#!/usr/bin/env bash

# Prowler - the handy cloud security tool (c) by Toni de la Fuente
#
# This Prowler check is licensed under a
# Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
#
# You should have received a copy of the license along with this
# work. If not, see <http://creativecommons.org/licenses/by-nc-sa/4.0/>.

CHECK_ID_check313="3.13"
CHECK_TITLE_check313="[check313] Ensure a log metric filter and alarm exist for route table changes (Scored)"
CHECK_SCORED_check313="SCORED"
CHECK_TYPE_check313="LEVEL1"
CHECK_ALTERNATE_check313="check313"

check313(){
  # "Ensure a log metric filter and alarm exist for route table changes (Scored)"
  CLOUDWATCH_GROUP=$($AWSCLI cloudtrail describe-trails $PROFILE_OPT --region $REGION --query 'trailList[*].CloudWatchLogsLogGroupArn' --output text | tr '	' '
' | awk -F: '{ print $7 }')
  if [[ $CLOUDWATCH_GROUP ]];then
    for group in $CLOUDWATCH_GROUP; do
      CLOUDWATCH_LOGGROUP_REGION=$($AWSCLI cloudtrail describe-trails $PROFILE_OPT --region $REGION --query 'trailList[*].CloudWatchLogsLogGroupArn' --output text | tr '	' '
' | grep $group | awk -F: '{ print $4 }'  | head -n 1)
      METRICFILTER_SET=$($AWSCLI logs describe-metric-filters --log-group-name $group $PROFILE_OPT --region $CLOUDWATCH_LOGGROUP_REGION --query 'metricFilters' | grep -E 'CreateRoute.*CreateRouteTable.*ReplaceRoute.*ReplaceRouteTableAssociation.*DeleteRouteTable.*DeleteRoute.*DisassociateRouteTable')
      if [[ $METRICFILTER_SET ]];then
        HAS_ALARM_ASSOCIATED=$($AWSCLI cloudwatch describe-alarms $PROFILE_OPT --region $CLOUDWATCH_LOGGROUP_REGION --query 'MetricAlarms[].MetricName' --output text | awk 'BEGIN {IGNORECASE=1}; /Route/;')
        if [[ $HAS_ALARM_ASSOCIATED ]];then
          textPass "CloudWatch group $group found with metric filters and alarms for route table changes"
        else
          textFail "CloudWatch group $group found with metric filters but no alarms associated"
        fi
      else
        textFail "CloudWatch group $group found but no metric filters or alarms associated"
      fi
    done
  else
    textFail "No CloudWatch group found for CloudTrail events"
  fi
}