mirror of
https://github.com/go-gitea/gitea
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d2ea21d0d8
* use certmagic for more extensible/robust ACME cert handling * accept TOS based on config option Signed-off-by: Andrew Thornton <art27@cantab.net> Co-authored-by: zeripath <art27@cantab.net> Co-authored-by: Lauris BH <lauris@nix.lv>
581 lines
18 KiB
Go
Vendored
581 lines
18 KiB
Go
Vendored
// Copyright 2015 Matthew Holt
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package certmagic
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import (
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"context"
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"crypto/x509"
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"encoding/pem"
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"fmt"
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"log"
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"path"
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"runtime"
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"strings"
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"time"
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"go.uber.org/zap"
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"golang.org/x/crypto/ocsp"
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)
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// maintainAssets is a permanently-blocking function
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// that loops indefinitely and, on a regular schedule, checks
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// certificates for expiration and initiates a renewal of certs
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// that are expiring soon. It also updates OCSP stapling. It
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// should only be called once per cache. Panics are recovered,
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// and if panicCount < 10, the function is called recursively,
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// incrementing panicCount each time. Initial invocation should
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// start panicCount at 0.
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func (certCache *Cache) maintainAssets(panicCount int) {
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log := loggerNamed(certCache.logger, "maintenance")
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if log != nil {
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log = log.With(zap.String("cache", fmt.Sprintf("%p", certCache)))
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}
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defer func() {
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if err := recover(); err != nil {
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buf := make([]byte, stackTraceBufferSize)
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buf = buf[:runtime.Stack(buf, false)]
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if log != nil {
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log.Error("panic", zap.Any("error", err), zap.ByteString("stack", buf))
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}
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if panicCount < 10 {
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certCache.maintainAssets(panicCount + 1)
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}
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}
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}()
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renewalTicker := time.NewTicker(certCache.options.RenewCheckInterval)
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ocspTicker := time.NewTicker(certCache.options.OCSPCheckInterval)
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if log != nil {
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log.Info("started background certificate maintenance")
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}
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ctx, cancel := context.WithCancel(context.Background())
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defer cancel()
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for {
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select {
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case <-renewalTicker.C:
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err := certCache.RenewManagedCertificates(ctx)
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if err != nil && log != nil {
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log.Error("renewing managed certificates", zap.Error(err))
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}
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case <-ocspTicker.C:
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certCache.updateOCSPStaples(ctx)
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case <-certCache.stopChan:
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renewalTicker.Stop()
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ocspTicker.Stop()
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// TODO: stop any in-progress maintenance operations and clear locks we made (this might be done now with our use of context)
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if log != nil {
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log.Info("stopped background certificate maintenance")
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}
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close(certCache.doneChan)
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return
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}
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}
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}
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// RenewManagedCertificates renews managed certificates,
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// including ones loaded on-demand. Note that this is done
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// automatically on a regular basis; normally you will not
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// need to call this. This method assumes non-interactive
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// mode (i.e. operating in the background).
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func (certCache *Cache) RenewManagedCertificates(ctx context.Context) error {
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log := loggerNamed(certCache.logger, "maintenance")
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// configs will hold a map of certificate name to the config
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// to use when managing that certificate
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configs := make(map[string]*Config)
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// we use the queues for a very important reason: to do any and all
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// operations that could require an exclusive write lock outside
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// of the read lock! otherwise we get a deadlock, yikes. in other
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// words, our first iteration through the certificate cache does NOT
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// perform any operations--only queues them--so that more fine-grained
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// write locks may be obtained during the actual operations.
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var renewQueue, reloadQueue, deleteQueue []Certificate
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certCache.mu.RLock()
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for certKey, cert := range certCache.cache {
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if !cert.managed {
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continue
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}
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// the list of names on this cert should never be empty... programmer error?
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if cert.Names == nil || len(cert.Names) == 0 {
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if log != nil {
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log.Warn("certificate has no names; removing from cache", zap.String("cert_key", certKey))
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}
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deleteQueue = append(deleteQueue, cert)
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continue
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}
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// get the config associated with this certificate
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cfg, err := certCache.getConfig(cert)
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if err != nil {
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if log != nil {
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log.Error("unable to get configuration to manage certificate; unable to renew",
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zap.Strings("identifiers", cert.Names),
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zap.Error(err))
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}
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continue
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}
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if cfg == nil {
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// this is bad if this happens, probably a programmer error (oops)
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if log != nil {
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log.Error("no configuration associated with certificate; unable to manage",
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zap.Strings("identifiers", cert.Names))
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}
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continue
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}
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// if time is up or expires soon, we need to try to renew it
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if cert.NeedsRenewal(cfg) {
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configs[cert.Names[0]] = cfg
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// see if the certificate in storage has already been renewed, possibly by another
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// instance that didn't coordinate with this one; if so, just load it (this
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// might happen if another instance already renewed it - kinda sloppy but checking disk
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// first is a simple way to possibly drastically reduce rate limit problems)
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storedCertExpiring, err := cfg.managedCertInStorageExpiresSoon(cert)
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if err != nil {
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// hmm, weird, but not a big deal, maybe it was deleted or something
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if log != nil {
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log.Warn("error while checking if stored certificate is also expiring soon",
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zap.Strings("identifiers", cert.Names),
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zap.Error(err))
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}
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} else if !storedCertExpiring {
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// if the certificate is NOT expiring soon and there was no error, then we
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// are good to just reload the certificate from storage instead of repeating
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// a likely-unnecessary renewal procedure
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reloadQueue = append(reloadQueue, cert)
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continue
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}
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// the certificate in storage has not been renewed yet, so we will do it
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// NOTE: It is super-important to note that the TLS-ALPN challenge requires
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// a write lock on the cache in order to complete its challenge, so it is extra
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// vital that this renew operation does not happen inside our read lock!
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renewQueue = append(renewQueue, cert)
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}
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}
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certCache.mu.RUnlock()
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// Reload certificates that merely need to be updated in memory
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for _, oldCert := range reloadQueue {
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timeLeft := oldCert.Leaf.NotAfter.Sub(time.Now().UTC())
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if log != nil {
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log.Info("certificate expires soon, but is already renewed in storage; reloading stored certificate",
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zap.Strings("identifiers", oldCert.Names),
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zap.Duration("remaining", timeLeft))
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}
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cfg := configs[oldCert.Names[0]]
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// crucially, this happens OUTSIDE a lock on the certCache
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err := cfg.reloadManagedCertificate(oldCert)
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if err != nil {
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if log != nil {
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log.Error("loading renewed certificate",
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zap.Strings("identifiers", oldCert.Names),
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zap.Error(err))
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}
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continue
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}
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}
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// Renewal queue
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for _, oldCert := range renewQueue {
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cfg := configs[oldCert.Names[0]]
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err := certCache.queueRenewalTask(ctx, oldCert, cfg)
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if err != nil {
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if log != nil {
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log.Error("queueing renewal task",
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zap.Strings("identifiers", oldCert.Names),
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zap.Error(err))
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}
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continue
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}
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}
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// Deletion queue
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certCache.mu.Lock()
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for _, cert := range deleteQueue {
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certCache.removeCertificate(cert)
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}
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certCache.mu.Unlock()
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return nil
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}
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func (certCache *Cache) queueRenewalTask(ctx context.Context, oldCert Certificate, cfg *Config) error {
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log := loggerNamed(certCache.logger, "maintenance")
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timeLeft := oldCert.Leaf.NotAfter.Sub(time.Now().UTC())
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if log != nil {
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log.Info("certificate expires soon; queuing for renewal",
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zap.Strings("identifiers", oldCert.Names),
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zap.Duration("remaining", timeLeft))
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}
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// Get the name which we should use to renew this certificate;
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// we only support managing certificates with one name per cert,
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// so this should be easy.
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renewName := oldCert.Names[0]
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// queue up this renewal job (is a no-op if already active or queued)
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jm.Submit(cfg.Logger, "renew_"+renewName, func() error {
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timeLeft := oldCert.Leaf.NotAfter.Sub(time.Now().UTC())
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if log != nil {
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log.Info("attempting certificate renewal",
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zap.Strings("identifiers", oldCert.Names),
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zap.Duration("remaining", timeLeft))
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}
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// perform renewal - crucially, this happens OUTSIDE a lock on certCache
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err := cfg.RenewCert(ctx, renewName, false)
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if err != nil {
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if cfg.OnDemand != nil {
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// loaded dynamically, remove dynamically
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certCache.mu.Lock()
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certCache.removeCertificate(oldCert)
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certCache.mu.Unlock()
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}
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return fmt.Errorf("%v %v", oldCert.Names, err)
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}
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// successful renewal, so update in-memory cache by loading
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// renewed certificate so it will be used with handshakes
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err = cfg.reloadManagedCertificate(oldCert)
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if err != nil {
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return ErrNoRetry{fmt.Errorf("%v %v", oldCert.Names, err)}
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}
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return nil
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})
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return nil
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}
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// updateOCSPStaples updates the OCSP stapling in all
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// eligible, cached certificates.
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//
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// OCSP maintenance strives to abide the relevant points on
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// Ryan Sleevi's recommendations for good OCSP support:
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// https://gist.github.com/sleevi/5efe9ef98961ecfb4da8
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func (certCache *Cache) updateOCSPStaples(ctx context.Context) {
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log := loggerNamed(certCache.logger, "maintenance")
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// temporary structures to store updates or tasks
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// so that we can keep our locks short-lived
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type ocspUpdate struct {
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rawBytes []byte
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parsed *ocsp.Response
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}
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type updateQueueEntry struct {
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cert Certificate
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certHash string
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lastNextUpdate time.Time
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}
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updated := make(map[string]ocspUpdate)
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var updateQueue []updateQueueEntry
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var renewQueue []Certificate
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configs := make(map[string]*Config)
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// obtain brief read lock during our scan to see which staples need updating
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certCache.mu.RLock()
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for certHash, cert := range certCache.cache {
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// no point in updating OCSP for expired or "synthetic" certificates
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if cert.Leaf == nil || cert.Expired() {
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continue
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}
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var lastNextUpdate time.Time
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if cert.ocsp != nil {
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lastNextUpdate = cert.ocsp.NextUpdate
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if freshOCSP(cert.ocsp) {
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continue // no need to update staple if ours is still fresh
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}
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}
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updateQueue = append(updateQueue, updateQueueEntry{cert, certHash, lastNextUpdate})
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}
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certCache.mu.RUnlock()
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// perform updates outside of any lock on certCache
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for _, qe := range updateQueue {
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cert := qe.cert
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certHash := qe.certHash
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lastNextUpdate := qe.lastNextUpdate
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cfg, err := certCache.getConfig(cert)
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if err != nil {
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if log != nil {
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log.Error("unable to refresh OCSP staple because getting automation config for certificate failed",
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zap.Strings("identifiers", cert.Names),
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zap.Error(err))
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}
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continue
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}
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if cfg == nil {
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// this is bad if this happens, probably a programmer error (oops)
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if log != nil {
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log.Error("no configuration associated with certificate; unable to manage OCSP staples",
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zap.Strings("identifiers", cert.Names))
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}
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continue
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}
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ocspResp, err := stapleOCSP(cfg.Storage, &cert, nil)
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if err != nil {
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if cert.ocsp != nil {
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// if there was no staple before, that's fine; otherwise we should log the error
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if log != nil {
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log.Error("stapling OCSP",
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zap.Strings("identifiers", cert.Names),
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zap.Error(err))
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}
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}
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continue
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}
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// By this point, we've obtained the latest OCSP response.
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// If there was no staple before, or if the response is updated, make
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// sure we apply the update to all names on the certificate.
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if cert.ocsp != nil && (lastNextUpdate.IsZero() || lastNextUpdate != cert.ocsp.NextUpdate) {
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if log != nil {
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log.Info("advancing OCSP staple",
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zap.Strings("identifiers", cert.Names),
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zap.Time("from", lastNextUpdate),
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zap.Time("to", cert.ocsp.NextUpdate))
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}
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updated[certHash] = ocspUpdate{rawBytes: cert.Certificate.OCSPStaple, parsed: cert.ocsp}
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}
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// If a managed certificate was revoked, we should attempt
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// to replace it with a new one. If that fails, oh well.
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if cert.managed && ocspResp.Status == ocsp.Revoked && len(cert.Names) > 0 {
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renewQueue = append(renewQueue, cert)
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configs[cert.Names[0]] = cfg
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}
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}
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// These write locks should be brief since we have all the info we need now.
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for certKey, update := range updated {
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certCache.mu.Lock()
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cert := certCache.cache[certKey]
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cert.ocsp = update.parsed
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cert.Certificate.OCSPStaple = update.rawBytes
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certCache.cache[certKey] = cert
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certCache.mu.Unlock()
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}
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// We attempt to replace any certificates that were revoked.
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// Crucially, this happens OUTSIDE a lock on the certCache.
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for _, oldCert := range renewQueue {
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if log != nil {
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log.Warn("OCSP status for managed certificate is REVOKED; attempting to replace with new certificate",
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zap.Strings("identifiers", oldCert.Names),
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zap.Time("expiration", oldCert.Leaf.NotAfter))
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}
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renewName := oldCert.Names[0]
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cfg := configs[renewName]
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// TODO: consider using a new key in this situation, but we don't know if key storage has been compromised...
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err := cfg.RenewCert(ctx, renewName, false)
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if err != nil {
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// probably better to not serve a revoked certificate at all
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if log != nil {
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log.Error("unable to obtain new to certificate after OCSP status of REVOKED; removing from cache",
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zap.Strings("identifiers", oldCert.Names),
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zap.Error(err))
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}
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certCache.mu.Lock()
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certCache.removeCertificate(oldCert)
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certCache.mu.Unlock()
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continue
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}
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err = cfg.reloadManagedCertificate(oldCert)
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if err != nil {
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if log != nil {
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log.Error("after obtaining new certificate due to OCSP status of REVOKED",
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zap.Strings("identifiers", oldCert.Names),
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zap.Error(err))
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}
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continue
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}
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}
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}
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// CleanStorageOptions specifies how to clean up a storage unit.
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type CleanStorageOptions struct {
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OCSPStaples bool
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ExpiredCerts bool
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ExpiredCertGracePeriod time.Duration
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}
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// CleanStorage removes assets which are no longer useful,
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// according to opts.
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func CleanStorage(ctx context.Context, storage Storage, opts CleanStorageOptions) {
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if opts.OCSPStaples {
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err := deleteOldOCSPStaples(ctx, storage)
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if err != nil {
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log.Printf("[ERROR] Deleting old OCSP staples: %v", err)
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}
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}
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if opts.ExpiredCerts {
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err := deleteExpiredCerts(ctx, storage, opts.ExpiredCertGracePeriod)
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if err != nil {
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log.Printf("[ERROR] Deleting expired certificates: %v", err)
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}
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}
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// TODO: delete stale locks?
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}
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|
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func deleteOldOCSPStaples(ctx context.Context, storage Storage) error {
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ocspKeys, err := storage.List(prefixOCSP, false)
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if err != nil {
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// maybe just hasn't been created yet; no big deal
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return nil
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}
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for _, key := range ocspKeys {
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// if context was cancelled, quit early; otherwise proceed
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select {
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case <-ctx.Done():
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return ctx.Err()
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default:
|
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}
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ocspBytes, err := storage.Load(key)
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if err != nil {
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log.Printf("[ERROR] While deleting old OCSP staples, unable to load staple file: %v", err)
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continue
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}
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resp, err := ocsp.ParseResponse(ocspBytes, nil)
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if err != nil {
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// contents are invalid; delete it
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err = storage.Delete(key)
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if err != nil {
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log.Printf("[ERROR] Purging corrupt staple file %s: %v", key, err)
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}
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continue
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}
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if time.Now().After(resp.NextUpdate) {
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// response has expired; delete it
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err = storage.Delete(key)
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if err != nil {
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log.Printf("[ERROR] Purging expired staple file %s: %v", key, err)
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}
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}
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}
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return nil
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}
|
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|
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func deleteExpiredCerts(ctx context.Context, storage Storage, gracePeriod time.Duration) error {
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issuerKeys, err := storage.List(prefixCerts, false)
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if err != nil {
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// maybe just hasn't been created yet; no big deal
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return nil
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}
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|
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for _, issuerKey := range issuerKeys {
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siteKeys, err := storage.List(issuerKey, false)
|
|
if err != nil {
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log.Printf("[ERROR] Listing contents of %s: %v", issuerKey, err)
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continue
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}
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|
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for _, siteKey := range siteKeys {
|
|
// if context was cancelled, quit early; otherwise proceed
|
|
select {
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|
case <-ctx.Done():
|
|
return ctx.Err()
|
|
default:
|
|
}
|
|
|
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siteAssets, err := storage.List(siteKey, false)
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|
if err != nil {
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log.Printf("[ERROR] Listing contents of %s: %v", siteKey, err)
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continue
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}
|
|
|
|
for _, assetKey := range siteAssets {
|
|
if path.Ext(assetKey) != ".crt" {
|
|
continue
|
|
}
|
|
|
|
certFile, err := storage.Load(assetKey)
|
|
if err != nil {
|
|
return fmt.Errorf("loading certificate file %s: %v", assetKey, err)
|
|
}
|
|
block, _ := pem.Decode(certFile)
|
|
if block == nil || block.Type != "CERTIFICATE" {
|
|
return fmt.Errorf("certificate file %s does not contain PEM-encoded certificate", assetKey)
|
|
}
|
|
cert, err := x509.ParseCertificate(block.Bytes)
|
|
if err != nil {
|
|
return fmt.Errorf("certificate file %s is malformed; error parsing PEM: %v", assetKey, err)
|
|
}
|
|
|
|
if expiredTime := time.Since(cert.NotAfter); expiredTime >= gracePeriod {
|
|
log.Printf("[INFO] Certificate %s expired %s ago; cleaning up", assetKey, expiredTime)
|
|
baseName := strings.TrimSuffix(assetKey, ".crt")
|
|
for _, relatedAsset := range []string{
|
|
assetKey,
|
|
baseName + ".key",
|
|
baseName + ".json",
|
|
} {
|
|
log.Printf("[INFO] Deleting %s because resource expired", relatedAsset)
|
|
err := storage.Delete(relatedAsset)
|
|
if err != nil {
|
|
log.Printf("[ERROR] Cleaning up asset related to expired certificate for %s: %s: %v",
|
|
baseName, relatedAsset, err)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// update listing; if folder is empty, delete it
|
|
siteAssets, err = storage.List(siteKey, false)
|
|
if err != nil {
|
|
continue
|
|
}
|
|
if len(siteAssets) == 0 {
|
|
log.Printf("[INFO] Deleting %s because key is empty", siteKey)
|
|
err := storage.Delete(siteKey)
|
|
if err != nil {
|
|
return fmt.Errorf("deleting empty site folder %s: %v", siteKey, err)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
const (
|
|
// DefaultRenewCheckInterval is how often to check certificates for expiration.
|
|
// Scans are very lightweight, so this can be semi-frequent. This default should
|
|
// be smaller than <Minimum Cert Lifetime>*DefaultRenewalWindowRatio/3, which
|
|
// gives certificates plenty of chance to be renewed on time.
|
|
DefaultRenewCheckInterval = 10 * time.Minute
|
|
|
|
// DefaultRenewalWindowRatio is how much of a certificate's lifetime becomes the
|
|
// renewal window. The renewal window is the span of time at the end of the
|
|
// certificate's validity period in which it should be renewed. A default value
|
|
// of ~1/3 is pretty safe and recommended for most certificates.
|
|
DefaultRenewalWindowRatio = 1.0 / 3.0
|
|
|
|
// DefaultOCSPCheckInterval is how often to check if OCSP stapling needs updating.
|
|
DefaultOCSPCheckInterval = 1 * time.Hour
|
|
)
|