#!/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_extra7145="7.145"
CHECK_TITLE_extra7145="[extra7145] Check if Lambda functions have policies which allow access to any AWS account"
CHECK_SCORED_extra7145="NOT_SCORED"
CHECK_TYPE_extra7145="EXTRA"
CHECK_SEVERITY_extra7145="Critical"
CHECK_ASFF_RESOURCE_TYPE_extra7145="AwsLambda"
CHECK_ALTERNATE_check7145="extra7145"
CHECK_SERVICENAME_extra7145="lambda"
CHECK_RISK_extra7145='Lambda function access to any AWS account may result security issues'
CHECK_REMEDIATION_extra7145='Ensure Lambda function policiy does not allow access to any account'
CHECK_DOC_extra7145='https://docs.aws.amazon.com/lambda/latest/dg/access-control-resource-based.html'
CHECK_CAF_EPIC_extra7145='IAM'

extra7145(){
  # "Check if lambda functions have policies which allow access to every aws account (Not Scored) (Not part of CIS benchmark)"
  for regx in $REGIONS; do
  LIST_OF_LAMBDA_FUNCTIONS=$($AWSCLI lambda list-functions $PROFILE_OPT --region $regx --query Functions[*].FunctionName --output text)
  if [[ $LIST_OF_LAMBDA_FUNCTIONS ]]; then
    for lambdaFunction in $LIST_OF_LAMBDA_FUNCTIONS;do
      FUNCTION_POLICY_STATEMENTS=$($AWSCLI lambda $PROFILE_OPT get-policy --region $regx --function-name $lambdaFunction --output json --query Policy 2>&1)
      if [[ $FUNCTION_POLICY_STATEMENTS == *ResourceNotFoundException* ]]; then
        textInfo "$regx: Lambda function $lambdaFunction doesn't have any policy" "$regx" "$lambdaFunction"
      else
        FUNCTION_POLICY_BAD_STATEMENTS=$(echo $FUNCTION_POLICY_STATEMENTS | jq '. | fromjson' | jq '.Statement[] | select(.Effect=="Allow")	 | select(.Principal=="*" or .Principal.AWS=="*" or .Principal.CanonicalUser=="*")')
        if [[ $FUNCTION_POLICY_BAD_STATEMENTS != "" ]]; then
          textFail "$regx: Lambda function $lambdaFunction allows public access to any AWS account" "$regx" "$lambdaFunction"
        else
          textPass "$regx: Lambda function $lambdaFunction has policy which doesn't allow access to everyone having an AWS account" "$regx" "$lambdaFunction"
        fi
      fi
    done

  else
    textInfo "$regx: No lambda functions found" "$regx"
  fi
 done
}