Update vendor (#1498)

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

@@ -363,6 +363,10 @@ func AcceptTOS(tosURL string) bool { return true }
 // Also see Error's Instance field for when a CA requires already registered accounts to agree
 // to an updated Terms of Service.
 func (c *Client) Register(ctx context.Context, acct *Account, prompt func(tosURL string) bool) (*Account, error) {
+	if c.Key == nil {
+		return nil, errors.New("acme: client.Key must be set to Register")
+	}
+
 	dir, err := c.Discover(ctx)
 	if err != nil {
 		return nil, err

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

@@ -1133,11 +1133,11 @@ func (s *certState) tlscert() (*tls.Certificate, error) {
 	}, nil
 }
 
-// certRequest generates a CSR for the given common name cn and optional SANs.
-func certRequest(key crypto.Signer, cn string, ext []pkix.Extension, san ...string) ([]byte, error) {
+// certRequest generates a CSR for the given common name.
+func certRequest(key crypto.Signer, name string, ext []pkix.Extension) ([]byte, error) {
 	req := &x509.CertificateRequest{
-		Subject:         pkix.Name{CommonName: cn},
-		DNSNames:        san,
+		Subject:         pkix.Name{CommonName: name},
+		DNSNames:        []string{name},
 		ExtraExtensions: ext,
 	}
 	return x509.CreateCertificateRequest(rand.Reader, req, key)

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

@@ -7,6 +7,7 @@ package acme
 import (
 	"crypto"
 	"crypto/ecdsa"
+	"crypto/hmac"
 	"crypto/rand"
 	"crypto/rsa"
 	"crypto/sha256"
@@ -14,6 +15,7 @@ import (
 	"encoding/asn1"
 	"encoding/base64"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"math/big"
 )
@@ -31,6 +33,14 @@ const noKeyID = keyID("")
 // See https://tools.ietf.org/html/rfc8555#section-6.3 for more details.
 const noPayload = ""
 
+// jsonWebSignature can be easily serialized into a JWS following
+// https://tools.ietf.org/html/rfc7515#section-3.2.
+type jsonWebSignature struct {
+	Protected string `json:"protected"`
+	Payload   string `json:"payload"`
+	Sig       string `json:"signature"`
+}
+
 // jwsEncodeJSON signs claimset using provided key and a nonce.
 // The result is serialized in JSON format containing either kid or jwk
 // fields based on the provided keyID value.
@@ -71,12 +81,7 @@ func jwsEncodeJSON(claimset interface{}, key crypto.Signer, kid keyID, nonce, ur
 	if err != nil {
 		return nil, err
 	}
-
-	enc := struct {
-		Protected string `json:"protected"`
-		Payload   string `json:"payload"`
-		Sig       string `json:"signature"`
-	}{
+	enc := jsonWebSignature{
 		Protected: phead,
 		Payload:   payload,
 		Sig:       base64.RawURLEncoding.EncodeToString(sig),
@@ -84,6 +89,43 @@ func jwsEncodeJSON(claimset interface{}, key crypto.Signer, kid keyID, nonce, ur
 	return json.Marshal(&enc)
 }
 
+// jwsWithMAC creates and signs a JWS using the given key and the HS256
+// algorithm. kid and url are included in the protected header. rawPayload
+// should not be base64-URL-encoded.
+func jwsWithMAC(key []byte, kid, url string, rawPayload []byte) (*jsonWebSignature, error) {
+	if len(key) == 0 {
+		return nil, errors.New("acme: cannot sign JWS with an empty MAC key")
+	}
+	header := struct {
+		Algorithm string `json:"alg"`
+		KID       string `json:"kid"`
+		URL       string `json:"url,omitempty"`
+	}{
+		// Only HMAC-SHA256 is supported.
+		Algorithm: "HS256",
+		KID:       kid,
+		URL:       url,
+	}
+	rawProtected, err := json.Marshal(header)
+	if err != nil {
+		return nil, err
+	}
+	protected := base64.RawURLEncoding.EncodeToString(rawProtected)
+	payload := base64.RawURLEncoding.EncodeToString(rawPayload)
+
+	h := hmac.New(sha256.New, key)
+	if _, err := h.Write([]byte(protected + "." + payload)); err != nil {
+		return nil, err
+	}
+	mac := h.Sum(nil)
+
+	return &jsonWebSignature{
+		Protected: protected,
+		Payload:   payload,
+		Sig:       base64.RawURLEncoding.EncodeToString(mac),
+	}, nil
+}
+
 // jwkEncode encodes public part of an RSA or ECDSA key into a JWK.
 // The result is also suitable for creating a JWK thumbprint.
 // https://tools.ietf.org/html/rfc7517

vendor/golang.org/x/crypto/acme/rfc8555.go

@@ -37,22 +37,32 @@ func (c *Client) DeactivateReg(ctx context.Context) error {
 	return nil
 }
 
-// registerRFC is quivalent to c.Register but for CAs implementing RFC 8555.
+// registerRFC is equivalent to c.Register but for CAs implementing RFC 8555.
 // It expects c.Discover to have already been called.
-// TODO: Implement externalAccountBinding.
 func (c *Client) registerRFC(ctx context.Context, acct *Account, prompt func(tosURL string) bool) (*Account, error) {
 	c.cacheMu.Lock() // guard c.kid access
 	defer c.cacheMu.Unlock()
 
 	req := struct {
-		TermsAgreed bool     `json:"termsOfServiceAgreed,omitempty"`
-		Contact     []string `json:"contact,omitempty"`
+		TermsAgreed            bool              `json:"termsOfServiceAgreed,omitempty"`
+		Contact                []string          `json:"contact,omitempty"`
+		ExternalAccountBinding *jsonWebSignature `json:"externalAccountBinding,omitempty"`
 	}{
 		Contact: acct.Contact,
 	}
 	if c.dir.Terms != "" {
 		req.TermsAgreed = prompt(c.dir.Terms)
 	}
+
+	// set 'externalAccountBinding' field if requested
+	if acct.ExternalAccountBinding != nil {
+		eabJWS, err := c.encodeExternalAccountBinding(acct.ExternalAccountBinding)
+		if err != nil {
+			return nil, fmt.Errorf("acme: failed to encode external account binding: %v", err)
+		}
+		req.ExternalAccountBinding = eabJWS
+	}
+
 	res, err := c.post(ctx, c.Key, c.dir.RegURL, req, wantStatus(
 		http.StatusOK,      // account with this key already registered
 		http.StatusCreated, // new account created
@@ -75,7 +85,17 @@ func (c *Client) registerRFC(ctx context.Context, acct *Account, prompt func(tos
 	return a, nil
 }
 
-// updateGegRFC is equivalent to c.UpdateReg but for CAs implementing RFC 8555.
+// encodeExternalAccountBinding will encode an external account binding stanza
+// as described in https://tools.ietf.org/html/rfc8555#section-7.3.4.
+func (c *Client) encodeExternalAccountBinding(eab *ExternalAccountBinding) (*jsonWebSignature, error) {
+	jwk, err := jwkEncode(c.Key.Public())
+	if err != nil {
+		return nil, err
+	}
+	return jwsWithMAC(eab.Key, eab.KID, c.dir.RegURL, []byte(jwk))
+}
+
+// updateRegRFC is equivalent to c.UpdateReg but for CAs implementing RFC 8555.
 // It expects c.Discover to have already been called.
 func (c *Client) updateRegRFC(ctx context.Context, a *Account) (*Account, error) {
 	url := string(c.accountKID(ctx))

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

@@ -199,6 +199,28 @@ type Account struct {
 	//
 	// It is non-RFC 8555 compliant and is obsoleted by OrdersURL.
 	Certificates string
+
+	// ExternalAccountBinding represents an arbitrary binding to an account of
+	// the CA which the ACME server is tied to.
+	// See https://tools.ietf.org/html/rfc8555#section-7.3.4 for more details.
+	ExternalAccountBinding *ExternalAccountBinding
+}
+
+// ExternalAccountBinding contains the data needed to form a request with
+// an external account binding.
+// See https://tools.ietf.org/html/rfc8555#section-7.3.4 for more details.
+type ExternalAccountBinding struct {
+	// KID is the Key ID of the symmetric MAC key that the CA provides to
+	// identify an external account from ACME.
+	KID string
+
+	// Key is the bytes of the symmetric key that the CA provides to identify
+	// the account. Key must correspond to the KID.
+	Key []byte
+}
+
+func (e *ExternalAccountBinding) String() string {
+	return fmt.Sprintf("&{KID: %q, Key: redacted}", e.KID)
 }
 
 // Directory is ACME server discovery data.

vendor/golang.org/x/crypto/acme/version_go112.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build go1.12
 // +build go1.12
 
 package acme