#!/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_extra793="7.93"
CHECK_TITLE_extra793="[extra793] Check if Elastic Load Balancers have SSL listeners "
CHECK_SCORED_extra793="NOT_SCORED"
CHECK_TYPE_extra793="EXTRA"
CHECK_SEVERITY_extra793="Medium"
CHECK_ASFF_RESOURCE_TYPE_extra793="AwsElbLoadBalancer"
CHECK_ALTERNATE_check793="extra793"
CHECK_ASFF_COMPLIANCE_TYPE_extra793="ens-mp.com.2.aws.elb.1"
CHECK_SERVICENAME_extra793="elb"
CHECK_RISK_extra793='Clear text communication could affect privacy of information in transit.'
CHECK_REMEDIATION_extra793='Scan for Load Balancers with HTTP or TCP listeners and understand the reason for each of them. Check if the listener can be implemented as TLS instead.'
CHECK_DOC_extra793='https://docs.aws.amazon.com/elasticloadbalancing/latest/application/create-https-listener.html'
CHECK_CAF_EPIC_extra793='Data Protection'

extra793(){
  # "Check if Elastic Load Balancers have encrypted listeners "
  for regx in $REGIONS; do
    LIST_OF_ELBS=$($AWSCLI elb describe-load-balancers $PROFILE_OPT --region $regx --query 'LoadBalancerDescriptions[*].LoadBalancerName' --output text|xargs -n1)
    LIST_OF_ELBSV2=$($AWSCLI elbv2 describe-load-balancers $PROFILE_OPT --region $regx --query 'LoadBalancers[?(Type == `application`)].LoadBalancerArn' --output text|xargs -n1)
    if [[ $LIST_OF_ELBS || $LIST_OF_ELBSV2 ]]; then
      if [[ $LIST_OF_ELBS ]]; then
        ENCRYPTEDPROTOCOLS=("HTTPS" "SSL") 
        for elb in $LIST_OF_ELBS; do
          ELB_PROTOCOLS=$($AWSCLI elb describe-load-balancers $PROFILE_OPT --region $regx --load-balancer-name $elb --query "LoadBalancerDescriptions[0].ListenerDescriptions[*].Listener.Protocol" --output text) 
          passed=true
          potential_redirect=false
          for protocol in $ELB_PROTOCOLS; do
            if array_contains ENCRYPTEDPROTOCOLS "$protocol"; then
              continue
            else
              # Check if both HTTP and HTTPS in use
              if [[ $(echo $ELB_PROTOCOLS | grep HTTPS) ]]; then 
                 potential_redirect=true
              fi
              passed=false
            fi
          done
          
          if $passed; then
            textPass "$regx: $elb has encrypted listeners" "$regx"
          else
            if $potential_redirect; then
              textInfo "$regx: $elb has both encrypted and non-encrypted listeners" "$regx"
            else
              textFail "$regx: $elb has non-encrypted listeners" "$regx" "$elb"
            fi 
          fi
        done
      fi
      if [[ $LIST_OF_ELBSV2 ]]; then
        for elbarn in $LIST_OF_ELBSV2; do
          https_only=true
          redirect_rule=false
          elbname=$(echo $elbarn | awk -F 'loadbalancer/app/' '{print $2}' | awk -F '/' '{print $1}')

          ELBV2_LISTENERS=$($AWSCLI elbv2 describe-listeners $PROFILE_OPT --region $regx --load-balancer-arn $elbarn --query "Listeners[*]")
          ELBV2_PROTOCOLS=$(echo $ELBV2_LISTENERS | jq -r '.[].Protocol')
  
          if [[ $(echo $ELBV2_PROTOCOLS | grep HTTPS) ]]; then
             for line in $(echo $ELBV2_LISTENERS | jq -r '.[] | .Protocol + "," + .ListenerArn'); do
                protocol=$(echo $line | awk -F ',' '{print $1}')
                listenerArn=$(echo $line | awk -F ',' '{print $2}')
                if [[ $protocol  == "HTTP" ]]; then
                  https_only=false
                  # Check for redirect rule
                  ELBV2_RULES=$($AWSCLI elbv2 describe-rules $PROFILE_OPT --region $regx --listener-arn $listenerArn --query 'Rules[]')
                  if [[ $(echo $ELBV2_RULES | jq -r '.[].Actions[].RedirectConfig.Protocol' | grep HTTPS) ]]; then
                     redirect_rule=true
                  fi
               fi
             done

             if $https_only; then
               textPass "$regx: $elbname has HTTPS listeners only" "$regx"
             else
               if $redirect_rule; then
                 textInfo "$regx: $elbname has HTTP listener that redirects to HTTPS" "$regx"
               else
                 textFail "$regx: $elbname has non-encrypted listeners" "$regx" "$elbname"
               fi
             fi
          else
            textFail "$regx: $elbname has non-encrypted listeners" "$regx" "$elbname"
          fi
        done
      fi
    else
      textInfo "$regx: No ELBs found" "$regx"
    fi
  done
}

array_contains () { 
    local array="$1[@]"
    local seeking=$2
    local in=1
    for element in "${!array}"; do
        if [[ $element == "$seeking" ]]; then
            in=0
            break
        fi
    done
    return $in
}