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8 files changed, 0 insertions, 3252 deletions

diff --git a/vendor/golang.org/x/crypto/acme/acme.go b/vendor/golang.org/x/crypto/acme/acme.go
deleted file mode 100644
index 7df6476..0000000
--- a/vendor/golang.org/x/crypto/acme/acme.go
+++ /dev/null
@@ -1,922 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Package acme provides an implementation of the
-// Automatic Certificate Management Environment (ACME) spec.
-// See https://tools.ietf.org/html/draft-ietf-acme-acme-02 for details.
-//
-// Most common scenarios will want to use autocert subdirectory instead,
-// which provides automatic access to certificates from Let's Encrypt
-// and any other ACME-based CA.
-//
-// This package is a work in progress and makes no API stability promises.
-package acme
-
-import (
-	"context"
-	"crypto"
-	"crypto/ecdsa"
-	"crypto/elliptic"
-	"crypto/rand"
-	"crypto/sha256"
-	"crypto/tls"
-	"crypto/x509"
-	"crypto/x509/pkix"
-	"encoding/asn1"
-	"encoding/base64"
-	"encoding/hex"
-	"encoding/json"
-	"encoding/pem"
-	"errors"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"math/big"
-	"net/http"
-	"strings"
-	"sync"
-	"time"
-)
-
-const (
-	// LetsEncryptURL is the Directory endpoint of Let's Encrypt CA.
-	LetsEncryptURL = "https://acme-v01.api.letsencrypt.org/directory"
-
-	// ALPNProto is the ALPN protocol name used by a CA server when validating
-	// tls-alpn-01 challenges.
-	//
-	// Package users must ensure their servers can negotiate the ACME ALPN in
-	// order for tls-alpn-01 challenge verifications to succeed.
-	// See the crypto/tls package's Config.NextProtos field.
-	ALPNProto = "acme-tls/1"
-)
-
-// idPeACMEIdentifierV1 is the OID for the ACME extension for the TLS-ALPN challenge.
-var idPeACMEIdentifierV1 = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 1, 30, 1}
-
-const (
-	maxChainLen = 5       // max depth and breadth of a certificate chain
-	maxCertSize = 1 << 20 // max size of a certificate, in bytes
-
-	// Max number of collected nonces kept in memory.
-	// Expect usual peak of 1 or 2.
-	maxNonces = 100
-)
-
-// Client is an ACME client.
-// The only required field is Key. An example of creating a client with a new key
-// is as follows:
-//
-// 	key, err := rsa.GenerateKey(rand.Reader, 2048)
-// 	if err != nil {
-// 		log.Fatal(err)
-// 	}
-// 	client := &Client{Key: key}
-//
-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.
-	Key crypto.Signer
-
-	// HTTPClient optionally specifies an HTTP client to use
-	// instead of http.DefaultClient.
-	HTTPClient *http.Client
-
-	// DirectoryURL points to the CA directory endpoint.
-	// If empty, LetsEncryptURL is used.
-	// Mutating this value after a successful call of Client's Discover method
-	// will have no effect.
-	DirectoryURL string
-
-	// RetryBackoff computes the duration after which the nth retry of a failed request
-	// should occur. The value of n for the first call on failure is 1.
-	// The values of r and resp are the request and response of the last failed attempt.
-	// If the returned value is negative or zero, no more retries are done and an error
-	// is returned to the caller of the original method.
-	//
-	// Requests which result in a 4xx client error are not retried,
-	// except for 400 Bad Request due to "bad nonce" errors and 429 Too Many Requests.
-	//
-	// If RetryBackoff is nil, a truncated exponential backoff algorithm
-	// with the ceiling of 10 seconds is used, where each subsequent retry n
-	// is done after either ("Retry-After" + jitter) or (2^n seconds + jitter),
-	// preferring the former if "Retry-After" header is found in the resp.
-	// The jitter is a random value up to 1 second.
-	RetryBackoff func(n int, r *http.Request, resp *http.Response) time.Duration
-
-	dirMu sync.Mutex // guards writes to dir
-	dir   *Directory // cached result of Client's Discover method
-
-	noncesMu sync.Mutex
-	nonces   map[string]struct{} // nonces collected from previous responses
-}
-
-// Discover performs ACME server discovery using c.DirectoryURL.
-//
-// It caches successful result. So, subsequent calls will not result in
-// a network round-trip. This also means mutating c.DirectoryURL after successful call
-// of this method will have no effect.
-func (c *Client) Discover(ctx context.Context) (Directory, error) {
-	c.dirMu.Lock()
-	defer c.dirMu.Unlock()
-	if c.dir != nil {
-		return *c.dir, nil
-	}
-
-	dirURL := c.DirectoryURL
-	if dirURL == "" {
-		dirURL = LetsEncryptURL
-	}
-	res, err := c.get(ctx, dirURL, wantStatus(http.StatusOK))
-	if err != nil {
-		return Directory{}, err
-	}
-	defer res.Body.Close()
-	c.addNonce(res.Header)
-
-	var v struct {
-		Reg    string `json:"new-reg"`
-		Authz  string `json:"new-authz"`
-		Cert   string `json:"new-cert"`
-		Revoke string `json:"revoke-cert"`
-		Meta   struct {
-			Terms   string   `json:"terms-of-service"`
-			Website string   `json:"website"`
-			CAA     []string `json:"caa-identities"`
-		}
-	}
-	if err := json.NewDecoder(res.Body).Decode(&v); err != nil {
-		return Directory{}, err
-	}
-	c.dir = &Directory{
-		RegURL:    v.Reg,
-		AuthzURL:  v.Authz,
-		CertURL:   v.Cert,
-		RevokeURL: v.Revoke,
-		Terms:     v.Meta.Terms,
-		Website:   v.Meta.Website,
-		CAA:       v.Meta.CAA,
-	}
-	return *c.dir, nil
-}
-
-// 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.
-// If the bundle argument is true, the returned value will also contain the CA (issuer) certificate chain.
-//
-// In the case where CA server does not provide the issued certificate in the response,
-// CreateCert will poll certURL using c.FetchCert, which will result in additional round-trips.
-// In such a scenario, the caller can cancel the polling with ctx.
-//
-// CreateCert returns an error if the CA's response or chain was unreasonably large.
-// Callers are encouraged to parse the returned value to ensure the certificate is valid and has the expected features.
-func (c *Client) CreateCert(ctx context.Context, csr []byte, exp time.Duration, bundle bool) (der [][]byte, certURL string, err error) {
-	if _, err := c.Discover(ctx); err != nil {
-		return nil, "", err
-	}
-
-	req := struct {
-		Resource  string `json:"resource"`
-		CSR       string `json:"csr"`
-		NotBefore string `json:"notBefore,omitempty"`
-		NotAfter  string `json:"notAfter,omitempty"`
-	}{
-		Resource: "new-cert",
-		CSR:      base64.RawURLEncoding.EncodeToString(csr),
-	}
-	now := timeNow()
-	req.NotBefore = now.Format(time.RFC3339)
-	if exp > 0 {
-		req.NotAfter = now.Add(exp).Format(time.RFC3339)
-	}
-
-	res, err := c.post(ctx, c.Key, c.dir.CertURL, req, wantStatus(http.StatusCreated))
-	if err != nil {
-		return nil, "", err
-	}
-	defer res.Body.Close()
-
-	curl := res.Header.Get("Location") // cert permanent URL
-	if res.ContentLength == 0 {
-		// no cert in the body; poll until we get it
-		cert, err := c.FetchCert(ctx, curl, bundle)
-		return cert, curl, err
-	}
-	// slurp issued cert and CA chain, if requested
-	cert, err := c.responseCert(ctx, res, bundle)
-	return cert, curl, err
-}
-
-// FetchCert retrieves already issued certificate from the given url, in DER format.
-// It retries the request until the certificate is successfully retrieved,
-// context is cancelled by the caller or an error response is received.
-//
-// The returned value will also contain the CA (issuer) certificate if the bundle argument is true.
-//
-// FetchCert returns an error if the CA's response or chain was unreasonably large.
-// Callers are encouraged to parse the returned value to ensure the certificate is valid
-// and has expected features.
-func (c *Client) FetchCert(ctx context.Context, url string, bundle bool) ([][]byte, error) {
-	res, err := c.get(ctx, url, wantStatus(http.StatusOK))
-	if err != nil {
-		return nil, err
-	}
-	return c.responseCert(ctx, res, bundle)
-}
-
-// RevokeCert revokes a previously issued certificate cert, provided in DER format.
-//
-// The key argument, used to sign the request, must be authorized
-// to revoke the certificate. It's up to the CA to decide which keys are authorized.
-// For instance, the key pair of the certificate may be authorized.
-// If the key is nil, c.Key is used instead.
-func (c *Client) RevokeCert(ctx context.Context, key crypto.Signer, cert []byte, reason CRLReasonCode) error {
-	if _, err := c.Discover(ctx); err != nil {
-		return err
-	}
-
-	body := &struct {
-		Resource string `json:"resource"`
-		Cert     string `json:"certificate"`
-		Reason   int    `json:"reason"`
-	}{
-		Resource: "revoke-cert",
-		Cert:     base64.RawURLEncoding.EncodeToString(cert),
-		Reason:   int(reason),
-	}
-	if key == nil {
-		key = c.Key
-	}
-	res, err := c.post(ctx, key, c.dir.RevokeURL, body, wantStatus(http.StatusOK))
-	if err != nil {
-		return err
-	}
-	defer res.Body.Close()
-	return nil
-}
-
-// AcceptTOS always returns true to indicate the acceptance of a CA's Terms of Service
-// during account registration. See Register method of Client for more details.
-func AcceptTOS(tosURL string) bool { return true }
-
-// Register creates a new account registration by following the "new-reg" flow.
-// It returns the registered account. The account is not modified.
-//
-// The registration may require the caller to agree to the CA's Terms of Service (TOS).
-// If so, and the account has not indicated the acceptance of the terms (see Account for details),
-// Register calls prompt with a TOS URL provided by the CA. Prompt should report
-// whether the caller agrees to the terms. To always accept the terms, the caller can use AcceptTOS.
-func (c *Client) Register(ctx context.Context, a *Account, prompt func(tosURL string) bool) (*Account, error) {
-	if _, err := c.Discover(ctx); err != nil {
-		return nil, err
-	}
-
-	var err error
-	if a, err = c.doReg(ctx, c.dir.RegURL, "new-reg", a); err != nil {
-		return nil, err
-	}
-	var accept bool
-	if a.CurrentTerms != "" && a.CurrentTerms != a.AgreedTerms {
-		accept = prompt(a.CurrentTerms)
-	}
-	if accept {
-		a.AgreedTerms = a.CurrentTerms
-		a, err = c.UpdateReg(ctx, a)
-	}
-	return a, err
-}
-
-// GetReg retrieves an existing registration.
-// The url argument is an Account URI.
-func (c *Client) GetReg(ctx context.Context, url string) (*Account, error) {
-	a, err := c.doReg(ctx, url, "reg", nil)
-	if err != nil {
-		return nil, err
-	}
-	a.URI = url
-	return a, nil
-}
-
-// UpdateReg updates an existing registration.
-// It returns an updated account copy. The provided account is not modified.
-func (c *Client) UpdateReg(ctx context.Context, a *Account) (*Account, error) {
-	uri := a.URI
-	a, err := c.doReg(ctx, uri, "reg", a)
-	if err != nil {
-		return nil, err
-	}
-	a.URI = uri
-	return a, nil
-}
-
-// Authorize performs the initial step in an authorization flow.
-// The caller will then need to choose from and perform a set of returned
-// challenges using c.Accept in order to successfully complete authorization.
-//
-// If an authorization has been previously granted, the CA may return
-// 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) {
-	if _, err := c.Discover(ctx); err != nil {
-		return nil, err
-	}
-
-	type authzID struct {
-		Type  string `json:"type"`
-		Value string `json:"value"`
-	}
-	req := struct {
-		Resource   string  `json:"resource"`
-		Identifier authzID `json:"identifier"`
-	}{
-		Resource:   "new-authz",
-		Identifier: authzID{Type: "dns", Value: domain},
-	}
-	res, err := c.post(ctx, c.Key, c.dir.AuthzURL, req, wantStatus(http.StatusCreated))
-	if err != nil {
-		return nil, err
-	}
-	defer res.Body.Close()
-
-	var v wireAuthz
-	if err := json.NewDecoder(res.Body).Decode(&v); err != nil {
-		return nil, fmt.Errorf("acme: invalid response: %v", err)
-	}
-	if v.Status != StatusPending && v.Status != StatusValid {
-		return nil, fmt.Errorf("acme: unexpected status: %s", v.Status)
-	}
-	return v.authorization(res.Header.Get("Location")), nil
-}
-
-// GetAuthorization retrieves an authorization identified by the given URL.
-//
-// If a caller needs to poll an authorization until its status is final,
-// see the WaitAuthorization method.
-func (c *Client) GetAuthorization(ctx context.Context, url string) (*Authorization, error) {
-	res, err := c.get(ctx, url, wantStatus(http.StatusOK, http.StatusAccepted))
-	if err != nil {
-		return nil, err
-	}
-	defer res.Body.Close()
-	var v wireAuthz
-	if err := json.NewDecoder(res.Body).Decode(&v); err != nil {
-		return nil, fmt.Errorf("acme: invalid response: %v", err)
-	}
-	return v.authorization(url), nil
-}
-
-// RevokeAuthorization relinquishes an existing authorization identified
-// by the given URL.
-// The url argument is an Authorization.URI value.
-//
-// If successful, the caller will be required to obtain a new authorization
-// using the Authorize method before being able to request a new certificate
-// for the domain associated with the authorization.
-//
-// It does not revoke existing certificates.
-func (c *Client) RevokeAuthorization(ctx context.Context, url string) error {
-	req := struct {
-		Resource string `json:"resource"`
-		Status   string `json:"status"`
-		Delete   bool   `json:"delete"`
-	}{
-		Resource: "authz",
-		Status:   "deactivated",
-		Delete:   true,
-	}
-	res, err := c.post(ctx, c.Key, url, req, wantStatus(http.StatusOK))
-	if err != nil {
-		return err
-	}
-	defer res.Body.Close()
-	return nil
-}
-
-// WaitAuthorization polls an authorization at the given URL
-// until it is in one of the final states, StatusValid or StatusInvalid,
-// the ACME CA responded with a 4xx error code, or the context is done.
-//
-// It returns a non-nil Authorization only if its Status is StatusValid.
-// In all other cases WaitAuthorization returns an error.
-// If the Status is StatusInvalid, the returned error is of type *AuthorizationError.
-func (c *Client) WaitAuthorization(ctx context.Context, url string) (*Authorization, error) {
-	for {
-		res, err := c.get(ctx, url, wantStatus(http.StatusOK, http.StatusAccepted))
-		if err != nil {
-			return nil, err
-		}
-
-		var raw wireAuthz
-		err = json.NewDecoder(res.Body).Decode(&raw)
-		res.Body.Close()
-		switch {
-		case err != nil:
-			// Skip and retry.
-		case raw.Status == StatusValid:
-			return raw.authorization(url), nil
-		case raw.Status == StatusInvalid:
-			return nil, raw.error(url)
-		}
-
-		// Exponential backoff is implemented in c.get above.
-		// This is just to prevent continuously hitting the CA
-		// while waiting for a final authorization status.
-		d := retryAfter(res.Header.Get("Retry-After"))
-		if d == 0 {
-			// Given that the fastest challenges TLS-SNI and HTTP-01
-			// require a CA to make at least 1 network round trip
-			// and most likely persist a challenge state,
-			// this default delay seems reasonable.
-			d = time.Second
-		}
-		t := time.NewTimer(d)
-		select {
-		case <-ctx.Done():
-			t.Stop()
-			return nil, ctx.Err()
-		case <-t.C:
-			// Retry.
-		}
-	}
-}
-
-// GetChallenge retrieves the current status of an challenge.
-//
-// A client typically polls a challenge status using this method.
-func (c *Client) GetChallenge(ctx context.Context, url string) (*Challenge, error) {
-	res, err := c.get(ctx, url, wantStatus(http.StatusOK, http.StatusAccepted))
-	if err != nil {
-		return nil, err
-	}
-	defer res.Body.Close()
-	v := wireChallenge{URI: url}
-	if err := json.NewDecoder(res.Body).Decode(&v); err != nil {
-		return nil, fmt.Errorf("acme: invalid response: %v", err)
-	}
-	return v.challenge(), nil
-}
-
-// Accept informs the server that the client accepts one of its challenges
-// previously obtained with c.Authorize.
-//
-// The server will then perform the validation asynchronously.
-func (c *Client) Accept(ctx context.Context, chal *Challenge) (*Challenge, error) {
-	auth, err := keyAuth(c.Key.Public(), chal.Token)
-	if err != nil {
-		return nil, err
-	}
-
-	req := struct {
-		Resource string `json:"resource"`
-		Type     string `json:"type"`
-		Auth     string `json:"keyAuthorization"`
-	}{
-		Resource: "challenge",
-		Type:     chal.Type,
-		Auth:     auth,
-	}
-	res, err := c.post(ctx, c.Key, chal.URI, req, wantStatus(
-		http.StatusOK,       // according to the spec
-		http.StatusAccepted, // Let's Encrypt: see https://goo.gl/WsJ7VT (acme-divergences.md)
-	))
-	if err != nil {
-		return nil, err
-	}
-	defer res.Body.Close()
-
-	var v wireChallenge
-	if err := json.NewDecoder(res.Body).Decode(&v); err != nil {
-		return nil, fmt.Errorf("acme: invalid response: %v", err)
-	}
-	return v.challenge(), nil
-}
-
-// DNS01ChallengeRecord returns a DNS record value for a dns-01 challenge response.
-// A TXT record containing the returned value must be provisioned under
-// "_acme-challenge" name of the domain being validated.
-//
-// The token argument is a Challenge.Token value.
-func (c *Client) DNS01ChallengeRecord(token string) (string, error) {
-	ka, err := keyAuth(c.Key.Public(), token)
-	if err != nil {
-		return "", err
-	}
-	b := sha256.Sum256([]byte(ka))
-	return base64.RawURLEncoding.EncodeToString(b[:]), nil
-}
-
-// HTTP01ChallengeResponse returns the response for an http-01 challenge.
-// Servers should respond with the value to HTTP requests at the URL path
-// provided by HTTP01ChallengePath to validate the challenge and prove control
-// over a domain name.
-//
-// The token argument is a Challenge.Token value.
-func (c *Client) HTTP01ChallengeResponse(token string) (string, error) {
-	return keyAuth(c.Key.Public(), token)
-}
-
-// HTTP01ChallengePath returns the URL path at which the response for an http-01 challenge
-// should be provided by the servers.
-// The response value can be obtained with HTTP01ChallengeResponse.
-//
-// The token argument is a Challenge.Token value.
-func (c *Client) HTTP01ChallengePath(token string) string {
-	return "/.well-known/acme-challenge/" + token
-}
-
-// TLSSNI01ChallengeCert creates a certificate for TLS-SNI-01 challenge response.
-// Servers can present the certificate to validate the challenge and prove control
-// over a domain name.
-//
-// The implementation is incomplete in that the returned value is a single certificate,
-// computed only for Z0 of the key authorization. ACME CAs are expected to update
-// their implementations to use the newer version, TLS-SNI-02.
-// For more details on TLS-SNI-01 see https://tools.ietf.org/html/draft-ietf-acme-acme-01#section-7.3.
-//
-// The token argument is a Challenge.Token value.
-// If a WithKey option is provided, its private part signs the returned cert,
-// and the public part is used to specify the signee.
-// If no WithKey option is provided, a new ECDSA key is generated using P-256 curve.
-//
-// The returned certificate is valid for the next 24 hours and must be presented only when
-// the server name of the TLS ClientHello matches exactly the returned name value.
-func (c *Client) TLSSNI01ChallengeCert(token string, opt ...CertOption) (cert tls.Certificate, name string, err error) {
-	ka, err := keyAuth(c.Key.Public(), token)
-	if err != nil {
-		return tls.Certificate{}, "", err
-	}
-	b := sha256.Sum256([]byte(ka))
-	h := hex.EncodeToString(b[:])
-	name = fmt.Sprintf("%s.%s.acme.invalid", h[:32], h[32:])
-	cert, err = tlsChallengeCert([]string{name}, opt)
-	if err != nil {
-		return tls.Certificate{}, "", err
-	}
-	return cert, name, nil
-}
-
-// TLSSNI02ChallengeCert creates a certificate for TLS-SNI-02 challenge response.
-// Servers can present the certificate to validate the challenge and prove control
-// over a domain name. For more details on TLS-SNI-02 see
-// https://tools.ietf.org/html/draft-ietf-acme-acme-03#section-7.3.
-//
-// The token argument is a Challenge.Token value.
-// If a WithKey option is provided, its private part signs the returned cert,
-// and the public part is used to specify the signee.
-// If no WithKey option is provided, a new ECDSA key is generated using P-256 curve.
-//
-// The returned certificate is valid for the next 24 hours and must be presented only when
-// the server name in the TLS ClientHello matches exactly the returned name value.
-func (c *Client) TLSSNI02ChallengeCert(token string, opt ...CertOption) (cert tls.Certificate, name string, err error) {
-	b := sha256.Sum256([]byte(token))
-	h := hex.EncodeToString(b[:])
-	sanA := fmt.Sprintf("%s.%s.token.acme.invalid", h[:32], h[32:])
-
-	ka, err := keyAuth(c.Key.Public(), token)
-	if err != nil {
-		return tls.Certificate{}, "", err
-	}
-	b = sha256.Sum256([]byte(ka))
-	h = hex.EncodeToString(b[:])
-	sanB := fmt.Sprintf("%s.%s.ka.acme.invalid", h[:32], h[32:])
-
-	cert, err = tlsChallengeCert([]string{sanA, sanB}, opt)
-	if err != nil {
-		return tls.Certificate{}, "", err
-	}
-	return cert, sanA, nil
-}
-
-// TLSALPN01ChallengeCert creates a certificate for TLS-ALPN-01 challenge response.
-// Servers can present the certificate to validate the challenge and prove control
-// over a domain name. For more details on TLS-ALPN-01 see
-// https://tools.ietf.org/html/draft-shoemaker-acme-tls-alpn-00#section-3
-//
-// The token argument is a Challenge.Token value.
-// If a WithKey option is provided, its private part signs the returned cert,
-// and the public part is used to specify the signee.
-// If no WithKey option is provided, a new ECDSA key is generated using P-256 curve.
-//
-// The returned certificate is valid for the next 24 hours and must be presented only when
-// the server name in the TLS ClientHello matches the domain, and the special acme-tls/1 ALPN protocol
-// has been specified.
-func (c *Client) TLSALPN01ChallengeCert(token, domain string, opt ...CertOption) (cert tls.Certificate, err error) {
-	ka, err := keyAuth(c.Key.Public(), token)
-	if err != nil {
-		return tls.Certificate{}, err
-	}
-	shasum := sha256.Sum256([]byte(ka))
-	extValue, err := asn1.Marshal(shasum[:])
-	if err != nil {
-		return tls.Certificate{}, err
-	}
-	acmeExtension := pkix.Extension{
-		Id:       idPeACMEIdentifierV1,
-		Critical: true,
-		Value:    extValue,
-	}
-
-	tmpl := defaultTLSChallengeCertTemplate()
-
-	var newOpt []CertOption
-	for _, o := range opt {
-		switch o := o.(type) {
-		case *certOptTemplate:
-			t := *(*x509.Certificate)(o) // shallow copy is ok
-			tmpl = &t
-		default:
-			newOpt = append(newOpt, o)
-		}
-	}
-	tmpl.ExtraExtensions = append(tmpl.ExtraExtensions, acmeExtension)
-	newOpt = append(newOpt, WithTemplate(tmpl))
-	return tlsChallengeCert([]string{domain}, newOpt)
-}
-
-// doReg sends all types of registration requests.
-// The type of request is identified by typ argument, which is a "resource"
-// in the ACME spec terms.
-//
-// A non-nil acct argument indicates whether the intention is to mutate data
-// of the Account. Only Contact and Agreement of its fields are used
-// in such cases.
-func (c *Client) doReg(ctx context.Context, url string, typ string, acct *Account) (*Account, error) {
-	req := struct {
-		Resource  string   `json:"resource"`
-		Contact   []string `json:"contact,omitempty"`
-		Agreement string   `json:"agreement,omitempty"`
-	}{
-		Resource: typ,
-	}
-	if acct != nil {
-		req.Contact = acct.Contact
-		req.Agreement = acct.AgreedTerms
-	}
-	res, err := c.post(ctx, c.Key, url, req, wantStatus(
-		http.StatusOK,       // updates and deletes
-		http.StatusCreated,  // new account creation
-		http.StatusAccepted, // Let's Encrypt divergent implementation
-	))
-	if err != nil {
-		return nil, err
-	}
-	defer res.Body.Close()
-
-	var v struct {
-		Contact        []string
-		Agreement      string
-		Authorizations string
-		Certificates   string
-	}
-	if err := json.NewDecoder(res.Body).Decode(&v); err != nil {
-		return nil, fmt.Errorf("acme: invalid response: %v", err)
-	}
-	var tos string
-	if v := linkHeader(res.Header, "terms-of-service"); len(v) > 0 {
-		tos = v[0]
-	}
-	var authz string
-	if v := linkHeader(res.Header, "next"); len(v) > 0 {
-		authz = v[0]
-	}
-	return &Account{
-		URI:            res.Header.Get("Location"),
-		Contact:        v.Contact,
-		AgreedTerms:    v.Agreement,
-		CurrentTerms:   tos,
-		Authz:          authz,
-		Authorizations: v.Authorizations,
-		Certificates:   v.Certificates,
-	}, nil
-}
-
-// popNonce returns a nonce value previously stored with c.addNonce
-// or fetches a fresh one from the given URL.
-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)
-	}
-	var nonce string
-	for nonce = range c.nonces {
-		delete(c.nonces, nonce)
-		break
-	}
-	return nonce, nil
-}
-
-// clearNonces clears any stored nonces
-func (c *Client) clearNonces() {
-	c.noncesMu.Lock()
-	defer c.noncesMu.Unlock()
-	c.nonces = make(map[string]struct{})
-}
-
-// addNonce stores a nonce value found in h (if any) for future use.
-func (c *Client) addNonce(h http.Header) {
-	v := nonceFromHeader(h)
-	if v == "" {
-		return
-	}
-	c.noncesMu.Lock()
-	defer c.noncesMu.Unlock()
-	if len(c.nonces) >= maxNonces {
-		return
-	}
-	if c.nonces == nil {
-		c.nonces = make(map[string]struct{})
-	}
-	c.nonces[v] = struct{}{}
-}
-
-func (c *Client) fetchNonce(ctx context.Context, url string) (string, error) {
-	r, err := http.NewRequest("HEAD", url, nil)
-	if err != nil {
-		return "", err
-	}
-	resp, err := c.doNoRetry(ctx, r)
-	if err != nil {
-		return "", err
-	}
-	defer resp.Body.Close()
-	nonce := nonceFromHeader(resp.Header)
-	if nonce == "" {
-		if resp.StatusCode > 299 {
-			return "", responseError(resp)
-		}
-		return "", errors.New("acme: nonce not found")
-	}
-	return nonce, nil
-}
-
-func nonceFromHeader(h http.Header) string {
-	return h.Get("Replay-Nonce")
-}
-
-func (c *Client) responseCert(ctx context.Context, res *http.Response, bundle bool) ([][]byte, error) {
-	b, err := ioutil.ReadAll(io.LimitReader(res.Body, maxCertSize+1))
-	if err != nil {
-		return nil, fmt.Errorf("acme: response stream: %v", err)
-	}
-	if len(b) > maxCertSize {
-		return nil, errors.New("acme: certificate is too big")
-	}
-	cert := [][]byte{b}
-	if !bundle {
-		return cert, nil
-	}
-
-	// Append CA chain cert(s).
-	// At least one is required according to the spec:
-	// https://tools.ietf.org/html/draft-ietf-acme-acme-03#section-6.3.1
-	up := linkHeader(res.Header, "up")
-	if len(up) == 0 {
-		return nil, errors.New("acme: rel=up link not found")
-	}
-	if len(up) > maxChainLen {
-		return nil, errors.New("acme: rel=up link is too large")
-	}
-	for _, url := range up {
-		cc, err := c.chainCert(ctx, url, 0)
-		if err != nil {
-			return nil, err
-		}
-		cert = append(cert, cc...)
-	}
-	return cert, nil
-}
-
-// chainCert fetches CA certificate chain recursively by following "up" links.
-// Each recursive call increments the depth by 1, resulting in an error
-// if the recursion level reaches maxChainLen.
-//
-// First chainCert call starts with depth of 0.
-func (c *Client) chainCert(ctx context.Context, url string, depth int) ([][]byte, error) {
-	if depth >= maxChainLen {
-		return nil, errors.New("acme: certificate chain is too deep")
-	}
-
-	res, err := c.get(ctx, url, wantStatus(http.StatusOK))
-	if err != nil {
-		return nil, err
-	}
-	defer res.Body.Close()
-	b, err := ioutil.ReadAll(io.LimitReader(res.Body, maxCertSize+1))
-	if err != nil {
-		return nil, err
-	}
-	if len(b) > maxCertSize {
-		return nil, errors.New("acme: certificate is too big")
-	}
-	chain := [][]byte{b}
-
-	uplink := linkHeader(res.Header, "up")
-	if len(uplink) > maxChainLen {
-		return nil, errors.New("acme: certificate chain is too large")
-	}
-	for _, up := range uplink {
-		cc, err := c.chainCert(ctx, up, depth+1)
-		if err != nil {
-			return nil, err
-		}
-		chain = append(chain, cc...)
-	}
-
-	return chain, nil
-}
-
-// linkHeader returns URI-Reference values of all Link headers
-// with relation-type rel.
-// See https://tools.ietf.org/html/rfc5988#section-5 for details.
-func linkHeader(h http.Header, rel string) []string {
-	var links []string
-	for _, v := range h["Link"] {
-		parts := strings.Split(v, ";")
-		for _, p := range parts {
-			p = strings.TrimSpace(p)
-			if !strings.HasPrefix(p, "rel=") {
-				continue
-			}
-			if v := strings.Trim(p[4:], `"`); v == rel {
-				links = append(links, strings.Trim(parts[0], "<>"))
-			}
-		}
-	}
-	return links
-}
-
-// keyAuth generates a key authorization string for a given token.
-func keyAuth(pub crypto.PublicKey, token string) (string, error) {
-	th, err := JWKThumbprint(pub)
-	if err != nil {
-		return "", err
-	}
-	return fmt.Sprintf("%s.%s", token, th), nil
-}
-
-// defaultTLSChallengeCertTemplate is a template used to create challenge certs for TLS challenges.
-func defaultTLSChallengeCertTemplate() *x509.Certificate {
-	return &x509.Certificate{
-		SerialNumber:          big.NewInt(1),
-		NotBefore:             time.Now(),
-		NotAfter:              time.Now().Add(24 * time.Hour),
-		BasicConstraintsValid: true,
-		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
-		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
-	}
-}
-
-// tlsChallengeCert creates a temporary certificate for TLS-SNI challenges
-// with the given SANs and auto-generated public/private key pair.
-// The Subject Common Name is set to the first SAN to aid debugging.
-// To create a cert with a custom key pair, specify WithKey option.
-func tlsChallengeCert(san []string, opt []CertOption) (tls.Certificate, error) {
-	var key crypto.Signer
-	tmpl := defaultTLSChallengeCertTemplate()
-	for _, o := range opt {
-		switch o := o.(type) {
-		case *certOptKey:
-			if key != nil {
-				return tls.Certificate{}, errors.New("acme: duplicate key option")
-			}
-			key = o.key
-		case *certOptTemplate:
-			t := *(*x509.Certificate)(o) // shallow copy is ok
-			tmpl = &t
-		default:
-			// package's fault, if we let this happen:
-			panic(fmt.Sprintf("unsupported option type %T", o))
-		}
-	}
-	if key == nil {
-		var err error
-		if key, err = ecdsa.GenerateKey(elliptic.P256(), rand.Reader); err != nil {
-			return tls.Certificate{}, err
-		}
-	}
-	tmpl.DNSNames = san
-	if len(san) > 0 {
-		tmpl.Subject.CommonName = san[0]
-	}
-
-	der, err := x509.CreateCertificate(rand.Reader, tmpl, tmpl, key.Public(), key)
-	if err != nil {
-		return tls.Certificate{}, err
-	}
-	return tls.Certificate{
-		Certificate: [][]byte{der},
-		PrivateKey:  key,
-	}, nil
-}
-
-// encodePEM returns b encoded as PEM with block of type typ.
-func encodePEM(typ string, b []byte) []byte {
-	pb := &pem.Block{Type: typ, Bytes: b}
-	return pem.EncodeToMemory(pb)
-}
-
-// timeNow is useful for testing for fixed current time.
-var timeNow = time.Now
diff --git a/vendor/golang.org/x/crypto/acme/autocert/autocert.go b/vendor/golang.org/x/crypto/acme/autocert/autocert.go
deleted file mode 100644
index 4c2fc07..0000000
--- a/vendor/golang.org/x/crypto/acme/autocert/autocert.go
+++ /dev/null
@@ -1,1139 +0,0 @@
-// Copyright 2016 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Package autocert provides automatic access to certificates from Let's Encrypt
-// and any other ACME-based CA.
-//
-// This package is a work in progress and makes no API stability promises.
-package autocert
-
-import (
-	"bytes"
-	"context"
-	"crypto"
-	"crypto/ecdsa"
-	"crypto/elliptic"
-	"crypto/rand"
-	"crypto/rsa"
-	"crypto/tls"
-	"crypto/x509"
-	"crypto/x509/pkix"
-	"encoding/pem"
-	"errors"
-	"fmt"
-	"io"
-	mathrand "math/rand"
-	"net"
-	"net/http"
-	"path"
-	"strings"
-	"sync"
-	"time"
-
-	"golang.org/x/crypto/acme"
-)
-
-// createCertRetryAfter is how much time to wait before removing a failed state
-// entry due to an unsuccessful createCert call.
-// This is a variable instead of a const for testing.
-// TODO: Consider making it configurable or an exp backoff?
-var createCertRetryAfter = time.Minute
-
-// pseudoRand is safe for concurrent use.
-var pseudoRand *lockedMathRand
-
-func init() {
-	src := mathrand.NewSource(time.Now().UnixNano())
-	pseudoRand = &lockedMathRand{rnd: mathrand.New(src)}
-}
-
-// AcceptTOS is a Manager.Prompt function that always returns true to
-// indicate acceptance of the CA's Terms of Service during account
-// registration.
-func AcceptTOS(tosURL string) bool { return true }
-
-// HostPolicy specifies which host names the Manager is allowed to respond to.
-// It returns a non-nil error if the host should be rejected.
-// The returned error is accessible via tls.Conn.Handshake and its callers.
-// See Manager's HostPolicy field and GetCertificate method docs for more details.
-type HostPolicy func(ctx context.Context, host string) error
-
-// HostWhitelist returns a policy where only the specified host names are allowed.
-// Only exact matches are currently supported. Subdomains, regexp or wildcard
-// will not match.
-func HostWhitelist(hosts ...string) HostPolicy {
-	whitelist := make(map[string]bool, len(hosts))
-	for _, h := range hosts {
-		whitelist[h] = true
-	}
-	return func(_ context.Context, host string) error {
-		if !whitelist[host] {
-			return errors.New("acme/autocert: host not configured")
-		}
-		return nil
-	}
-}
-
-// defaultHostPolicy is used when Manager.HostPolicy is not set.
-func defaultHostPolicy(context.Context, string) error {
-	return nil
-}
-
-// Manager is a stateful certificate manager built on top of acme.Client.
-// It obtains and refreshes certificates automatically using "tls-alpn-01",
-// "tls-sni-01", "tls-sni-02" and "http-01" challenge types,
-// as well as providing them to a TLS server via tls.Config.
-//
-// You must specify a cache implementation, such as DirCache,
-// to reuse obtained certificates across program restarts.
-// Otherwise your server is very likely to exceed the certificate
-// issuer's request rate limits.
-type Manager struct {
-	// Prompt specifies a callback function to conditionally accept a CA's Terms of Service (TOS).
-	// The registration may require the caller to agree to the CA's TOS.
-	// If so, Manager calls Prompt with a TOS URL provided by the CA. Prompt should report
-	// whether the caller agrees to the terms.
-	//
-	// To always accept the terms, the callers can use AcceptTOS.
-	Prompt func(tosURL string) bool
-
-	// Cache optionally stores and retrieves previously-obtained certificates
-	// and other state. If nil, certs will only be cached for the lifetime of
-	// the Manager. Multiple Managers can share the same Cache.
-	//
-	// Using a persistent Cache, such as DirCache, is strongly recommended.
-	Cache Cache
-
-	// HostPolicy controls which domains the Manager will attempt
-	// to retrieve new certificates for. It does not affect cached certs.
-	//
-	// If non-nil, HostPolicy is called before requesting a new cert.
-	// If nil, all hosts are currently allowed. This is not recommended,
-	// as it opens a potential attack where clients connect to a server
-	// by IP address and pretend to be asking for an incorrect host name.
-	// Manager will attempt to obtain a certificate for that host, incorrectly,
-	// eventually reaching the CA's rate limit for certificate requests
-	// and making it impossible to obtain actual certificates.
-	//
-	// See GetCertificate for more details.
-	HostPolicy HostPolicy
-
-	// RenewBefore optionally specifies how early certificates should
-	// be renewed before they expire.
-	//
-	// If zero, they're renewed 30 days before expiration.
-	RenewBefore time.Duration
-
-	// Client is used to perform low-level operations, such as account registration
-	// and requesting new certificates.
-	//
-	// If Client is nil, a zero-value acme.Client is used with acme.LetsEncryptURL
-	// as directory endpoint. If the Client.Key is nil, a new ECDSA P-256 key is
-	// generated and, if Cache is not nil, stored in cache.
-	//
-	// Mutating the field after the first call of GetCertificate method will have no effect.
-	Client *acme.Client
-
-	// Email optionally specifies a contact email address.
-	// This is used by CAs, such as Let's Encrypt, to notify about problems
-	// with issued certificates.
-	//
-	// If the Client's account key is already registered, Email is not used.
-	Email string
-
-	// ForceRSA used to make the Manager generate RSA certificates. It is now ignored.
-	//
-	// Deprecated: the Manager will request the correct type of certificate based
-	// on what each client supports.
-	ForceRSA bool
-
-	// ExtraExtensions are used when generating a new CSR (Certificate Request),
-	// thus allowing customization of the resulting certificate.
-	// For instance, TLS Feature Extension (RFC 7633) can be used
-	// to prevent an OCSP downgrade attack.
-	//
-	// The field value is passed to crypto/x509.CreateCertificateRequest
-	// in the template's ExtraExtensions field as is.
-	ExtraExtensions []pkix.Extension
-
-	clientMu sync.Mutex
-	client   *acme.Client // initialized by acmeClient method
-
-	stateMu sync.Mutex
-	state   map[certKey]*certState
-
-	// renewal tracks the set of domains currently running renewal timers.
-	renewalMu sync.Mutex
-	renewal   map[certKey]*domainRenewal
-
-	// tokensMu guards the rest of the fields: tryHTTP01, certTokens and httpTokens.
-	tokensMu sync.RWMutex
-	// tryHTTP01 indicates whether the Manager should try "http-01" challenge type
-	// during the authorization flow.
-	tryHTTP01 bool
-	// httpTokens contains response body values for http-01 challenges
-	// and is keyed by the URL path at which a challenge response is expected
-	// to be provisioned.
-	// The entries are stored for the duration of the authorization flow.
-	httpTokens map[string][]byte
-	// certTokens contains temporary certificates for tls-sni and tls-alpn challenges
-	// and is keyed by token domain name, which matches server name of ClientHello.
-	// Keys always have ".acme.invalid" suffix for tls-sni. Otherwise, they are domain names
-	// for tls-alpn.
-	// The entries are stored for the duration of the authorization flow.
-	certTokens map[string]*tls.Certificate
-	// nowFunc, if not nil, returns the current time. This may be set for
-	// testing purposes.
-	nowFunc func() time.Time
-}
-
-// certKey is the key by which certificates are tracked in state, renewal and cache.
-type certKey struct {
-	domain  string // without trailing dot
-	isRSA   bool   // RSA cert for legacy clients (as opposed to default ECDSA)
-	isToken bool   // tls-based challenge token cert; key type is undefined regardless of isRSA
-}
-
-func (c certKey) String() string {
-	if c.isToken {
-		return c.domain + "+token"
-	}
-	if c.isRSA {
-		return c.domain + "+rsa"
-	}
-	return c.domain
-}
-
-// TLSConfig creates a new TLS config suitable for net/http.Server servers,
-// supporting HTTP/2 and the tls-alpn-01 ACME challenge type.
-func (m *Manager) TLSConfig() *tls.Config {
-	return &tls.Config{
-		GetCertificate: m.GetCertificate,
-		NextProtos: []string{
-			"h2", "http/1.1", // enable HTTP/2
-			acme.ALPNProto, // enable tls-alpn ACME challenges
-		},
-	}
-}
-
-// GetCertificate implements the tls.Config.GetCertificate hook.
-// It provides a TLS certificate for hello.ServerName host, including answering
-// tls-alpn-01 and *.acme.invalid (tls-sni-01 and tls-sni-02) challenges.
-// All other fields of hello are ignored.
-//
-// If m.HostPolicy is non-nil, GetCertificate calls the policy before requesting
-// a new cert. A non-nil error returned from m.HostPolicy halts TLS negotiation.
-// The error is propagated back to the caller of GetCertificate and is user-visible.
-// This does not affect cached certs. See HostPolicy field description for more details.
-//
-// If GetCertificate is used directly, instead of via Manager.TLSConfig, package users will
-// also have to add acme.ALPNProto to NextProtos for tls-alpn-01, or use HTTPHandler
-// for http-01. (The tls-sni-* challenges have been deprecated by popular ACME providers
-// due to security issues in the ecosystem.)
-func (m *Manager) GetCertificate(hello *tls.ClientHelloInfo) (*tls.Certificate, error) {
-	if m.Prompt == nil {
-		return nil, errors.New("acme/autocert: Manager.Prompt not set")
-	}
-
-	name := hello.ServerName
-	if name == "" {
-		return nil, errors.New("acme/autocert: missing server name")
-	}
-	if !strings.Contains(strings.Trim(name, "."), ".") {
-		return nil, errors.New("acme/autocert: server name component count invalid")
-	}
-	if strings.ContainsAny(name, `+/\`) {
-		return nil, errors.New("acme/autocert: server name contains invalid character")
-	}
-
-	// In the worst-case scenario, the timeout needs to account for caching, host policy,
-	// domain ownership verification and certificate issuance.
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Minute)
-	defer cancel()
-
-	// Check whether this is a token cert requested for TLS-SNI or TLS-ALPN challenge.
-	if wantsTokenCert(hello) {
-		m.tokensMu.RLock()
-		defer m.tokensMu.RUnlock()
-		// It's ok to use the same token cert key for both tls-sni and tls-alpn
-		// because there's always at most 1 token cert per on-going domain authorization.
-		// See m.verify for details.
-		if cert := m.certTokens[name]; cert != nil {
-			return cert, nil
-		}
-		if cert, err := m.cacheGet(ctx, certKey{domain: name, isToken: true}); err == nil {
-			return cert, nil
-		}
-		// TODO: cache error results?
-		return nil, fmt.Errorf("acme/autocert: no token cert for %q", name)
-	}
-
-	// regular domain
-	ck := certKey{
-		domain: strings.TrimSuffix(name, "."), // golang.org/issue/18114
-		isRSA:  !supportsECDSA(hello),
-	}
-	cert, err := m.cert(ctx, ck)
-	if err == nil {
-		return cert, nil
-	}
-	if err != ErrCacheMiss {
-		return nil, err
-	}
-
-	// first-time
-	if err := m.hostPolicy()(ctx, name); err != nil {
-		return nil, err
-	}
-	cert, err = m.createCert(ctx, ck)
-	if err != nil {
-		return nil, err
-	}
-	m.cachePut(ctx, ck, cert)
-	return cert, nil
-}
-
-// wantsTokenCert reports whether a TLS request with SNI is made by a CA server
-// for a challenge verification.
-func wantsTokenCert(hello *tls.ClientHelloInfo) bool {
-	// tls-alpn-01
-	if len(hello.SupportedProtos) == 1 && hello.SupportedProtos[0] == acme.ALPNProto {
-		return true
-	}
-	// tls-sni-xx
-	return strings.HasSuffix(hello.ServerName, ".acme.invalid")
-}
-
-func supportsECDSA(hello *tls.ClientHelloInfo) bool {
-	// The "signature_algorithms" extension, if present, limits the key exchange
-	// algorithms allowed by the cipher suites. See RFC 5246, section 7.4.1.4.1.
-	if hello.SignatureSchemes != nil {
-		ecdsaOK := false
-	schemeLoop:
-		for _, scheme := range hello.SignatureSchemes {
-			const tlsECDSAWithSHA1 tls.SignatureScheme = 0x0203 // constant added in Go 1.10
-			switch scheme {
-			case tlsECDSAWithSHA1, tls.ECDSAWithP256AndSHA256,
-				tls.ECDSAWithP384AndSHA384, tls.ECDSAWithP521AndSHA512:
-				ecdsaOK = true
-				break schemeLoop
-			}
-		}
-		if !ecdsaOK {
-			return false
-		}
-	}
-	if hello.SupportedCurves != nil {
-		ecdsaOK := false
-		for _, curve := range hello.SupportedCurves {
-			if curve == tls.CurveP256 {
-				ecdsaOK = true
-				break
-			}
-		}
-		if !ecdsaOK {
-			return false
-		}
-	}
-	for _, suite := range hello.CipherSuites {
-		switch suite {
-		case tls.TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
-			tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
-			tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
-			tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,
-			tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
-			tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
-			tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305:
-			return true
-		}
-	}
-	return false
-}
-
-// HTTPHandler configures the Manager to provision ACME "http-01" challenge responses.
-// It returns an http.Handler that responds to the challenges and must be
-// running on port 80. If it receives a request that is not an ACME challenge,
-// it delegates the request to the optional fallback handler.
-//
-// If fallback is nil, the returned handler redirects all GET and HEAD requests
-// to the default TLS port 443 with 302 Found status code, preserving the original
-// request path and query. It responds with 400 Bad Request to all other HTTP methods.
-// The fallback is not protected by the optional HostPolicy.
-//
-// Because the fallback handler is run with unencrypted port 80 requests,
-// the fallback should not serve TLS-only requests.
-//
-// If HTTPHandler is never called, the Manager will only use the "tls-alpn-01"
-// challenge for domain verification.
-func (m *Manager) HTTPHandler(fallback http.Handler) http.Handler {
-	m.tokensMu.Lock()
-	defer m.tokensMu.Unlock()
-	m.tryHTTP01 = true
-
-	if fallback == nil {
-		fallback = http.HandlerFunc(handleHTTPRedirect)
-	}
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if !strings.HasPrefix(r.URL.Path, "/.well-known/acme-challenge/") {
-			fallback.ServeHTTP(w, r)
-			return
-		}
-		// A reasonable context timeout for cache and host policy only,
-		// because we don't wait for a new certificate issuance here.
-		ctx, cancel := context.WithTimeout(r.Context(), time.Minute)
-		defer cancel()
-		if err := m.hostPolicy()(ctx, r.Host); err != nil {
-			http.Error(w, err.Error(), http.StatusForbidden)
-			return
-		}
-		data, err := m.httpToken(ctx, r.URL.Path)
-		if err != nil {
-			http.Error(w, err.Error(), http.StatusNotFound)
-			return
-		}
-		w.Write(data)
-	})
-}
-
-func handleHTTPRedirect(w http.ResponseWriter, r *http.Request) {
-	if r.Method != "GET" && r.Method != "HEAD" {
-		http.Error(w, "Use HTTPS", http.StatusBadRequest)
-		return
-	}
-	target := "https://" + stripPort(r.Host) + r.URL.RequestURI()
-	http.Redirect(w, r, target, http.StatusFound)
-}
-
-func stripPort(hostport string) string {
-	host, _, err := net.SplitHostPort(hostport)
-	if err != nil {
-		return hostport
-	}
-	return net.JoinHostPort(host, "443")
-}
-
-// cert returns an existing certificate either from m.state or cache.
-// If a certificate is found in cache but not in m.state, the latter will be filled
-// with the cached value.
-func (m *Manager) cert(ctx context.Context, ck certKey) (*tls.Certificate, error) {
-	m.stateMu.Lock()
-	if s, ok := m.state[ck]; ok {
-		m.stateMu.Unlock()
-		s.RLock()
-		defer s.RUnlock()
-		return s.tlscert()
-	}
-	defer m.stateMu.Unlock()
-	cert, err := m.cacheGet(ctx, ck)
-	if err != nil {
-		return nil, err
-	}
-	signer, ok := cert.PrivateKey.(crypto.Signer)
-	if !ok {
-		return nil, errors.New("acme/autocert: private key cannot sign")
-	}
-	if m.state == nil {
-		m.state = make(map[certKey]*certState)
-	}
-	s := &certState{
-		key:  signer,
-		cert: cert.Certificate,
-		leaf: cert.Leaf,
-	}
-	m.state[ck] = s
-	go m.renew(ck, s.key, s.leaf.NotAfter)
-	return cert, nil
-}
-
-// cacheGet always returns a valid certificate, or an error otherwise.
-// If a cached certificate exists but is not valid, ErrCacheMiss is returned.
-func (m *Manager) cacheGet(ctx context.Context, ck certKey) (*tls.Certificate, error) {
-	if m.Cache == nil {
-		return nil, ErrCacheMiss
-	}
-	data, err := m.Cache.Get(ctx, ck.String())
-	if err != nil {
-		return nil, err
-	}
-
-	// private
-	priv, pub := pem.Decode(data)
-	if priv == nil || !strings.Contains(priv.Type, "PRIVATE") {
-		return nil, ErrCacheMiss
-	}
-	privKey, err := parsePrivateKey(priv.Bytes)
-	if err != nil {
-		return nil, err
-	}
-
-	// public
-	var pubDER [][]byte
-	for len(pub) > 0 {
-		var b *pem.Block
-		b, pub = pem.Decode(pub)
-		if b == nil {
-			break
-		}
-		pubDER = append(pubDER, b.Bytes)
-	}
-	if len(pub) > 0 {
-		// Leftover content not consumed by pem.Decode. Corrupt. Ignore.
-		return nil, ErrCacheMiss
-	}
-
-	// verify and create TLS cert
-	leaf, err := validCert(ck, pubDER, privKey, m.now())
-	if err != nil {
-		return nil, ErrCacheMiss
-	}
-	tlscert := &tls.Certificate{
-		Certificate: pubDER,
-		PrivateKey:  privKey,
-		Leaf:        leaf,
-	}
-	return tlscert, nil
-}
-
-func (m *Manager) cachePut(ctx context.Context, ck certKey, tlscert *tls.Certificate) error {
-	if m.Cache == nil {
-		return nil
-	}
-
-	// contains PEM-encoded data
-	var buf bytes.Buffer
-
-	// private
-	switch key := tlscert.PrivateKey.(type) {
-	case *ecdsa.PrivateKey:
-		if err := encodeECDSAKey(&buf, key); err != nil {
-			return err
-		}
-	case *rsa.PrivateKey:
-		b := x509.MarshalPKCS1PrivateKey(key)
-		pb := &pem.Block{Type: "RSA PRIVATE KEY", Bytes: b}
-		if err := pem.Encode(&buf, pb); err != nil {
-			return err
-		}
-	default:
-		return errors.New("acme/autocert: unknown private key type")
-	}
-
-	// public
-	for _, b := range tlscert.Certificate {
-		pb := &pem.Block{Type: "CERTIFICATE", Bytes: b}
-		if err := pem.Encode(&buf, pb); err != nil {
-			return err
-		}
-	}
-
-	return m.Cache.Put(ctx, ck.String(), buf.Bytes())
-}
-
-func encodeECDSAKey(w io.Writer, key *ecdsa.PrivateKey) error {
-	b, err := x509.MarshalECPrivateKey(key)
-	if err != nil {
-		return err
-	}
-	pb := &pem.Block{Type: "EC PRIVATE KEY", Bytes: b}
-	return pem.Encode(w, pb)
-}
-
-// createCert starts the domain ownership verification and returns a certificate
-// for that domain upon success.
-//
-// If the domain is already being verified, it waits for the existing verification to complete.
-// Either way, createCert blocks for the duration of the whole process.
-func (m *Manager) createCert(ctx context.Context, ck certKey) (*tls.Certificate, error) {
-	// TODO: maybe rewrite this whole piece using sync.Once
-	state, err := m.certState(ck)
-	if err != nil {
-		return nil, err
-	}
-	// state may exist if another goroutine is already working on it
-	// in which case just wait for it to finish
-	if !state.locked {
-		state.RLock()
-		defer state.RUnlock()
-		return state.tlscert()
-	}
-
-	// We are the first; state is locked.
-	// Unblock the readers when domain ownership is verified
-	// and we got the cert or the process failed.
-	defer state.Unlock()
-	state.locked = false
-
-	der, leaf, err := m.authorizedCert(ctx, state.key, ck)
-	if err != nil {
-		// Remove the failed state after some time,
-		// making the manager call createCert again on the following TLS hello.
-		time.AfterFunc(createCertRetryAfter, func() {
-			defer testDidRemoveState(ck)
-			m.stateMu.Lock()
-			defer m.stateMu.Unlock()
-			// Verify the state hasn't changed and it's still invalid
-			// before deleting.
-			s, ok := m.state[ck]
-			if !ok {
-				return
-			}
-			if _, err := validCert(ck, s.cert, s.key, m.now()); err == nil {
-				return
-			}
-			delete(m.state, ck)
-		})
-		return nil, err
-	}
-	state.cert = der
-	state.leaf = leaf
-	go m.renew(ck, state.key, state.leaf.NotAfter)
-	return state.tlscert()
-}
-
-// certState returns a new or existing certState.
-// If a new certState is returned, state.exist is false and the state is locked.
-// The returned error is non-nil only in the case where a new state could not be created.
-func (m *Manager) certState(ck certKey) (*certState, error) {
-	m.stateMu.Lock()
-	defer m.stateMu.Unlock()
-	if m.state == nil {
-		m.state = make(map[certKey]*certState)
-	}
-	// existing state
-	if state, ok := m.state[ck]; ok {
-		return state, nil
-	}
-
-	// new locked state
-	var (
-		err error
-		key crypto.Signer
-	)
-	if ck.isRSA {
-		key, err = rsa.GenerateKey(rand.Reader, 2048)
-	} else {
-		key, err = ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
-	}
-	if err != nil {
-		return nil, err
-	}
-
-	state := &certState{
-		key:    key,
-		locked: true,
-	}
-	state.Lock() // will be unlocked by m.certState caller
-	m.state[ck] = state
-	return state, nil
-}
-
-// authorizedCert starts the domain ownership verification process and requests a new cert upon success.
-// The key argument is the certificate private key.
-func (m *Manager) authorizedCert(ctx context.Context, key crypto.Signer, ck certKey) (der [][]byte, leaf *x509.Certificate, err error) {
-	client, err := m.acmeClient(ctx)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	if err := m.verify(ctx, client, ck.domain); err != nil {
-		return nil, nil, err
-	}
-	csr, err := certRequest(key, ck.domain, m.ExtraExtensions)
-	if err != nil {
-		return nil, nil, err
-	}
-	der, _, err = client.CreateCert(ctx, csr, 0, true)
-	if err != nil {
-		return nil, nil, err
-	}
-	leaf, err = validCert(ck, der, key, m.now())
-	if err != nil {
-		return nil, nil, err
-	}
-	return der, leaf, nil
-}
-
-// revokePendingAuthz revokes all authorizations idenfied by the elements of uri slice.
-// It ignores revocation errors.
-func (m *Manager) revokePendingAuthz(ctx context.Context, uri []string) {
-	client, err := m.acmeClient(ctx)
-	if err != nil {
-		return
-	}
-	for _, u := range uri {
-		client.RevokeAuthorization(ctx, u)
-	}
-}
-
-// verify runs the identifier (domain) authorization flow
-// using each applicable ACME challenge type.
-func (m *Manager) verify(ctx context.Context, client *acme.Client, domain string) error {
-	// The list of challenge types we'll try to fulfill
-	// in this specific order.
-	challengeTypes := []string{"tls-alpn-01", "tls-sni-02", "tls-sni-01"}
-	m.tokensMu.RLock()
-	if m.tryHTTP01 {
-		challengeTypes = append(challengeTypes, "http-01")
-	}
-	m.tokensMu.RUnlock()
-
-	// Keep track of pending authzs and revoke the ones that did not validate.
-	pendingAuthzs := make(map[string]bool)
-	defer func() {
-		var uri []string
-		for k, pending := range pendingAuthzs {
-			if pending {
-				uri = append(uri, k)
-			}
-		}
-		if len(uri) > 0 {
-			// Use "detached" background context.
-			// The revocations need not happen in the current verification flow.
-			go m.revokePendingAuthz(context.Background(), uri)
-		}
-	}()
-
-	// errs accumulates challenge failure errors, printed if all fail
-	errs := make(map[*acme.Challenge]error)
-	var nextTyp int // challengeType index of the next challenge type to try
-	for {
-		// Start domain authorization and get the challenge.
-		authz, err := client.Authorize(ctx, domain)
-		if err != nil {
-			return err
-		}
-		// No point in accepting challenges if the authorization status
-		// is in a final state.
-		switch authz.Status {
-		case acme.StatusValid:
-			return nil // already authorized
-		case acme.StatusInvalid:
-			return fmt.Errorf("acme/autocert: invalid authorization %q", authz.URI)
-		}
-
-		pendingAuthzs[authz.URI] = true
-
-		// Pick the next preferred challenge.
-		var chal *acme.Challenge
-		for chal == nil && nextTyp < len(challengeTypes) {
-			chal = pickChallenge(challengeTypes[nextTyp], authz.Challenges)
-			nextTyp++
-		}
-		if chal == nil {
-			errorMsg := fmt.Sprintf("acme/autocert: unable to authorize %q", domain)
-			for chal, err := range errs {
-				errorMsg += fmt.Sprintf("; challenge %q failed with error: %v", chal.Type, err)
-			}
-			return errors.New(errorMsg)
-		}
-		cleanup, err := m.fulfill(ctx, client, chal, domain)
-		if err != nil {
-			errs[chal] = err
-			continue
-		}
-		defer cleanup()
-		if _, err := client.Accept(ctx, chal); err != nil {
-			errs[chal] = err
-			continue
-		}
-
-		// A challenge is fulfilled and accepted: wait for the CA to validate.
-		if _, err := client.WaitAuthorization(ctx, authz.URI); err != nil {
-			errs[chal] = err
-			continue
-		}
-		delete(pendingAuthzs, authz.URI)
-		return nil
-	}
-}
-
-// fulfill provisions a response to the challenge chal.
-// The cleanup is non-nil only if provisioning succeeded.
-func (m *Manager) fulfill(ctx context.Context, client *acme.Client, chal *acme.Challenge, domain string) (cleanup func(), err error) {
-	switch chal.Type {
-	case "tls-alpn-01":
-		cert, err := client.TLSALPN01ChallengeCert(chal.Token, domain)
-		if err != nil {
-			return nil, err
-		}
-		m.putCertToken(ctx, domain, &cert)
-		return func() { go m.deleteCertToken(domain) }, nil
-	case "tls-sni-01":
-		cert, name, err := client.TLSSNI01ChallengeCert(chal.Token)
-		if err != nil {
-			return nil, err
-		}
-		m.putCertToken(ctx, name, &cert)
-		return func() { go m.deleteCertToken(name) }, nil
-	case "tls-sni-02":
-		cert, name, err := client.TLSSNI02ChallengeCert(chal.Token)
-		if err != nil {
-			return nil, err
-		}
-		m.putCertToken(ctx, name, &cert)
-		return func() { go m.deleteCertToken(name) }, nil
-	case "http-01":
-		resp, err := client.HTTP01ChallengeResponse(chal.Token)
-		if err != nil {
-			return nil, err
-		}
-		p := client.HTTP01ChallengePath(chal.Token)
-		m.putHTTPToken(ctx, p, resp)
-		return func() { go m.deleteHTTPToken(p) }, nil
-	}
-	return nil, fmt.Errorf("acme/autocert: unknown challenge type %q", chal.Type)
-}
-
-func pickChallenge(typ string, chal []*acme.Challenge) *acme.Challenge {
-	for _, c := range chal {
-		if c.Type == typ {
-			return c
-		}
-	}
-	return nil
-}
-
-// putCertToken stores the token certificate with the specified name
-// in both m.certTokens map and m.Cache.
-func (m *Manager) putCertToken(ctx context.Context, name string, cert *tls.Certificate) {
-	m.tokensMu.Lock()
-	defer m.tokensMu.Unlock()
-	if m.certTokens == nil {
-		m.certTokens = make(map[string]*tls.Certificate)
-	}
-	m.certTokens[name] = cert
-	m.cachePut(ctx, certKey{domain: name, isToken: true}, cert)
-}
-
-// deleteCertToken removes the token certificate with the specified name
-// from both m.certTokens map and m.Cache.
-func (m *Manager) deleteCertToken(name string) {
-	m.tokensMu.Lock()
-	defer m.tokensMu.Unlock()
-	delete(m.certTokens, name)
-	if m.Cache != nil {
-		ck := certKey{domain: name, isToken: true}
-		m.Cache.Delete(context.Background(), ck.String())
-	}
-}
-
-// httpToken retrieves an existing http-01 token value from an in-memory map
-// or the optional cache.
-func (m *Manager) httpToken(ctx context.Context, tokenPath string) ([]byte, error) {
-	m.tokensMu.RLock()
-	defer m.tokensMu.RUnlock()
-	if v, ok := m.httpTokens[tokenPath]; ok {
-		return v, nil
-	}
-	if m.Cache == nil {
-		return nil, fmt.Errorf("acme/autocert: no token at %q", tokenPath)
-	}
-	return m.Cache.Get(ctx, httpTokenCacheKey(tokenPath))
-}
-
-// putHTTPToken stores an http-01 token value using tokenPath as key
-// in both in-memory map and the optional Cache.
-//
-// It ignores any error returned from Cache.Put.
-func (m *Manager) putHTTPToken(ctx context.Context, tokenPath, val string) {
-	m.tokensMu.Lock()
-	defer m.tokensMu.Unlock()
-	if m.httpTokens == nil {
-		m.httpTokens = make(map[string][]byte)
-	}
-	b := []byte(val)
-	m.httpTokens[tokenPath] = b
-	if m.Cache != nil {
-		m.Cache.Put(ctx, httpTokenCacheKey(tokenPath), b)
-	}
-}
-
-// deleteHTTPToken removes an http-01 token value from both in-memory map
-// and the optional Cache, ignoring any error returned from the latter.
-//
-// If m.Cache is non-nil, it blocks until Cache.Delete returns without a timeout.
-func (m *Manager) deleteHTTPToken(tokenPath string) {
-	m.tokensMu.Lock()
-	defer m.tokensMu.Unlock()
-	delete(m.httpTokens, tokenPath)
-	if m.Cache != nil {
-		m.Cache.Delete(context.Background(), httpTokenCacheKey(tokenPath))
-	}
-}
-
-// httpTokenCacheKey returns a key at which an http-01 token value may be stored
-// in the Manager's optional Cache.
-func httpTokenCacheKey(tokenPath string) string {
-	return path.Base(tokenPath) + "+http-01"
-}
-
-// renew starts a cert renewal timer loop, one per domain.
-//
-// The loop is scheduled in two cases:
-// - a cert was fetched from cache for the first time (wasn't in m.state)
-// - a new cert was created by m.createCert
-//
-// The key argument is a certificate private key.
-// The exp argument is the cert expiration time (NotAfter).
-func (m *Manager) renew(ck certKey, key crypto.Signer, exp time.Time) {
-	m.renewalMu.Lock()
-	defer m.renewalMu.Unlock()
-	if m.renewal[ck] != nil {
-		// another goroutine is already on it
-		return
-	}
-	if m.renewal == nil {
-		m.renewal = make(map[certKey]*domainRenewal)
-	}
-	dr := &domainRenewal{m: m, ck: ck, key: key}
-	m.renewal[ck] = dr
-	dr.start(exp)
-}
-
-// stopRenew stops all currently running cert renewal timers.
-// The timers are not restarted during the lifetime of the Manager.
-func (m *Manager) stopRenew() {
-	m.renewalMu.Lock()
-	defer m.renewalMu.Unlock()
-	for name, dr := range m.renewal {
-		delete(m.renewal, name)
-		dr.stop()
-	}
-}
-
-func (m *Manager) accountKey(ctx context.Context) (crypto.Signer, error) {
-	const keyName = "acme_account+key"
-
-	// Previous versions of autocert stored the value under a different key.
-	const legacyKeyName = "acme_account.key"
-
-	genKey := func() (*ecdsa.PrivateKey, error) {
-		return ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
-	}
-
-	if m.Cache == nil {
-		return genKey()
-	}
-
-	data, err := m.Cache.Get(ctx, keyName)
-	if err == ErrCacheMiss {
-		data, err = m.Cache.Get(ctx, legacyKeyName)
-	}
-	if err == ErrCacheMiss {
-		key, err := genKey()
-		if err != nil {
-			return nil, err
-		}
-		var buf bytes.Buffer
-		if err := encodeECDSAKey(&buf, key); err != nil {
-			return nil, err
-		}
-		if err := m.Cache.Put(ctx, keyName, buf.Bytes()); err != nil {
-			return nil, err
-		}
-		return key, nil
-	}
-	if err != nil {
-		return nil, err
-	}
-
-	priv, _ := pem.Decode(data)
-	if priv == nil || !strings.Contains(priv.Type, "PRIVATE") {
-		return nil, errors.New("acme/autocert: invalid account key found in cache")
-	}
-	return parsePrivateKey(priv.Bytes)
-}
-
-func (m *Manager) acmeClient(ctx context.Context) (*acme.Client, error) {
-	m.clientMu.Lock()
-	defer m.clientMu.Unlock()
-	if m.client != nil {
-		return m.client, nil
-	}
-
-	client := m.Client
-	if client == nil {
-		client = &acme.Client{DirectoryURL: acme.LetsEncryptURL}
-	}
-	if client.Key == nil {
-		var err error
-		client.Key, err = m.accountKey(ctx)
-		if err != nil {
-			return nil, err
-		}
-	}
-	var contact []string
-	if m.Email != "" {
-		contact = []string{"mailto:" + m.Email}
-	}
-	a := &acme.Account{Contact: contact}
-	_, err := client.Register(ctx, a, m.Prompt)
-	if ae, ok := err.(*acme.Error); err == nil || ok && ae.StatusCode == http.StatusConflict {
-		// conflict indicates the key is already registered
-		m.client = client
-		err = nil
-	}
-	return m.client, err
-}
-
-func (m *Manager) hostPolicy() HostPolicy {
-	if m.HostPolicy != nil {
-		return m.HostPolicy
-	}
-	return defaultHostPolicy
-}
-
-func (m *Manager) renewBefore() time.Duration {
-	if m.RenewBefore > renewJitter {
-		return m.RenewBefore
-	}
-	return 720 * time.Hour // 30 days
-}
-
-func (m *Manager) now() time.Time {
-	if m.nowFunc != nil {
-		return m.nowFunc()
-	}
-	return time.Now()
-}
-
-// certState is ready when its mutex is unlocked for reading.
-type certState struct {
-	sync.RWMutex
-	locked bool              // locked for read/write
-	key    crypto.Signer     // private key for cert
-	cert   [][]byte          // DER encoding
-	leaf   *x509.Certificate // parsed cert[0]; always non-nil if cert != nil
-}
-
-// tlscert creates a tls.Certificate from s.key and s.cert.
-// Callers should wrap it in s.RLock() and s.RUnlock().
-func (s *certState) tlscert() (*tls.Certificate, error) {
-	if s.key == nil {
-		return nil, errors.New("acme/autocert: missing signer")
-	}
-	if len(s.cert) == 0 {
-		return nil, errors.New("acme/autocert: missing certificate")
-	}
-	return &tls.Certificate{
-		PrivateKey:  s.key,
-		Certificate: s.cert,
-		Leaf:        s.leaf,
-	}, 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) {
-	req := &x509.CertificateRequest{
-		Subject:         pkix.Name{CommonName: cn},
-		DNSNames:        san,
-		ExtraExtensions: ext,
-	}
-	return x509.CreateCertificateRequest(rand.Reader, req, key)
-}
-
-// Attempt to parse the given private key DER block. OpenSSL 0.9.8 generates
-// PKCS#1 private keys by default, while OpenSSL 1.0.0 generates PKCS#8 keys.
-// OpenSSL ecparam generates SEC1 EC private keys for ECDSA. We try all three.
-//
-// Inspired by parsePrivateKey in crypto/tls/tls.go.
-func parsePrivateKey(der []byte) (crypto.Signer, error) {
-	if key, err := x509.ParsePKCS1PrivateKey(der); err == nil {
-		return key, nil
-	}
-	if key, err := x509.ParsePKCS8PrivateKey(der); err == nil {
-		switch key := key.(type) {
-		case *rsa.PrivateKey:
-			return key, nil
-		case *ecdsa.PrivateKey:
-			return key, nil
-		default:
-			return nil, errors.New("acme/autocert: unknown private key type in PKCS#8 wrapping")
-		}
-	}
-	if key, err := x509.ParseECPrivateKey(der); err == nil {
-		return key, nil
-	}
-
-	return nil, errors.New("acme/autocert: failed to parse private key")
-}
-
-// validCert parses a cert chain provided as der argument and verifies the leaf and der[0]
-// correspond to the private key, the domain and key type match, and expiration dates
-// are valid. It doesn't do any revocation checking.
-//
-// The returned value is the verified leaf cert.
-func validCert(ck certKey, der [][]byte, key crypto.Signer, now time.Time) (leaf *x509.Certificate, err error) {
-	// parse public part(s)
-	var n int
-	for _, b := range der {
-		n += len(b)
-	}
-	pub := make([]byte, n)
-	n = 0
-	for _, b := range der {
-		n += copy(pub[n:], b)
-	}
-	x509Cert, err := x509.ParseCertificates(pub)
-	if err != nil || len(x509Cert) == 0 {
-		return nil, errors.New("acme/autocert: no public key found")
-	}
-	// verify the leaf is not expired and matches the domain name
-	leaf = x509Cert[0]
-	if now.Before(leaf.NotBefore) {
-		return nil, errors.New("acme/autocert: certificate is not valid yet")
-	}
-	if now.After(leaf.NotAfter) {
-		return nil, errors.New("acme/autocert: expired certificate")
-	}
-	if err := leaf.VerifyHostname(ck.domain); err != nil {
-		return nil, err
-	}
-	// ensure the leaf corresponds to the private key and matches the certKey type
-	switch pub := leaf.PublicKey.(type) {
-	case *rsa.PublicKey:
-		prv, ok := key.(*rsa.PrivateKey)
-		if !ok {
-			return nil, errors.New("acme/autocert: private key type does not match public key type")
-		}
-		if pub.N.Cmp(prv.N) != 0 {
-			return nil, errors.New("acme/autocert: private key does not match public key")
-		}
-		if !ck.isRSA && !ck.isToken {
-			return nil, errors.New("acme/autocert: key type does not match expected value")
-		}
-	case *ecdsa.PublicKey:
-		prv, ok := key.(*ecdsa.PrivateKey)
-		if !ok {
-			return nil, errors.New("acme/autocert: private key type does not match public key type")
-		}
-		if pub.X.Cmp(prv.X) != 0 || pub.Y.Cmp(prv.Y) != 0 {
-			return nil, errors.New("acme/autocert: private key does not match public key")
-		}
-		if ck.isRSA && !ck.isToken {
-			return nil, errors.New("acme/autocert: key type does not match expected value")
-		}
-	default:
-		return nil, errors.New("acme/autocert: unknown public key algorithm")
-	}
-	return leaf, nil
-}
-
-type lockedMathRand struct {
-	sync.Mutex
-	rnd *mathrand.Rand
-}
-
-func (r *lockedMathRand) int63n(max int64) int64 {
-	r.Lock()
-	n := r.rnd.Int63n(max)
-	r.Unlock()
-	return n
-}
-
-// For easier testing.
-var (
-	// Called when a state is removed.
-	testDidRemoveState = func(certKey) {}
-)
diff --git a/vendor/golang.org/x/crypto/acme/autocert/cache.go b/vendor/golang.org/x/crypto/acme/autocert/cache.go
deleted file mode 100644
index aa9aa84..0000000
--- a/vendor/golang.org/x/crypto/acme/autocert/cache.go
+++ /dev/null
@@ -1,130 +0,0 @@
-// Copyright 2016 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package autocert
-
-import (
-	"context"
-	"errors"
-	"io/ioutil"
-	"os"
-	"path/filepath"
-)
-
-// ErrCacheMiss is returned when a certificate is not found in cache.
-var ErrCacheMiss = errors.New("acme/autocert: certificate cache miss")
-
-// Cache is used by Manager to store and retrieve previously obtained certificates
-// and other account data as opaque blobs.
-//
-// Cache implementations should not rely on the key naming pattern. Keys can
-// include any printable ASCII characters, except the following: \/:*?"<>|
-type Cache interface {
-	// Get returns a certificate data for the specified key.
-	// If there's no such key, Get returns ErrCacheMiss.
-	Get(ctx context.Context, key string) ([]byte, error)
-
-	// Put stores the data in the cache under the specified key.
-	// Underlying implementations may use any data storage format,
-	// as long as the reverse operation, Get, results in the original data.
-	Put(ctx context.Context, key string, data []byte) error
-
-	// Delete removes a certificate data from the cache under the specified key.
-	// If there's no such key in the cache, Delete returns nil.
-	Delete(ctx context.Context, key string) error
-}
-
-// DirCache implements Cache using a directory on the local filesystem.
-// If the directory does not exist, it will be created with 0700 permissions.
-type DirCache string
-
-// Get reads a certificate data from the specified file name.
-func (d DirCache) Get(ctx context.Context, name string) ([]byte, error) {
-	name = filepath.Join(string(d), name)
-	var (
-		data []byte
-		err  error
-		done = make(chan struct{})
-	)
-	go func() {
-		data, err = ioutil.ReadFile(name)
-		close(done)
-	}()
-	select {
-	case <-ctx.Done():
-		return nil, ctx.Err()
-	case <-done:
-	}
-	if os.IsNotExist(err) {
-		return nil, ErrCacheMiss
-	}
-	return data, err
-}
-
-// Put writes the certificate data to the specified file name.
-// The file will be created with 0600 permissions.
-func (d DirCache) Put(ctx context.Context, name string, data []byte) error {
-	if err := os.MkdirAll(string(d), 0700); err != nil {
-		return err
-	}
-
-	done := make(chan struct{})
-	var err error
-	go func() {
-		defer close(done)
-		var tmp string
-		if tmp, err = d.writeTempFile(name, data); err != nil {
-			return
-		}
-		select {
-		case <-ctx.Done():
-			// Don't overwrite the file if the context was canceled.
-		default:
-			newName := filepath.Join(string(d), name)
-			err = os.Rename(tmp, newName)
-		}
-	}()
-	select {
-	case <-ctx.Done():
-		return ctx.Err()
-	case <-done:
-	}
-	return err
-}
-
-// Delete removes the specified file name.
-func (d DirCache) Delete(ctx context.Context, name string) error {
-	name = filepath.Join(string(d), name)
-	var (
-		err  error
-		done = make(chan struct{})
-	)
-	go func() {
-		err = os.Remove(name)
-		close(done)
-	}()
-	select {
-	case <-ctx.Done():
-		return ctx.Err()
-	case <-done:
-	}
-	if err != nil && !os.IsNotExist(err) {
-		return err
-	}
-	return nil
-}
-
-// writeTempFile writes b to a temporary file, closes the file and returns its path.
-func (d DirCache) writeTempFile(prefix string, b []byte) (string, error) {
-	// TempFile uses 0600 permissions
-	f, err := ioutil.TempFile(string(d), prefix)
-	if err != nil {
-		return "", err
-	}
-	if _, err := f.Write(b); err != nil {
-		f.Close()
-		return "", err
-	}
-	return f.Name(), f.Close()
-}
diff --git a/vendor/golang.org/x/crypto/acme/autocert/listener.go b/vendor/golang.org/x/crypto/acme/autocert/listener.go
deleted file mode 100644
index 1e06981..0000000
--- a/vendor/golang.org/x/crypto/acme/autocert/listener.go
+++ /dev/null
@@ -1,157 +0,0 @@
-// Copyright 2017 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package autocert
-
-import (
-	"crypto/tls"
-	"log"
-	"net"
-	"os"
-	"path/filepath"
-	"runtime"
-	"time"
-)
-
-// NewListener returns a net.Listener that listens on the standard TLS
-// port (443) on all interfaces and returns *tls.Conn connections with
-// LetsEncrypt certificates for the provided domain or domains.
-//
-// It enables one-line HTTPS servers:
-//
-//     log.Fatal(http.Serve(autocert.NewListener("example.com"), handler))
-//
-// NewListener is a convenience function for a common configuration.
-// More complex or custom configurations can use the autocert.Manager
-// type instead.
-//
-// Use of this function implies acceptance of the LetsEncrypt Terms of
-// Service. If domains is not empty, the provided domains are passed
-// to HostWhitelist. If domains is empty, the listener will do
-// LetsEncrypt challenges for any requested domain, which is not
-// recommended.
-//
-// Certificates are cached in a "golang-autocert" directory under an
-// operating system-specific cache or temp directory. This may not
-// be suitable for servers spanning multiple machines.
-//
-// The returned listener uses a *tls.Config that enables HTTP/2, and
-// should only be used with servers that support HTTP/2.
-//
-// The returned Listener also enables TCP keep-alives on the accepted
-// connections. The returned *tls.Conn are returned before their TLS
-// handshake has completed.
-func NewListener(domains ...string) net.Listener {
-	m := &Manager{
-		Prompt: AcceptTOS,
-	}
-	if len(domains) > 0 {
-		m.HostPolicy = HostWhitelist(domains...)
-	}
-	dir := cacheDir()
-	if err := os.MkdirAll(dir, 0700); err != nil {
-		log.Printf("warning: autocert.NewListener not using a cache: %v", err)
-	} else {
-		m.Cache = DirCache(dir)
-	}
-	return m.Listener()
-}
-
-// Listener listens on the standard TLS port (443) on all interfaces
-// and returns a net.Listener returning *tls.Conn connections.
-//
-// The returned listener uses a *tls.Config that enables HTTP/2, and
-// should only be used with servers that support HTTP/2.
-//
-// The returned Listener also enables TCP keep-alives on the accepted
-// connections. The returned *tls.Conn are returned before their TLS
-// handshake has completed.
-//
-// Unlike NewListener, it is the caller's responsibility to initialize
-// the Manager m's Prompt, Cache, HostPolicy, and other desired options.
-func (m *Manager) Listener() net.Listener {
-	ln := &listener{
-		m:    m,
-		conf: m.TLSConfig(),
-	}
-	ln.tcpListener, ln.tcpListenErr = net.Listen("tcp", ":443")
-	return ln
-}
-
-type listener struct {
-	m    *Manager
-	conf *tls.Config
-
-	tcpListener  net.Listener
-	tcpListenErr error
-}
-
-func (ln *listener) Accept() (net.Conn, error) {
-	if ln.tcpListenErr != nil {
-		return nil, ln.tcpListenErr
-	}
-	conn, err := ln.tcpListener.Accept()
-	if err != nil {
-		return nil, err
-	}
-	tcpConn := conn.(*net.TCPConn)
-
-	// Because Listener is a convenience function, help out with
-	// this too.  This is not possible for the caller to set once
-	// we return a *tcp.Conn wrapping an inaccessible net.Conn.
-	// If callers don't want this, they can do things the manual
-	// way and tweak as needed. But this is what net/http does
-	// itself, so copy that. If net/http changes, we can change
-	// here too.
-	tcpConn.SetKeepAlive(true)
-	tcpConn.SetKeepAlivePeriod(3 * time.Minute)
-
-	return tls.Server(tcpConn, ln.conf), nil
-}
-
-func (ln *listener) Addr() net.Addr {
-	if ln.tcpListener != nil {
-		return ln.tcpListener.Addr()
-	}
-	// net.Listen failed. Return something non-nil in case callers
-	// call Addr before Accept:
-	return &net.TCPAddr{IP: net.IP{0, 0, 0, 0}, Port: 443}
-}
-
-func (ln *listener) Close() error {
-	if ln.tcpListenErr != nil {
-		return ln.tcpListenErr
-	}
-	return ln.tcpListener.Close()
-}
-
-func homeDir() string {
-	if runtime.GOOS == "windows" {
-		return os.Getenv("HOMEDRIVE") + os.Getenv("HOMEPATH")
-	}
-	if h := os.Getenv("HOME"); h != "" {
-		return h
-	}
-	return "/"
-}
-
-func cacheDir() string {
-	const base = "golang-autocert"
-	switch runtime.GOOS {
-	case "darwin":
-		return filepath.Join(homeDir(), "Library", "Caches", base)
-	case "windows":
-		for _, ev := range []string{"APPDATA", "CSIDL_APPDATA", "TEMP", "TMP"} {
-			if v := os.Getenv(ev); v != "" {
-				return filepath.Join(v, base)
-			}
-		}
-		// Worst case:
-		return filepath.Join(homeDir(), base)
-	}
-	if xdg := os.Getenv("XDG_CACHE_HOME"); xdg != "" {
-		return filepath.Join(xdg, base)
-	}
-	return filepath.Join(homeDir(), ".cache", base)
-}
diff --git a/vendor/golang.org/x/crypto/acme/autocert/renewal.go b/vendor/golang.org/x/crypto/acme/autocert/renewal.go
deleted file mode 100644
index 665f870..0000000
--- a/vendor/golang.org/x/crypto/acme/autocert/renewal.go
+++ /dev/null
@@ -1,141 +0,0 @@
-// Copyright 2016 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package autocert
-
-import (
-	"context"
-	"crypto"
-	"sync"
-	"time"
-)
-
-// renewJitter is the maximum deviation from Manager.RenewBefore.
-const renewJitter = time.Hour
-
-// domainRenewal tracks the state used by the periodic timers
-// renewing a single domain's cert.
-type domainRenewal struct {
-	m   *Manager
-	ck  certKey
-	key crypto.Signer
-
-	timerMu sync.Mutex
-	timer   *time.Timer
-}
-
-// start starts a cert renewal timer at the time
-// defined by the certificate expiration time exp.
-//
-// If the timer is already started, calling start is a noop.
-func (dr *domainRenewal) start(exp time.Time) {
-	dr.timerMu.Lock()
-	defer dr.timerMu.Unlock()
-	if dr.timer != nil {
-		return
-	}
-	dr.timer = time.AfterFunc(dr.next(exp), dr.renew)
-}
-
-// stop stops the cert renewal timer.
-// If the timer is already stopped, calling stop is a noop.
-func (dr *domainRenewal) stop() {
-	dr.timerMu.Lock()
-	defer dr.timerMu.Unlock()
-	if dr.timer == nil {
-		return
-	}
-	dr.timer.Stop()
-	dr.timer = nil
-}
-
-// renew is called periodically by a timer.
-// The first renew call is kicked off by dr.start.
-func (dr *domainRenewal) renew() {
-	dr.timerMu.Lock()
-	defer dr.timerMu.Unlock()
-	if dr.timer == nil {
-		return
-	}
-
-	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Minute)
-	defer cancel()
-	// TODO: rotate dr.key at some point?
-	next, err := dr.do(ctx)
-	if err != nil {
-		next = renewJitter / 2
-		next += time.Duration(pseudoRand.int63n(int64(next)))
-	}
-	dr.timer = time.AfterFunc(next, dr.renew)
-	testDidRenewLoop(next, err)
-}
-
-// updateState locks and replaces the relevant Manager.state item with the given
-// state. It additionally updates dr.key with the given state's key.
-func (dr *domainRenewal) updateState(state *certState) {
-	dr.m.stateMu.Lock()
-	defer dr.m.stateMu.Unlock()
-	dr.key = state.key
-	dr.m.state[dr.ck] = state
-}
-
-// do is similar to Manager.createCert but it doesn't lock a Manager.state item.
-// Instead, it requests a new certificate independently and, upon success,
-// replaces dr.m.state item with a new one and updates cache for the given domain.
-//
-// It may lock and update the Manager.state if the expiration date of the currently
-// cached cert is far enough in the future.
-//
-// The returned value is a time interval after which the renewal should occur again.
-func (dr *domainRenewal) do(ctx context.Context) (time.Duration, error) {
-	// a race is likely unavoidable in a distributed environment
-	// but we try nonetheless
-	if tlscert, err := dr.m.cacheGet(ctx, dr.ck); err == nil {
-		next := dr.next(tlscert.Leaf.NotAfter)
-		if next > dr.m.renewBefore()+renewJitter {
-			signer, ok := tlscert.PrivateKey.(crypto.Signer)
-			if ok {
-				state := &certState{
-					key:  signer,
-					cert: tlscert.Certificate,
-					leaf: tlscert.Leaf,
-				}
-				dr.updateState(state)
-				return next, nil
-			}
-		}
-	}
-
-	der, leaf, err := dr.m.authorizedCert(ctx, dr.key, dr.ck)
-	if err != nil {
-		return 0, err
-	}
-	state := &certState{
-		key:  dr.key,
-		cert: der,
-		leaf: leaf,
-	}
-	tlscert, err := state.tlscert()
-	if err != nil {
-		return 0, err
-	}
-	if err := dr.m.cachePut(ctx, dr.ck, tlscert); err != nil {
-		return 0, err
-	}
-	dr.updateState(state)
-	return dr.next(leaf.NotAfter), nil
-}
-
-func (dr *domainRenewal) next(expiry time.Time) time.Duration {
-	d := expiry.Sub(dr.m.now()) - dr.m.renewBefore()
-	// add a bit of randomness to renew deadline
-	n := pseudoRand.int63n(int64(renewJitter))
-	d -= time.Duration(n)
-	if d < 0 {
-		return 0
-	}
-	return d
-}
-
-var testDidRenewLoop = func(next time.Duration, err error) {}
diff --git a/vendor/golang.org/x/crypto/acme/http.go b/vendor/golang.org/x/crypto/acme/http.go
deleted file mode 100644
index a43ce6a..0000000
--- a/vendor/golang.org/x/crypto/acme/http.go
+++ /dev/null
@@ -1,281 +0,0 @@
-// Copyright 2018 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package acme
-
-import (
-	"bytes"
-	"context"
-	"crypto"
-	"crypto/rand"
-	"encoding/json"
-	"fmt"
-	"io/ioutil"
-	"math/big"
-	"net/http"
-	"strconv"
-	"strings"
-	"time"
-)
-
-// retryTimer encapsulates common logic for retrying unsuccessful requests.
-// It is not safe for concurrent use.
-type retryTimer struct {
-	// backoffFn provides backoff delay sequence for retries.
-	// See Client.RetryBackoff doc comment.
-	backoffFn func(n int, r *http.Request, res *http.Response) time.Duration
-	// n is the current retry attempt.
-	n int
-}
-
-func (t *retryTimer) inc() {
-	t.n++
-}
-
-// backoff pauses the current goroutine as described in Client.RetryBackoff.
-func (t *retryTimer) backoff(ctx context.Context, r *http.Request, res *http.Response) error {
-	d := t.backoffFn(t.n, r, res)
-	if d <= 0 {
-		return fmt.Errorf("acme: no more retries for %s; tried %d time(s)", r.URL, t.n)
-	}
-	wakeup := time.NewTimer(d)
-	defer wakeup.Stop()
-	select {
-	case <-ctx.Done():
-		return ctx.Err()
-	case <-wakeup.C:
-		return nil
-	}
-}
-
-func (c *Client) retryTimer() *retryTimer {
-	f := c.RetryBackoff
-	if f == nil {
-		f = defaultBackoff
-	}
-	return &retryTimer{backoffFn: f}
-}
-
-// defaultBackoff provides default Client.RetryBackoff implementation
-// using a truncated exponential backoff algorithm,
-// as described in Client.RetryBackoff.
-//
-// The n argument is always bounded between 1 and 30.
-// The returned value is always greater than 0.
-func defaultBackoff(n int, r *http.Request, res *http.Response) time.Duration {
-	const max = 10 * time.Second
-	var jitter time.Duration
-	if x, err := rand.Int(rand.Reader, big.NewInt(1000)); err == nil {
-		// Set the minimum to 1ms to avoid a case where
-		// an invalid Retry-After value is parsed into 0 below,
-		// resulting in the 0 returned value which would unintentionally
-		// stop the retries.
-		jitter = (1 + time.Duration(x.Int64())) * time.Millisecond
-	}
-	if v, ok := res.Header["Retry-After"]; ok {
-		return retryAfter(v[0]) + jitter
-	}
-
-	if n < 1 {
-		n = 1
-	}
-	if n > 30 {
-		n = 30
-	}
-	d := time.Duration(1<<uint(n-1))*time.Second + jitter
-	if d > max {
-		return max
-	}
-	return d
-}
-
-// retryAfter parses a Retry-After HTTP header value,
-// trying to convert v into an int (seconds) or use http.ParseTime otherwise.
-// It returns zero value if v cannot be parsed.
-func retryAfter(v string) time.Duration {
-	if i, err := strconv.Atoi(v); err == nil {
-		return time.Duration(i) * time.Second
-	}
-	t, err := http.ParseTime(v)
-	if err != nil {
-		return 0
-	}
-	return t.Sub(timeNow())
-}
-
-// resOkay is a function that reports whether the provided response is okay.
-// It is expected to keep the response body unread.
-type resOkay func(*http.Response) bool
-
-// wantStatus returns a function which reports whether the code
-// matches the status code of a response.
-func wantStatus(codes ...int) resOkay {
-	return func(res *http.Response) bool {
-		for _, code := range codes {
-			if code == res.StatusCode {
-				return true
-			}
-		}
-		return false
-	}
-}
-
-// get issues an unsigned GET request to the specified URL.
-// It returns a non-error value only when ok reports true.
-//
-// get retries unsuccessful attempts according to c.RetryBackoff
-// until the context is done or a non-retriable error is received.
-func (c *Client) get(ctx context.Context, url string, ok resOkay) (*http.Response, error) {
-	retry := c.retryTimer()
-	for {
-		req, err := http.NewRequest("GET", url, nil)
-		if err != nil {
-			return nil, err
-		}
-		res, err := c.doNoRetry(ctx, req)
-		switch {
-		case err != nil:
-			return nil, err
-		case ok(res):
-			return res, nil
-		case isRetriable(res.StatusCode):
-			retry.inc()
-			resErr := responseError(res)
-			res.Body.Close()
-			// Ignore the error value from retry.backoff
-			// and return the one from last retry, as received from the CA.
-			if retry.backoff(ctx, req, res) != nil {
-				return nil, resErr
-			}
-		default:
-			defer res.Body.Close()
-			return nil, responseError(res)
-		}
-	}
-}
-
-// post issues a signed POST request in JWS format using the provided key
-// to the specified URL.
-// It returns a non-error value only when ok reports true.
-//
-// post retries unsuccessful attempts according to c.RetryBackoff
-// until the context is done or a non-retriable error is received.
-// It uses postNoRetry to make individual requests.
-func (c *Client) post(ctx context.Context, key crypto.Signer, url string, body interface{}, ok resOkay) (*http.Response, error) {
-	retry := c.retryTimer()
-	for {
-		res, req, err := c.postNoRetry(ctx, key, url, body)
-		if err != nil {
-			return nil, err
-		}
-		if ok(res) {
-			return res, nil
-		}
-		resErr := responseError(res)
-		res.Body.Close()
-		switch {
-		// Check for bad nonce before isRetriable because it may have been returned
-		// with an unretriable response code such as 400 Bad Request.
-		case isBadNonce(resErr):
-			// Consider any previously stored nonce values to be invalid.
-			c.clearNonces()
-		case !isRetriable(res.StatusCode):
-			return nil, resErr
-		}
-		retry.inc()
-		// Ignore the error value from retry.backoff
-		// and return the one from last retry, as received from the CA.
-		if err := retry.backoff(ctx, req, res); err != nil {
-			return nil, resErr
-		}
-	}
-}
-
-// postNoRetry signs the body with the given key and POSTs it to the provided url.
-// The body argument must be JSON-serializable.
-// It is used by c.post to retry unsuccessful attempts.
-func (c *Client) postNoRetry(ctx context.Context, key crypto.Signer, url string, body interface{}) (*http.Response, *http.Request, error) {
-	nonce, err := c.popNonce(ctx, url)
-	if err != nil {
-		return nil, nil, err
-	}
-	b, err := jwsEncodeJSON(body, key, nonce)
-	if err != nil {
-		return nil, nil, err
-	}
-	req, err := http.NewRequest("POST", url, bytes.NewReader(b))
-	if err != nil {
-		return nil, nil, err
-	}
-	req.Header.Set("Content-Type", "application/jose+json")
-	res, err := c.doNoRetry(ctx, req)
-	if err != nil {
-		return nil, nil, err
-	}
-	c.addNonce(res.Header)
-	return res, req, nil
-}
-
-// doNoRetry issues a request req, replacing its context (if any) with ctx.
-func (c *Client) doNoRetry(ctx context.Context, req *http.Request) (*http.Response, error) {
-	res, err := c.httpClient().Do(req.WithContext(ctx))
-	if err != nil {
-		select {
-		case <-ctx.Done():
-			// Prefer the unadorned context error.
-			// (The acme package had tests assuming this, previously from ctxhttp's
-			// behavior, predating net/http supporting contexts natively)
-			// TODO(bradfitz): reconsider this in the future. But for now this
-			// requires no test updates.
-			return nil, ctx.Err()
-		default:
-			return nil, err
-		}
-	}
-	return res, nil
-}
-
-func (c *Client) httpClient() *http.Client {
-	if c.HTTPClient != nil {
-		return c.HTTPClient
-	}
-	return http.DefaultClient
-}
-
-// isBadNonce reports whether err is an ACME "badnonce" error.
-func isBadNonce(err error) bool {
-	// According to the spec badNonce is urn:ietf:params:acme:error:badNonce.
-	// However, ACME servers in the wild return their versions of the error.
-	// See https://tools.ietf.org/html/draft-ietf-acme-acme-02#section-5.4
-	// and https://github.com/letsencrypt/boulder/blob/0e07eacb/docs/acme-divergences.md#section-66.
-	ae, ok := err.(*Error)
-	return ok && strings.HasSuffix(strings.ToLower(ae.ProblemType), ":badnonce")
-}
-
-// isRetriable reports whether a request can be retried
-// based on the response status code.
-//
-// Note that a "bad nonce" error is returned with a non-retriable 400 Bad Request code.
-// Callers should parse the response and check with isBadNonce.
-func isRetriable(code int) bool {
-	return code <= 399 || code >= 500 || code == http.StatusTooManyRequests
-}
-
-// responseError creates an error of Error type from resp.
-func responseError(resp *http.Response) error {
-	// don't care if ReadAll returns an error:
-	// json.Unmarshal will fail in that case anyway
-	b, _ := ioutil.ReadAll(resp.Body)
-	e := &wireError{Status: resp.StatusCode}
-	if err := json.Unmarshal(b, e); err != nil {
-		// this is not a regular error response:
-		// populate detail with anything we received,
-		// e.Status will already contain HTTP response code value
-		e.Detail = string(b)
-		if e.Detail == "" {
-			e.Detail = resp.Status
-		}
-	}
-	return e.error(resp.Header)
-}
diff --git a/vendor/golang.org/x/crypto/acme/jws.go b/vendor/golang.org/x/crypto/acme/jws.go
deleted file mode 100644
index 6cbca25..0000000
--- a/vendor/golang.org/x/crypto/acme/jws.go
+++ /dev/null
@@ -1,153 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package acme
-
-import (
-	"crypto"
-	"crypto/ecdsa"
-	"crypto/rand"
-	"crypto/rsa"
-	"crypto/sha256"
-	_ "crypto/sha512" // need for EC keys
-	"encoding/base64"
-	"encoding/json"
-	"fmt"
-	"math/big"
-)
-
-// jwsEncodeJSON signs claimset using provided key and a nonce.
-// The result is serialized in JSON format.
-// See https://tools.ietf.org/html/rfc7515#section-7.
-func jwsEncodeJSON(claimset interface{}, key crypto.Signer, nonce string) ([]byte, error) {
-	jwk, err := jwkEncode(key.Public())
-	if err != nil {
-		return nil, err
-	}
-	alg, sha := jwsHasher(key)
-	if alg == "" || !sha.Available() {
-		return nil, ErrUnsupportedKey
-	}
-	phead := fmt.Sprintf(`{"alg":%q,"jwk":%s,"nonce":%q}`, alg, jwk, nonce)
-	phead = base64.RawURLEncoding.EncodeToString([]byte(phead))
-	cs, err := json.Marshal(claimset)
-	if err != nil {
-		return nil, err
-	}
-	payload := base64.RawURLEncoding.EncodeToString(cs)
-	hash := sha.New()
-	hash.Write([]byte(phead + "." + payload))
-	sig, err := jwsSign(key, sha, hash.Sum(nil))
-	if err != nil {
-		return nil, err
-	}
-
-	enc := struct {
-		Protected string `json:"protected"`
-		Payload   string `json:"payload"`
-		Sig       string `json:"signature"`
-	}{
-		Protected: phead,
-		Payload:   payload,
-		Sig:       base64.RawURLEncoding.EncodeToString(sig),
-	}
-	return json.Marshal(&enc)
-}
-
-// 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
-func jwkEncode(pub crypto.PublicKey) (string, error) {
-	switch pub := pub.(type) {
-	case *rsa.PublicKey:
-		// https://tools.ietf.org/html/rfc7518#section-6.3.1
-		n := pub.N
-		e := big.NewInt(int64(pub.E))
-		// Field order is important.
-		// See https://tools.ietf.org/html/rfc7638#section-3.3 for details.
-		return fmt.Sprintf(`{"e":"%s","kty":"RSA","n":"%s"}`,
-			base64.RawURLEncoding.EncodeToString(e.Bytes()),
-			base64.RawURLEncoding.EncodeToString(n.Bytes()),
-		), nil
-	case *ecdsa.PublicKey:
-		// https://tools.ietf.org/html/rfc7518#section-6.2.1
-		p := pub.Curve.Params()
-		n := p.BitSize / 8
-		if p.BitSize%8 != 0 {
-			n++
-		}
-		x := pub.X.Bytes()
-		if n > len(x) {
-			x = append(make([]byte, n-len(x)), x...)
-		}
-		y := pub.Y.Bytes()
-		if n > len(y) {
-			y = append(make([]byte, n-len(y)), y...)
-		}
-		// Field order is important.
-		// See https://tools.ietf.org/html/rfc7638#section-3.3 for details.
-		return fmt.Sprintf(`{"crv":"%s","kty":"EC","x":"%s","y":"%s"}`,
-			p.Name,
-			base64.RawURLEncoding.EncodeToString(x),
-			base64.RawURLEncoding.EncodeToString(y),
-		), nil
-	}
-	return "", ErrUnsupportedKey
-}
-
-// 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.
-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:
-		r, s, err := ecdsa.Sign(rand.Reader, key, digest)
-		if err != nil {
-			return nil, err
-		}
-		rb, sb := r.Bytes(), s.Bytes()
-		size := key.Params().BitSize / 8
-		if size%8 > 0 {
-			size++
-		}
-		sig := make([]byte, size*2)
-		copy(sig[size-len(rb):], rb)
-		copy(sig[size*2-len(sb):], sb)
-		return sig, nil
-	}
-	return nil, ErrUnsupportedKey
-}
-
-// 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:
-		return "RS256", crypto.SHA256
-	case *ecdsa.PrivateKey:
-		switch key.Params().Name {
-		case "P-256":
-			return "ES256", crypto.SHA256
-		case "P-384":
-			return "ES384", crypto.SHA384
-		case "P-521":
-			return "ES512", crypto.SHA512
-		}
-	}
-	return "", 0
-}
-
-// JWKThumbprint creates a JWK thumbprint out of pub
-// as specified in https://tools.ietf.org/html/rfc7638.
-func JWKThumbprint(pub crypto.PublicKey) (string, error) {
-	jwk, err := jwkEncode(pub)
-	if err != nil {
-		return "", err
-	}
-	b := sha256.Sum256([]byte(jwk))
-	return base64.RawURLEncoding.EncodeToString(b[:]), nil
-}
diff --git a/vendor/golang.org/x/crypto/acme/types.go b/vendor/golang.org/x/crypto/acme/types.go
deleted file mode 100644
index 54792c0..0000000
--- a/vendor/golang.org/x/crypto/acme/types.go
+++ /dev/null
@@ -1,329 +0,0 @@
-// Copyright 2016 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package acme
-
-import (
-	"crypto"
-	"crypto/x509"
-	"errors"
-	"fmt"
-	"net/http"
-	"strings"
-	"time"
-)
-
-// ACME server response statuses used to describe Authorization and Challenge states.
-const (
-	StatusUnknown    = "unknown"
-	StatusPending    = "pending"
-	StatusProcessing = "processing"
-	StatusValid      = "valid"
-	StatusInvalid    = "invalid"
-	StatusRevoked    = "revoked"
-)
-
-// CRLReasonCode identifies the reason for a certificate revocation.
-type CRLReasonCode int
-
-// CRL reason codes as defined in RFC 5280.
-const (
-	CRLReasonUnspecified          CRLReasonCode = 0
-	CRLReasonKeyCompromise        CRLReasonCode = 1
-	CRLReasonCACompromise         CRLReasonCode = 2
-	CRLReasonAffiliationChanged   CRLReasonCode = 3
-	CRLReasonSuperseded           CRLReasonCode = 4
-	CRLReasonCessationOfOperation CRLReasonCode = 5
-	CRLReasonCertificateHold      CRLReasonCode = 6
-	CRLReasonRemoveFromCRL        CRLReasonCode = 8
-	CRLReasonPrivilegeWithdrawn   CRLReasonCode = 9
-	CRLReasonAACompromise         CRLReasonCode = 10
-)
-
-// ErrUnsupportedKey is returned when an unsupported key type is encountered.
-var ErrUnsupportedKey = errors.New("acme: unknown key type; only RSA and ECDSA are supported")
-
-// Error is an ACME error, defined in Problem Details for HTTP APIs doc
-// http://tools.ietf.org/html/draft-ietf-appsawg-http-problem.
-type Error struct {
-	// StatusCode is The HTTP status code generated by the origin server.
-	StatusCode int
-	// ProblemType is a URI reference that identifies the problem type,
-	// typically in a "urn:acme:error:xxx" form.
-	ProblemType string
-	// Detail is a human-readable explanation specific to this occurrence of the problem.
-	Detail string
-	// Header is the original server error response headers.
-	// It may be nil.
-	Header http.Header
-}
-
-func (e *Error) Error() string {
-	return fmt.Sprintf("%d %s: %s", e.StatusCode, e.ProblemType, e.Detail)
-}
-
-// AuthorizationError indicates that an authorization for an identifier
-// did not succeed.
-// It contains all errors from Challenge items of the failed Authorization.
-type AuthorizationError struct {
-	// URI uniquely identifies the failed Authorization.
-	URI string
-
-	// Identifier is an AuthzID.Value of the failed Authorization.
-	Identifier string
-
-	// Errors is a collection of non-nil error values of Challenge items
-	// of the failed Authorization.
-	Errors []error
-}
-
-func (a *AuthorizationError) Error() string {
-	e := make([]string, len(a.Errors))
-	for i, err := range a.Errors {
-		e[i] = err.Error()
-	}
-	return fmt.Sprintf("acme: authorization error for %s: %s", a.Identifier, strings.Join(e, "; "))
-}
-
-// RateLimit reports whether err represents a rate limit error and
-// any Retry-After duration returned by the server.
-//
-// See the following for more details on rate limiting:
-// https://tools.ietf.org/html/draft-ietf-acme-acme-05#section-5.6
-func RateLimit(err error) (time.Duration, bool) {
-	e, ok := err.(*Error)
-	if !ok {
-		return 0, false
-	}
-	// Some CA implementations may return incorrect values.
-	// Use case-insensitive comparison.
-	if !strings.HasSuffix(strings.ToLower(e.ProblemType), ":ratelimited") {
-		return 0, false
-	}
-	if e.Header == nil {
-		return 0, true
-	}
-	return retryAfter(e.Header.Get("Retry-After")), true
-}
-
-// Account is a user account. It is associated with a private key.
-type Account struct {
-	// URI is the account unique ID, which is also a URL used to retrieve
-	// account data from the CA.
-	URI string
-
-	// Contact is a slice of contact info used during registration.
-	Contact []string
-
-	// The terms user has agreed to.
-	// A value not matching CurrentTerms indicates that the user hasn't agreed
-	// to the actual Terms of Service of the CA.
-	AgreedTerms string
-
-	// Actual terms of a CA.
-	CurrentTerms string
-
-	// Authz is the authorization URL used to initiate a new authz flow.
-	Authz string
-
-	// Authorizations is a URI from which a list of authorizations
-	// granted to this account can be fetched via a GET request.
-	Authorizations string
-
-	// Certificates is a URI from which a list of certificates
-	// issued for this account can be fetched via a GET request.
-	Certificates string
-}
-
-// Directory is ACME server discovery data.
-type Directory struct {
-	// RegURL is an account endpoint URL, allowing for creating new
-	// and modifying existing accounts.
-	RegURL string
-
-	// AuthzURL is used to initiate Identifier Authorization flow.
-	AuthzURL string
-
-	// CertURL is a new certificate issuance endpoint URL.
-	CertURL string
-
-	// RevokeURL is used to initiate a certificate revocation flow.
-	RevokeURL string
-
-	// Term is a URI identifying the current terms of service.
-	Terms string
-
-	// Website is an HTTP or HTTPS URL locating a website
-	// providing more information about the ACME server.
-	Website string
-
-	// CAA consists of lowercase hostname elements, which the ACME server
-	// recognises as referring to itself for the purposes of CAA record validation
-	// as defined in RFC6844.
-	CAA []string
-}
-
-// Challenge encodes a returned CA challenge.
-// Its Error field may be non-nil if the challenge is part of an Authorization
-// with StatusInvalid.
-type Challenge struct {
-	// Type is the challenge type, e.g. "http-01", "tls-sni-02", "dns-01".
-	Type string
-
-	// URI is where a challenge response can be posted to.
-	URI string
-
-	// Token is a random value that uniquely identifies the challenge.
-	Token string
-
-	// Status identifies the status of this challenge.
-	Status string
-
-	// Error indicates the reason for an authorization failure
-	// when this challenge was used.
-	// The type of a non-nil value is *Error.
-	Error error
-}
-
-// Authorization encodes an authorization response.
-type Authorization struct {
-	// URI uniquely identifies a authorization.
-	URI string
-
-	// Status identifies the status of an authorization.
-	Status string
-
-	// Identifier is what the account is authorized to represent.
-	Identifier AuthzID
-
-	// Challenges that the client needs to fulfill in order to prove possession
-	// of the identifier (for pending authorizations).
-	// For final authorizations, the challenges that were used.
-	Challenges []*Challenge
-
-	// A collection of sets of challenges, each of which would be sufficient
-	// to prove possession of the identifier.
-	// Clients must complete a set of challenges that covers at least one set.
-	// Challenges are identified by their indices in the challenges array.
-	// If this field is empty, the client needs to complete all challenges.
-	Combinations [][]int
-}
-
-// AuthzID is an identifier that an account is authorized to represent.
-type AuthzID struct {
-	Type  string // The type of identifier, e.g. "dns".
-	Value string // The identifier itself, e.g. "example.org".
-}
-
-// wireAuthz is ACME JSON representation of Authorization objects.
-type wireAuthz struct {
-	Status       string
-	Challenges   []wireChallenge
-	Combinations [][]int
-	Identifier   struct {
-		Type  string
-		Value string
-	}
-}
-
-func (z *wireAuthz) authorization(uri string) *Authorization {
-	a := &Authorization{
-		URI:          uri,
-		Status:       z.Status,
-		Identifier:   AuthzID{Type: z.Identifier.Type, Value: z.Identifier.Value},
-		Combinations: z.Combinations, // shallow copy
-		Challenges:   make([]*Challenge, len(z.Challenges)),
-	}
-	for i, v := range z.Challenges {
-		a.Challenges[i] = v.challenge()
-	}
-	return a
-}
-
-func (z *wireAuthz) error(uri string) *AuthorizationError {
-	err := &AuthorizationError{
-		URI:        uri,
-		Identifier: z.Identifier.Value,
-	}
-	for _, raw := range z.Challenges {
-		if raw.Error != nil {
-			err.Errors = append(err.Errors, raw.Error.error(nil))
-		}
-	}
-	return err
-}
-
-// wireChallenge is ACME JSON challenge representation.
-type wireChallenge struct {
-	URI    string `json:"uri"`
-	Type   string
-	Token  string
-	Status string
-	Error  *wireError
-}
-
-func (c *wireChallenge) challenge() *Challenge {
-	v := &Challenge{
-		URI:    c.URI,
-		Type:   c.Type,
-		Token:  c.Token,
-		Status: c.Status,
-	}
-	if v.Status == "" {
-		v.Status = StatusPending
-	}
-	if c.Error != nil {
-		v.Error = c.Error.error(nil)
-	}
-	return v
-}
-
-// wireError is a subset of fields of the Problem Details object
-// as described in https://tools.ietf.org/html/rfc7807#section-3.1.
-type wireError struct {
-	Status int
-	Type   string
-	Detail string
-}
-
-func (e *wireError) error(h http.Header) *Error {
-	return &Error{
-		StatusCode:  e.Status,
-		ProblemType: e.Type,
-		Detail:      e.Detail,
-		Header:      h,
-	}
-}
-
-// CertOption is an optional argument type for the TLS ChallengeCert methods for
-// customizing a temporary certificate for TLS-based challenges.
-type CertOption interface {
-	privateCertOpt()
-}
-
-// WithKey creates an option holding a private/public key pair.
-// The private part signs a certificate, and the public part represents the signee.
-func WithKey(key crypto.Signer) CertOption {
-	return &certOptKey{key}
-}
-
-type certOptKey struct {
-	key crypto.Signer
-}
-
-func (*certOptKey) privateCertOpt() {}
-
-// WithTemplate creates an option for specifying a certificate template.
-// See x509.CreateCertificate for template usage details.
-//
-// In TLS ChallengeCert methods, the template is also used as parent,
-// resulting in a self-signed certificate.
-// The DNSNames field of t is always overwritten for tls-sni challenge certs.
-func WithTemplate(t *x509.Certificate) CertOption {
-	return (*certOptTemplate)(t)
-}
-
-type certOptTemplate x509.Certificate
-
-func (*certOptTemplate) privateCertOpt() {}