#!/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_extra7172="7.172"
CHECK_TITLE_extra7172="[extra7172] Check if S3 buckets have ACLs enabled"
CHECK_SCORED_extra7172="NOT_SCORED"
CHECK_CIS_LEVEL_extra7172="EXTRA"
CHECK_SEVERITY_extra7172="Medium"
CHECK_ASFF_RESOURCE_TYPE_extra7172="AwsS3Bucket"
CHECK_ALTERNATE_check7172="extra7172"
CHECK_SERVICENAME_extra7172="s3"
CHECK_RISK_extra7172='S3 ACLs are a legacy access control mechanism that predates IAM. IAM and bucket policies are currently the preferred methods.'
CHECK_REMEDIATION_extra7172='Ensure that S3 ACLs are disabled (BucketOwnerEnforced). Use IAM policies and bucket policies to manage access.'
CHECK_DOC_extra7172='https://docs.aws.amazon.com/AmazonS3/latest/userguide/about-object-ownership.html'
CHECK_CAF_EPIC_extra7172='Logging and Monitoring'

extra7172(){
  # "Check if S3 buckets have server access logging enabled"
  LIST_OF_BUCKETS=$("${AWSCLI}" s3api list-buckets ${PROFILE_OPT} --query Buckets[*].Name --region "${REGION}" --output text 2>&1)
  if grep -q -E 'AccessDenied|UnauthorizedOperation|AuthorizationError' <<< "$LIST_OF_BUCKETS"; then
    textInfo "${REGION}: Access Denied Trying to list buckets" "${REGION}"
    exit
  fi
  if [[ $LIST_OF_BUCKETS ]]; then
    for bucket in $LIST_OF_BUCKETS;do
      # Recover Bucket region
      BUCKET_REGION=$("${AWSCLI}" ${PROFILE_OPT} s3api get-bucket-location --bucket "${bucket}" --region "${REGION}" --query LocationConstraint --output text)
      if grep -q -E 'AccessDenied|UnauthorizedOperation|AuthorizationError' <<< "${BUCKET_REGION}"; then
          textInfo "${REGION}: Access Denied trying to get bucket location for ${bucket}" "${REGION}"
      fi
      # If None use default region
      if [[ "${BUCKET_REGION}" == "None" ]]; then
        BUCKET_REGION="${REGION}"
      fi

      BUCKET_ACLS_DISABLED=$(${AWSCLI} ${PROFILE_OPT} s3api get-bucket-ownership-controls --bucket "${bucket}" --region "${BUCKET_REGION}" --output text 2>&1)
      if grep -q -E 'AccessDenied|UnauthorizedOperation|AuthorizationError' <<< "${BUCKET_ACLS_DISABLED}" ; then
        textInfo "${BUCKET_REGION}: Access Denied Trying to Get Bucket Ownership Controls for ${bucket}" "${BUCKET_REGION}" "${bucket}"
        continue
      elif grep -q -E 'IllegalLocationConstraintException' <<< "${BUCKET_ACLS_DISABLED}"; then
        textInfo "${BUCKET_REGION}: Location Constraint Trying to Get Bucket Ownership Controls for ${bucket}" "${BUCKET_REGION}" "${bucket}"
        continue
      fi
      if grep -q "BucketOwnerEnforced" <<< "${BUCKET_ACLS_DISABLED}"; then
        textPass "${BUCKET_REGION}: Bucket ${bucket} has bucket ACLs disabled!" "${BUCKET_REGION}" "${bucket}"
      elif grep -q "BucketOwnerPreferred" <<< "${BUCKET_ACLS_DISABLED}"; then
        textFail "${BUCKET_REGION}: Bucket ${bucket} has bucket ACLs enabled!" "${BUCKET_REGION}" "${bucket}"
      elif grep -q "OwnershipControlsNotFoundError" <<< "${BUCKET_ACLS_DISABLED}"; then
        textFail "${BUCKET_REGION}: Bucket ${bucket} has bucket ACLs enabled!" "${BUCKET_REGION}" "${bucket}"
      else
        textFail "${BUCKET_REGION}: Bucket ${bucket} returned an unknown error" "${BUCKET_REGION}" "${bucket}"
      fi
    done
  else
    textInfo "${REGION}: No S3 Buckets found" "${REGION}"
  fi
}