goutils/cmd/stealchain-server/main.go

84 lines
1.6 KiB
Go

package main
import (
"crypto/rand"
"crypto/tls"
"crypto/x509"
"encoding/hex"
"encoding/pem"
"flag"
"fmt"
"io/ioutil"
"net"
"os"
"github.com/kisom/goutils/die"
)
func main() {
cfg := &tls.Config{}
var sysRoot, listenAddr string
var verify bool
flag.StringVar(&sysRoot, "ca", "", "provide an alternate CA bundle")
flag.StringVar(&listenAddr, "listen", ":443", "address to listen on")
flag.BoolVar(&verify, "verify", false, "verify client certificates")
flag.Parse()
if verify {
cfg.ClientAuth = tls.RequireAndVerifyClientCert
}
if sysRoot != "" {
pemList, err := ioutil.ReadFile(sysRoot)
die.If(err)
roots := x509.NewCertPool()
if !roots.AppendCertsFromPEM(pemList) {
fmt.Printf("[!] no valid roots found")
roots = nil
}
cfg.RootCAs = roots
}
l, err := net.Listen("tcp", listenAddr)
if err != nil {
fmt.Println(err.Error())
os.Exit(1)
}
for {
conn, err := l.Accept()
if err != nil {
fmt.Println(err.Error())
}
raddr := conn.RemoteAddr()
tconn := tls.Server(conn, cfg)
cs := tconn.ConnectionState()
if len(cs.PeerCertificates) == 0 {
fmt.Printf("[+] %v: no chain presented\n", raddr)
continue
}
var chain []byte
for _, cert := range cs.PeerCertificates {
p := &pem.Block{
Type: "CERTIFICATE",
Bytes: cert.Raw,
}
chain = append(chain, pem.EncodeToMemory(p)...)
}
var nonce [16]byte
_, err = rand.Read(nonce[:])
if err != nil {
panic(err)
}
fname := fmt.Sprintf("%v-%v.pem", raddr, hex.EncodeToString(nonce[:]))
err = ioutil.WriteFile(fname, chain, 0644)
die.If(err)
fmt.Printf("%v: [+] wrote %v.\n", raddr, fname)
}
}