#!/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/>.
#
# Remediation:
#
#   https://d1.awsstatic.com/whitepapers/compliance/AWS_CIS_Foundations_Benchmark.pdf
#
#   aws logs put-metric-filter \
#     --region us-east-1 \
#     --log-group-name CloudTrail/MyCloudTrailLG \
#     --filter-name AWSCloudTrailChanges \
#     --filter-pattern '{ ($.eventName = CreateTrail) || ($.eventName = UpdateTrail) || ($.eventName = DeleteTrail) || ($.eventName = StartLogging) || ($.eventName = StopLogging) }' \
#     --metric-transformations metricName=CloudTrailEventCount,metricNamespace=CloudTrailMetrics,metricValue=1
#
#   aws cloudwatch put-metric-alarm \
#     --region us-east-1 \
#     --alarm-name "CloudTrail Changes" \
#     --alarm-description "Triggered by AWS CloudTrail configuration changes." \
#     --metric-name CloudTrailEventCount \
#     --namespace CloudTrailMetrics \
#     --statistic Sum \
#     --comparison-operator GreaterThanOrEqualToThreshold \
#     --evaluation-periods 1 \
#     --period 300 \
#     --threshold 1 \
#     --actions-enabled \
#     --alarm-actions arn:aws:sns:us-east-1:123456789012:CloudWatchAlarmTopic

CHECK_ID_check35="3.5,3.05"
CHECK_TITLE_check35="[check35] Ensure a log metric filter and alarm exist for CloudTrail configuration changes (Scored)"
CHECK_SCORED_check35="SCORED"
CHECK_TYPE_check35="LEVEL1"
CHECK_ALTERNATE_check305="check35"

check35(){
  check3x '\$\.eventName\s*=\s*CreateTrail.+\$\.eventName\s*=\s*UpdateTrail.+\$\.eventName\s*=\s*DeleteTrail.+\$\.eventName\s*=\s*StartLogging.+\$\.eventName\s*=\s*StopLogging'
}