#!/usr/bin/env bash

# Prowler - the handy cloud security tool (copyright 2019) by Toni de la Fuente
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not
# use this file except in compliance with the License. You may obtain a copy
# of the License at http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software distributed
# under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
# CONDITIONS OF ANY KIND, either express or implied. See the License for the
# specific language governing permissions and limitations under the License.
#
# 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/CloudWatchLogGroup \
#     --filter-name RootAccountUsage \
#     --filter-pattern '{ $.userIdentity.type = "Root" && $.userIdentity.invokedBy NOT EXISTS && $.eventType != "AwsServiceEvent" }' \
#     --metric-transformations metricName=RootAccountUsageEventCount,metricNamespace=CloudTrailMetrics,metricValue=1 \
#
#   aws cloudwatch put-metric-alarm \
#     --region us-east-1 \
#     --alarm-name RootAccountUsageAlarm \
#     --alarm-description "Triggered by AWS Root Account usage." \
#     --metric-name RootAccountUsageEventCount \
#     --namespace CloudTrailMetrics \
#     --statistic \
#     --comparison-operator GreaterThanOrEqualToThreshold \
#     --evaluation-periods 1 \
#     --period 300 \
#     --threshold 1 \
#     --actions-enabled \
#     --alarm-actions arn:aws:sns:us-east-1:123456789012:CloudWatchAlarmTopic

CHECK_ID_check33="3.3"
CHECK_TITLE_check33="[check33] Ensure a log metric filter and alarm exist for usage of root account"
CHECK_SCORED_check33="SCORED"
CHECK_CIS_LEVEL_check33="LEVEL1"
CHECK_SEVERITY_check33="Medium"
CHECK_ASFF_TYPE_check33="Software and Configuration Checks/Industry and Regulatory Standards/CIS AWS Foundations Benchmark"
CHECK_ASFF_RESOURCE_TYPE_check33="AwsCloudTrailTrail"
CHECK_ALTERNATE_check303="check33"
CHECK_ASFF_COMPLIANCE_TYPE_check33="ens-op.exp.8.aws.trail.5"
CHECK_SERVICENAME_check33="iam"
CHECK_RISK_check33='Monitoring unauthorized API calls will help reveal application errors and may reduce time to detect malicious activity.'
CHECK_REMEDIATION_check33='It is recommended that a metric filter and alarm be established for unauthorized requests.'
CHECK_DOC_check33='https://docs.aws.amazon.com/awscloudtrail/latest/userguide/cloudwatch-alarms-for-cloudtrail.html'
CHECK_CAF_EPIC_check33='Logging and Monitoring'

check33(){
  if [[ "${REGION}" == "us-gov-west-1" || "${REGION}" == "us-gov-east-1" ]]; then
    textInfo "${REGION}: This is an AWS GovCloud account and there is no root account to perform checks."
  else
    check3x '\$\.userIdentity\.type\s*=\s*"Root".+\$\.userIdentity\.invokedBy NOT EXISTS.+\$\.eventType\s*!=\s*"AwsServiceEvent"'
  fi
}