gtsocial-umbx

rfc8555.go (14354B)

---

 // Copyright 2019 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 (
 	"context"
 	"crypto"
 	"encoding/base64"
 	"encoding/json"
 	"encoding/pem"
 	"errors"
 	"fmt"
 	"io"
 	"net/http"
 	"time"
 )
 
 // DeactivateReg permanently disables an existing account associated with c.Key.
 // A deactivated account can no longer request certificate issuance or access
 // resources related to the account, such as orders or authorizations.
 //
 // It only works with CAs implementing RFC 8555.
 func (c *Client) DeactivateReg(ctx context.Context) error {
 	if _, err := c.Discover(ctx); err != nil { // required by c.accountKID
 		return err
 	}
 	url := string(c.accountKID(ctx))
 	if url == "" {
 		return ErrNoAccount
 	}
 	req := json.RawMessage(`{"status": "deactivated"}`)
 	res, err := c.post(ctx, nil, url, req, wantStatus(http.StatusOK))
 	if err != nil {
 		return err
 	}
 	res.Body.Close()
 	return nil
 }
 
 // registerRFC is equivalent to c.Register but for CAs implementing RFC 8555.
 // It expects c.Discover to have already been called.
 func (c *Client) registerRFC(ctx context.Context, acct *Account, prompt func(tosURL string) bool) (*Account, error) {
 	c.cacheMu.Lock() // guard c.kid access
 	defer c.cacheMu.Unlock()
 
 	req := struct {
 		TermsAgreed            bool              `json:"termsOfServiceAgreed,omitempty"`
 		Contact                []string          `json:"contact,omitempty"`
 		ExternalAccountBinding *jsonWebSignature `json:"externalAccountBinding,omitempty"`
 	}{
 		Contact: acct.Contact,
 	}
 	if c.dir.Terms != "" {
 		req.TermsAgreed = prompt(c.dir.Terms)
 	}
 
 	// set 'externalAccountBinding' field if requested
 	if acct.ExternalAccountBinding != nil {
 		eabJWS, err := c.encodeExternalAccountBinding(acct.ExternalAccountBinding)
 		if err != nil {
 			return nil, fmt.Errorf("acme: failed to encode external account binding: %v", err)
 		}
 		req.ExternalAccountBinding = eabJWS
 	}
 
 	res, err := c.post(ctx, c.Key, c.dir.RegURL, req, wantStatus(
 		http.StatusOK,      // account with this key already registered
 		http.StatusCreated, // new account created
 	))
 	if err != nil {
 		return nil, err
 	}
 
 	defer res.Body.Close()
 	a, err := responseAccount(res)
 	if err != nil {
 		return nil, err
 	}
 	// Cache Account URL even if we return an error to the caller.
 	// It is by all means a valid and usable "kid" value for future requests.
 	c.KID = KeyID(a.URI)
 	if res.StatusCode == http.StatusOK {
 		return nil, ErrAccountAlreadyExists
 	}
 	return a, nil
 }
 
 // encodeExternalAccountBinding will encode an external account binding stanza
 // as described in https://tools.ietf.org/html/rfc8555#section-7.3.4.
 func (c *Client) encodeExternalAccountBinding(eab *ExternalAccountBinding) (*jsonWebSignature, error) {
 	jwk, err := jwkEncode(c.Key.Public())
 	if err != nil {
 		return nil, err
 	}
 	return jwsWithMAC(eab.Key, eab.KID, c.dir.RegURL, []byte(jwk))
 }
 
 // updateRegRFC is equivalent to c.UpdateReg but for CAs implementing RFC 8555.
 // It expects c.Discover to have already been called.
 func (c *Client) updateRegRFC(ctx context.Context, a *Account) (*Account, error) {
 	url := string(c.accountKID(ctx))
 	if url == "" {
 		return nil, ErrNoAccount
 	}
 	req := struct {
 		Contact []string `json:"contact,omitempty"`
 	}{
 		Contact: a.Contact,
 	}
 	res, err := c.post(ctx, nil, url, req, wantStatus(http.StatusOK))
 	if err != nil {
 		return nil, err
 	}
 	defer res.Body.Close()
 	return responseAccount(res)
 }
 
 // getRegRFC is equivalent to c.GetReg but for CAs implementing RFC 8555.
 // It expects c.Discover to have already been called.
 func (c *Client) getRegRFC(ctx context.Context) (*Account, error) {
 	req := json.RawMessage(`{"onlyReturnExisting": true}`)
 	res, err := c.post(ctx, c.Key, c.dir.RegURL, req, wantStatus(http.StatusOK))
 	if e, ok := err.(*Error); ok && e.ProblemType == "urn:ietf:params:acme:error:accountDoesNotExist" {
 		return nil, ErrNoAccount
 	}
 	if err != nil {
 		return nil, err
 	}
 
 	defer res.Body.Close()
 	return responseAccount(res)
 }
 
 func responseAccount(res *http.Response) (*Account, error) {
 	var v struct {
 		Status  string
 		Contact []string
 		Orders  string
 	}
 	if err := json.NewDecoder(res.Body).Decode(&v); err != nil {
 		return nil, fmt.Errorf("acme: invalid account response: %v", err)
 	}
 	return &Account{
 		URI:       res.Header.Get("Location"),
 		Status:    v.Status,
 		Contact:   v.Contact,
 		OrdersURL: v.Orders,
 	}, nil
 }
 
 // accountKeyRollover attempts to perform account key rollover.
 // On success it will change client.Key to the new key.
 func (c *Client) accountKeyRollover(ctx context.Context, newKey crypto.Signer) error {
 	dir, err := c.Discover(ctx) // Also required by c.accountKID
 	if err != nil {
 		return err
 	}
 	kid := c.accountKID(ctx)
 	if kid == noKeyID {
 		return ErrNoAccount
 	}
 	oldKey, err := jwkEncode(c.Key.Public())
 	if err != nil {
 		return err
 	}
 	payload := struct {
 		Account string          `json:"account"`
 		OldKey  json.RawMessage `json:"oldKey"`
 	}{
 		Account: string(kid),
 		OldKey:  json.RawMessage(oldKey),
 	}
 	inner, err := jwsEncodeJSON(payload, newKey, noKeyID, noNonce, dir.KeyChangeURL)
 	if err != nil {
 		return err
 	}
 
 	res, err := c.post(ctx, nil, dir.KeyChangeURL, base64.RawURLEncoding.EncodeToString(inner), wantStatus(http.StatusOK))
 	if err != nil {
 		return err
 	}
 	defer res.Body.Close()
 	c.Key = newKey
 	return nil
 }
 
 // AuthorizeOrder initiates the order-based application for certificate issuance,
 // as opposed to pre-authorization in Authorize.
 // It is only supported by CAs implementing RFC 8555.
 //
 // The caller then needs to fetch each authorization with GetAuthorization,
 // identify those with StatusPending status and fulfill a challenge using Accept.
 // Once all authorizations are satisfied, the caller will typically want to poll
 // order status using WaitOrder until it's in StatusReady state.
 // To finalize the order and obtain a certificate, the caller submits a CSR with CreateOrderCert.
 func (c *Client) AuthorizeOrder(ctx context.Context, id []AuthzID, opt ...OrderOption) (*Order, error) {
 	dir, err := c.Discover(ctx)
 	if err != nil {
 		return nil, err
 	}
 
 	req := struct {
 		Identifiers []wireAuthzID `json:"identifiers"`
 		NotBefore   string        `json:"notBefore,omitempty"`
 		NotAfter    string        `json:"notAfter,omitempty"`
 	}{}
 	for _, v := range id {
 		req.Identifiers = append(req.Identifiers, wireAuthzID{
 			Type:  v.Type,
 			Value: v.Value,
 		})
 	}
 	for _, o := range opt {
 		switch o := o.(type) {
 		case orderNotBeforeOpt:
 			req.NotBefore = time.Time(o).Format(time.RFC3339)
 		case orderNotAfterOpt:
 			req.NotAfter = time.Time(o).Format(time.RFC3339)
 		default:
 			// Package's fault if we let this happen.
 			panic(fmt.Sprintf("unsupported order option type %T", o))
 		}
 	}
 
 	res, err := c.post(ctx, nil, dir.OrderURL, req, wantStatus(http.StatusCreated))
 	if err != nil {
 		return nil, err
 	}
 	defer res.Body.Close()
 	return responseOrder(res)
 }
 
 // GetOrder retrives an order identified by the given URL.
 // For orders created with AuthorizeOrder, the url value is Order.URI.
 //
 // If a caller needs to poll an order until its status is final,
 // see the WaitOrder method.
 func (c *Client) GetOrder(ctx context.Context, url string) (*Order, error) {
 	if _, err := c.Discover(ctx); err != nil {
 		return nil, err
 	}
 
 	res, err := c.postAsGet(ctx, url, wantStatus(http.StatusOK))
 	if err != nil {
 		return nil, err
 	}
 	defer res.Body.Close()
 	return responseOrder(res)
 }
 
 // WaitOrder polls an order from the given URL until it is in one of the final states,
 // StatusReady, StatusValid or StatusInvalid, the CA responded with a non-retryable error
 // or the context is done.
 //
 // It returns a non-nil Order only if its Status is StatusReady or StatusValid.
 // In all other cases WaitOrder returns an error.
 // If the Status is StatusInvalid, the returned error is of type *OrderError.
 func (c *Client) WaitOrder(ctx context.Context, url string) (*Order, error) {
 	if _, err := c.Discover(ctx); err != nil {
 		return nil, err
 	}
 	for {
 		res, err := c.postAsGet(ctx, url, wantStatus(http.StatusOK))
 		if err != nil {
 			return nil, err
 		}
 		o, err := responseOrder(res)
 		res.Body.Close()
 		switch {
 		case err != nil:
 			// Skip and retry.
 		case o.Status == StatusInvalid:
 			return nil, &OrderError{OrderURL: o.URI, Status: o.Status}
 		case o.Status == StatusReady || o.Status == StatusValid:
 			return o, nil
 		}
 
 		d := retryAfter(res.Header.Get("Retry-After"))
 		if d == 0 {
 			// Default retry-after.
 			// Same reasoning as in WaitAuthorization.
 			d = time.Second
 		}
 		t := time.NewTimer(d)
 		select {
 		case <-ctx.Done():
 			t.Stop()
 			return nil, ctx.Err()
 		case <-t.C:
 			// Retry.
 		}
 	}
 }
 
 func responseOrder(res *http.Response) (*Order, error) {
 	var v struct {
 		Status         string
 		Expires        time.Time
 		Identifiers    []wireAuthzID
 		NotBefore      time.Time
 		NotAfter       time.Time
 		Error          *wireError
 		Authorizations []string
 		Finalize       string
 		Certificate    string
 	}
 	if err := json.NewDecoder(res.Body).Decode(&v); err != nil {
 		return nil, fmt.Errorf("acme: error reading order: %v", err)
 	}
 	o := &Order{
 		URI:         res.Header.Get("Location"),
 		Status:      v.Status,
 		Expires:     v.Expires,
 		NotBefore:   v.NotBefore,
 		NotAfter:    v.NotAfter,
 		AuthzURLs:   v.Authorizations,
 		FinalizeURL: v.Finalize,
 		CertURL:     v.Certificate,
 	}
 	for _, id := range v.Identifiers {
 		o.Identifiers = append(o.Identifiers, AuthzID{Type: id.Type, Value: id.Value})
 	}
 	if v.Error != nil {
 		o.Error = v.Error.error(nil /* headers */)
 	}
 	return o, nil
 }
 
 // CreateOrderCert submits the CSR (Certificate Signing Request) to a CA at the specified URL.
 // The URL is the FinalizeURL field of an Order created with AuthorizeOrder.
 //
 // If the bundle argument is true, the returned value also contain the CA (issuer)
 // certificate chain. Otherwise, only a leaf certificate is returned.
 // The returned URL can be used to re-fetch the certificate using FetchCert.
 //
 // This method is only supported by CAs implementing RFC 8555. See CreateCert for pre-RFC CAs.
 //
 // CreateOrderCert returns an error if the CA's response is unreasonably large.
 // Callers are encouraged to parse the returned value to ensure the certificate is valid and has the expected features.
 func (c *Client) CreateOrderCert(ctx context.Context, url string, csr []byte, bundle bool) (der [][]byte, certURL string, err error) {
 	if _, err := c.Discover(ctx); err != nil { // required by c.accountKID
 		return nil, "", err
 	}
 
 	// RFC describes this as "finalize order" request.
 	req := struct {
 		CSR string `json:"csr"`
 	}{
 		CSR: base64.RawURLEncoding.EncodeToString(csr),
 	}
 	res, err := c.post(ctx, nil, url, req, wantStatus(http.StatusOK))
 	if err != nil {
 		return nil, "", err
 	}
 	defer res.Body.Close()
 	o, err := responseOrder(res)
 	if err != nil {
 		return nil, "", err
 	}
 
 	// Wait for CA to issue the cert if they haven't.
 	if o.Status != StatusValid {
 		o, err = c.WaitOrder(ctx, o.URI)
 	}
 	if err != nil {
 		return nil, "", err
 	}
 	// The only acceptable status post finalize and WaitOrder is "valid".
 	if o.Status != StatusValid {
 		return nil, "", &OrderError{OrderURL: o.URI, Status: o.Status}
 	}
 	crt, err := c.fetchCertRFC(ctx, o.CertURL, bundle)
 	return crt, o.CertURL, err
 }
 
 // fetchCertRFC downloads issued certificate from the given URL.
 // It expects the CA to respond with PEM-encoded certificate chain.
 //
 // The URL argument is the CertURL field of Order.
 func (c *Client) fetchCertRFC(ctx context.Context, url string, bundle bool) ([][]byte, error) {
 	res, err := c.postAsGet(ctx, url, wantStatus(http.StatusOK))
 	if err != nil {
 		return nil, err
 	}
 	defer res.Body.Close()
 
 	// Get all the bytes up to a sane maximum.
 	// Account very roughly for base64 overhead.
 	const max = maxCertChainSize + maxCertChainSize/33
 	b, err := io.ReadAll(io.LimitReader(res.Body, max+1))
 	if err != nil {
 		return nil, fmt.Errorf("acme: fetch cert response stream: %v", err)
 	}
 	if len(b) > max {
 		return nil, errors.New("acme: certificate chain is too big")
 	}
 
 	// Decode PEM chain.
 	var chain [][]byte
 	for {
 		var p *pem.Block
 		p, b = pem.Decode(b)
 		if p == nil {
 			break
 		}
 		if p.Type != "CERTIFICATE" {
 			return nil, fmt.Errorf("acme: invalid PEM cert type %q", p.Type)
 		}
 
 		chain = append(chain, p.Bytes)
 		if !bundle {
 			return chain, nil
 		}
 		if len(chain) > maxChainLen {
 			return nil, errors.New("acme: certificate chain is too long")
 		}
 	}
 	if len(chain) == 0 {
 		return nil, errors.New("acme: certificate chain is empty")
 	}
 	return chain, nil
 }
 
 // sends a cert revocation request in either JWK form when key is non-nil or KID form otherwise.
 func (c *Client) revokeCertRFC(ctx context.Context, key crypto.Signer, cert []byte, reason CRLReasonCode) error {
 	req := &struct {
 		Cert   string `json:"certificate"`
 		Reason int    `json:"reason"`
 	}{
 		Cert:   base64.RawURLEncoding.EncodeToString(cert),
 		Reason: int(reason),
 	}
 	res, err := c.post(ctx, key, c.dir.RevokeURL, req, wantStatus(http.StatusOK))
 	if err != nil {
 		if isAlreadyRevoked(err) {
 			// Assume it is not an error to revoke an already revoked cert.
 			return nil
 		}
 		return err
 	}
 	defer res.Body.Close()
 	return nil
 }
 
 func isAlreadyRevoked(err error) bool {
 	e, ok := err.(*Error)
 	return ok && e.ProblemType == "urn:ietf:params:acme:error:alreadyRevoked"
 }
 
 // ListCertAlternates retrieves any alternate certificate chain URLs for the
 // given certificate chain URL. These alternate URLs can be passed to FetchCert
 // in order to retrieve the alternate certificate chains.
 //
 // If there are no alternate issuer certificate chains, a nil slice will be
 // returned.
 func (c *Client) ListCertAlternates(ctx context.Context, url string) ([]string, error) {
 	if _, err := c.Discover(ctx); err != nil { // required by c.accountKID
 		return nil, err
 	}
 
 	res, err := c.postAsGet(ctx, url, wantStatus(http.StatusOK))
 	if err != nil {
 		return nil, err
 	}
 	defer res.Body.Close()
 
 	// We don't need the body but we need to discard it so we don't end up
 	// preventing keep-alive
 	if _, err := io.Copy(io.Discard, res.Body); err != nil {
 		return nil, fmt.Errorf("acme: cert alternates response stream: %v", err)
 	}
 	alts := linkHeader(res.Header, "alternate")
 	return alts, nil
 }