From 8f91c777559748fa6e857d9fc1f4ae079a532813 Mon Sep 17 00:00:00 2001 From: Christopher Speller Date: Mon, 3 Oct 2016 16:03:15 -0400 Subject: Adding ability to serve TLS directly from Mattermost server (#4119) --- vendor/github.com/xenolf/lego/acme/client.go | 804 +++++++++++++++++++++++++++ 1 file changed, 804 insertions(+) create mode 100644 vendor/github.com/xenolf/lego/acme/client.go (limited to 'vendor/github.com/xenolf/lego/acme/client.go') diff --git a/vendor/github.com/xenolf/lego/acme/client.go b/vendor/github.com/xenolf/lego/acme/client.go new file mode 100644 index 000000000..5eae8d26a --- /dev/null +++ b/vendor/github.com/xenolf/lego/acme/client.go @@ -0,0 +1,804 @@ +// Package acme implements the ACME protocol for Let's Encrypt and other conforming providers. +package acme + +import ( + "crypto" + "crypto/x509" + "encoding/base64" + "encoding/json" + "errors" + "fmt" + "io/ioutil" + "log" + "net" + "regexp" + "strconv" + "strings" + "time" +) + +var ( + // Logger is an optional custom logger. + Logger *log.Logger +) + +// logf writes a log entry. It uses Logger if not +// nil, otherwise it uses the default log.Logger. +func logf(format string, args ...interface{}) { + if Logger != nil { + Logger.Printf(format, args...) + } else { + log.Printf(format, args...) + } +} + +// User interface is to be implemented by users of this library. +// It is used by the client type to get user specific information. +type User interface { + GetEmail() string + GetRegistration() *RegistrationResource + GetPrivateKey() crypto.PrivateKey +} + +// Interface for all challenge solvers to implement. +type solver interface { + Solve(challenge challenge, domain string) error +} + +type validateFunc func(j *jws, domain, uri string, chlng challenge) error + +// Client is the user-friendy way to ACME +type Client struct { + directory directory + user User + jws *jws + keyType KeyType + issuerCert []byte + solvers map[Challenge]solver +} + +// NewClient creates a new ACME client on behalf of the user. The client will depend on +// the ACME directory located at caDirURL for the rest of its actions. A private +// key of type keyType (see KeyType contants) will be generated when requesting a new +// certificate if one isn't provided. +func NewClient(caDirURL string, user User, keyType KeyType) (*Client, error) { + privKey := user.GetPrivateKey() + if privKey == nil { + return nil, errors.New("private key was nil") + } + + var dir directory + if _, err := getJSON(caDirURL, &dir); err != nil { + return nil, fmt.Errorf("get directory at '%s': %v", caDirURL, err) + } + + if dir.NewRegURL == "" { + return nil, errors.New("directory missing new registration URL") + } + if dir.NewAuthzURL == "" { + return nil, errors.New("directory missing new authz URL") + } + if dir.NewCertURL == "" { + return nil, errors.New("directory missing new certificate URL") + } + if dir.RevokeCertURL == "" { + return nil, errors.New("directory missing revoke certificate URL") + } + + jws := &jws{privKey: privKey, directoryURL: caDirURL} + + // REVIEW: best possibility? + // Add all available solvers with the right index as per ACME + // spec to this map. Otherwise they won`t be found. + solvers := make(map[Challenge]solver) + solvers[HTTP01] = &httpChallenge{jws: jws, validate: validate, provider: &HTTPProviderServer{}} + solvers[TLSSNI01] = &tlsSNIChallenge{jws: jws, validate: validate, provider: &TLSProviderServer{}} + + return &Client{directory: dir, user: user, jws: jws, keyType: keyType, solvers: solvers}, nil +} + +// SetChallengeProvider specifies a custom provider that will make the solution available +func (c *Client) SetChallengeProvider(challenge Challenge, p ChallengeProvider) error { + switch challenge { + case HTTP01: + c.solvers[challenge] = &httpChallenge{jws: c.jws, validate: validate, provider: p} + case TLSSNI01: + c.solvers[challenge] = &tlsSNIChallenge{jws: c.jws, validate: validate, provider: p} + case DNS01: + c.solvers[challenge] = &dnsChallenge{jws: c.jws, validate: validate, provider: p} + default: + return fmt.Errorf("Unknown challenge %v", challenge) + } + return nil +} + +// SetHTTPAddress specifies a custom interface:port to be used for HTTP based challenges. +// If this option is not used, the default port 80 and all interfaces will be used. +// To only specify a port and no interface use the ":port" notation. +func (c *Client) SetHTTPAddress(iface string) error { + host, port, err := net.SplitHostPort(iface) + if err != nil { + return err + } + + if chlng, ok := c.solvers[HTTP01]; ok { + chlng.(*httpChallenge).provider = NewHTTPProviderServer(host, port) + } + + return nil +} + +// SetTLSAddress specifies a custom interface:port to be used for TLS based challenges. +// If this option is not used, the default port 443 and all interfaces will be used. +// To only specify a port and no interface use the ":port" notation. +func (c *Client) SetTLSAddress(iface string) error { + host, port, err := net.SplitHostPort(iface) + if err != nil { + return err + } + + if chlng, ok := c.solvers[TLSSNI01]; ok { + chlng.(*tlsSNIChallenge).provider = NewTLSProviderServer(host, port) + } + return nil +} + +// ExcludeChallenges explicitly removes challenges from the pool for solving. +func (c *Client) ExcludeChallenges(challenges []Challenge) { + // Loop through all challenges and delete the requested one if found. + for _, challenge := range challenges { + delete(c.solvers, challenge) + } +} + +// Register the current account to the ACME server. +func (c *Client) Register() (*RegistrationResource, error) { + if c == nil || c.user == nil { + return nil, errors.New("acme: cannot register a nil client or user") + } + logf("[INFO] acme: Registering account for %s", c.user.GetEmail()) + + regMsg := registrationMessage{ + Resource: "new-reg", + } + if c.user.GetEmail() != "" { + regMsg.Contact = []string{"mailto:" + c.user.GetEmail()} + } else { + regMsg.Contact = []string{} + } + + var serverReg Registration + var regURI string + hdr, err := postJSON(c.jws, c.directory.NewRegURL, regMsg, &serverReg) + if err != nil { + remoteErr, ok := err.(RemoteError) + if ok && remoteErr.StatusCode == 409 { + regURI = hdr.Get("Location") + regMsg = registrationMessage{ + Resource: "reg", + } + if hdr, err = postJSON(c.jws, regURI, regMsg, &serverReg); err != nil { + return nil, err + } + } else { + return nil, err + } + } + + reg := &RegistrationResource{Body: serverReg} + + links := parseLinks(hdr["Link"]) + + if regURI == "" { + regURI = hdr.Get("Location") + } + reg.URI = regURI + if links["terms-of-service"] != "" { + reg.TosURL = links["terms-of-service"] + } + + if links["next"] != "" { + reg.NewAuthzURL = links["next"] + } else { + return nil, errors.New("acme: The server did not return 'next' link to proceed") + } + + return reg, nil +} + +// DeleteRegistration deletes the client's user registration from the ACME +// server. +func (c *Client) DeleteRegistration() error { + if c == nil || c.user == nil { + return errors.New("acme: cannot unregister a nil client or user") + } + logf("[INFO] acme: Deleting account for %s", c.user.GetEmail()) + + regMsg := registrationMessage{ + Resource: "reg", + Delete: true, + } + + _, err := postJSON(c.jws, c.user.GetRegistration().URI, regMsg, nil) + if err != nil { + return err + } + + return nil +} + +// QueryRegistration runs a POST request on the client's registration and +// returns the result. +// +// This is similar to the Register function, but acting on an existing +// registration link and resource. +func (c *Client) QueryRegistration() (*RegistrationResource, error) { + if c == nil || c.user == nil { + return nil, errors.New("acme: cannot query the registration of a nil client or user") + } + // Log the URL here instead of the email as the email may not be set + logf("[INFO] acme: Querying account for %s", c.user.GetRegistration().URI) + + regMsg := registrationMessage{ + Resource: "reg", + } + + var serverReg Registration + hdr, err := postJSON(c.jws, c.user.GetRegistration().URI, regMsg, &serverReg) + if err != nil { + return nil, err + } + + reg := &RegistrationResource{Body: serverReg} + + links := parseLinks(hdr["Link"]) + // Location: header is not returned so this needs to be populated off of + // existing URI + reg.URI = c.user.GetRegistration().URI + if links["terms-of-service"] != "" { + reg.TosURL = links["terms-of-service"] + } + + if links["next"] != "" { + reg.NewAuthzURL = links["next"] + } else { + return nil, errors.New("acme: No new-authz link in response to registration query") + } + + return reg, nil +} + +// AgreeToTOS updates the Client registration and sends the agreement to +// the server. +func (c *Client) AgreeToTOS() error { + reg := c.user.GetRegistration() + + reg.Body.Agreement = c.user.GetRegistration().TosURL + reg.Body.Resource = "reg" + _, err := postJSON(c.jws, c.user.GetRegistration().URI, c.user.GetRegistration().Body, nil) + return err +} + +// ObtainCertificateForCSR tries to obtain a certificate matching the CSR passed into it. +// The domains are inferred from the CommonName and SubjectAltNames, if any. The private key +// for this CSR is not required. +// If bundle is true, the []byte contains both the issuer certificate and +// your issued certificate as a bundle. +// This function will never return a partial certificate. If one domain in the list fails, +// the whole certificate will fail. +func (c *Client) ObtainCertificateForCSR(csr x509.CertificateRequest, bundle bool) (CertificateResource, map[string]error) { + // figure out what domains it concerns + // start with the common name + domains := []string{csr.Subject.CommonName} + + // loop over the SubjectAltName DNS names +DNSNames: + for _, sanName := range csr.DNSNames { + for _, existingName := range domains { + if existingName == sanName { + // duplicate; skip this name + continue DNSNames + } + } + + // name is unique + domains = append(domains, sanName) + } + + if bundle { + logf("[INFO][%s] acme: Obtaining bundled SAN certificate given a CSR", strings.Join(domains, ", ")) + } else { + logf("[INFO][%s] acme: Obtaining SAN certificate given a CSR", strings.Join(domains, ", ")) + } + + challenges, failures := c.getChallenges(domains) + // If any challenge fails - return. Do not generate partial SAN certificates. + if len(failures) > 0 { + return CertificateResource{}, failures + } + + errs := c.solveChallenges(challenges) + // If any challenge fails - return. Do not generate partial SAN certificates. + if len(errs) > 0 { + return CertificateResource{}, errs + } + + logf("[INFO][%s] acme: Validations succeeded; requesting certificates", strings.Join(domains, ", ")) + + cert, err := c.requestCertificateForCsr(challenges, bundle, csr.Raw, nil) + if err != nil { + for _, chln := range challenges { + failures[chln.Domain] = err + } + } + + // Add the CSR to the certificate so that it can be used for renewals. + cert.CSR = pemEncode(&csr) + + return cert, failures +} + +// ObtainCertificate tries to obtain a single certificate using all domains passed into it. +// The first domain in domains is used for the CommonName field of the certificate, all other +// domains are added using the Subject Alternate Names extension. A new private key is generated +// for every invocation of this function. If you do not want that you can supply your own private key +// in the privKey parameter. If this parameter is non-nil it will be used instead of generating a new one. +// If bundle is true, the []byte contains both the issuer certificate and +// your issued certificate as a bundle. +// This function will never return a partial certificate. If one domain in the list fails, +// the whole certificate will fail. +func (c *Client) ObtainCertificate(domains []string, bundle bool, privKey crypto.PrivateKey) (CertificateResource, map[string]error) { + if bundle { + logf("[INFO][%s] acme: Obtaining bundled SAN certificate", strings.Join(domains, ", ")) + } else { + logf("[INFO][%s] acme: Obtaining SAN certificate", strings.Join(domains, ", ")) + } + + challenges, failures := c.getChallenges(domains) + // If any challenge fails - return. Do not generate partial SAN certificates. + if len(failures) > 0 { + return CertificateResource{}, failures + } + + errs := c.solveChallenges(challenges) + // If any challenge fails - return. Do not generate partial SAN certificates. + if len(errs) > 0 { + return CertificateResource{}, errs + } + + logf("[INFO][%s] acme: Validations succeeded; requesting certificates", strings.Join(domains, ", ")) + + cert, err := c.requestCertificate(challenges, bundle, privKey) + if err != nil { + for _, chln := range challenges { + failures[chln.Domain] = err + } + } + + return cert, failures +} + +// RevokeCertificate takes a PEM encoded certificate or bundle and tries to revoke it at the CA. +func (c *Client) RevokeCertificate(certificate []byte) error { + certificates, err := parsePEMBundle(certificate) + if err != nil { + return err + } + + x509Cert := certificates[0] + if x509Cert.IsCA { + return fmt.Errorf("Certificate bundle starts with a CA certificate") + } + + encodedCert := base64.URLEncoding.EncodeToString(x509Cert.Raw) + + _, err = postJSON(c.jws, c.directory.RevokeCertURL, revokeCertMessage{Resource: "revoke-cert", Certificate: encodedCert}, nil) + return err +} + +// RenewCertificate takes a CertificateResource and tries to renew the certificate. +// If the renewal process succeeds, the new certificate will ge returned in a new CertResource. +// Please be aware that this function will return a new certificate in ANY case that is not an error. +// If the server does not provide us with a new cert on a GET request to the CertURL +// this function will start a new-cert flow where a new certificate gets generated. +// If bundle is true, the []byte contains both the issuer certificate and +// your issued certificate as a bundle. +// For private key reuse the PrivateKey property of the passed in CertificateResource should be non-nil. +func (c *Client) RenewCertificate(cert CertificateResource, bundle bool) (CertificateResource, error) { + // Input certificate is PEM encoded. Decode it here as we may need the decoded + // cert later on in the renewal process. The input may be a bundle or a single certificate. + certificates, err := parsePEMBundle(cert.Certificate) + if err != nil { + return CertificateResource{}, err + } + + x509Cert := certificates[0] + if x509Cert.IsCA { + return CertificateResource{}, fmt.Errorf("[%s] Certificate bundle starts with a CA certificate", cert.Domain) + } + + // This is just meant to be informal for the user. + timeLeft := x509Cert.NotAfter.Sub(time.Now().UTC()) + logf("[INFO][%s] acme: Trying renewal with %d hours remaining", cert.Domain, int(timeLeft.Hours())) + + // The first step of renewal is to check if we get a renewed cert + // directly from the cert URL. + resp, err := httpGet(cert.CertURL) + if err != nil { + return CertificateResource{}, err + } + defer resp.Body.Close() + serverCertBytes, err := ioutil.ReadAll(resp.Body) + if err != nil { + return CertificateResource{}, err + } + + serverCert, err := x509.ParseCertificate(serverCertBytes) + if err != nil { + return CertificateResource{}, err + } + + // If the server responds with a different certificate we are effectively renewed. + // TODO: Further test if we can actually use the new certificate (Our private key works) + if !x509Cert.Equal(serverCert) { + logf("[INFO][%s] acme: Server responded with renewed certificate", cert.Domain) + issuedCert := pemEncode(derCertificateBytes(serverCertBytes)) + // If bundle is true, we want to return a certificate bundle. + // To do this, we need the issuer certificate. + if bundle { + // The issuer certificate link is always supplied via an "up" link + // in the response headers of a new certificate. + links := parseLinks(resp.Header["Link"]) + issuerCert, err := c.getIssuerCertificate(links["up"]) + if err != nil { + // If we fail to acquire the issuer cert, return the issued certificate - do not fail. + logf("[ERROR][%s] acme: Could not bundle issuer certificate: %v", cert.Domain, err) + } else { + // Success - append the issuer cert to the issued cert. + issuerCert = pemEncode(derCertificateBytes(issuerCert)) + issuedCert = append(issuedCert, issuerCert...) + } + } + + cert.Certificate = issuedCert + return cert, nil + } + + // If the certificate is the same, then we need to request a new certificate. + // Start by checking to see if the certificate was based off a CSR, and + // use that if it's defined. + if len(cert.CSR) > 0 { + csr, err := pemDecodeTox509CSR(cert.CSR) + if err != nil { + return CertificateResource{}, err + } + newCert, failures := c.ObtainCertificateForCSR(*csr, bundle) + return newCert, failures[cert.Domain] + } + + var privKey crypto.PrivateKey + if cert.PrivateKey != nil { + privKey, err = parsePEMPrivateKey(cert.PrivateKey) + if err != nil { + return CertificateResource{}, err + } + } + + var domains []string + var failures map[string]error + // check for SAN certificate + if len(x509Cert.DNSNames) > 1 { + domains = append(domains, x509Cert.Subject.CommonName) + for _, sanDomain := range x509Cert.DNSNames { + if sanDomain == x509Cert.Subject.CommonName { + continue + } + domains = append(domains, sanDomain) + } + } else { + domains = append(domains, x509Cert.Subject.CommonName) + } + + newCert, failures := c.ObtainCertificate(domains, bundle, privKey) + return newCert, failures[cert.Domain] +} + +// Looks through the challenge combinations to find a solvable match. +// Then solves the challenges in series and returns. +func (c *Client) solveChallenges(challenges []authorizationResource) map[string]error { + // loop through the resources, basically through the domains. + failures := make(map[string]error) + for _, authz := range challenges { + if authz.Body.Status == "valid" { + // Boulder might recycle recent validated authz (see issue #267) + logf("[INFO][%s] acme: Authorization already valid; skipping challenge", authz.Domain) + continue + } + // no solvers - no solving + if solvers := c.chooseSolvers(authz.Body, authz.Domain); solvers != nil { + for i, solver := range solvers { + // TODO: do not immediately fail if one domain fails to validate. + err := solver.Solve(authz.Body.Challenges[i], authz.Domain) + if err != nil { + failures[authz.Domain] = err + } + } + } else { + failures[authz.Domain] = fmt.Errorf("[%s] acme: Could not determine solvers", authz.Domain) + } + } + + return failures +} + +// Checks all combinations from the server and returns an array of +// solvers which should get executed in series. +func (c *Client) chooseSolvers(auth authorization, domain string) map[int]solver { + for _, combination := range auth.Combinations { + solvers := make(map[int]solver) + for _, idx := range combination { + if solver, ok := c.solvers[auth.Challenges[idx].Type]; ok { + solvers[idx] = solver + } else { + logf("[INFO][%s] acme: Could not find solver for: %s", domain, auth.Challenges[idx].Type) + } + } + + // If we can solve the whole combination, return the solvers + if len(solvers) == len(combination) { + return solvers + } + } + return nil +} + +// Get the challenges needed to proof our identifier to the ACME server. +func (c *Client) getChallenges(domains []string) ([]authorizationResource, map[string]error) { + resc, errc := make(chan authorizationResource), make(chan domainError) + + for _, domain := range domains { + go func(domain string) { + authMsg := authorization{Resource: "new-authz", Identifier: identifier{Type: "dns", Value: domain}} + var authz authorization + hdr, err := postJSON(c.jws, c.user.GetRegistration().NewAuthzURL, authMsg, &authz) + if err != nil { + errc <- domainError{Domain: domain, Error: err} + return + } + + links := parseLinks(hdr["Link"]) + if links["next"] == "" { + logf("[ERROR][%s] acme: Server did not provide next link to proceed", domain) + return + } + + resc <- authorizationResource{Body: authz, NewCertURL: links["next"], AuthURL: hdr.Get("Location"), Domain: domain} + }(domain) + } + + responses := make(map[string]authorizationResource) + failures := make(map[string]error) + for i := 0; i < len(domains); i++ { + select { + case res := <-resc: + responses[res.Domain] = res + case err := <-errc: + failures[err.Domain] = err.Error + } + } + + challenges := make([]authorizationResource, 0, len(responses)) + for _, domain := range domains { + if challenge, ok := responses[domain]; ok { + challenges = append(challenges, challenge) + } + } + + close(resc) + close(errc) + + return challenges, failures +} + +func (c *Client) requestCertificate(authz []authorizationResource, bundle bool, privKey crypto.PrivateKey) (CertificateResource, error) { + if len(authz) == 0 { + return CertificateResource{}, errors.New("Passed no authorizations to requestCertificate!") + } + + var err error + if privKey == nil { + privKey, err = generatePrivateKey(c.keyType) + if err != nil { + return CertificateResource{}, err + } + } + + // determine certificate name(s) based on the authorization resources + commonName := authz[0] + var san []string + for _, auth := range authz[1:] { + san = append(san, auth.Domain) + } + + // TODO: should the CSR be customizable? + csr, err := generateCsr(privKey, commonName.Domain, san) + if err != nil { + return CertificateResource{}, err + } + + return c.requestCertificateForCsr(authz, bundle, csr, pemEncode(privKey)) +} + +func (c *Client) requestCertificateForCsr(authz []authorizationResource, bundle bool, csr []byte, privateKeyPem []byte) (CertificateResource, error) { + commonName := authz[0] + + var authURLs []string + for _, auth := range authz[1:] { + authURLs = append(authURLs, auth.AuthURL) + } + + csrString := base64.URLEncoding.EncodeToString(csr) + jsonBytes, err := json.Marshal(csrMessage{Resource: "new-cert", Csr: csrString, Authorizations: authURLs}) + if err != nil { + return CertificateResource{}, err + } + + resp, err := c.jws.post(commonName.NewCertURL, jsonBytes) + if err != nil { + return CertificateResource{}, err + } + + cerRes := CertificateResource{ + Domain: commonName.Domain, + CertURL: resp.Header.Get("Location"), + PrivateKey: privateKeyPem} + + for { + switch resp.StatusCode { + case 201, 202: + cert, err := ioutil.ReadAll(limitReader(resp.Body, 1024*1024)) + resp.Body.Close() + if err != nil { + return CertificateResource{}, err + } + + // The server returns a body with a length of zero if the + // certificate was not ready at the time this request completed. + // Otherwise the body is the certificate. + if len(cert) > 0 { + + cerRes.CertStableURL = resp.Header.Get("Content-Location") + cerRes.AccountRef = c.user.GetRegistration().URI + + issuedCert := pemEncode(derCertificateBytes(cert)) + // If bundle is true, we want to return a certificate bundle. + // To do this, we need the issuer certificate. + if bundle { + // The issuer certificate link is always supplied via an "up" link + // in the response headers of a new certificate. + links := parseLinks(resp.Header["Link"]) + issuerCert, err := c.getIssuerCertificate(links["up"]) + if err != nil { + // If we fail to acquire the issuer cert, return the issued certificate - do not fail. + logf("[WARNING][%s] acme: Could not bundle issuer certificate: %v", commonName.Domain, err) + } else { + // Success - append the issuer cert to the issued cert. + issuerCert = pemEncode(derCertificateBytes(issuerCert)) + issuedCert = append(issuedCert, issuerCert...) + } + } + + cerRes.Certificate = issuedCert + logf("[INFO][%s] Server responded with a certificate.", commonName.Domain) + return cerRes, nil + } + + // The certificate was granted but is not yet issued. + // Check retry-after and loop. + ra := resp.Header.Get("Retry-After") + retryAfter, err := strconv.Atoi(ra) + if err != nil { + return CertificateResource{}, err + } + + logf("[INFO][%s] acme: Server responded with status 202; retrying after %ds", commonName.Domain, retryAfter) + time.Sleep(time.Duration(retryAfter) * time.Second) + + break + default: + return CertificateResource{}, handleHTTPError(resp) + } + + resp, err = httpGet(cerRes.CertURL) + if err != nil { + return CertificateResource{}, err + } + } +} + +// getIssuerCertificate requests the issuer certificate and caches it for +// subsequent requests. +func (c *Client) getIssuerCertificate(url string) ([]byte, error) { + logf("[INFO] acme: Requesting issuer cert from %s", url) + if c.issuerCert != nil { + return c.issuerCert, nil + } + + resp, err := httpGet(url) + if err != nil { + return nil, err + } + defer resp.Body.Close() + + issuerBytes, err := ioutil.ReadAll(limitReader(resp.Body, 1024*1024)) + if err != nil { + return nil, err + } + + _, err = x509.ParseCertificate(issuerBytes) + if err != nil { + return nil, err + } + + c.issuerCert = issuerBytes + return issuerBytes, err +} + +func parseLinks(links []string) map[string]string { + aBrkt := regexp.MustCompile("[<>]") + slver := regexp.MustCompile("(.+) *= *\"(.+)\"") + linkMap := make(map[string]string) + + for _, link := range links { + + link = aBrkt.ReplaceAllString(link, "") + parts := strings.Split(link, ";") + + matches := slver.FindStringSubmatch(parts[1]) + if len(matches) > 0 { + linkMap[matches[2]] = parts[0] + } + } + + return linkMap +} + +// validate makes the ACME server start validating a +// challenge response, only returning once it is done. +func validate(j *jws, domain, uri string, chlng challenge) error { + var challengeResponse challenge + + hdr, err := postJSON(j, uri, chlng, &challengeResponse) + if err != nil { + return err + } + + // After the path is sent, the ACME server will access our server. + // Repeatedly check the server for an updated status on our request. + for { + switch challengeResponse.Status { + case "valid": + logf("[INFO][%s] The server validated our request", domain) + return nil + case "pending": + break + case "invalid": + return handleChallengeError(challengeResponse) + default: + return errors.New("The server returned an unexpected state.") + } + + ra, err := strconv.Atoi(hdr.Get("Retry-After")) + if err != nil { + // The ACME server MUST return a Retry-After. + // If it doesn't, we'll just poll hard. + ra = 1 + } + time.Sleep(time.Duration(ra) * time.Second) + + hdr, err = getJSON(uri, &challengeResponse) + if err != nil { + return err + } + } +} -- cgit v1.2.3-1-g7c22