocked by ansipa policy" "$WRAPPER" 2>/dev/null; then
log "Applying PATH wrapper block: $BIN"
cat > "$WRAPPER" <<WRAPPER
#!/bin/bash
# blocked by ansipa policy
echo "[$LOG_TAG] '$BIN' is blocked by system policy on this host." >&2
exit 1
WRAPPER
chmod 755 "$WRAPPER"
fi
apply_apparmor_block "$BIN"
done
# Remove blocks for binaries no longer in any active policy group.
while IFS= read -r OLD_BIN; do
[[ -z "$OLD_BIN" ]] && continue
if ! in_active_list "$OLD_BIN"; then
WRAPPER="$BLOCK_DIR/$OLD_BIN"
if [[ -f "$WRAPPER" ]] && grep -q "blocked by ansipa policy" "$WRAPPER" 2>/dev/null; then
rm -f "$WRAPPER"
log "Removed PATH wrapper block: $OLD_BIN"
fi
remove_apparmor_block "$OLD_BIN"
fi
done < "$BLOCK_STATE"
# Persist current blocked list.
if [[ ${#ACTIVE_BLOCK_BINARIES[@]} -gt 0 ]]; then
printf '%s\n' "${ACTIVE_BLOCK_BINARIES[@]}" | sort -u > "$BLOCK_STATE"
else
> "$BLOCK_STATE"
fi
# ── Timeshift daily backup ─────────────────────────────────────────────────────
TIMESHIFT_CRON="$CRON_DIR/ansipa-timeshift-backup"
if [[ "$WANT_TIMESHIFT_BACKUP" == true ]]; then
if [[ ! -f "$TIMESHIFT_CRON" ]]; then
if ! command -v timeshift &>/dev/null; then
warn "timeshift not found — add host to ansipa-module-timeshift first. Cron will be installed anyway."
fi
log "Enabling daily Timeshift backups"
cat > "$TIMESHIFT_CRON" <<'CRON'
# ansipa-policy-timeshift-backup: managed by ansipa-enforce-policies — do not edit manually.
# Timeshift must be configured on this host (type + target device) before snapshots work.
0 3 * * * root /usr/bin/timeshift --create --comments "ansipa-daily" --tags D 2>&1 | logger -t timeshift-backup
CRON
chmod 644 "$TIMESHIFT_CRON"
fi
else
if [[ -f "$TIMESHIFT_CRON" ]]; then
rm -f "$TIMESHIFT_CRON"
log "Removed Timeshift backup cron (host left policy-timeshift-backup group)"
fi
fi
# ── Security scan ─────────────────────────────────────────────────────────────
SCAN_CRON="$CRON_DIR/ansipa-security-scan"
SCAN_SCRIPT="/usr/local/bin/ansipa-security-scan.sh"
if [[ "$WANT_SECURITY_SCAN" == true ]]; then
# (Re-)write the scan script so it stays current with this version of the enforcer.
cat > "$SCAN_SCRIPT" <<'SCAN'
#!/bin/bash
# ansipa-security-scan — daily ClamAV / rkhunter / chkrootkit run.
# Managed by ansipa-enforce-policies — do not edit manually.
LOG=/var/log/ansipa-security-scan.log
{
echo "=== ansipa-security-scan: $(date) ==="
if command -v freshclam &>/dev/null; then
freshclam --quiet 2>/dev/null || true
fi
if command -v clamscan &>/dev/null; then
clamscan -r --infected --quiet /home /etc /tmp /var/tmp 2>/dev/null || true
fi
if command -v rkhunter &>/dev/null; then
rkhunter --update --quiet 2>/dev/null || true
rkhunter --check --skip-keypress --quiet 2>/dev/null || true
fi
if command -v chkrootkit &>/dev/null; then
chkrootkit 2>/dev/null || true
fi
echo "=== scan complete ==="
} >> "$LOG" 2>&1
SCAN
chmod 755 "$SCAN_SCRIPT"
if [[ ! -f "$SCAN_CRON" ]]; then
log "Enabling daily security scans (ClamAV / rkhunter / chkrootkit)"
cat > "$SCAN_CRON" <<'CRON'
# ansipa-policy-security-scan: managed by ansipa-enforce-policies — do not edit manually.
# Install scan tools by adding the host to the ansipa-module-anti-malware group.
0 2 * * * root /usr/local/bin/ansipa-security-scan.sh
CRON
chmod 644 "$SCAN_CRON"
fi
else
if [[ -f "$SCAN_CRON" ]]; then
rm -f "$SCAN_CRON"
rm -f "$SCAN_SCRIPT"
log "Removed security scan policy (host left policy-security-scan group)"
fi
fi
log "Policy enforcement complete."