Handle CORS requests (#6289)

vendor/golang.org/x/crypto/acme/acme.go

@@ -77,6 +77,10 @@ const (
 type Client struct {
 	// Key is the account key used to register with a CA and sign requests.
 	// Key.Public() must return a *rsa.PublicKey or *ecdsa.PublicKey.
+	//
+	// The following algorithms are supported:
+	// RS256, ES256, ES384 and ES512.
+	// See RFC7518 for more details about the algorithms.
 	Key crypto.Signer
 
 	// HTTPClient optionally specifies an HTTP client to use
@@ -124,11 +128,7 @@ func (c *Client) Discover(ctx context.Context) (Directory, error) {
 		return *c.dir, nil
 	}
 
-	dirURL := c.DirectoryURL
-	if dirURL == "" {
-		dirURL = LetsEncryptURL
-	}
-	res, err := c.get(ctx, dirURL, wantStatus(http.StatusOK))
+	res, err := c.get(ctx, c.directoryURL(), wantStatus(http.StatusOK))
 	if err != nil {
 		return Directory{}, err
 	}
@@ -161,6 +161,13 @@ func (c *Client) Discover(ctx context.Context) (Directory, error) {
 	return *c.dir, nil
 }
 
+func (c *Client) directoryURL() string {
+	if c.DirectoryURL != "" {
+		return c.DirectoryURL
+	}
+	return LetsEncryptURL
+}
+
 // CreateCert requests a new certificate using the Certificate Signing Request csr encoded in DER format.
 // The exp argument indicates the desired certificate validity duration. CA may issue a certificate
 // with a different duration.
@@ -319,6 +326,20 @@ func (c *Client) UpdateReg(ctx context.Context, a *Account) (*Account, error) {
 // a valid authorization (Authorization.Status is StatusValid). If so, the caller
 // need not fulfill any challenge and can proceed to requesting a certificate.
 func (c *Client) Authorize(ctx context.Context, domain string) (*Authorization, error) {
+	return c.authorize(ctx, "dns", domain)
+}
+
+// AuthorizeIP is the same as Authorize but requests IP address authorization.
+// Clients which successfully obtain such authorization may request to issue
+// a certificate for IP addresses.
+//
+// See the ACME spec extension for more details about IP address identifiers:
+// https://tools.ietf.org/html/draft-ietf-acme-ip.
+func (c *Client) AuthorizeIP(ctx context.Context, ipaddr string) (*Authorization, error) {
+	return c.authorize(ctx, "ip", ipaddr)
+}
+
+func (c *Client) authorize(ctx context.Context, typ, val string) (*Authorization, error) {
 	if _, err := c.Discover(ctx); err != nil {
 		return nil, err
 	}
@@ -332,7 +353,7 @@ func (c *Client) Authorize(ctx context.Context, domain string) (*Authorization,
 		Identifier authzID `json:"identifier"`
 	}{
 		Resource:   "new-authz",
-		Identifier: authzID{Type: "dns", Value: domain},
+		Identifier: authzID{Type: typ, Value: val},
 	}
 	res, err := c.post(ctx, c.Key, c.dir.AuthzURL, req, wantStatus(http.StatusCreated))
 	if err != nil {
@@ -693,12 +714,18 @@ func (c *Client) doReg(ctx context.Context, url string, typ string, acct *Accoun
 }
 
 // popNonce returns a nonce value previously stored with c.addNonce
-// or fetches a fresh one from the given URL.
+// or fetches a fresh one from a URL by issuing a HEAD request.
+// It first tries c.directoryURL() and then the provided url if the former fails.
 func (c *Client) popNonce(ctx context.Context, url string) (string, error) {
 	c.noncesMu.Lock()
 	defer c.noncesMu.Unlock()
 	if len(c.nonces) == 0 {
-		return c.fetchNonce(ctx, url)
+		dirURL := c.directoryURL()
+		v, err := c.fetchNonce(ctx, dirURL)
+		if err != nil && url != dirURL {
+			v, err = c.fetchNonce(ctx, url)
+		}
+		return v, err
 	}
 	var nonce string
 	for nonce = range c.nonces {

vendor/golang.org/x/crypto/acme/autocert/autocert.go

@@ -69,7 +69,7 @@ func HostWhitelist(hosts ...string) HostPolicy {
 	}
 	return func(_ context.Context, host string) error {
 		if !whitelist[host] {
-			return errors.New("acme/autocert: host not configured")
+			return fmt.Errorf("acme/autocert: host %q not configured in HostWhitelist", host)
 		}
 		return nil
 	}

vendor/golang.org/x/crypto/acme/jws.go

@@ -25,7 +25,7 @@ func jwsEncodeJSON(claimset interface{}, key crypto.Signer, nonce string) ([]byt
 	if err != nil {
 		return nil, err
 	}
-	alg, sha := jwsHasher(key)
+	alg, sha := jwsHasher(key.Public())
 	if alg == "" || !sha.Available() {
 		return nil, ErrUnsupportedKey
 	}
@@ -97,13 +97,16 @@ func jwkEncode(pub crypto.PublicKey) (string, error) {
 }
 
 // jwsSign signs the digest using the given key.
-// It returns ErrUnsupportedKey if the key type is unknown.
-// The hash is used only for RSA keys.
+// The hash is unused for ECDSA keys.
+//
+// Note: non-stdlib crypto.Signer implementations are expected to return
+// the signature in the format as specified in RFC7518.
+// See https://tools.ietf.org/html/rfc7518 for more details.
 func jwsSign(key crypto.Signer, hash crypto.Hash, digest []byte) ([]byte, error) {
-	switch key := key.(type) {
-	case *rsa.PrivateKey:
-		return key.Sign(rand.Reader, digest, hash)
-	case *ecdsa.PrivateKey:
+	if key, ok := key.(*ecdsa.PrivateKey); ok {
+		// The key.Sign method of ecdsa returns ASN1-encoded signature.
+		// So, we use the package Sign function instead
+		// to get R and S values directly and format the result accordingly.
 		r, s, err := ecdsa.Sign(rand.Reader, key, digest)
 		if err != nil {
 			return nil, err
@@ -118,18 +121,18 @@ func jwsSign(key crypto.Signer, hash crypto.Hash, digest []byte) ([]byte, error)
 		copy(sig[size*2-len(sb):], sb)
 		return sig, nil
 	}
-	return nil, ErrUnsupportedKey
+	return key.Sign(rand.Reader, digest, hash)
 }
 
 // jwsHasher indicates suitable JWS algorithm name and a hash function
 // to use for signing a digest with the provided key.
 // It returns ("", 0) if the key is not supported.
-func jwsHasher(key crypto.Signer) (string, crypto.Hash) {
-	switch key := key.(type) {
-	case *rsa.PrivateKey:
+func jwsHasher(pub crypto.PublicKey) (string, crypto.Hash) {
+	switch pub := pub.(type) {
+	case *rsa.PublicKey:
 		return "RS256", crypto.SHA256
-	case *ecdsa.PrivateKey:
-		switch key.Params().Name {
+	case *ecdsa.PublicKey:
+		switch pub.Params().Name {
 		case "P-256":
 			return "ES256", crypto.SHA256
 		case "P-384":