Initial work on HTTP-01

acme/http_challenge.go

@@ -0,0 +1,138 @@
+package acme
+
+import (
+	"crypto"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net"
+	"net/http"
+	"strings"
+	"time"
+)
+
+type httpChallenge struct {
+	jws     *jws
+	optPort string
+	start   chan net.Listener
+	end     chan error
+}
+
+func (s *httpChallenge) Solve(chlng challenge, domain string) error {
+
+	logf("[INFO] acme: Trying to solve HTTP-01")
+
+	s.start = make(chan net.Listener)
+	s.end = make(chan error)
+
+	// Generate the Key Authorization for the challenge
+	key := keyAsJWK(&s.jws.privKey.PublicKey)
+	thumbBytes, err := key.Thumbprint(crypto.SHA256)
+	if err != nil {
+		return err
+	}
+
+	keyAuth := chlng.Token + "." + base64.RawURLEncoding.EncodeToString(thumbBytes)
+
+	go s.startHTTPServer(domain, chlng.Token, keyAuth)
+	var listener net.Listener
+	select {
+	case listener = <-s.start:
+		break
+	case err := <-s.end:
+		return fmt.Errorf("Could not start HTTP server for challenge -> %v", err)
+	}
+
+	// Make sure we properly close the HTTP server before we return
+	defer func() {
+		listener.Close()
+		err = <-s.end
+		close(s.start)
+		close(s.end)
+	}()
+
+	jsonBytes, err := json.Marshal(challenge{Resource: "challenge", Type: chlng.Type, Token: chlng.Token, KeyAuthorization: keyAuth})
+	if err != nil {
+		return errors.New("Failed to marshal network message...")
+	}
+
+	// Tell the server we handle HTTP-01
+	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 {
+		if resp.StatusCode >= http.StatusBadRequest {
+			return handleHTTPError(resp)
+		}
+
+		err = json.NewDecoder(resp.Body).Decode(&challengeResponse)
+		resp.Body.Close()
+		if err != nil {
+			return err
+		}
+
+		switch challengeResponse.Status {
+		case "valid":
+			logf("The server validated our request")
+			break Loop
+		case "pending":
+			break
+		case "invalid":
+			return errors.New("The server could not validate our request.")
+		default:
+			return errors.New("The server returned an unexpected state.")
+		}
+
+		time.Sleep(1 * time.Second)
+		resp, err = http.Get(chlng.URI)
+	}
+
+	return nil
+}
+
+func (s *httpChallenge) startHTTPServer(domain string, token string, keyAuth string) {
+
+	// Allow for CLI port override
+	port := ":80"
+	if s.optPort != "" {
+		port = ":" + s.optPort
+	}
+
+	listener, err := net.Listen("tcp", domain+port)
+	if err != nil {
+		// if the domain:port bind failed, fall back to :port bind and try that instead.
+		listener, err = net.Listen("tcp", port)
+		if err != nil {
+			s.end <- err
+		}
+	}
+	// Signal successfull start
+	s.start <- listener
+
+	path := "/.well-known/acme-challenge/" + token
+
+	// 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 strings.HasPrefix(r.Host, domain) && r.Method == "GET" {
+			w.Header().Add("Content-Type", "text/plain")
+			w.Write([]byte(keyAuth))
+			logf("Served Key Authentication ...")
+		} else {
+			logf("Received request for domain %s with method %s", r.Host, r.Method)
+			w.Write([]byte("TEST"))
+		}
+	})
+
+	http.Serve(listener, nil)
+
+	// Signal that the server was shut down
+	s.end <- nil
+}

acme/messages.go

@@ -78,6 +78,7 @@ type challenge struct {
 	Status           string `json:"status,omitempty"`
 	URI              string `json:"uri,omitempty"`
 	Token            string `json:"token,omitempty"`
+	KeyAuthorization string `json:"keyAuthorization,omitempty"`
 	TLS              bool   `json:"tls,omitempty"`
 }