S3Finder

Yet another program to find readable S3 buckets.

Can search using a wordlist or by monitoring the certstream network for domain names from certificate transparency logs. If a name contains dots, a name with the dots replaced by dashes will be tried, as well. All queries are done via HTTPS.

Found buckets will be written to stdout. All other messages are written to stderr, to make for easy logging.

Heavily influenced by https://github.com/eth0izzle/bucket-stream.

For legal use only.

Installation

go get -u -v github.com/magisterquis/s3finder

Usage

Bucket names can be specified on the command line or in a file with one name per line.

To search for four buckets named after some stooges:

cat <<_eof >names
curl
moe
larry
_eof
s3finder -f names shemp

Please run s3finder with -h for a complete list of options.

CTL Stream

Instead of checking a static list of names, the certificate tranpsarency logs may be streamed from the certstream network with -certs. The domain names in the streamed certificates will be checked as bucket names. This can be combined with a file and names on the command line.

s3finder -f possible_names -certs kitten mug tea

CTL Subdomains

Additional subdomains of a given domain can be found from the certificate transparency logs with -ctl. This causes a considerably longer runtime but greatly expands the number of buckets which will be searched. Another downside is that as subdomains are searched without parent domains (e.g. foo.bar.tridge.com will cause foo.bar and foo to be searched), a lot of open buckets for common names are found. Even still, using -ctl greatly increases the chance of finding relevant buckets.

Tags

As it's fairly common for buckets to be something other than just a domain name, S3Finder can add tags like "backup" or "images" to queried names. Thus, for foo.example.com, backup-foo.example.com, foo-example-com-images, and a handful of other combinations will be tried. A comprehensive list is built-in to S3Finder, but a custom list can be specified with -tags. Tags can be disabled with -tags no.

All of the buckets which would be searched for division.example.com using the built-in list are in the file division.example.com_buckets.