find speculative ec2 regions by brute force dns

ec2-search-regions

#!/bin/bash
# https://gist.github.com/1367800

CR=$'\n'
dns_server="@8.8.8.8"
KNOWN=(
  us-east-1
  us-west-1
  ap-southeast-1
  eu-west-1
  ap-northeast-1
  us-west-2       # dns found 2011-09-21, opened 2011-11-11
  sa-east-1       # dns found 2011-11-15, opened 2011-12-15
  ap-southeast-2  # dns found 2012-09-27, opened 2012-11-12
  cn-north-1      # dns found 2013-12-01, opened 2013-12-18
  eu-central-1    # opened 2014-10-23
  ap-northeast-2  # dns found 2015-12-05, opened 2016-01-06
  ap-south-1      # dns found 2016-03-09
  us-east-2       # dns found 2016-06-06
)

VERBOSE=1
full=0
[ "$1" = "-q" ] && VERBOSE=0 && shift;
[ "$1" = "-v" ] && VERBOSE=$(($VERBOSE+1)) && shift;
[ "$1" = "-vv" ] && VERBOSE=$(($VERBOSE+2)) && shift;
[ "$1" = "-vvv" ] && VERBOSE=$(($VERBOSE+3)) && shift;
[ "$1" = "--full" ] && { full=1; shift; }

error() { echo "$@" 1>&2; }
vout() { [ $VERBOSE -ge 1 ] && out "$@"; }
vvout() { [ $VERBOSE -ge 2 ] && out "$@"; }
vvvout() { [ $VERBOSE -ge 3 ] && out "$@"; }
out() { echo "$@"; }

dirs="north northeast east southeast south southwest west northwest central"
known=" ${KNOWN[*]} "

#for cc in us ap eu la af; do
alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"
if [ $full -eq 0 ]; then
	# first token of all known
	c1list=( $(for r in ${KNOWN[@]%%-*}; do echo $r; done | sort -u) )
	c2list=( "" )
else
	c1list=( $alphabet )
	c2list=( $alphabet )
fi

dns_tries=0
reg_tries=0
found=0
# c1=( u ); c2=( s ); dirs="east west" ## testing
for c1 in "${c1list[@]}"; do
 for c2 in "${c2list[@]}"; do
	cc="$c1$c2"
	for dir in ${dirs}; do
		for n in 1 2 3; do
			found_1=0
			r="${cc}-${dir}-${n}"
			reg_tries=$(($reg_tries+1))
			# note, 'p' is vestigal. the we used to search for
			# ec2.region.amazonaws.com endpoint, but now
			# we ask about NS for region.amazonaws.com
			for p in ec2; do
				dns_tries=$(($dns_tries+1))
				h="$r.amazonaws.com";
				vvvout dig ${dns_server} +time=3 +short NS "$h"
				i=$(dig $dns_server +time=3 +short NS "${h}" 2>&1)
				ret=$?
				vvvout " $ret: ${i//$CR/ }"
				if [ $ret -ne 0 ]; then
					error "${h}: FAILED [${i//$CR/ }]"
				elif [ -z "${i}" ]; then
					vvout "${h}: none"
				else
					[ $found_1 -eq 0 ] && found=$(($found+1));
					found_1=1
					if [ "${known#* ${r} }" != "${known}" ]; then
						vout "${h} [known]"
					else
						out "${h} UNKNOWN!"
					fi
				fi
			done
			# no reason to search 2,3,4... if there is no 1
			[ $found_1 -eq 0 ] && break
		done
	done
 done
done

vout "regions searched: $reg_tries dns_queries: $dns_tries, found: $found duration: ${SECONDS}s"
exit 0

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