aboutsummaryrefslogtreecommitdiff
path: root/vendor/golang.org/x/crypto/acme/autocert
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/golang.org/x/crypto/acme/autocert')
-rw-r--r--vendor/golang.org/x/crypto/acme/autocert/autocert.go793
-rw-r--r--vendor/golang.org/x/crypto/acme/autocert/cache.go130
-rw-r--r--vendor/golang.org/x/crypto/acme/autocert/renewal.go125
3 files changed, 1048 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/acme/autocert/autocert.go b/vendor/golang.org/x/crypto/acme/autocert/autocert.go
new file mode 100644
index 0000000..4b15816
--- /dev/null
+++ b/vendor/golang.org/x/crypto/acme/autocert/autocert.go
@@ -0,0 +1,793 @@
+// 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"
+ "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/http"
+ "strconv"
+ "strings"
+ "sync"
+ "time"
+
+ "golang.org/x/crypto/acme"
+ "golang.org/x/net/context"
+)
+
+// pseudoRand is safe for concurrent use.
+var pseudoRand *lockedMathRand
+
+func init() {
+ src := mathrand.NewSource(timeNow().UnixNano())
+ pseudoRand = &lockedMathRand{rnd: mathrand.New(src)}
+}
+
+// AcceptTOS always returns true to indicate the acceptance of a CA 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,
+// as well as providing them to a TLS server via tls.Config.
+//
+// A simple usage example:
+//
+// m := autocert.Manager{
+// Prompt: autocert.AcceptTOS,
+// HostPolicy: autocert.HostWhitelist("example.org"),
+// }
+// s := &http.Server{
+// Addr: ":https",
+// TLSConfig: &tls.Config{GetCertificate: m.GetCertificate},
+// }
+// s.ListenAndServeTLS("", "")
+//
+// To preserve issued certificates and improve overall performance,
+// use a cache implementation of Cache. For instance, DirCache.
+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.
+ // If nil, certs will only be cached for the lifetime of the Manager.
+ //
+ // Manager passes the Cache certificates data encoded in PEM, with private/public
+ // parts combined in a single Cache.Put call, private key first.
+ 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 1 week 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
+ // directory endpoint and a newly-generated ECDSA P-256 key.
+ //
+ // 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 makes the Manager generate certificates with 2048-bit RSA keys.
+ //
+ // If false, a default is used. Currently the default
+ // is EC-based keys using the P-256 curve.
+ ForceRSA bool
+
+ clientMu sync.Mutex
+ client *acme.Client // initialized by acmeClient method
+
+ 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
+}
+
+// GetCertificate implements the tls.Config.GetCertificate hook.
+// It provides a TLS certificate for hello.ServerName host, including answering
+// *.acme.invalid (TLS-SNI) 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.
+func (m *Manager) GetCertificate(hello *tls.ClientHelloInfo) (*tls.Certificate, error) {
+ name := hello.ServerName
+ if name == "" {
+ return nil, errors.New("acme/autocert: missing server name")
+ }
+
+ // 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 {
+ return cert, nil
+ }
+ if cert, err := m.cacheGet(name); err == nil {
+ return cert, nil
+ }
+ // TODO: cache error results?
+ return nil, fmt.Errorf("acme/autocert: no token cert for %q", name)
+ }
+
+ // regular domain
+ name = strings.TrimSuffix(name, ".") // golang.org/issue/18114
+ cert, err := m.cert(name)
+ if err == nil {
+ return cert, nil
+ }
+ if err != ErrCacheMiss {
+ return nil, err
+ }
+
+ // first-time
+ ctx := context.Background() // TODO: use a deadline?
+ if err := m.hostPolicy()(ctx, name); err != nil {
+ return nil, err
+ }
+ cert, err = m.createCert(ctx, name)
+ if err != nil {
+ return nil, err
+ }
+ m.cachePut(name, cert)
+ return cert, nil
+}
+
+// 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(name string) (*tls.Certificate, error) {
+ m.stateMu.Lock()
+ if s, ok := m.state[name]; ok {
+ m.stateMu.Unlock()
+ s.RLock()
+ defer s.RUnlock()
+ return s.tlscert()
+ }
+ defer m.stateMu.Unlock()
+ cert, err := m.cacheGet(name)
+ 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[string]*certState)
+ }
+ s := &certState{
+ key: signer,
+ cert: cert.Certificate,
+ leaf: cert.Leaf,
+ }
+ m.state[name] = s
+ go m.renew(name, s.key, s.leaf.NotAfter)
+ return cert, nil
+}
+
+// cacheGet always returns a valid certificate, or an error otherwise.
+func (m *Manager) cacheGet(domain string) (*tls.Certificate, error) {
+ if m.Cache == nil {
+ return nil, ErrCacheMiss
+ }
+ // TODO: might want to define a cache timeout on m
+ ctx := context.Background()
+ data, err := m.Cache.Get(ctx, domain)
+ if err != nil {
+ return nil, err
+ }
+
+ // private
+ priv, pub := pem.Decode(data)
+ if priv == nil || !strings.Contains(priv.Type, "PRIVATE") {
+ return nil, errors.New("acme/autocert: no private key found in cache")
+ }
+ 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 {
+ return nil, errors.New("acme/autocert: invalid public key")
+ }
+
+ // verify and create TLS cert
+ leaf, err := validCert(domain, pubDER, privKey)
+ if err != nil {
+ return nil, err
+ }
+ tlscert := &tls.Certificate{
+ Certificate: pubDER,
+ PrivateKey: privKey,
+ Leaf: leaf,
+ }
+ return tlscert, nil
+}
+
+func (m *Manager) cachePut(domain string, 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
+ }
+ }
+
+ // TODO: might want to define a cache timeout on m
+ ctx := context.Background()
+ return m.Cache.Put(ctx, domain, 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, domain string) (*tls.Certificate, error) {
+ // TODO: maybe rewrite this whole piece using sync.Once
+ state, err := m.certState(domain)
+ 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 the we got the cert or the process failed.
+ defer state.Unlock()
+ state.locked = false
+
+ der, leaf, err := m.authorizedCert(ctx, state.key, domain)
+ if err != nil {
+ return nil, err
+ }
+ state.cert = der
+ state.leaf = leaf
+ go m.renew(domain, 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(domain string) (*certState, error) {
+ m.stateMu.Lock()
+ defer m.stateMu.Unlock()
+ if m.state == nil {
+ m.state = make(map[string]*certState)
+ }
+ // existing state
+ if state, ok := m.state[domain]; ok {
+ return state, nil
+ }
+
+ // new locked state
+ var (
+ err error
+ key crypto.Signer
+ )
+ if m.ForceRSA {
+ 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[domain] = state
+ return state, nil
+}
+
+// authorizedCert starts 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) {
+ // TODO: make m.verify retry or retry m.verify calls here
+ if err := m.verify(ctx, domain); err != nil {
+ return nil, nil, err
+ }
+ client, err := m.acmeClient(ctx)
+ if err != nil {
+ return nil, nil, err
+ }
+ csr, err := certRequest(key, domain)
+ 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(domain, der, key)
+ if err != nil {
+ return nil, nil, err
+ }
+ 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
+ }
+
+ // 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
+ }
+ if c.Type == "tls-sni-01" {
+ chal = c
+ }
+ }
+ 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
+ )
+ switch chal.Type {
+ case "tls-sni-01":
+ cert, name, err = client.TLSSNI01ChallengeCert(chal.Token)
+ 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
+ }
+ m.putTokenCert(name, &cert)
+ defer func() {
+ // verification has ended at this point
+ // don't need token cert anymore
+ go m.deleteTokenCert(name)
+ }()
+
+ // ready to fulfill the challenge
+ if _, err := client.Accept(ctx, chal); err != nil {
+ return err
+ }
+ // wait for the CA to validate
+ _, err = client.WaitAuthorization(ctx, authz.URI)
+ return err
+}
+
+// putTokenCert stores the cert under the named key in both m.tokenCert map
+// and m.Cache.
+func (m *Manager) putTokenCert(name string, cert *tls.Certificate) {
+ m.tokenCertMu.Lock()
+ defer m.tokenCertMu.Unlock()
+ if m.tokenCert == nil {
+ m.tokenCert = make(map[string]*tls.Certificate)
+ }
+ m.tokenCert[name] = cert
+ m.cachePut(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)
+ if m.Cache != nil {
+ m.Cache.Delete(context.Background(), name)
+ }
+}
+
+// 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(domain string, key crypto.Signer, exp time.Time) {
+ m.renewalMu.Lock()
+ defer m.renewalMu.Unlock()
+ if m.renewal[domain] != nil {
+ // another goroutine is already on it
+ return
+ }
+ if m.renewal == nil {
+ m.renewal = make(map[string]*domainRenewal)
+ }
+ dr := &domainRenewal{m: m, domain: domain, key: key}
+ m.renewal[domain] = 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"
+
+ 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 {
+ 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 > maxRandRenew {
+ return m.RenewBefore
+ }
+ return 7 * 24 * time.Hour // 1 week
+}
+
+// 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 creates a certificate request for the given common name cn
+// and optional SANs.
+func certRequest(key crypto.Signer, cn string, san ...string) ([]byte, error) {
+ req := &x509.CertificateRequest{
+ Subject: pkix.Name{CommonName: cn},
+ DNSNames: san,
+ }
+ 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, der[0],
+// corresponds to the private key, as well as the domain match and expiration dates.
+// It doesn't do any revocation checking.
+//
+// The returned value is the verified leaf cert.
+func validCert(domain string, der [][]byte, key crypto.Signer) (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 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]
+ now := timeNow()
+ 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(domain); err != nil {
+ return nil, err
+ }
+ // ensure the leaf corresponds to the private key
+ 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")
+ }
+ 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")
+ }
+ default:
+ return nil, errors.New("acme/autocert: unknown public key algorithm")
+ }
+ return leaf, nil
+}
+
+func retryAfter(v string) time.Duration {
+ if i, err := strconv.Atoi(v); err == nil {
+ return time.Duration(i) * time.Second
+ }
+ if t, err := http.ParseTime(v); err == nil {
+ return t.Sub(timeNow())
+ }
+ return time.Second
+}
+
+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 timeNow = time.Now
diff --git a/vendor/golang.org/x/crypto/acme/autocert/cache.go b/vendor/golang.org/x/crypto/acme/autocert/cache.go
new file mode 100644
index 0000000..1c67f6c
--- /dev/null
+++ b/vendor/golang.org/x/crypto/acme/autocert/cache.go
@@ -0,0 +1,130 @@
+// 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 (
+ "errors"
+ "io/ioutil"
+ "os"
+ "path/filepath"
+
+ "golang.org/x/net/context"
+)
+
+// 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
+// as opaque data.
+//
+// The key argument of the methods refers to a domain name but need not be an FQDN.
+// Cache implementations should not rely on the key naming pattern.
+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.
+ // Inderlying 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
+ }
+ // prevent overwriting the file if the context was cancelled
+ if ctx.Err() != nil {
+ return // no need to set err
+ }
+ name = filepath.Join(string(d), name)
+ err = os.Rename(tmp, name)
+ }()
+ 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/renewal.go b/vendor/golang.org/x/crypto/acme/autocert/renewal.go
new file mode 100644
index 0000000..1a5018c
--- /dev/null
+++ b/vendor/golang.org/x/crypto/acme/autocert/renewal.go
@@ -0,0 +1,125 @@
+// 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 (
+ "crypto"
+ "sync"
+ "time"
+
+ "golang.org/x/net/context"
+)
+
+// maxRandRenew is a maximum deviation from Manager.RenewBefore.
+const maxRandRenew = time.Hour
+
+// domainRenewal tracks the state used by the periodic timers
+// renewing a single domain's cert.
+type domainRenewal struct {
+ m *Manager
+ domain string
+ 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 = maxRandRenew / 2
+ next += time.Duration(pseudoRand.int63n(int64(next)))
+ }
+ dr.timer = time.AfterFunc(next, dr.renew)
+ testDidRenewLoop(next, err)
+}
+
+// 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 return immediately 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(dr.domain); err == nil {
+ next := dr.next(tlscert.Leaf.NotAfter)
+ if next > dr.m.renewBefore()+maxRandRenew {
+ return next, nil
+ }
+ }
+
+ der, leaf, err := dr.m.authorizedCert(ctx, dr.key, dr.domain)
+ 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
+ }
+ dr.m.cachePut(dr.domain, tlscert)
+ dr.m.stateMu.Lock()
+ defer dr.m.stateMu.Unlock()
+ // m.state is guaranteed to be non-nil at this point
+ dr.m.state[dr.domain] = state
+ return dr.next(leaf.NotAfter), nil
+}
+
+func (dr *domainRenewal) next(expiry time.Time) time.Duration {
+ d := expiry.Sub(timeNow()) - dr.m.renewBefore()
+ // add a bit of randomness to renew deadline
+ n := pseudoRand.int63n(int64(maxRandRenew))
+ d -= time.Duration(n)
+ if d < 0 {
+ return 0
+ }
+ return d
+}
+
+var testDidRenewLoop = func(next time.Duration, err error) {}