#!/bin/bash

# run-shellcheck
#
# CIS Debian Hardening
#

#
# 4.1.10 Ensure discretionary access control permission modification events are collected (Scored)
#

set -e # One error, it's over
set -u # One variable unset, it's over

HARDENING_LEVEL=4
DESCRIPTION="Collect discretionary access control (DAC) permission modification events."

AUDIT_PARAMS='-a always,exit -F arch=b64 -S chmod -S fchmod -S fchmodat -F auid>=1000 -F auid!=4294967295 -k perm_mod
-a always,exit -F arch=b32 -S chmod -S fchmod -S fchmodat -F auid>=1000 -F auid!=4294967295 -k perm_mod
-a always,exit -F arch=b64 -S chown -S fchown -S fchownat -S lchown -F auid>=1000 -F auid!=4294967295 -k perm_mod
-a always,exit -F arch=b32 -S chown -S fchown -S fchownat -S lchown -F auid>=1000 -F auid!=4294967295 -k perm_mod
-a always,exit -F arch=b64 -S setxattr -S lsetxattr -S fsetxattr -S removexattr -S lremovexattr -S fremovexattr -F auid>=1000 -F auid!=4294967295 -k perm_mod
-a always,exit -F arch=b32 -S setxattr -S lsetxattr -S fsetxattr -S removexattr -S lremovexattr -S fremovexattr -F auid>=1000 -F auid!=4294967295 -k perm_mod'
FILE='/etc/audit/audit.rules'

# This function will be called if the script status is on enabled / audit mode
audit () {
    # define custom IFS and save default one
    d_IFS=$IFS
    c_IFS=$'\n'
    IFS=$c_IFS
    for AUDIT_VALUE in $AUDIT_PARAMS; do
        debug "$AUDIT_VALUE should be in file $FILE"
        IFS=$d_IFS
        does_pattern_exist_in_file $FILE $AUDIT_VALUE
        IFS=$c_IFS
        if [ $FNRET != 0 ]; then
            crit "$AUDIT_VALUE is not in file $FILE"
        else
            ok "$AUDIT_VALUE is present in $FILE"
        fi
    done
    IFS=$d_IFS
}

# This function will be called if the script status is on enabled mode
apply () {
    IFS=$'\n'
    for AUDIT_VALUE in $AUDIT_PARAMS; do
        debug "$AUDIT_VALUE should be in file $FILE"
        does_pattern_exist_in_file $FILE $AUDIT_VALUE
        if [ $FNRET != 0 ]; then
            warn "$AUDIT_VALUE is not in file $FILE, adding it"
            add_end_of_file $FILE $AUDIT_VALUE
            eval $(pkill -HUP -P 1 auditd)
        else
            ok "$AUDIT_VALUE is present in $FILE"
        fi
    done
}

# This function will check config parameters required
check_config() {
    :
}

# Source Root Dir Parameter
if [ -r /etc/default/cis-hardening ]; then
    . /etc/default/cis-hardening
fi
if [ -z "$CIS_ROOT_DIR" ]; then
     echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
     echo "Cannot source CIS_ROOT_DIR variable, aborting."
    exit 128
fi

# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
if [ -r $CIS_ROOT_DIR/lib/main.sh ]; then
    . $CIS_ROOT_DIR/lib/main.sh
else
    echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_ROOT_DIR in /etc/default/cis-hardening"
    exit 128
fi