Implement TLS-SNI-01 to match Boulder. Not spec conform.

acme/client.go

@@ -100,6 +100,7 @@ func NewClient(caDirURL string, user User, keyBits int, optPort string) (*Client
 	// spec to this map. Otherwise they won`t be found.
 	solvers := make(map[string]solver)
 	solvers["http-01"] = &httpChallenge{jws: jws, optPort: optPort}
+	solvers["tls-sni-01"] = &tlsSNIChallenge{jws: jws, optPort: optPort}
 
 	return &Client{directory: dir, user: user, jws: jws, keyBits: keyBits, solvers: solvers}, nil
 }
@@ -409,7 +410,7 @@ func (c *Client) chooseSolvers(auth authorization, domain string) map[int]solver
 			if solver, ok := c.solvers[auth.Challenges[idx].Type]; ok {
 				solvers[idx] = solver
 			} else {
-				logf("[ERROR] acme: Could not find solver for: %s", auth.Challenges[idx].Type)
+				logf("[INFO] acme: Could not find solver for: %s", auth.Challenges[idx].Type)
 			}
 		}
 

acme/tls_sni_challenge.go

@@ -1,10 +1,16 @@
 package acme
 
 import (
+	"crypto/rsa"
 	"crypto/sha256"
-	"crypto/x509"
+	"crypto/tls"
 	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
 	"net"
+	"net/http"
+	"time"
 )
 
 type tlsSNIChallenge struct {
@@ -15,30 +21,133 @@ type tlsSNIChallenge struct {
 }
 
 func (t *tlsSNIChallenge) Solve(chlng challenge, domain string) error {
+	// FIXME: https://github.com/ietf-wg-acme/acme/pull/22
+	// Currently we implement this challenge to track boulder, not the current spec!
 
 	logf("[INFO] acme: Trying to solve TLS-SNI-01")
 
+	t.start = make(chan net.Listener)
+	t.end = make(chan error)
+
 	// Generate the Key Authorization for the challenge
 	keyAuth, err := getKeyAuthorization(chlng.Token, &t.jws.privKey.PublicKey)
 	if err != nil {
 		return err
 	}
 
-	zet := make([]string, chlng.Iterations)
-
-	zetBytes := sha256.Sum256([]byte(keyAuth))
-	zet[0] = hex.EncodeToString(zetBytes[:sha256.Size])
-	for i := 1; i < chlng.Iterations; i++ {
-		zetBytes = sha256.Sum256([]byte(zet[i-1]))
-		zet[i] = hex.EncodeToString(zetBytes[:sha256.Size])
+	certificate, err := t.generateCertificate(keyAuth)
+	if err != nil {
+		return err
 	}
 
-	certificates, err := t.generateCertificates(zet)
+	go t.startSNITLSServer(certificate)
+	var listener net.Listener
+	select {
+	case listener = <-t.start:
+		break
+	case err := <-t.end:
+		return fmt.Errorf("Could not start HTTPS server for challenge -> %v", err)
+	}
+
+	// Make sure we properly close the HTTP server before we return
+	defer func() {
+		listener.Close()
+		err = <-t.end
+		close(t.start)
+		close(t.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 TLS-SNI-01
+	resp, err := t.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 (t *tlsSNIChallenge) generateCertificates(zet []string) ([]*x509.Certificate, error) {
+func (t *tlsSNIChallenge) generateCertificate(keyAuth string) (tls.Certificate, error) {
 
-	return nil, nil
+	zBytes := sha256.Sum256([]byte(keyAuth))
+	z := hex.EncodeToString(zBytes[:sha256.Size])
+
+	// generate a new RSA key for the certificates
+	tempPrivKey, err := generatePrivateKey(rsakey, 2048)
+	if err != nil {
+		return tls.Certificate{}, err
+	}
+	rsaPrivKey := tempPrivKey.(*rsa.PrivateKey)
+	rsaPrivPEM := pemEncode(rsaPrivKey)
+
+	domain := fmt.Sprintf("%s.%s.acme.invalid", z[:32], z[32:])
+	tempCertPEM, err := generatePemCert(rsaPrivKey, domain)
+	if err != nil {
+		return tls.Certificate{}, err
+	}
+
+	certificate, err := tls.X509KeyPair(tempCertPEM, rsaPrivPEM)
+	if err != nil {
+		return tls.Certificate{}, err
+	}
+
+	return certificate, nil
+}
+
+func (t *tlsSNIChallenge) startSNITLSServer(cert tls.Certificate) {
+
+	// Allow for CLI port override
+	port := ":443"
+	if t.optPort != "" {
+		port = ":" + t.optPort
+	}
+
+	tlsConf := new(tls.Config)
+	tlsConf.Certificates = []tls.Certificate{cert}
+
+	tlsListener, err := tls.Listen("tcp", port, tlsConf)
+	if err != nil {
+		t.end <- err
+	}
+	// Signal successfull start
+	t.start <- tlsListener
+	
+	http.Serve(tlsListener, nil)
+	
+	t.end <- nil
 }