dksslcheck.go

// Copyright (c) 2014 John Graham-Cumming
//
// Takes a CSV containing rows in the form
//
// ip,name
//
// Connects to 'ip' on port 443 using TLS presenting the SNI name 'name' and
// verifies the result.

package main

import (
	"bufio"
	"crypto/tls"
	"flag"
	"fmt"
	"log"
	"net"
	"os"
	"strings"
	"sync"
)

type task interface {
	process()
	print()
}

type factory interface {
	make(line string) task
}

type check struct {
	ip string
	name string
	err error
	success bool
}

var workers int

func (c *check) process() {
	conf := &tls.Config{ServerName: c.name,
		InsecureSkipVerify: false}

	conn, err := tls.Dial("tcp", net.JoinHostPort(c.ip, "443"), conf)
	c.err = err
	c.success = c.err == nil
	if conn != nil {
		conn.Close()
	}
}

func (c *check) print() {
	if c.err == nil {
		c.err = fmt.Errorf("OK")
	}
	fmt.Printf("%s,%s,%t,%s\n", c.ip, c.name, c.success, c.err)
}

type usine struct {
}

func (u *usine) make(line string) task {
	parts := strings.Split(line, ",")
	if len(parts) != 2 {
		log.Fatalf("Don't understand line '%s'\n", line)
	}

	return &check{ip: parts[0], name: parts[1]}
}

func run(f factory) {
	var wg sync.WaitGroup

	in := make(chan task)

	wg.Add(1)
	go func() {
		s := bufio.NewScanner(os.Stdin)
		for s.Scan() {
			in <- f.make(s.Text())
		}
		if s.Err() != nil {
			log.Fatalf("Error reading STDIN: %s", s.Err())
		}
		close(in)
		wg.Done()
	}()

	out := make(chan task)

	for i := 0; i < workers; i++ {
		wg.Add(1)
		go func() {
			for t := range in {
				t.process()
				out <- t
			}
			wg.Done()
		}()
	}

	go func() {
		wg.Wait()
		close(out)
	}()

	for t := range out {
		t.print()
	}
}

func main() {
	flag.IntVar(&workers, "workers", 100, "Number of workers")
	flag.Parse()
	run(&usine{})
}