Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
Certificate fetcher in Go
package main
import "crypto/tls"
import "crypto/sha1"
import "crypto/x509"
import "fmt"
import "encoding/pem"
import "os"
import "time"
import "bufio"
import "strings"
import "net"
func storeCertificate(cert *x509.Certificate) {
hash := sha1.New()
hash.Write(cert.Raw)
filename := fmt.Sprintf("%X", hash.Sum(nil))
if _, err := os.Stat(filename); os.IsNotExist(err) {
f, _ := os.Create(filename)
defer f.Close()
block := &pem.Block{"CERTIFICATE", nil, cert.Raw}
fmt.Println("\x1b[32;1madded", filename, "\x1b[0m")
pem.Encode(f, block)
}
}
func analyzeDomain(domain string) {
fmt.Println("analyzing", domain)
dialer := net.Dialer{}
dialer.Timeout = 10 * time.Second
conn, err := tls.DialWithDialer(&dialer, "tcp", domain, &tls.Config{
InsecureSkipVerify: true,
})
if err != nil {
fmt.Println(fmt.Sprintf("\x1b[31;1mfailed to connect to %s", domain), err, "\x1b[0m")
return
}
defer conn.Close()
for _, cert := range conn.ConnectionState().PeerCertificates {
storeCertificate(cert)
}
}
func analyzeDomains(queue chan string) {
for {
domain := <-queue
analyzeDomain(domain)
}
}
func main () {
cs := make(chan string)
for i := 0; i < 80; i++ {
go analyzeDomains(cs)
}
scanner := bufio.NewScanner(os.Stdin)
for scanner.Scan() {
line := scanner.Text()
if ! strings.Contains(line, ":") {
line = line + ":443"
}
cs <- line
}
time.Sleep(2 * time.Second)
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.