CertGraph
A tool to crawl the graph of certificate Alternate Names
CertGraph crawls SSL certificates creating a directed graph where each domain is a node and the certificate alternative names for that domain's certificate are the edges to other domain nodes. New domains are printed as they are found. In Detailed mode upon completion the Graph's adjacency list is printed.
Crawling defaults to collectng certificate by connecting over TCP, however there are multiple drivers that can search Certificate Transparency logs.
This tool was designed to be used for host name enumeration via SSL certificates, but it can also show you a "chain" of trust between domains and the certificates that re-used between them.
Blog post with more information
Usage
Usage of ./certgraph: [OPTION]... HOST...
https://github.com/lanrat/certgraph
OPTIONS:
-cdn
include certificates from CDNs
-ct-expired
include expired certificates in certificate transparancy search
-ct-subdomains
include sub-domains in certificate transparancy search
-depth uint
maximum BFS depth to go (default 5)
-details
print details about the domains crawled
-driver string
driver to use [http, smtp, google, crtsh] (default "http")
-json
print the graph as json, can be used for graph in web UI
-parallel uint
number of certificates to retrieve in parallel (default 10)
-save string
save certs to folder in PEM formate
-timeout uint
tcp timeout in seconds (default 10)
-verbose
verbose logging
-version
print version and exit
Drivers
CertGraph has multiple options for querying SSL certificates. The driver is responsible for retrieving the certificates for a given domain. Currently there are the following drivers:
-
http this is the default driver which works by connecting to the hosts over HTTPS and retrieving the certificates from the SSL connection
-
smtp like the http driver, but connects over port 25 and issues the starttls command to retrieve the certificates from the SSL connection
-
crtsh this driver searches Certificate Transparency logs via crt.sh. No packets are sent to any of the domains when using this driver
-
google this is another Certificate Transparency driver that behaves like crtsh but uses the Googe Certificate Transparency Lookup Tool
Example
$ ./certgraph -details eff.org
eff.org 0 Good 42E3E4605D8BB4608EB64936E2176A98B97EBF2E0F8F93A64A6640713C7D4325
maps.eff.org 1 Good 42E3E4605D8BB4608EB64936E2176A98B97EBF2E0F8F93A64A6640713C7D4325
https-everywhere-atlas.eff.org 1 Good 42E3E4605D8BB4608EB64936E2176A98B97EBF2E0F8F93A64A6640713C7D4325
httpse-atlas.eff.org 1 Good 42E3E4605D8BB4608EB64936E2176A98B97EBF2E0F8F93A64A6640713C7D4325
atlas.eff.org 1 Good 42E3E4605D8BB4608EB64936E2176A98B97EBF2E0F8F93A64A6640713C7D4325
kittens.eff.org 1 Good 42E3E4605D8BB4608EB64936E2176A98B97EBF2E0F8F93A64A6640713C7D4325
The above output represents the adjacency list for the graph for the root domain eff.org. The adjacency list is in the form:
Node Depth Status Cert-Fingerprint
Releases
Precompiled releases will occasionally be uploaded to the releases github page. https://github.com/lanrat/certgraph/releases
Compiling
To compile certgraph you must have a working go 1.9 or newer compiler on your system, as well as the golang dep dependency management tool. To compile for the running system compilation is as easy as running make
certgraph$ make dep
dep ensure
certgraph$ make
go build -o certgraph certgraph.go
Alternatively you can use go get to install with this one-liner:
go get -u github.com/lanrat/certgraph
Web UI
A web UI is provided in the docs folder and is accessable at the github pages url https://lanrat.github.io/certgraph/.
The web UI takes the output provided with the -json flag.
The JSON graph can be sent to the web interface as an uploaded file, remote URL, or as the query string using the data variable.
Example 1: eff.org
Example 2: google.com
Example 3: whitehouse.gov
