diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/acme/autocert/autocert.go')
| -rw-r--r-- | vendor/golang.org/x/crypto/acme/autocert/autocert.go | 316 |
1 files changed, 234 insertions, 82 deletions
diff --git a/vendor/golang.org/x/crypto/acme/autocert/autocert.go b/vendor/golang.org/x/crypto/acme/autocert/autocert.go index 94edba9..453e722 100644 --- a/vendor/golang.org/x/crypto/acme/autocert/autocert.go +++ b/vendor/golang.org/x/crypto/acme/autocert/autocert.go @@ -24,7 +24,9 @@ import ( "fmt" "io" mathrand "math/rand" + "net" "net/http" + "path" "strconv" "strings" "sync" @@ -80,8 +82,9 @@ func defaultHostPolicy(context.Context, string) error { } // Manager is a stateful certificate manager built on top of acme.Client. -// It obtains and refreshes certificates automatically, -// as well as providing them to a TLS server via tls.Config. +// It obtains and refreshes certificates automatically using "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. @@ -150,15 +153,26 @@ type Manager struct { stateMu sync.Mutex state map[string]*certState // keyed by domain name - // tokenCert is keyed by token domain name, which matches server name - // of ClientHello. Keys always have ".acme.invalid" suffix. - tokenCertMu sync.RWMutex - tokenCert map[string]*tls.Certificate - // renewal tracks the set of domains currently running renewal timers. // It is keyed by domain name. renewalMu sync.Mutex renewal map[string]*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 challenges + // and is keyed by token domain name, which matches server name of ClientHello. + // Keys always have ".acme.invalid" suffix. + // The entries are stored for the duration of the authorization flow. + certTokens map[string]*tls.Certificate } // GetCertificate implements the tls.Config.GetCertificate hook. @@ -185,14 +199,16 @@ func (m *Manager) GetCertificate(hello *tls.ClientHelloInfo) (*tls.Certificate, 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 challenge if strings.HasSuffix(name, ".acme.invalid") { - m.tokenCertMu.RLock() - defer m.tokenCertMu.RUnlock() - if cert := m.tokenCert[name]; cert != nil { + m.tokensMu.RLock() + defer m.tokensMu.RUnlock() + if cert := m.certTokens[name]; cert != nil { return cert, nil } if cert, err := m.cacheGet(ctx, name); err == nil { @@ -224,6 +240,68 @@ func (m *Manager) GetCertificate(hello *tls.ClientHelloInfo) (*tls.Certificate, return cert, nil } +// 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 TLS SNI +// challenges 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. @@ -442,13 +520,14 @@ func (m *Manager) certState(domain string) (*certState, error) { // 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, domain string) (der [][]byte, leaf *x509.Certificate, err error) { - if err := m.verify(ctx, domain); err != nil { - return nil, nil, err - } client, err := m.acmeClient(ctx) if err != nil { return nil, nil, err } + + if err := m.verify(ctx, client, domain); err != nil { + return nil, nil, err + } csr, err := certRequest(key, domain) if err != nil { return nil, nil, err @@ -464,98 +543,171 @@ func (m *Manager) authorizedCert(ctx context.Context, key crypto.Signer, domain return der, leaf, nil } -// verify starts a new identifier (domain) authorization flow. -// It prepares a challenge response and then blocks until the authorization -// is marked as "completed" by the CA (either succeeded or failed). -// -// verify returns nil iff the verification was successful. -func (m *Manager) verify(ctx context.Context, domain string) error { - client, err := m.acmeClient(ctx) - if err != nil { - return err - } - - // start domain authorization and get the challenge - authz, err := client.Authorize(ctx, domain) - if err != nil { - return err - } - // maybe don't need to at all - if authz.Status == acme.StatusValid { - return nil - } +// 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-sni-02", "tls-sni-01"} + m.tokensMu.RLock() + if m.tryHTTP01 { + challengeTypes = append(challengeTypes, "http-01") + } + m.tokensMu.RUnlock() + + 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) + } - // pick a challenge: prefer tls-sni-02 over tls-sni-01 - // TODO: consider authz.Combinations - var chal *acme.Challenge - for _, c := range authz.Challenges { - if c.Type == "tls-sni-02" { - chal = c - break + // Pick the next preferred challenge. + var chal *acme.Challenge + for chal == nil && nextTyp < len(challengeTypes) { + chal = pickChallenge(challengeTypes[nextTyp], authz.Challenges) + nextTyp++ } - if c.Type == "tls-sni-01" { - chal = c + if chal == nil { + return fmt.Errorf("acme/autocert: unable to authorize %q; tried %q", domain, challengeTypes) + } + cleanup, err := m.fulfill(ctx, client, chal) + if err != nil { + continue + } + defer cleanup() + if _, err := client.Accept(ctx, chal); err != nil { + continue + } + + // A challenge is fulfilled and accepted: wait for the CA to validate. + if _, err := client.WaitAuthorization(ctx, authz.URI); err == nil { + return nil } } - if chal == nil { - return errors.New("acme/autocert: no supported challenge type found") - } +} - // create a token cert for the challenge response - var ( - cert tls.Certificate - name string - ) +// 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) (cleanup func(), err error) { switch chal.Type { case "tls-sni-01": - cert, name, err = client.TLSSNI01ChallengeCert(chal.Token) + 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) - default: - err = fmt.Errorf("acme/autocert: unknown challenge type %q", chal.Type) - } - if err != nil { - return err + 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 } - m.putTokenCert(ctx, name, &cert) - defer func() { - // verification has ended at this point - // don't need token cert anymore - go m.deleteTokenCert(name) - }() + return nil, fmt.Errorf("acme/autocert: unknown challenge type %q", chal.Type) +} - // ready to fulfill the challenge - if _, err := client.Accept(ctx, chal); err != nil { - return err +func pickChallenge(typ string, chal []*acme.Challenge) *acme.Challenge { + for _, c := range chal { + if c.Type == typ { + return c + } } - // wait for the CA to validate - _, err = client.WaitAuthorization(ctx, authz.URI) - return err + return nil } -// putTokenCert stores the cert under the named key in both m.tokenCert map +// putCertToken stores the cert under the named key in both m.certTokens map // and m.Cache. -func (m *Manager) putTokenCert(ctx context.Context, name string, cert *tls.Certificate) { - m.tokenCertMu.Lock() - defer m.tokenCertMu.Unlock() - if m.tokenCert == nil { - m.tokenCert = make(map[string]*tls.Certificate) +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.tokenCert[name] = cert + m.certTokens[name] = cert m.cachePut(ctx, name, cert) } -// deleteTokenCert removes the token certificate for the specified domain name -// from both m.tokenCert map and m.Cache. -func (m *Manager) deleteTokenCert(name string) { - m.tokenCertMu.Lock() - defer m.tokenCertMu.Unlock() - delete(m.tokenCert, name) +// deleteCertToken removes the token certificate for the specified domain 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 { m.Cache.Delete(context.Background(), name) } } +// 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 "http-01-" + path.Base(tokenPath) +} + // renew starts a cert renewal timer loop, one per domain. // // The loop is scheduled in two cases: |