Changed the client to pull the urls down from the directory on the CA server.

CA Url now needs to point to the root of the CA

acme/client.go

@@ -41,11 +41,11 @@ type solver interface {
 
 // Client is the user-friendy way to ACME
 type Client struct {
-	regURL  string
-	user    User
-	jws     *jws
-	keyBits int
-	solvers map[string]solver
+	directory directory
+	user      User
+	jws       *jws
+	keyBits   int
+	solvers   map[string]solver
 }
 
 // NewClient creates a new client for the set user.
@@ -53,7 +53,6 @@ func NewClient(caURL string, usr User, keyBits int, optPort string) *Client {
 	if err := usr.GetPrivateKey().Validate(); err != nil {
 		logger().Fatalf("Could not validate the private account key of %s\n\t%v", usr.GetEmail(), err)
 	}
-
 	jws := &jws{privKey: usr.GetPrivateKey()}
 
 	// REVIEW: best possibility?
@@ -62,7 +61,21 @@ func NewClient(caURL string, usr User, keyBits int, optPort string) *Client {
 	solvers := make(map[string]solver)
 	solvers["simpleHttp"] = &simpleHTTPChallenge{jws: jws, optPort: optPort}
 
-	return &Client{regURL: caURL, user: usr, jws: jws, keyBits: keyBits, solvers: solvers}
+	dirResp, err := http.Get(caURL + "/directory")
+	if err != nil {
+		logger().Fatalf("Could not get directory from CA URL. Please check the URL.\n\t%v", err)
+	}
+	var dir directory
+	decoder := json.NewDecoder(dirResp.Body)
+	err = decoder.Decode(&dir)
+	if err != nil {
+		logger().Fatalf("Could not parse directory response from CA URL.\n\t%v", err)
+	}
+	if dir.NewRegURL == "" || dir.NewAuthzURL == "" || dir.NewCertURL == "" || dir.RevokeCertURL == "" {
+		logger().Fatal("The directory returned by the server was invalid.")
+	}
+
+	return &Client{directory: dir, user: usr, jws: jws, keyBits: keyBits, solvers: solvers}
 }
 
 // Register the current account to the ACME server.
@@ -73,7 +86,7 @@ func (c *Client) Register() (*RegistrationResource, error) {
 		return nil, err
 	}
 
-	resp, err := c.jws.post(c.regURL, jsonBytes)
+	resp, err := c.jws.post(c.directory.NewRegURL, jsonBytes)
 	if err != nil {
 		return nil, err
 	}

acme/client_test.go

@@ -3,6 +3,9 @@ package acme
 import (
 	"crypto/rand"
 	"crypto/rsa"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
 	"testing"
 )
 
@@ -17,7 +20,13 @@ func TestNewClient(t *testing.T) {
 		regres:     new(RegistrationResource),
 		privatekey: key,
 	}
-	caURL, optPort := "https://foobar", "1234"
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		data, _ := json.Marshal(directory{NewAuthzURL: "http://test", NewCertURL: "http://test", NewRegURL: "http://test", RevokeCertURL: "http://test"})
+		w.Write(data)
+	}))
+
+	caURL, optPort := ts.URL, "1234"
 	client := NewClient(caURL, user, keyBits, optPort)
 
 	if client.jws == nil {
@@ -27,9 +36,6 @@ func TestNewClient(t *testing.T) {
 		t.Errorf("Expected jws.privKey to be %p but was %p", expected, actual)
 	}
 
-	if client.regURL != caURL {
-		t.Errorf("Expected regURL to be '%s' but was '%s'", caURL, client.regURL)
-	}
 	if client.keyBits != keyBits {
 		t.Errorf("Expected keyBits to be %d but was %d", keyBits, client.keyBits)
 	}

acme/messages.go

@@ -2,6 +2,13 @@ package acme
 
 import "time"
 
+type directory struct {
+	NewAuthzURL   string `json:"new-authz"`
+	NewCertURL    string `json:"new-cert"`
+	NewRegURL     string `json:"new-reg"`
+	RevokeCertURL string `json:"revoke-cert"`
+}
+
 type registrationMessage struct {
 	Resource string   `json:"resource"`
 	Contact  []string `json:"contact"`

cli.go

@@ -91,7 +91,7 @@ func main() {
 		},
 		cli.StringFlag{
 			Name:  "server, s",
-			Value: "https://acme-staging.api.letsencrypt.org/acme/new-reg",
+			Value: "https://acme-staging.api.letsencrypt.org/",
 			Usage: "CA hostname (and optionally :port). The server certificate must be trusted in order to avoid further modifications to the client.",
 		},
 		cli.StringFlag{