Subgen - a subdomain concating-utility with some smarts

If you've come to the realisation that you'd like to split up your DNS enumeration methodology by generating combinations and/or pulling passive data from other sources, then subgen is the sorter & concator you're probably looking for

### Installation

If you have a properly configured GOPATH and $GOPATH/bin is in your PATH, then run this command for a one-liner install, thank you golang!

go get -u github.com/pry0cc/subgen

Cat a very large unsorted wordlist.

cat wordlist.txt | subgen -d "uber.com" | zdns A | jq -r "select(.data.answers[0].name) | .name" 

Crawl website with Cewl and generated unresolved subdomain combinations

cewl.rb -d 3 -u https://uber.com/ | subgen -d "uber.com"

tldr;

This will take a wordlist, concate with a domain, sort unique in real time (filtering lines that have already been produced) and filtering out with regex any non-DNS safe characters like special characters.

wordlist.txt

admin
dashboard
www
helloworld
HELLOWORLD
helLoWorld
autodiscover
aUtOdiscover
*sd&^%$£$%^&*
zabbix
login

cat wordlist.txt | subgen -d "uber.com"

Will produce:

admin.uber.com
dashboard.uber.com
www.uber.com
helloworld.uber.com
autodiscover.uber.com
zabbix.uber.com
login.uber.com

Which you can pipe to a resolver tool such as MassDNS or ZDNS and print out resolved subdomains.

cat ~/lists/sorted-all.txt | subgen -d uber.com | zdns A | jq -r "select(.data.answers[0].name) | .name" 

cat ~/lists/jhaddix-all.txt | subgen -d uber.com |  massdns -r dns.txt -t A -o S -w results.txt