Go commandline utility to determine whether a site supports HSTS.

README

DOES_HSTS
=========

This is a very simple Go command line utility that, given a list of sites
to check, will determine whether those sites support HSTS [1]. 

Example usage:
<monalisa: ~> $ does_hsts conformal.com google.com reddit.com
[+] checking whether conformal.com supports HSTS: ok
[+] checking whether google.com supports HSTS: not supported
[+] checking whether reddit.com supports HSTS: SSL failure!

Installing:
does_hsts requires the go compiler to be installed. See the Go language
website's instructions [2] for installation. To build, run 'make';
installation defaults to /usr/local/bin and can be installed with
'make install'. The PREFIX environment variable can be used to change
the installation directory: 'PREFIX=${HOME} make install' would install
to ${HOME}/bin.


[1] https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security
[2] http://golang.org/doc/install

does_hsts.go

package main

import (
    "fmt"
    "net/http"
    "os"
)

const (
    SSLerror = iota
    HSTSyes
    HSTSno
)

// check_site expects a host and prepends 'https://' onto it to create
// an HTTPS url. A GET request is performed on this URL, and the
// returned headers are checked for the HSTS header.
func Check (site string) int {
    res := HSTSno
    url := "https://" + site

    resp, err := http.Get(url)
    if err != nil {
        return SSLerror
    } else {
        defer resp.Body.Close()
    }

    _, ok := resp.Header["Strict-Transport-Security"]
    if ok {
        res = HSTSyes
    }
    
    return res
}

func main () {
    for _, site := range os.Args[1:] {
        fmt.Printf("[+] checking whether %v supports HSTS: ", site)
    
        switch res := Check(site) ; res {
        case SSLerror: fmt.Println("SSL failure!")
        case HSTSno: fmt.Println("not supported")
        case HSTSyes: fmt.Println("ok")
        default: fmt.Println("oh god there was so much blood")
        }
    }
}

Makefile

TARGET := does_hsts
PREFIX ?= /usr/local

all: $(TARGET)

$(TARGET): $(TARGET).go
	go build -o $(TARGET)

clean:
	rm $(TARGET)

install: $(TARGET)
	install -m 0755 -d $(PREFIX)/bin
	install -m 0755 $(TARGET)  $(PREFIX)/bin/$(TARGET)

uninstall:
	-rm -f $(PREFIX)/bin/$(TARGET)

.PHONY: clean all