mirror of
https://github.com/go-acme/lego.git
synced 2024-12-05 03:58:54 +02:00
201 lines
5.2 KiB
Go
201 lines
5.2 KiB
Go
package acme
|
|
|
|
import (
|
|
"crypto/rand"
|
|
"crypto/rsa"
|
|
"crypto/tls"
|
|
"crypto/x509"
|
|
"crypto/x509/pkix"
|
|
"encoding/json"
|
|
"encoding/pem"
|
|
"errors"
|
|
"fmt"
|
|
"io/ioutil"
|
|
"math/big"
|
|
"net"
|
|
"net/http"
|
|
"strings"
|
|
"time"
|
|
)
|
|
|
|
type simpleHTTPChallenge struct {
|
|
jws *jws
|
|
optPort string
|
|
}
|
|
|
|
// SimpleHTTPS checks for DNS, public IP and port bindings
|
|
func (s *simpleHTTPChallenge) CanSolve(domain string) bool {
|
|
// determine public ip
|
|
resp, err := http.Get("https://icanhazip.com/")
|
|
if err != nil {
|
|
logger().Printf("Could not get public IP -> %v", err)
|
|
return false
|
|
}
|
|
|
|
ip, err := ioutil.ReadAll(resp.Body)
|
|
if err != nil {
|
|
logger().Printf("Could not get public IP -> %v", err)
|
|
return false
|
|
}
|
|
ipStr := string(ip)
|
|
ipStr = strings.Replace(ipStr, "\n", "", -1)
|
|
|
|
// resolve domain we should solve for
|
|
resolvedIPs, err := net.LookupHost(domain)
|
|
if err != nil {
|
|
logger().Printf("Could not lookup DNS A record for %s", domain)
|
|
return false
|
|
}
|
|
|
|
// if the resolve does not resolve to our public ip, we can't solve.
|
|
for _, resolvedIP := range resolvedIPs {
|
|
if resolvedIP == ipStr {
|
|
return true
|
|
}
|
|
}
|
|
|
|
logger().Printf("SimpleHTTPS: Domain %s does not resolve to the public ip of this server. Determined ip: %s", domain, ipStr)
|
|
return false
|
|
}
|
|
|
|
func (s *simpleHTTPChallenge) Solve(chlng challenge, domain string) error {
|
|
|
|
logger().Print("Trying to solve SimpleHTTPS")
|
|
|
|
// Generate random string for the path. The acme server will
|
|
// access this path on the server in order to validate the request
|
|
responseToken := getRandomString(15)
|
|
listener, err := s.startHTTPSServer(domain, chlng.Token, responseToken)
|
|
if err != nil {
|
|
return fmt.Errorf("Could not start HTTPS server for challenge -> %v", err)
|
|
}
|
|
|
|
// Tell the server about the generated random path
|
|
jsonBytes, err := json.Marshal(challenge{Type: chlng.Type, Path: responseToken})
|
|
if err != nil {
|
|
return errors.New("Failed to marshal network message...")
|
|
}
|
|
|
|
resp, err := s.jws.post(chlng.URI, jsonBytes)
|
|
if err != nil {
|
|
return fmt.Errorf("Failed to post JWS message. -> %v", err)
|
|
}
|
|
|
|
// After the path is sent, the ACME server will access our server.
|
|
// Repeatedly check the server for an updated status on our request.
|
|
var challengeResponse challenge
|
|
loop:
|
|
for {
|
|
decoder := json.NewDecoder(resp.Body)
|
|
decoder.Decode(&challengeResponse)
|
|
|
|
switch challengeResponse.Status {
|
|
case "valid":
|
|
logger().Print("The server validated our request")
|
|
listener.Close()
|
|
break loop
|
|
case "pending":
|
|
break
|
|
case "invalid":
|
|
listener.Close()
|
|
return errors.New("The server could not validate our request.")
|
|
default:
|
|
listener.Close()
|
|
return errors.New("The server returned an unexpected state.")
|
|
}
|
|
|
|
time.Sleep(1 * time.Second)
|
|
resp, err = http.Get(chlng.URI)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// Starts a temporary HTTPS server on port 443. As soon as the challenge passed validation,
|
|
// this server will get shut down. The certificate generated here is only held in memory.
|
|
func (s *simpleHTTPChallenge) startHTTPSServer(domain string, token string, responseToken string) (net.Listener, error) {
|
|
|
|
// Generate a new RSA key and a self-signed certificate.
|
|
tempPrivKey, err := generatePrivateKey(2048)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
tempCertPEM, err := generateCert(tempPrivKey, domain)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
pemBytes := pem.EncodeToMemory(&pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(tempPrivKey)})
|
|
tempKeyPair, err := tls.X509KeyPair(
|
|
tempCertPEM,
|
|
pemBytes)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
tlsConf := new(tls.Config)
|
|
tlsConf.Certificates = []tls.Certificate{tempKeyPair}
|
|
|
|
path := "/.well-known/acme-challenge/" + responseToken
|
|
|
|
// Allow for CLI override
|
|
port := ":443"
|
|
if s.optPort != "" {
|
|
port = ":" + s.optPort
|
|
}
|
|
|
|
tlsListener, err := tls.Listen("tcp", port, tlsConf)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("Could not start HTTP listener! -> %v", err)
|
|
}
|
|
|
|
// The handler validates the HOST header and request type.
|
|
// For validation it then writes the token the server returned with the challenge
|
|
http.HandleFunc(path, func(w http.ResponseWriter, r *http.Request) {
|
|
if r.Host == domain && r.Method == "GET" {
|
|
w.Write([]byte(token))
|
|
}
|
|
})
|
|
|
|
go http.Serve(tlsListener, nil)
|
|
|
|
return tlsListener, nil
|
|
}
|
|
|
|
func getRandomString(length int) string {
|
|
const alphanum = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
|
|
var bytes = make([]byte, length)
|
|
rand.Read(bytes)
|
|
for i, b := range bytes {
|
|
bytes[i] = alphanum[b%byte(len(alphanum))]
|
|
}
|
|
return string(bytes)
|
|
}
|
|
|
|
func generateCert(privKey *rsa.PrivateKey, domain string) ([]byte, error) {
|
|
serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
|
|
serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
template := x509.Certificate{
|
|
SerialNumber: serialNumber,
|
|
Subject: pkix.Name{
|
|
CommonName: "ACME Challenge TEMP",
|
|
},
|
|
NotBefore: time.Now(),
|
|
NotAfter: time.Now().Add(365),
|
|
|
|
KeyUsage: x509.KeyUsageKeyEncipherment,
|
|
BasicConstraintsValid: true,
|
|
DNSNames: []string{domain},
|
|
}
|
|
|
|
derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, &privKey.PublicKey, privKey)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: derBytes}), nil
|
|
}
|