#!/usr/bin/env bash

# Prowler - the handy cloud security tool (copyright 2018) 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.
CHECK_ID_extra720="7.20"
CHECK_TITLE_extra720="[extra720] Check if Lambda functions invoke API operations are being recorded by CloudTrail"
CHECK_SCORED_extra720="NOT_SCORED"
CHECK_CIS_LEVEL_extra720="EXTRA"
CHECK_SEVERITY_extra720="Low"
CHECK_ASFF_RESOURCE_TYPE_extra720="AwsLambdaFunction"
CHECK_ALTERNATE_check720="extra720"
CHECK_SERVICENAME_extra720="lambda"
CHECK_RISK_extra720='If logs are not enabled; monitoring of service use and threat analysis is not possible.'
CHECK_REMEDIATION_extra720='Make sure you are logging information about Lambda operations. Create a lifecycle and use cases for each trail.'
CHECK_DOC_extra720='https://docs.aws.amazon.com/lambda/latest/dg/logging-using-cloudtrail.html'
CHECK_CAF_EPIC_extra720='Logging and Monitoring'

extra720(){
  # "Check if Lambda functions invoke API operations are being recorded by CloudTrail "
  for regx in $REGIONS; do
    LIST_OF_FUNCTIONS=$($AWSCLI lambda list-functions $PROFILE_OPT --region $regx --query 'Functions[*].FunctionName' --output text 2>&1)
    if [[ $(echo "$LIST_OF_FUNCTIONS" | grep AccessDenied) ]]; then
      textInfo "$regx: Access Denied trying to list functions" "$regx"
      continue
    fi
    if [[ $LIST_OF_FUNCTIONS ]]; then
      LIST_OF_TRAILS=$($AWSCLI cloudtrail describe-trails $PROFILE_OPT --region $regx --query 'trailList[*].TrailARN' --output text 2>&1)
      if [[ $(echo "$LIST_OF_TRAILS" | grep AccessDenied) ]]; then
        textInfo "$regx: Access Denied trying to describe trails" "$regx"
        continue
      fi
      for lambdafunction in $LIST_OF_FUNCTIONS; do
        if [[ $LIST_OF_TRAILS ]]; then
          for trail in $LIST_OF_TRAILS; do
            FUNCTION_ENABLED_IN_TRAIL=$($AWSCLI cloudtrail get-event-selectors $PROFILE_OPT --trail-name $trail --region $regx --query "EventSelectors[*].DataResources[?Type == \`AWS::Lambda::Function\`].Values" --output text |xargs -n1| grep -E "^arn:${AWS_PARTITION}:lambda.*function:$lambdafunction$|^arn:${AWS_PARTITION}:lambda$")
            if [[ $FUNCTION_ENABLED_IN_TRAIL ]]; then
              textPass "$regx: Lambda function $lambdafunction enabled in trail $trail" "$regx" "$trail"
            else
              textFail "$regx: Lambda function $lambdafunction NOT enabled in trail $trail" "$regx" "$trail"
            fi
          done
          # LIST_OF_MULTIREGION_TRAILS=$($AWSCLI cloudtrail describe-trails $PROFILE_OPT --region $regx --query "trailList[?IsMultiRegionTrail == \`true\`].Name" --output text)
          # if [[ $LIST_OF_MULTIREGION_TRAILS ]]; then
          #   for trail in $LIST_OF_MULTIREGION_TRAILS; do
          #     REGION_OF_TRAIL=$($AWSCLI cloudtrail describe-trails $PROFILE_OPT --region $regx --query "trailList[?IsMultiRegionTrail == \`true\` && Name == \`$trail\` ].HomeRegion" --output text)
          #     FUNCTION_ENABLED_IN_THIS_REGION=$($AWSCLI cloudtrail get-event-selectors $PROFILE_OPT --trail-name $trail --region $REGION_OF_TRAIL --query "EventSelectors[*].DataResources[?Type == \`AWS::Lambda::Function\`].Values" --output text |xargs -n1| grep -E "^arn:aws:lambda.*function:$lambdafunction$")
          #     if [[ $FUNCTION_ENABLED_IN_THIS_REGION ]]; then
          #       textPass "$regx: Lambda function $lambdafunction enabled in trail $trail" "$regx"
          #     else
          #       textFail "$regx: Lambda function $lambdafunction NOT enabled in trail $trail" "$regx"
          #     fi
          #   done
          # else
          #   textFail "$regx: Lambda function $lambdafunction is not being recorded!" "$regx"
          # fi
        else
          textFail "$regx: Lambda function $lambdafunction is not being recorded no CloudTrail found!" "$regx" "$trail"
        fi
     done
    else
      textInfo "$regx: No Lambda functions found" "$regx"
    fi
  done
}