prowler

#!/usr/bin/env bash

# Copyright 2018 Toni de la Fuente

# Prowler is a tool that provides automate auditing and hardening guidance of an
# AWS account. It is based on AWS-CLI commands. It follows some guidelines
# present in the CIS Amazon Web Services Foundations Benchmark at:
# https://d0.awsstatic.com/whitepapers/compliance/AWS_CIS_Foundations_Benchmark.pdf

# Contact the author at https://blyx.com/contact
# and open issues or ask questions at https://github.com/toniblyx/prowler


# All CIS based checks in checks folder are licensed under a Creative Commons
# Attribution-NonCommercial-ShareAlike 4.0 International Public License.
# The link to the license terms can be found at
# https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode
#
# Any other piece of code is licensed as Apache License 2.0 as specified in
# each file. You may obtain a copy of the License at
# http://www.apache.org/licenses/LICENSE-2.0

# Prowler - Iron Maiden
#
# Walking through the city, looking oh so pretty
# I've just got to find my way
# See the ladies flashing
# All there legs and lashes
# I've just got to find my way...

OPTRED=""
OPTNORMAL=""

# Set the defaults variables
PROWLER_VERSION=2.3.0RC4
PROWLER_DIR=$(dirname "$0")

REGION=""
FILTERREGION=""
MAXITEMS=100
MONOCHROME=0
MODE="text"
QUIET=0
SEP=','
KEEPCREDREPORT=0
EXITCODE=0
SEND_TO_SECURITY_HUB=0
SCRIPT_START_TIME=$( date -u +"%Y-%m-%dT%H:%M:%S%z" )
TITLE_ID=""
TITLE_TEXT="CALLER ERROR - UNSET TITLE"
WHITELIST_FILE=""
TOTAL_CHECKS=()

# Command usage menu
usage(){
  echo "
USAGE:
      `basename $0` [ -p <profile> -r <region>  -h ]
  Options:
      -p <profile>        specify your AWS profile to use (i.e.: default)
      -r <region>         specify an AWS region to direct API requests to
                            (i.e.: us-east-1), all regions are checked anyway if the check requires it
      -c <check_id>       specify one or multiple check ids separated by commas, to see all available checks use "-l" option
                            (i.e.: "check11" for check 1.1 or "extra71,extra72" for extra check 71 and extra check 72)
      -g <group_id>       specify a group of checks by id, to see all available group of checks use "-L"
                            (i.e.: "group3" for entire section 3, "cislevel1" for CIS Level 1 Profile Definitions or "forensics-ready")
      -f <filterregion>   specify an AWS region to run checks against
                            (i.e.: us-west-1)
      -m <maxitems>       specify the maximum number of items to return for long-running requests (default: 100)
      -M <mode>           output mode: text (default), mono, html, json, json-asff, junit-xml, csv. They can be used combined comma separated.
                            (separator is ","; data is on stdout; progress on stderr).
      -k                  keep the credential report
      -n                  show check numbers to sort easier
                            (i.e.: 1.01 instead of 1.1)
      -l                  list all available checks only (does not perform any check). Add -g <group_id> to only list checks within the specified group
      -L                  list all groups (does not perform any check)
      -e                  exclude group extras
      -E                  execute all tests except a list of specified checks separated by comma (i.e. check21,check31)
      -b                  do not print Prowler banner
      -s                  show scoring report
      -S                  send check output to AWS Security Hub - only valid when the output mode is json-asff (i.e. "-M json-asff -S")
      -x                  specify external directory with custom checks (i.e. /my/own/checks, files must start by "check")
      -q                  suppress info messages and passing test output
      -A                  account id for the account where to assume a role, requires -R and -T
                            (i.e.: 123456789012)
      -R                  role name to assume in the account, requires -A and -T
                            (i.e.: ProwlerRole)
      -T                  session duration given to that role credentials in seconds, default 1h (3600) recommended 12h, requires -R and -T
                            (i.e.: 43200)
      -I                  External ID to be used when assuming roles (not mandatory), requires -A and -R
      -w                  whitelist file. See whitelist_sample.txt for reference and format
                            (i.e.: whitelist_sample.txt)
      -V                  show version number & exit
      -h                  this help
  "
  exit
}

while getopts ":hlLkqp:r:c:g:f:m:M:E:x:enbVsSI:A:R:T:w:" OPTION; do
   case $OPTION in
     h )
        usage
        EXITCODE=1
        exit $EXITCODE
        ;;
     l )
        PRINTCHECKSONLY=1
        ;;
     L )
        PRINTGROUPSONLY=1
        ;;
     k )
        KEEPCREDREPORT=1
        ;;
     p )
        PROFILE=$OPTARG
        ;;
     r )
        REGION_OPT=$OPTARG
        ;;
     c )
        CHECK_ID=$OPTARG
        ;;
     g )
        GROUP_ID_READ=$OPTARG
        ;;
     f )
        FILTERREGION=$OPTARG
        ;;
     m )
        MAXITEMS=$OPTARG
        ;;
     M )
        MODE=$OPTARG
        ;;
     n )
        NUMERAL=1
        ;;
     b )
        BANNER=0
        ;;
     e )
        EXTRAS=1
        ;;
     E )
        EXCLUDE_CHECK_ID=$OPTARG
        ;;
     V )
        echo "Prowler $PROWLER_VERSION"
        EXITCODE=0
        exit $EXITCODE
        ;;
     s )
        SCORING=1
        ;;
     S )
        SEND_TO_SECURITY_HUB=1
        ;;
     x )
        EXTERNAL_CHECKS_PATH=$OPTARG
        ;;
     q )
        QUIET=1
        ;;
     A )
        ACCOUNT_TO_ASSUME=$OPTARG
        ;;
     R )
        ROLE_TO_ASSUME=$OPTARG
        ;;
     I )
        ROLE_EXTERNAL_ID=$OPTARG
        ;;
     T )
        SESSION_DURATION_TO_ASSUME=$OPTARG
        ;;
     w )
        WHITELIST_FILE=$OPTARG
        ;;
     : )
        echo ""
        echo "$OPTRED ERROR!$OPTNORMAL  -$OPTARG requires an argument"
        usage
        EXITCODE=1
        exit $EXITCODE
        ;;
     ? )
        echo ""
        echo "$OPTRED ERROR!$OPTNORMAL Invalid option"
        usage
        EXITCODE=1
        exit $EXITCODE
        ;;
   esac
done

clean_up() {
  rm -f /tmp/prowler*.policy.*
  # in case html output is used, make sure it closes html file properly
  if [[ "${MODES[@]}" =~ "html" ]]; then
    addHtmlFooter >> ${OUTPUT_FILE_NAME}.$EXTENSION_HTML
  fi
}

handle_ctrl_c() {
  clean_up
  exit $EXITCODE
}

# Clean up any temp files when prowler quits unexpectedly
trap clean_up EXIT
# Clean up and exit if Ctrl-C occurs. Required to allow Ctrl-C to stop Prowler when running in Docker
trap handle_ctrl_c INT

. $PROWLER_DIR/include/colors
. $PROWLER_DIR/include/os_detector
. $PROWLER_DIR/include/aws_profile_loader
. $PROWLER_DIR/include/awscli_detector
. $PROWLER_DIR/include/whoami
. $PROWLER_DIR/include/assume_role
. $PROWLER_DIR/include/csv_header
. $PROWLER_DIR/include/banner
. $PROWLER_DIR/include/html_report
. $PROWLER_DIR/include/outputs
. $PROWLER_DIR/include/credentials_report
. $PROWLER_DIR/include/scoring
. $PROWLER_DIR/include/python_detector
. $PROWLER_DIR/include/secrets_detector
. $PROWLER_DIR/include/check_creds_last_used
. $PROWLER_DIR/include/check3x
. $PROWLER_DIR/include/connection_tests
. $PROWLER_DIR/include/securityhub_integration
. $PROWLER_DIR/include/junit_integration

# Get a list of all available AWS Regions
REGIONS=$($AWSCLI ec2 describe-regions --query 'Regions[].RegionName' \
  --output text \
  $PROFILE_OPT \
  --region $REGION \
  --region-names $FILTERREGION)

# Pre-process whitelist file if supplied
if [[ -n "$WHITELIST_FILE" ]]; then
  # ignore lines starting with # (comments)
  # ignore inline comments: check1:foo # inline comment
  WHITELIST="$(awk '!/^[[:space:]]*#/{print }' <(cat "$WHITELIST_FILE") | sed 's/[[:space:]]*#.*$//g')"
fi

# Load all of the groups of checks inside groups folder named as "groupNumber*"
for group in $(ls $PROWLER_DIR/groups/group[0-9]*|grep -v groupN_sample); do
	. "$group"
done

# Load all of the checks inside checks folder named as "check*"
# this includes also extra checks since they are "check_extraNN"
for checks in $(ls $PROWLER_DIR/checks/check*|grep -v check_sample); do
	. "$checks"
done

# include checks if external folder is specified
if [[ $EXTERNAL_CHECKS_PATH ]]; then
  for checks in $(ls $EXTERNAL_CHECKS_PATH/check*); do
	. "$checks"
  done
fi

# Get a list of total checks available by ID
for i in "${!GROUP_TITLE[@]}"; do
  IFS=',' read -ra CHECKS <<< "${GROUP_CHECKS[$i]}"
  for j in "${CHECKS[@]}"; do
    TOTAL_CHECKS+=("$CHECK_ID_$j")
  done
done
# Remove duplicates, sort checks numerically, and store the result as an array
# Note: the sort mechanism relies on the fact that the check ID prefixes 'check' and 'extra' are both 5 characters long.
#       6th character is the section number, 7th character onwards is the individual ID (e.g. check110 = check 1 10)
TOTAL_CHECKS=($(echo "${TOTAL_CHECKS[*]}" | tr ' ' '\n' | awk '!seen[$0]++' | sort -k 1.6,1.6n -k 1.7n))

# Function to show the title of the check, and optionally which group(s) it belongs to
# using this way instead of arrays to keep bash3 (osx) and bash4(linux) compatibility
show_check_title() {
  local check_id=CHECK_ID_$1
  local check_title=CHECK_TITLE_$1
  local check_scored=CHECK_SCORED_$1
  local check_type=CHECK_TYPE_$1
  local group_ids
  local group_index
  # If requested ($2 is any non-null value) iterate all GROUP_CHECKS and produce a comma-separated list of all
  # the GROUP_IDs that include this particular check
  if [[ -n "$2" ]]; then
    for group_index in "${!GROUP_ID[@]}"; do
      if [[ "${GROUP_CHECKS[$group_index]}" =~ "$1" ]]; then
        if [[ -n "$group_ids" ]]; then
          group_ids+=", "
        fi
        group_ids+="${GROUP_ID[$group_index]}"
      fi
    done
  fi
  textTitle "${!check_id}" "${!check_title}" "${!check_scored}" "${!check_type}" "$group_ids"
}

# Function to show the title of a group, by numeric id
show_group_title() {
	# when csv mode is used, no group title is shown
  if [[ "$MODE" != "csv" ]]; then
      textTitle "${GROUP_NUMBER[$1]}" "${GROUP_TITLE[$1]}" "NOT_SCORED" "SUPPORT"
  fi
}

# Function to execute the check
execute_check() {
  # See if this is an alternate name for a check
  # for example, we might have been passed 1.01 which is another name for 1.1
  local alternate_name_var=CHECK_ALTERNATE_$1
  local alternate_name=${!alternate_name_var}
  # See if this check defines an ASFF Type, if so, use this, falling back to a sane default
  # For a list of Types, see: https://docs.aws.amazon.com/securityhub/latest/userguide/securityhub-findings-format.html#securityhub-findings-format-type-taxonomy
  local asff_type_var=CHECK_ASFF_TYPE_$1

  local severity_var=CHECK_SEVERITY_$1
  
  CHECK_SEVERITY="${!severity_var}"

  CHECK_ID="$1"

  ASFF_TYPE="${!asff_type_var:-Software and Configuration Checks}"
  # See if this check defines an ASFF Resource Type, if so, use this, falling back to a sane default
  # For a list of Resource Types, see: https://docs.aws.amazon.com/securityhub/latest/userguide/securityhub-findings-format.html#asff-resources
  local asff_resource_type_var=CHECK_ASFF_RESOURCE_TYPE_$1

  ASFF_RESOURCE_TYPE="${!asff_resource_type_var:-AwsAccount}"

  # Generate the credential report, only if it is group1 related which checks we
  # run so that the checks can safely assume it's available
  # set the custom ignores list for this check
  ignores="$(awk "/${1}/{print}" <(echo "${WHITELIST}"))"

  if [ ${alternate_name} ];then
    if [[ ${alternate_name} == check1* || ${alternate_name} == extra71 ]];then
      if [ ! -s $TEMP_REPORT_FILE ];then
        genCredReport
        saveReport
      fi
    fi
    show_check_title ${alternate_name}
    if is_junit_output_enabled; then
      prepare_junit_check_output "$1"
    fi
    # Execute the check
    IGNORES="${ignores}" CHECK_NAME="$1" ${alternate_name}
    if is_junit_output_enabled; then
      finalise_junit_check_output "$1"
    fi

    if [[ "$SEND_TO_SECURITY_HUB" -eq 1 ]]; then
      resolveSecurityHubPreviousFails "$1"
    fi
  else
    # Check to see if this is a real check
    local check_id_var=CHECK_ID_$1
    local check_id=${!check_id_var}
    if [ ${check_id} ]; then
      if [[ ${check_id} == 1* || ${check_id} == 7.1 || ${check_id} == 7.74 ]];then
        if [ ! -s $TEMP_REPORT_FILE ];then
          genCredReport
          saveReport
        fi
      fi
      show_check_title "$1"
      if is_junit_output_enabled; then
        prepare_junit_check_output "$1"
      fi
      # Execute the check
      IGNORES="${ignores}" CHECK_NAME="$1" $1

      if is_junit_output_enabled; then
        finalise_junit_check_output "$1"
      fi

      if [[ "$SEND_TO_SECURITY_HUB" -eq 1 ]]; then
        resolveSecurityHubPreviousFails "$1"
      fi

    else
      textFail "ERROR! Use a valid check name (i.e. check41 or extra71)";
      exit $EXITCODE
    fi
  fi
}

# Function to execute all checks in a group
execute_group() {
    show_group_title $1
    # run the checks in the group
    IFS=',' read -ra CHECKS <<< ${GROUP_CHECKS[$1]}

    # Exclude any checks specified
    if [[ -n ${2} ]]; then
        EXCLUDED_CHECKS=()
        NEW_CHECKS=()
        IFS=',' read -ra EXCLUDED_CHECKS <<< "${2},"
        for exc in ${EXCLUDED_CHECKS[@]} ; do
            for i in ${!CHECKS[@]} ; do
                [[ ${CHECKS[i]} = ${exc} ]] && unset CHECKS[i]
            done
        done
        unset EXCLUDED_CHECKS
    fi
    for i in ${CHECKS[@]}; do
        execute_check ${i}
    done
}

# Function to execute group by name
execute_group_by_id() {
  
  	for i in "${!GROUP_ID[@]}"; do
		if [ "${GROUP_ID[$i]}" == "$1" ]; then
			execute_group ${i} $2
		fi
	done
}

# Function to execute all checks in all groups except extras if -e is invoked
execute_all() {
	for i in "${!GROUP_TITLE[@]}"; do
    if [[ $EXTRAS ]]; then
      GROUP_RUN_BY_DEFAULT[7]='N'
    fi
    if [ "${GROUP_RUN_BY_DEFAULT[$i]}" == "Y" ]; then
      execute_group $i
    fi
	done
}

# Function to show the titles of either all checks or only those in the specified group
show_all_titles() {
  local checks
  local check_id
  local group_index
  # If '-g <group_id>' has been specified, only show the titles of checks within the specified group
  if [[ $GROUP_ID_READ ]];then
    if [[ " ${GROUP_ID[@]} " =~ " ${GROUP_ID_READ} " ]]; then
      for group_index in "${!GROUP_ID[@]}"; do
        if [ "${GROUP_ID[$group_index]}" == "${GROUP_ID_READ}" ]; then
          show_group_title "$group_index"
          IFS=',' read -ra checks <<< "${GROUP_CHECKS[$group_index]}"
          for check_id in ${checks[@]}; do
            show_check_title "$check_id"
          done
        fi
      done
    else
      textFail "Use a valid check group ID i.e.: group1, extras, forensics-ready, etc."
      show_all_group_titles
      exit $EXITCODE
    fi
  else
    for check_id in "${TOTAL_CHECKS[@]}"; do
      # Pass 1 so that the group IDs that this check belongs to are printed
      show_check_title "$check_id" 1
    done
  fi
}

show_all_group_titles() {
  local group_index
  for group_index in "${!GROUP_TITLE[@]}"; do
    show_group_title "$group_index"
  done
}

# Function to execute all checks but exclude some of them
get_all_checks_without_exclusion() {
  CHECKS_EXCLUDED=()
  local CHECKS_TO_EXCLUDE=()
  # Get a list of checks to exclude
  IFS=',' read -ra E_CHECKS <<< "$1"
  for E_CHECK in "${E_CHECKS[@]}"; do
    CHECKS_TO_EXCLUDE+=($E_CHECK)
  done
  # Create a list that contains all checks but excluded ones
  for i in "${TOTAL_CHECKS[@]}"; do
    local COINCIDENCE=false
    for x in "${CHECKS_TO_EXCLUDE[@]}"; do
      if [[ "$i" == "$x" ]]; then
        COINCIDENCE=true
      fi
    done
    if [[ "$COINCIDENCE" = false ]]; then
      CHECKS_EXCLUDED+=($i)
    fi
  done
}

### All functions defined above ... run the workflow
if [[ " ${MODES[@]} " =~ " mono " || " ${MODES[@]} " =~ " text " ]]; then
  prowlerBanner
fi

# List only check tittles
if [[ $PRINTCHECKSONLY == "1" ]]; then
  show_all_titles
  exit $EXITCODE
fi

# List only group tittles
if [[ $PRINTGROUPSONLY == "1" ]]; then
  show_all_group_titles
  exit $EXITCODE
fi

# Check that jq is installed for JSON outputs
if [[ " ${MODES[@]} " =~ " json " || " ${MODES[@]} " =~ " json-asff " ]]; then
  . $PROWLER_DIR/include/jq_detector
fi

if [[ "$SEND_TO_SECURITY_HUB" -eq 1 ]]; then
  checkSecurityHubCompatibility
fi

if is_junit_output_enabled; then
  prepare_junit_output
fi

# Gather account data / test aws cli connectivity
getWhoami
if [[ $ACCOUNT_TO_ASSUME ]]; then
  assume_role
fi

# Execute group of checks if called with -g
if [[ $GROUP_ID_READ ]];then
  if [[ " ${GROUP_ID[@]} " =~ " ${GROUP_ID_READ} " ]]; then

    execute_group_by_id ${GROUP_ID_READ} ${EXCLUDE_CHECK_ID}
    if [[ "${MODES[@]}" =~ "html" ]]; then
      addHtmlFooter >> ${OUTPUT_FILE_NAME}.$EXTENSION_HTML
    fi
    cleanTemp
    scoring
    exit $EXITCODE
  else
    textFail "Use a valid check group ID i.e.: group1, extras, forensics-ready, etc."
    show_all_group_titles
    exit $EXITCODE
  fi
fi

# Get a list of total checks excluding a list provided by the user and overwrite CHECK_ID with the result
# if the list provided by the user contains an invalid check, this will be discarded.
# if the list provided by the user contains  just one argument and is invalid, then it will be discarded and all tests will be executed
if [[ ${EXCLUDE_CHECK_ID} ]];then
  get_all_checks_without_exclusion ${EXCLUDE_CHECK_ID}
  function join { local IFS="$1"; shift; echo "$*"; }
  CHECKS_EXCLUDED=$(join , "${CHECKS_EXCLUDED[@]}")
  CHECK_ID=${CHECKS_EXCLUDED}
fi

# Execute single check if called with -c
if [[ $CHECK_ID ]];then
  IFS=',' read -ra CHECKS <<< "$CHECK_ID"
  for CHECK in "${CHECKS[@]}"; do
    execute_check $CHECK
  done
  if [[ "${MODES[@]}" =~ "html" ]]; then
    addHtmlFooter >> ${OUTPUT_FILE_NAME}.$EXTENSION_HTML
  fi
  cleanTemp
  exit $EXITCODE
fi

execute_all

if [[ "${MODES[@]}" =~ "html" ]]; then
  addHtmlFooter >> ${OUTPUT_FILE_NAME}.$EXTENSION_HTML
fi
scoring
cleanTemp

if [[ $ACCOUNT_TO_ASSUME ]]; then
  # unset env variables with assumed role credentials
  unset AWS_ACCESS_KEY_ID
  unset AWS_SECRET_ACCESS_KEY
  unset AWS_SESSION_TOKEN
fi

exit $EXITCODE