prowler/include/os_detector

#!/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.

gnu_how_older_from_today() {
  DATE_TO_COMPARE=$1
  TODAY_IN_DAYS=$(date -d "$(date +%Y-%m-%d)" +%s)
  DATE_FROM_IN_DAYS=$(date -d $DATE_TO_COMPARE +%s)
  DAYS_SINCE=$((($TODAY_IN_DAYS - $DATE_FROM_IN_DAYS )/60/60/24))
  echo $DAYS_SINCE
}
bsd_how_older_from_today() {
  DATE_TO_COMPARE=$1
  TODAY_IN_DAYS=$(date +%s)
  DATE_FROM_IN_DAYS=$(date -jf %Y-%m-%d $DATE_TO_COMPARE +%s)
  DAYS_SINCE=$((($TODAY_IN_DAYS - $DATE_FROM_IN_DAYS )/60/60/24))
  echo $DAYS_SINCE
}

# function to convert from timestamp to date
# output date format %Y-%m-%d
gnu_timestamp_to_date() {
  # remove fractions of a second
  TIMESTAMP_TO_CONVERT=$(echo $1 | cut -f1 -d".")
  OUTPUT_DATE=$(date -d @$TIMESTAMP_TO_CONVERT +'%Y-%m-%d')
  echo $OUTPUT_DATE
}
bsd_timestamp_to_date() {
  # remove fractions of a second
  TIMESTAMP_TO_CONVERT=$(echo $1 | cut -f1 -d".")
  OUTPUT_DATE=$(date -r $TIMESTAMP_TO_CONVERT +'%Y-%m-%d')
  echo $OUTPUT_DATE
}

gnu_decode_report() {
  base64 -d
}
bsd_decode_report() {
  base64 -D
}

gnu_how_many_days_from_today() {
  DATE_TO_COMPARE=$1
  TODAY_IN_DAYS=$(date -d "$(date +%Y-%m-%d)" +%s)
  DATE_IN_DAYS=$(date -d $DATE_TO_COMPARE +%s)
  DAYS_TO=$((( $DATE_IN_DAYS - $TODAY_IN_DAYS )/60/60/24))
  echo $DAYS_TO
}
bsd_how_many_days_from_today() {
  DATE_TO_COMPARE=$1
  TODAY_IN_DAYS=$(date +%s)
  DATE_IN_DAYS=$(date -jf %Y-%m-%d $DATE_TO_COMPARE +%s)
  DAYS_TO=$((( $DATE_IN_DAYS - $TODAY_IN_DAYS )/60/60/24))
  echo $DAYS_TO
}

gnu_get_date_previous_than_months() {
  MONTHS_TO_COMPARE=$1
  MONTHS_TO_COMPARE_IN_SECONDS=$(( 60 * 60 * 24 * 31 * $MONTHS_TO_COMPARE ))
  CURRENTSECS=$(date +%s)
  STARTDATEINSECS=$(( $CURRENTSECS - $MONTHS_TO_COMPARE_IN_SECONDS ))
  DATE_BEFORE_MONTHS_TO_COMPARE=$(date -d @$STARTDATEINSECS '+%Y-%m-%d')
  echo $DATE_BEFORE_MONTHS_TO_COMPARE
}
bsd_get_date_previous_than_months() {
  MONTHS_TO_COMPARE=$1
  DATE_BEFORE_MONTHS_TO_COMPARE=$(date -v -$(echo $MONTHS_TO_COMPARE)m '+%Y-%m-%d')
  echo $DATE_BEFORE_MONTHS_TO_COMPARE
}

gnu_test_tcp_connectivity() {
  HOST=$1
  PORT=$2
  TIMEOUT=$3
  # This is initially for ES port 9300, not not HTTP but I add HTTP error
  # codes for better handling, so 200 is open and 000 is not responding
  timeout $TIMEOUT bash -c '(echo > /dev/tcp/'$HOST'/'$PORT') >/dev/null 2>&1 && echo "200" || echo "000"'
}
bsd_test_tcp_connectivity() {
  HOST=$1
  PORT=$2
  TIMEOUT=$3
  # This is initially for ES port 9300, not not HTTP but I add HTTP error
  # codes for better handling, so 200 is open and 000 is not responding
  nc -z -G $TIMEOUT $HOST $PORT >/dev/null 2>&1 && echo "200" || echo "000"
}

# Functions to manage dates depending on OS
if [ "$OSTYPE" == "linux-gnu" ] || [ "$OSTYPE" == "linux-musl" ]; then
  TEMP_REPORT_FILE=$(mktemp -t -p /tmp prowler.cred_report-XXXXXX)
  # function to compare in days, usage how_older_from_today date
  # date format %Y-%m-%d
  how_older_from_today() {
    gnu_how_older_from_today "$1"
  }
  timestamp_to_date() {
    gnu_timestamp_to_date "$1"
  }
  decode_report() {
    gnu_decode_report
  }
  how_many_days_from_today() {
    gnu_how_many_days_from_today "$1"
  }
  get_date_previous_than_months() {
    gnu_get_date_previous_than_months "$1"
  }
  test_tcp_connectivity() {
    gnu_test_tcp_connectivity "$1" "$2" "$3"
  }
elif [[ "$OSTYPE" == "darwin"* ]]; then
  # BSD/OSX commands compatibility
  TEMP_REPORT_FILE=$(mktemp -t prowler.cred_report-XXXXXX)
  # It is possible that the user has installed GNU coreutils, replacing the default Mac OS X BSD tools with
  # GNU coreutils equivalents. Only GNU date allows --version as a valid argument, so use the validity of this argument
  # as a means to detect that coreutils is installed and is overriding the default tools
  if date --version >/dev/null 2>&1 ; then
    how_older_from_today() {
      gnu_how_older_from_today "$1"
    }
    timestamp_to_date() {
      gnu_timestamp_to_date "$1"
    }
    decode_report() {
      gnu_decode_report
    }
    how_many_days_from_today() {
      gnu_how_many_days_from_today "$1"
    }
    get_date_previous_than_months() {
      gnu_get_date_previous_than_months "$1"
    }
  else
    how_older_from_today() {
      bsd_how_older_from_today "$1"
    }
    timestamp_to_date() {
      bsd_timestamp_to_date "$1"
    }
    decode_report() {
      bsd_decode_report
    }
    how_many_days_from_today() {
      bsd_how_many_days_from_today "$1"
    }
    get_date_previous_than_months() {
      bsd_get_date_previous_than_months "$1"
    }
  fi
  test_tcp_connectivity() {
    bsd_test_tcp_connectivity "$1" "$2" "$3"
  }
elif [[ "$OSTYPE" == "cygwin" ]]; then
  # POSIX compatibility layer and Linux environment emulation for Windows
  TEMP_REPORT_FILE=$(mktemp -t -p /tmp prowler.cred_report-XXXXXX)
  how_older_from_today() {
    gnu_how_older_from_today "$1"
  }
  timestamp_to_date() {
    gnu_timestamp_to_date "$1"
  }
  decode_report() {
    gnu_decode_report
  }
  how_many_days_from_today() {
    gnu_how_many_days_from_today "$1"
  }
  get_date_previous_than_months() {
    gnu_get_date_previous_than_months "$1"
  }
  test_tcp_connectivity() {
    gnu_test_tcp_connectivity "$1" "$2" "$3"
  }
else
  echo "Unknown Operating System! Valid \$OSTYPE: linux-gnu, linux-musl, darwin* or cygwin"
  echo "Found: $OSTYPE"
  EXITCODE=1
  exit $EXITCODE
fi