From 69d65dfa8528350e73409e684844344e3cdb3f16 Mon Sep 17 00:00:00 2001
From: ale <ale@incal.net>
Date: Thu, 9 Aug 2018 23:45:22 +0100
Subject: [PATCH] Refactor of the code
Add dns-01 support, make the code more readable, add a testing
mode that will generate self-signed certificates (for test
environments that are not reachable from outside).
---
README.md | 31 +++++
acme.go | 176 ++++++++++++++-----------
cmd/acmeserver/acmeserver.go | 43 +++++--
config.go | 86 +++++++++----
dns_challenge.go | 156 ++++++++++++++++++++++
http_challenge.go | 58 +++++++++
instrumentation.go | 47 +++++++
server.go => manager.go | 206 +++++++++++++-----------------
server_test.go => manager_test.go | 112 ++++++----------
selfsigned.go | 73 +++++++++++
storage.go | 6 +-
valid_cert.go | 92 +++++++++++++
12 files changed, 787 insertions(+), 299 deletions(-)
create mode 100644 dns_challenge.go
create mode 100644 http_challenge.go
create mode 100644 instrumentation.go
rename server.go => manager.go (61%)
rename server_test.go => manager_test.go (53%)
create mode 100644 selfsigned.go
create mode 100644 valid_cert.go
diff --git a/README.md b/README.md
index 669664f9..0932128e 100644
--- a/README.md
+++ b/README.md
@@ -3,3 +3,34 @@ acmeserver
Runs a daemon to manage a set of SSL certificates using the ACME protocol.
+There are many similar tools, why another one? Well we need a few
+unique features:
+
+* custom output code for certificates and private keys, so we can
+ write them to [replds](https://git.autistici.org/ai3/replds) and
+ have them replicated to all front-ends;
+* support for our DNS setup for *dns-01* challenges, by sending RFC
+ 2136 updates to all DNS servers in parallel.
+
+For the rest it's a fairly common ACME automation tool, it supports
+the *http-01* and *dns-01* challenges (no *tls-sni-01* because the
+tool is meant to be run behind a HTTPS proxy so it can't directly
+control the serving certificates).
+
+Since this is a particularly critical piece of software, a few extra
+cautions are necessary in its development:
+
+* do not implement any ACME-specific code but use a well-maintained
+ library instead
+ (like [golang.org/x/crypto/acme](https://golang.org/x/crypto/acme))
+* try to be robust against ACME high-level protocol changes by keeping
+ this tool replaceable with *certbot* and a bunch of shell
+ scripts. In particular we can do this by:
+ * keeping a directory structure for the output that's compatible
+ with certbot
+ * having a way to independently push content to replds (which we do,
+ by way of the *replds* command itself)
+
+ So the advantage of *acmeserver* becomes just the integration
+ between the various components in a single package / binary (and
+ monitoring, etc).
diff --git a/acme.go b/acme.go
index fe52a6b9..51eccf9d 100644
--- a/acme.go
+++ b/acme.go
@@ -14,22 +14,31 @@ import (
"log"
"net/http"
"path/filepath"
- "strings"
- "sync"
"golang.org/x/crypto/acme"
)
-// ACME handles the certificate creation/renewal workflow using acme
-// http-01 challenges. It serves validation tokens under the
-// /.well-known/acme-challenge path when used as an HTTP handler.
+const (
+ http01Challenge = "http-01"
+ dns01Challenge = "dns-01"
+)
+
+type validator interface {
+ Fulfill(context.Context, *acme.Client, string, *acme.Challenge) (func(), error)
+}
+
+// ACME is a simple wrapper for an acme.Client that handles the
+// certificate creation/renewal workflow using http-01 or dns-01
+// challenges.
type ACME struct {
email string
accountKeyPath string
+ directoryURL string
client *acme.Client
- mx sync.Mutex
- httpTokens map[string][]byte
+ handler http.Handler
+ validators map[string]validator
+ defaultChallengeType string
}
// NewACME returns a new ACME object with the provided config.
@@ -38,14 +47,46 @@ func NewACME(config *Config) (*ACME, error) {
return nil, errors.New("configuration parameter 'email' is unset")
}
+ var h http.Handler
+ v := make(map[string]validator)
+ if config.HTTP.Enabled {
+ httpv := newHTTPValidator()
+ h = httpv
+ v[http01Challenge] = httpv
+ }
+ if config.DNS.Enabled {
+ dnsv, err := newDNSValidator(config)
+ if err != nil {
+ return nil, err
+ }
+ v[dns01Challenge] = dnsv
+ }
+
+ defaultChalType := config.DefaultChallengeType
+ if defaultChalType == "" {
+ defaultChalType = http01Challenge
+ }
+ if _, ok := v[defaultChalType]; !ok {
+ return nil, fmt.Errorf("the default challenge type '%s' is not configured", defaultChalType)
+ }
+
+ directoryURL := config.DirectoryURL
+ if directoryURL == "" {
+ directoryURL = acme.LetsEncryptURL
+ }
+
return &ACME{
- email: config.Email,
- accountKeyPath: filepath.Join(config.Dir, "account.key"),
- httpTokens: make(map[string][]byte),
+ email: config.Email,
+ accountKeyPath: filepath.Join(config.Dir, "account.key"),
+ directoryURL: directoryURL,
+ handler: h,
+ validators: v,
+ defaultChallengeType: defaultChalType,
}, nil
}
-func (a *ACME) accountKey(ctx context.Context) (crypto.Signer, error) {
+// Return the account key, possibly initializing it if it does not exist.
+func (a *ACME) accountKey() (crypto.Signer, error) {
if key, err := parsePrivateKeyFromFile(a.accountKeyPath); err == nil {
return key, err
}
@@ -66,15 +107,18 @@ func (a *ACME) accountKey(ctx context.Context) (crypto.Signer, error) {
return eckey, err
}
+// Return a new acme.Client, possibly initializing the account key if
+// it does not exist yet. The Client is created on the first call and
+// cached thereafter.
func (a *ACME) acmeClient(ctx context.Context) (*acme.Client, error) {
if a.client != nil {
return a.client, nil
}
client := &acme.Client{
- DirectoryURL: acme.LetsEncryptURL,
+ DirectoryURL: a.directoryURL,
}
- key, err := a.accountKey(ctx)
+ key, err := a.accountKey()
if err != nil {
return nil, err
}
@@ -82,6 +126,10 @@ func (a *ACME) acmeClient(ctx context.Context) (*acme.Client, error) {
ac := &acme.Account{
Contact: []string{"mailto:" + a.email},
}
+
+ // Register the account (accept TOS) if necessary. If the
+ // account is already registered we get a StatusConflict,
+ // which we can ignore.
_, err = client.Register(ctx, ac, func(_ string) bool { return true })
if ae, ok := err.(*acme.Error); err == nil || ok && ae.StatusCode == http.StatusConflict {
a.client = client
@@ -93,17 +141,17 @@ func (a *ACME) acmeClient(ctx context.Context) (*acme.Client, error) {
// GetCertificate returns a certificate chain (and the parsed leaf
// cert), given a private key and a list of domains. The first domain
// will be the subject CN, the others will be added as subjectAltNames.
-func (a *ACME) GetCertificate(ctx context.Context, key crypto.Signer, domains []string) (der [][]byte, leaf *x509.Certificate, err error) {
+func (a *ACME) GetCertificate(ctx context.Context, key crypto.Signer, c *certConfig) (der [][]byte, leaf *x509.Certificate, err error) {
client, err := a.acmeClient(ctx)
if err != nil {
return nil, nil, err
}
- if err = a.verifyAll(ctx, client, domains); err != nil {
+ if err = a.verifyAll(ctx, client, c); err != nil {
return nil, nil, err
}
- csr, err := certRequest(key, domains)
+ csr, err := certRequest(key, c.Names)
if err != nil {
return nil, nil, err
}
@@ -111,28 +159,29 @@ func (a *ACME) GetCertificate(ctx context.Context, key crypto.Signer, domains []
if err != nil {
return nil, nil, err
}
- leaf, err = validCert(domains, der, key)
+ leaf, err = validCert(c.Names, der, key)
if err != nil {
return nil, nil, err
}
return der, leaf, nil
}
-func (a *ACME) verifyAll(ctx context.Context, client *acme.Client, domains []string) error {
- for _, domain := range domains {
- if err := a.verify(ctx, client, domain); err != nil {
+func (a *ACME) verifyAll(ctx context.Context, client *acme.Client, c *certConfig) error {
+ for _, domain := range c.Names {
+ if err := a.verify(ctx, client, c, domain); err != nil {
return err
}
}
return nil
}
-func (a *ACME) verify(ctx context.Context, client *acme.Client, domain string) error {
+func (a *ACME) verify(ctx context.Context, client *acme.Client, c *certConfig, domain string) error {
+ // Make an authorization request to the ACME server, and
+ // verify that it returns a valid response with challenges.
authz, err := client.Authorize(ctx, domain)
if err != nil {
return err
}
-
switch authz.Status {
case acme.StatusValid:
return nil // already authorized
@@ -140,16 +189,28 @@ func (a *ACME) verify(ctx context.Context, client *acme.Client, domain string) e
return fmt.Errorf("invalid authorization %q", authz.URI)
}
- chal := pickChallenge("http-01", authz.Challenges)
+ // Pick a challenge that matches our preferences and the
+ // available validators. The validator fulfills the challenge,
+ // and returns a cleanup function that we're going to call
+ // before we return. All steps are sequential and idempotent.
+ chal := a.pickChallenge(authz.Challenges, c)
if chal == nil {
return fmt.Errorf("unable to authorize %q", domain)
}
- cleanup, err := a.fulfill(ctx, client, chal)
+ v, ok := a.validators[chal.Type]
+ if !ok {
+ return fmt.Errorf("challenge type '%s' is not available", chal.Type)
+ }
+ cleanup, err := v.Fulfill(ctx, client, domain, chal)
if err != nil {
return err
}
defer cleanup()
+ // Tell the ACME server that we've accepted the challenge, and
+ // then wait, possibly for some time, until there is an
+ // authorization response (either successful or not) from the
+ // server.
if _, err = client.Accept(ctx, chal); err != nil {
return err
}
@@ -157,56 +218,25 @@ func (a *ACME) verify(ctx context.Context, client *acme.Client, domain string) e
return err
}
-func (a *ACME) fulfill(ctx context.Context, client *acme.Client, chal *acme.Challenge) (cleanup func(), err error) {
- if chal.Type != "http-01" {
- return nil, errors.New("unsupported challenge type")
- }
-
- resp, err := client.HTTP01ChallengeResponse(chal.Token)
- if err != nil {
- return nil, err
- }
- p := client.HTTP01ChallengePath(chal.Token)
- a.putHTTPToken(ctx, p, resp)
- return func() { go a.deleteHTTPToken(p) }, nil
-}
-
-func (a *ACME) httpToken(ctx context.Context, tokenPath string) ([]byte, error) {
- a.mx.Lock()
- defer a.mx.Unlock()
-
- if v, ok := a.httpTokens[tokenPath]; ok {
- return v, nil
+// Pick a challenge with the right type from the Challenge response
+// returned by the ACME server. We have a pretty specific idea of the
+// challenge type we want (either the default, or the ChallengeType
+// specified in the cert config), so we just search for that one.
+func (a *ACME) pickChallenge(chal []*acme.Challenge, c *certConfig) *acme.Challenge {
+ ctype := a.defaultChallengeType
+ if c.ChallengeType != "" {
+ ctype = c.ChallengeType
+ }
+ for _, ch := range chal {
+ if ch.Type == ctype {
+ return ch
+ }
}
- return nil, errors.New("token not found")
-}
-
-func (a *ACME) putHTTPToken(ctx context.Context, tokenPath, val string) {
- a.mx.Lock()
- a.httpTokens[tokenPath] = []byte(val)
- a.mx.Unlock()
-}
-
-func (a *ACME) deleteHTTPToken(tokenPath string) {
- a.mx.Lock()
- delete(a.httpTokens, tokenPath)
- a.mx.Unlock()
+ return nil
}
-func (a *ACME) ServeHTTP(w http.ResponseWriter, r *http.Request) {
- if !strings.HasPrefix(r.URL.Path, "/.well-known/acme-challenge/") {
- http.NotFound(w, r)
- return
- }
-
- a.mx.Lock()
- defer a.mx.Unlock()
-
- data, err := a.httpToken(r.Context(), r.URL.Path)
- if err != nil {
- http.Error(w, err.Error(), http.StatusNotFound)
- return
- }
-
- w.Write(data)
+// Handler returns the http.Handler that is used to satisfy the
+// http-01 validation requests.
+func (a *ACME) Handler() http.Handler {
+ return a.handler
}
diff --git a/cmd/acmeserver/acmeserver.go b/cmd/acmeserver/acmeserver.go
index 46accd3b..31e4d0c8 100644
--- a/cmd/acmeserver/acmeserver.go
+++ b/cmd/acmeserver/acmeserver.go
@@ -5,6 +5,7 @@ import (
"flag"
"io/ioutil"
"log"
+ "net/http"
"os"
"os/signal"
"syscall"
@@ -19,6 +20,8 @@ var (
configFile = flag.String("config", "/etc/acmeserver/config.yml", "configuration `file`")
)
+// Config ties together the acmeserver Config and the standard
+// serverutil HTTP server configuration.
type Config struct {
ACME *acmeserver.Config `yaml:",inline"`
Server *serverutil.ServerConfig `yaml:"http_server"`
@@ -26,7 +29,7 @@ type Config struct {
func loadConfig(path string) (*Config, error) {
// Read YAML config.
- data, err := ioutil.ReadFile(path)
+ data, err := ioutil.ReadFile(path) // nolint: gosec
if err != nil {
return nil, err
}
@@ -46,22 +49,41 @@ func main() {
log.Fatal(err)
}
- acme, err := acmeserver.NewACME(config.ACME)
- if err != nil {
- log.Fatal(err)
+ var h http.Handler
+ var cg acmeserver.CertGenerator
+ if !config.ACME.Testing {
+ acme, err := acmeserver.NewACME(config.ACME) // nolint: vetshadow
+ if err != nil {
+ log.Fatal(err)
+ }
+ cg = acme
+ h = acme.Handler()
+
+ } else {
+ // When testing=true there's no content to serve over
+ // HTTP. Metrics and other debug pages are added
+ // automatically by the serverutil package.
+ cg = acmeserver.NewSelfSignedCertGenerator()
+ h = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ http.NotFound(w, r)
+ })
}
- m, err := acmeserver.NewManager(config.ACME, acme)
+ m, err := acmeserver.NewManager(config.ACME, cg)
if err != nil {
log.Fatal(err)
}
- // Start the acmeserver.Manager, and set up a SIGHUP handler to reload its config.
- if err := m.Start(context.Background()); err != nil {
+ // Start the acmeserver.Manager in the background. The
+ // serverutil package installs SIGTERM handlers that stop the
+ // HTTP server, so when it terminates we also kill the context
+ // attached to the Manager.
+ ctx, cancel := context.WithCancel(context.Background())
+ if err := m.Start(ctx); err != nil {
log.Fatal(err)
}
- defer m.Stop()
+ // Set up a SIGHUP handler to reload the configuration.
hupCh := make(chan os.Signal, 1)
go func() {
for {
@@ -71,7 +93,10 @@ func main() {
}()
signal.Notify(hupCh, syscall.SIGHUP)
- if err := serverutil.Serve(acme, config.Server, *addr); err != nil {
+ if err := serverutil.Serve(h, config.Server, *addr); err != nil {
log.Fatal(err)
}
+
+ cancel()
+ m.Wait()
}
diff --git a/config.go b/config.go
index f367a568..b009de49 100644
--- a/config.go
+++ b/config.go
@@ -1,6 +1,8 @@
package acmeserver
import (
+ "errors"
+ "fmt"
"io/ioutil"
"log"
"path/filepath"
@@ -11,58 +13,92 @@ import (
)
// Config holds the configuration for an acmeserver instance.
+//
+// nolint: maligned
type Config struct {
Addr string `yaml:"addr"`
- Email string `yaml:"email"`
- UseRSA bool `yaml:"use_rsa"`
+ Testing bool `yaml:"testing"`
+ DirectoryURL string `yaml:"directory_url"`
+ DefaultChallengeType string `yaml:"default_challenge"`
+ UseRSA bool `yaml:"use_rsa"`
+ RenewalDays int `yaml:"renewal_days"`
+ Email string `yaml:"email"`
+
Dir string `yaml:"cert_dir"`
ReplDS *clientutil.BackendConfig `yaml:"replds"`
+
+ HTTP struct {
+ Enabled bool `yaml:"enabled"`
+ } `yaml:"http"`
+
+ DNS struct {
+ Enabled bool `yaml:"enabled"`
+ Nameservers []string `yaml:"nameservers"`
+ TSIGKeyName string `yaml:"tsig_key_name"`
+ TSIGKeyAlgo string `yaml:"tsig_key_algo"`
+ TSIGKeySecret string `yaml:"tsig_key_secret"`
+ } `yaml:"dns"`
}
-// Definition of a single certificate: the main CN, and optionally a
-// list of subjectAltName entries.
+// This is all the configuration we need to generate a certificate.
type certConfig struct {
- CN string `yaml:"cn"`
- AltNames []string `yaml:"alt_names"`
+ // List of names for this certificate. The first one will be
+ // the certificate CN, all of them will be subjectAltNames.
+ Names []string `yaml:"names"`
+
+ // Challenge type to use for this domain. If empty, the
+ // defaults will be applied.
+ ChallengeType string `yaml:"challenge,omitempty"`
}
-func decodeCertConfig(data []byte) ([][]string, error) {
- var cc []certConfig
- if err := yaml.Unmarshal(data, &cc); err != nil {
- return nil, err
+func (c *certConfig) check() error {
+ if len(c.Names) == 0 {
+ return errors.New("empty names list")
}
-
- var domains [][]string
- for _, c := range cc {
- d := []string{c.CN}
- d = append(d, c.AltNames...)
- domains = append(domains, d)
+ // We can't check here if the challenge type is actually
+ // configured or not, but at least we can report unknown /
+ // unsupported types as syntax errors.
+ switch c.ChallengeType {
+ case "", dns01Challenge, http01Challenge:
+ default:
+ return fmt.Errorf("unkown or unsupported challenge type '%s'", c.ChallengeType)
}
- return domains, nil
+ return nil
}
-func readCertConfig(path string) ([][]string, error) {
- data, err := ioutil.ReadFile(path)
+func readCertConfigs(path string) ([]*certConfig, error) {
+ data, err := ioutil.ReadFile(path) // nolint: gosec
if err != nil {
return nil, err
}
- return decodeCertConfig(data)
+ var cc []*certConfig
+ if err := yaml.Unmarshal(data, &cc); err != nil {
+ return nil, err
+ }
+ return cc, nil
}
-func readCertConfigsFromDir(dir string) ([][]string, error) {
+func readCertConfigsFromDir(dir string) ([]*certConfig, error) {
files, err := filepath.Glob(filepath.Join(dir, "*.yml"))
if err != nil {
return nil, err
}
- var domains [][]string
+ var out []*certConfig
for _, f := range files {
- d, err := readCertConfig(f)
+ cc, err := readCertConfigs(f)
if err != nil {
log.Printf("error reading %s: %v", f, err)
continue
}
- domains = append(domains, d...)
+ // Validate the cert configs, skip ones with errors.
+ for _, c := range cc {
+ if err := c.check(); err != nil {
+ log.Printf("configuration error in %s: %v", f, err)
+ continue
+ }
+ out = append(out, c)
+ }
}
- return domains, nil
+ return out, nil
}
diff --git a/dns_challenge.go b/dns_challenge.go
new file mode 100644
index 00000000..af04a08b
--- /dev/null
+++ b/dns_challenge.go
@@ -0,0 +1,156 @@
+package acmeserver
+
+import (
+ "context"
+ "errors"
+ "fmt"
+ "log"
+ "strings"
+ "time"
+
+ "github.com/miekg/dns"
+ "golang.org/x/crypto/acme"
+)
+
+const (
+ rfc2136Timeout = 600
+ tsigFudgeSeconds = 300
+)
+
+type dnsValidator struct {
+ nameservers []string
+ enableTSIG bool
+ keyName string
+ keyAlgo string
+ keySecret string
+}
+
+func newDNSValidator(config *Config) (*dnsValidator, error) {
+ if len(config.DNS.Nameservers) == 0 {
+ return nil, errors.New("no nameservers configured")
+ }
+
+ // Check that the TSIG parameters are consistent, if provided at all.
+ n := 0
+ if config.DNS.TSIGKeyName != "" {
+ n++
+ }
+ if config.DNS.TSIGKeyAlgo != "" {
+ n++
+ }
+ if config.DNS.TSIGKeySecret != "" {
+ n++
+ }
+ if n != 0 && n != 3 {
+ return nil, errors.New("either none or all of 'tsig_key_name', 'tsig_key_algo' and 'tsig_key_secret' must be set")
+ }
+
+ return &dnsValidator{
+ nameservers: config.DNS.Nameservers,
+ enableTSIG: n > 0,
+ keyName: dns.Fqdn(config.DNS.TSIGKeyName),
+ keyAlgo: config.DNS.TSIGKeyAlgo,
+ keySecret: config.DNS.TSIGKeySecret,
+ }, nil
+}
+
+func (d *dnsValidator) makeRR(fqdn, value string, ttl int) []dns.RR {
+ rr := new(dns.TXT)
+ rr.Hdr = dns.RR_Header{Name: fqdn, Rrtype: dns.TypeTXT, Class: dns.ClassINET, Ttl: uint32(ttl)}
+ rr.Txt = []string{value}
+ return []dns.RR{rr}
+}
+
+func (d *dnsValidator) makeMsg(zone string, rrs []dns.RR, remove bool) *dns.Msg {
+ m := new(dns.Msg)
+ m.SetUpdate(zone)
+ if remove {
+ m.Remove(rrs)
+ } else {
+ m.RemoveRRset(rrs)
+ m.Insert(rrs)
+ }
+ if d.enableTSIG {
+ m.SetTsig(d.keyName, d.keyAlgo, tsigFudgeSeconds, time.Now().Unix())
+ }
+ return m
+}
+
+func (d *dnsValidator) client() *dns.Client {
+ c := new(dns.Client)
+ c.SingleInflight = true
+ if d.enableTSIG {
+ // TSIG authentication / msg signing.
+ c.TsigSecret = map[string]string{d.keyName: d.keySecret}
+ }
+ return c
+}
+
+func (d *dnsValidator) Fulfill(ctx context.Context, client *acme.Client, domain string, chal *acme.Challenge) (func(), error) {
+ zone := domain[strings.Index(domain, ".")+1:]
+ fqdn := dns.Fqdn(domain)
+ value, err := client.DNS01ChallengeRecord(chal.Token)
+ if err != nil {
+ return nil, err
+ }
+
+ if err := d.onAllNS(ctx, func(ns string) error {
+ return d.updateNS(ctx, ns, zone, fqdn, value, false)
+ }); err != nil {
+ return nil, err
+ }
+
+ return func() {
+ // nolint
+ d.onAllNS(ctx, func(ns string) error {
+ return d.updateNS(ctx, ns, zone, fqdn, value, true)
+ })
+ }, nil
+}
+
+func (d *dnsValidator) updateNS(ctx context.Context, ns, zone, fqdn, value string, remove bool) error {
+ rrs := d.makeRR(fqdn, value, rfc2136Timeout)
+ m := d.makeMsg(zone, rrs, remove)
+ c := d.client()
+
+ // Send the query
+ reply, _, err := c.Exchange(m, ns)
+ if err != nil {
+ return err
+ }
+ if reply != nil && reply.Rcode != dns.RcodeSuccess {
+ return fmt.Errorf("DNS server replied: %s", dns.RcodeToString[reply.Rcode])
+ }
+
+ return nil
+}
+
+// Run a function for each configured nameserver.
+func (d *dnsValidator) onAllNS(ctx context.Context, f func(string) error) error {
+ ch := make(chan error, len(d.nameservers))
+ defer close(ch)
+
+ for _, ns := range d.nameservers {
+ if !strings.Contains(ns, ":") {
+ ns += ":53"
+ }
+ go func(ns string) {
+ err := f(ns)
+ if err != nil {
+ log.Printf("error updating DNS server %s: %v", ns, err)
+ }
+ ch <- err
+ }(ns)
+ }
+
+ var ok bool
+ for i := 0; i < len(d.nameservers); i++ {
+ if err := <-ch; err == nil {
+ ok = true
+ }
+ }
+ if !ok {
+ return errors.New("all nameservers failed")
+ }
+ return nil
+}
diff --git a/http_challenge.go b/http_challenge.go
new file mode 100644
index 00000000..f99a28af
--- /dev/null
+++ b/http_challenge.go
@@ -0,0 +1,58 @@
+package acmeserver
+
+import (
+ "context"
+ "net/http"
+ "sync"
+
+ "golang.org/x/crypto/acme"
+)
+
+// httpValidator can validate http-01 challenges. It serves
+// validation tokens under the /.well-known/acme-challenge path when
+// used as an HTTP handler.
+type httpValidator struct {
+ mx sync.Mutex
+ tokens map[string][]byte
+}
+
+func newHTTPValidator() *httpValidator {
+ return &httpValidator{
+ tokens: make(map[string][]byte),
+ }
+}
+
+func (h *httpValidator) Fulfill(_ context.Context, client *acme.Client, _ string, chal *acme.Challenge) (func(), error) {
+ resp, err := client.HTTP01ChallengeResponse(chal.Token)
+ if err != nil {
+ return nil, err
+ }
+ path := client.HTTP01ChallengePath(chal.Token)
+
+ h.mx.Lock()
+ h.tokens[path] = []byte(resp)
+ h.mx.Unlock()
+
+ return func() {
+ go func() {
+ h.mx.Lock()
+ delete(h.tokens, path)
+ h.mx.Unlock()
+ }()
+ }, nil
+}
+
+func (h *httpValidator) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+ // No defer because it's not polite to Write() while holding the lock.
+ h.mx.Lock()
+ data, ok := h.tokens[r.URL.Path]
+ h.mx.Unlock()
+
+ if !ok {
+ http.NotFound(w, r)
+ return
+ }
+
+ // Not interested in errors writing the response.
+ w.Write(data) // nolint
+}
diff --git a/instrumentation.go b/instrumentation.go
new file mode 100644
index 00000000..3e1ce04b
--- /dev/null
+++ b/instrumentation.go
@@ -0,0 +1,47 @@
+package acmeserver
+
+import (
+ "github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+ certExpirationTimes = prometheus.NewGaugeVec(
+ prometheus.GaugeOpts{
+ Name: "cert_expiration_time",
+ Help: "Certificate expiration time.",
+ },
+ []string{"cn"},
+ )
+ certOk = prometheus.NewGaugeVec(
+ prometheus.GaugeOpts{
+ Name: "cert_ok",
+ Help: "Do we have a valid certificate.",
+ },
+ []string{"cn"},
+ )
+ certRenewalCount = prometheus.NewCounterVec(
+ prometheus.CounterOpts{
+ Name: "cert_renewal_total",
+ Help: "Total certificate renewal attempts.",
+ },
+ []string{"cn"},
+ )
+ certRenewalErrorCount = prometheus.NewCounterVec(
+ prometheus.CounterOpts{
+ Name: "cert_renewal_errors",
+ Help: "Errors while renewing certificates.",
+ },
+ []string{"cn"},
+ )
+)
+
+func init() {
+ prometheus.MustRegister(certExpirationTimes, certOk, certRenewalErrorCount)
+}
+
+func b2f(b bool) float64 {
+ if b {
+ return 1
+ }
+ return 0
+}
diff --git a/server.go b/manager.go
similarity index 61%
rename from server.go
rename to manager.go
index 79d25a48..76910d12 100644
--- a/server.go
+++ b/manager.go
@@ -11,7 +11,6 @@ import (
"crypto/x509/pkix"
"encoding/pem"
"errors"
- "fmt"
"io"
"log"
"path/filepath"
@@ -19,17 +18,46 @@ import (
"time"
"git.autistici.org/ai3/go-common/clientutil"
- "golang.org/x/crypto/acme"
+ "github.com/prometheus/client_golang/prometheus"
)
+// certInfo represents what we know about the state of the certificate
+// at runtime.
type certInfo struct {
- domains []string
+ config *certConfig
retryDeadline time.Time
- // A write-only attribute (not part of the logic) to indicate
- // whether we think we have a valid certificate or not. Used
- // for monitoring and debugging.
- valid bool
+ // Write-only attributes (not part of the renewal logic) to
+ // indicate whether we think we have a valid certificate or
+ // not. Used for monitoring and debugging.
+ valid bool
+ expiresAt time.Time
+}
+
+func (i *certInfo) cn() string {
+ return i.config.Names[0]
+}
+
+func (i *certInfo) setOk(cert *x509.Certificate, renewalDays int) {
+ i.retryDeadline = cert.NotAfter.AddDate(0, 0, -renewalDays)
+ i.expiresAt = cert.NotAfter
+ i.valid = true
+
+ l := prometheus.Labels{"cn": i.cn()}
+ certOk.With(l).Set(1)
+}
+
+func (i *certInfo) setErr() {
+ now := time.Now()
+ i.retryDeadline = now.Add(errorRetryTimeout)
+ i.valid = false
+ if !i.expiresAt.IsZero() {
+ i.valid = i.expiresAt.After(now)
+ }
+
+ l := prometheus.Labels{"cn": i.cn()}
+ certRenewalErrorCount.With(l).Inc()
+ certOk.With(l).Set(b2f(i.valid))
}
type certStorage interface {
@@ -37,23 +65,24 @@ type certStorage interface {
PutCert(string, [][]byte, crypto.Signer) error
}
+// CertGenerator is an interface to something that can generate a new
+// certificate, given a list of domains and a private key. The ACME
+// type implements this interface.
type CertGenerator interface {
- GetCertificate(context.Context, crypto.Signer, []string) ([][]byte, *x509.Certificate, error)
+ GetCertificate(context.Context, crypto.Signer, *certConfig) ([][]byte, *x509.Certificate, error)
}
// Manager periodically renews certificates before they expire, and
// responds to http-01 validation requests.
type Manager struct {
- //email string
- //accountKeyPath string
- configDir string
- useRSA bool
- storage certStorage
- certs []*certInfo
- certGen CertGenerator
-
- configCh chan [][]string
- stopCh chan bool
+ configDir string
+ useRSA bool
+ storage certStorage
+ certs []*certInfo
+ certGen CertGenerator
+ renewalDays int
+
+ configCh chan []*certConfig
doneCh chan bool
}
@@ -65,12 +94,15 @@ func NewManager(config *Config, certGen CertGenerator) (*Manager, error) {
}
m := &Manager{
- useRSA: config.UseRSA,
- configDir: filepath.Join(config.Dir, "config"),
- stopCh: make(chan bool),
- doneCh: make(chan bool),
- configCh: make(chan [][]string, 1),
- certGen: certGen,
+ useRSA: config.UseRSA,
+ configDir: filepath.Join(config.Dir, "config"),
+ doneCh: make(chan bool),
+ configCh: make(chan []*certConfig, 1),
+ certGen: certGen,
+ renewalDays: config.RenewalDays,
+ }
+ if m.renewalDays <= 0 {
+ m.renewalDays = 15
}
ds := &dirStorage{root: filepath.Join(config.Dir, "certs")}
@@ -91,7 +123,8 @@ func NewManager(config *Config, certGen CertGenerator) (*Manager, error) {
}
// Start the renewal processes. Canceling the provided context will
-// cause background processing to stop.
+// cause background processing to stop, interrupting all running
+// updates.
func (m *Manager) Start(ctx context.Context) error {
domains, err := readCertConfigsFromDir(m.configDir)
if err != nil {
@@ -105,9 +138,8 @@ func (m *Manager) Start(ctx context.Context) error {
return nil
}
-// Stop any pending operation and release all resources.
-func (m *Manager) Stop() {
- close(m.stopCh)
+// Wait for the Manager to terminate once it has been canceled.
+func (m *Manager) Wait() {
<-m.doneCh
}
@@ -140,19 +172,21 @@ func (m *Manager) updateAllCerts(ctx context.Context, certs []*certInfo) {
default:
}
+ certRenewalCount.With(prometheus.Labels{"cn": certInfo.cn()}).Inc()
uctx, cancel := context.WithTimeout(ctx, renewalTimeout)
- err := m.updateCert(uctx, certInfo)
+ leaf, err := m.updateCert(uctx, certInfo)
cancel()
- if err != nil {
- log.Printf("error updating %s: %v", certInfo.domains[0], err)
- // Retry in a little while.
- certInfo.retryDeadline = time.Now().Add(errorRetryTimeout)
- certInfo.valid = false
+ if err == nil {
+ log.Printf("successfully renewed %s", certInfo.cn())
+ certInfo.setOk(leaf, m.renewalDays)
+ } else {
+ log.Printf("error updating %s: %v", certInfo.cn(), err)
+ certInfo.setErr()
}
}
}
-func (m *Manager) updateCert(ctx context.Context, certInfo *certInfo) error {
+func (m *Manager) updateCert(ctx context.Context, certInfo *certInfo) (*x509.Certificate, error) {
// Create a new private key.
var (
err error
@@ -164,49 +198,45 @@ func (m *Manager) updateCert(ctx context.Context, certInfo *certInfo) error {
key, err = ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
}
if err != nil {
- return err
+ return nil, err
}
- der, leaf, err := m.certGen.GetCertificate(ctx, key, certInfo.domains)
+ der, leaf, err := m.certGen.GetCertificate(ctx, key, certInfo.config)
if err != nil {
- return err
+ return nil, err
}
- if err := m.storage.PutCert(certInfo.domains[0], der, key); err != nil {
- return err
+ if err := m.storage.PutCert(certInfo.cn(), der, key); err != nil {
+ return nil, err
}
- certInfo.retryDeadline = renewalDeadline(leaf)
- certInfo.valid = true
-
- return nil
+ return leaf, nil
}
// Replace the current configuration.
-func (m *Manager) loadConfig(certDomains [][]string) []*certInfo {
- var certs []*certInfo
- for _, domains := range certDomains {
- cn := domains[0]
+func (m *Manager) loadConfig(certs []*certConfig) []*certInfo {
+ var out []*certInfo
+ for _, c := range certs {
+ cn := c.Names[0]
certInfo := &certInfo{
- domains: domains,
+ config: c,
}
pub, priv, err := m.storage.GetCert(cn)
if err != nil {
log.Printf("cert for %s is missing", cn)
} else {
// By calling validCert we catch things like subjectAltName changes.
- leaf, err := validCert(domains, pub, priv)
+ leaf, err := validCert(c.Names, pub, priv)
if err == nil {
log.Printf("cert for %s loaded from storage", cn)
- certInfo.retryDeadline = renewalDeadline(leaf)
- certInfo.valid = true
+ certInfo.setOk(leaf, m.renewalDays)
} else {
log.Printf("cert for %s loaded from storage but parameters have changed", cn)
}
}
- certs = append(certs, certInfo)
+ out = append(out, certInfo)
}
- return certs
+ return out
}
// This channel is used by the testing code to trigger an update,
@@ -233,6 +263,8 @@ func (m *Manager) loop(ctx context.Context) {
return cancel
}
+ // Cancel the running update, if any. Called on config
+ // updates, when exiting.
cancelUpdate := func() {
if upCancel != nil {
upCancel()
@@ -242,6 +274,7 @@ func (m *Manager) loop(ctx context.Context) {
defer cancelUpdate()
tick := time.NewTicker(5 * time.Minute)
+ defer tick.Stop()
for {
select {
case <-tick.C:
@@ -251,20 +284,12 @@ func (m *Manager) loop(ctx context.Context) {
case certDomains := <-m.configCh:
cancelUpdate()
m.certs = m.loadConfig(certDomains)
- case <-m.stopCh:
- return
case <-ctx.Done():
return
}
}
}
-var renewalDays = 15
-
-func renewalDeadline(cert *x509.Certificate) time.Time {
- return cert.NotAfter.AddDate(0, 0, -renewalDays)
-}
-
func concatDER(der [][]byte) []byte {
// Append DERs to a single []byte buffer and parse the results.
var n int
@@ -279,54 +304,6 @@ func concatDER(der [][]byte) []byte {
return out
}
-func validCert(domains []string, der [][]byte, key crypto.Signer) (leaf *x509.Certificate, err error) {
- x509Cert, err := x509.ParseCertificates(concatDER(der))
- if err != nil {
- return nil, err
- }
- if len(x509Cert) == 0 {
- return nil, errors.New("no public key found")
- }
- leaf = x509Cert[0]
-
- // verify the leaf is not expired and matches the given domains
- now := time.Now()
- if now.Before(leaf.NotBefore) {
- return nil, errors.New("certificate isn't valid yet")
- }
- if now.After(leaf.NotAfter) {
- return nil, errors.New("certificate expired")
- }
- for _, domain := range domains {
- if err := leaf.VerifyHostname(domain); err != nil {
- return nil, fmt.Errorf("certificate does not match domain %q", domain)
- }
- }
-
- // 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("private key type does not match public key type")
- }
- if pub.N.Cmp(prv.N) != 0 {
- return nil, errors.New("private key does not match public key")
- }
- case *ecdsa.PublicKey:
- prv, ok := key.(*ecdsa.PrivateKey)
- if !ok {
- return nil, errors.New("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("private key does not match public key")
- }
- default:
- return nil, errors.New("unsupported public key algorithm")
- }
- return leaf, nil
-}
-
func certRequest(key crypto.Signer, domains []string) ([]byte, error) {
req := &x509.CertificateRequest{
Subject: pkix.Name{CommonName: domains[0]},
@@ -366,12 +343,3 @@ func encodeECDSAKey(w io.Writer, key *ecdsa.PrivateKey) error {
pb := &pem.Block{Type: "EC PRIVATE KEY", Bytes: b}
return pem.Encode(w, pb)
}
-
-func pickChallenge(typ string, chal []*acme.Challenge) *acme.Challenge {
- for _, c := range chal {
- if c.Type == typ {
- return c
- }
- }
- return nil
-}
diff --git a/server_test.go b/manager_test.go
similarity index 53%
rename from server_test.go
rename to manager_test.go
index 377c1bd3..ced4b0cb 100644
--- a/server_test.go
+++ b/manager_test.go
@@ -3,77 +3,33 @@ package acmeserver
import (
"context"
"crypto"
- "crypto/ecdsa"
- "crypto/rand"
- "crypto/rsa"
"crypto/x509"
- "crypto/x509/pkix"
+ "errors"
"io/ioutil"
- "log"
- "math/big"
"os"
"path/filepath"
"testing"
"time"
)
-type fakeACME struct {
-}
-
-func (f *fakeACME) GetCertificate(_ context.Context, priv crypto.Signer, domains []string) ([][]byte, *x509.Certificate, error) {
- notBefore := time.Now()
- notAfter := notBefore.AddDate(1, 0, 0)
-
- serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
- serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
- if err != nil {
- return nil, nil, err
- }
-
- template := x509.Certificate{
- SerialNumber: serialNumber,
- Subject: pkix.Name{
- CommonName: domains[0],
- },
- NotBefore: notBefore,
- NotAfter: notAfter,
-
- KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
- ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
- BasicConstraintsValid: true,
- }
-
- if len(domains) > 1 {
- template.DNSNames = domains[1:]
- }
-
- der, err := x509.CreateCertificate(rand.Reader, &template, &template, publicKey(priv), priv)
- if err != nil {
- return nil, nil, err
- }
+// A CertGenerator that is just very slow (and will return an error
+// in any case).
+type slowACME struct{}
- cert, err := x509.ParseCertificate(der)
- if err != nil {
- return nil, nil, err
- }
-
- log.Printf("created certificate for %s", domains[0])
-
- return [][]byte{der}, cert, nil
-}
-
-func publicKey(priv interface{}) interface{} {
- switch k := priv.(type) {
- case *rsa.PrivateKey:
- return &k.PublicKey
- case *ecdsa.PrivateKey:
- return &k.PublicKey
- default:
- return nil
+func (s *slowACME) GetCertificate(ctx context.Context, _ crypto.Signer, _ *certConfig) ([][]byte, *x509.Certificate, error) {
+ t := time.After(60 * time.Second)
+ select {
+ case <-t:
+ return nil, nil, errors.New("timed out")
+ case <-ctx.Done():
+ return nil, nil, ctx.Err()
}
}
-func newTestManager(t testing.TB) (func(), *Manager) {
+// Create a new test function.
+// The first function returned is a cleanup callback.
+// The second function returned is the cancel callback.
+func newTestManager(t testing.TB, g CertGenerator) (func(), context.CancelFunc, *Manager) {
dir, err := ioutil.TempDir("", "")
if err != nil {
t.Fatal(err)
@@ -82,19 +38,20 @@ func newTestManager(t testing.TB) (func(), *Manager) {
os.Mkdir(filepath.Join(dir, "config"), 0700)
ioutil.WriteFile(
filepath.Join(dir, "config", "test.yml"),
- []byte("- { cn: example.com }\n"),
+ []byte("- { names: [example.com] }\n"),
0644,
)
m, err := NewManager(&Config{
Dir: dir,
Email: "test@example.com",
- }, &fakeACME{})
+ }, g)
if err != nil {
t.Fatal(err)
}
- if err := m.Start(context.Background()); err != nil {
+ ctx, cancel := context.WithCancel(context.Background())
+ if err := m.Start(ctx); err != nil {
t.Fatal("Start:", err)
}
@@ -102,21 +59,22 @@ func newTestManager(t testing.TB) (func(), *Manager) {
time.Sleep(50 * time.Millisecond)
return func() {
- m.Stop()
+ cancel()
+ m.Wait()
os.RemoveAll(dir)
- }, m
+ }, cancel, m
}
func TestManager_Reload(t *testing.T) {
- cleanup, m := newTestManager(t)
+ cleanup, _, m := newTestManager(t, NewSelfSignedCertGenerator())
defer cleanup()
// Data race: we read data owned by another goroutine!
if len(m.certs) < 1 {
t.Fatal("configuration not loaded?")
}
- if m.certs[0].domains[0] != "example.com" {
- t.Fatalf("certs[0].domains[0] is %s, expected example.com", m.certs[0].domains[0])
+ if m.certs[0].cn() != "example.com" {
+ t.Fatalf("certs[0].cn() is %s, expected example.com", m.certs[0].cn())
}
// Try a reload, catch obvious errors.
@@ -126,13 +84,13 @@ func TestManager_Reload(t *testing.T) {
if len(m.certs) != 1 {
t.Fatalf("certs count is %d, expected 1", len(m.certs))
}
- if m.certs[0].domains[0] != "example.com" {
- t.Fatalf("certs[0].domains[0] is %s, expected example.com", m.certs[0].domains[0])
+ if m.certs[0].cn() != "example.com" {
+ t.Fatalf("certs[0].cn() is %s, expected example.com", m.certs[0].cn())
}
}
func TestManager_NewCert(t *testing.T) {
- cleanup, m := newTestManager(t)
+ cleanup, _, m := newTestManager(t, NewSelfSignedCertGenerator())
defer cleanup()
now := time.Now()
@@ -175,3 +133,17 @@ func TestManager_NewCert(t *testing.T) {
t.Fatal("certificate is invalid after a reload")
}
}
+
+func TestManager_CancelUpdate(t *testing.T) {
+ start := time.Now()
+ cleanup, cancel, m := newTestManager(t, &slowACME{})
+ defer cleanup()
+
+ time.Sleep(100 * time.Millisecond)
+ cancel()
+ m.Wait()
+ elapsed := time.Since(start)
+ if elapsed > 1*time.Second {
+ t.Fatalf("too much time elapsed (%fs), canceling didn't work?", elapsed.Seconds())
+ }
+}
diff --git a/selfsigned.go b/selfsigned.go
new file mode 100644
index 00000000..888ab84e
--- /dev/null
+++ b/selfsigned.go
@@ -0,0 +1,73 @@
+package acmeserver
+
+import (
+ "context"
+ "crypto"
+ "crypto/ecdsa"
+ "crypto/rand"
+ "crypto/rsa"
+ "crypto/x509"
+ "crypto/x509/pkix"
+ "log"
+ "math/big"
+ "time"
+)
+
+type selfSignedGenerator struct{}
+
+// NewSelfSignedCertGenerator returns a CertGenerator that will create
+// self-signed certificates for every request. Primarily useful for
+// testing acmeserver as a functional component in integration tests.
+func NewSelfSignedCertGenerator() CertGenerator {
+ return &selfSignedGenerator{}
+}
+
+func (g *selfSignedGenerator) GetCertificate(_ context.Context, priv crypto.Signer, c *certConfig) ([][]byte, *x509.Certificate, error) {
+ notBefore := time.Now()
+ notAfter := notBefore.AddDate(1, 0, 0)
+
+ serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
+ serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
+ if err != nil {
+ return nil, nil, err
+ }
+
+ template := x509.Certificate{
+ SerialNumber: serialNumber,
+ Subject: pkix.Name{
+ CommonName: c.Names[0],
+ },
+ DNSNames: c.Names,
+ NotBefore: notBefore,
+ NotAfter: notAfter,
+
+ KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
+ ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
+ BasicConstraintsValid: true,
+ }
+
+ der, err := x509.CreateCertificate(rand.Reader, &template, &template, publicKey(priv), priv)
+ if err != nil {
+ return nil, nil, err
+ }
+
+ cert, err := x509.ParseCertificate(der)
+ if err != nil {
+ return nil, nil, err
+ }
+
+ log.Printf("created certificate for %s", c.Names[0])
+
+ return [][]byte{der}, cert, nil
+}
+
+func publicKey(priv interface{}) interface{} {
+ switch k := priv.(type) {
+ case *rsa.PrivateKey:
+ return &k.PublicKey
+ case *ecdsa.PrivateKey:
+ return &k.PublicKey
+ default:
+ return nil
+ }
+}
diff --git a/storage.go b/storage.go
index f0c5f703..b94d6545 100644
--- a/storage.go
+++ b/storage.go
@@ -47,7 +47,7 @@ func (d *dirStorage) PutCert(cn string, der [][]byte, key crypto.Signer) error {
dir := filepath.Join(d.root, cn)
if _, err := os.Stat(dir); err != nil && os.IsNotExist(err) {
- if err = os.MkdirAll(dir, 0755); err != nil {
+ if err = os.MkdirAll(dir, 0750); err != nil {
return err
}
}
@@ -126,7 +126,7 @@ func (d *replStorage) PutCert(cn string, der [][]byte, key crypto.Signer) error
}
func parseCertsFromFile(path string) ([][]byte, error) {
- data, err := ioutil.ReadFile(path)
+ data, err := ioutil.ReadFile(path) // nolint: gosec
if err != nil {
return nil, err
}
@@ -144,7 +144,7 @@ func parseCertsFromFile(path string) ([][]byte, error) {
}
func parsePrivateKeyFromFile(path string) (crypto.Signer, error) {
- data, err := ioutil.ReadFile(path)
+ data, err := ioutil.ReadFile(path) // nolint: gosec
if err != nil {
return nil, err
}
diff --git a/valid_cert.go b/valid_cert.go
new file mode 100644
index 00000000..bce5bcf5
--- /dev/null
+++ b/valid_cert.go
@@ -0,0 +1,92 @@
+package acmeserver
+
+import (
+ "crypto"
+ "crypto/ecdsa"
+ "crypto/rsa"
+ "crypto/x509"
+ "errors"
+ "fmt"
+ "time"
+)
+
+// Verify that a certificate is valid according both to the current
+// time and to the specified parameters.
+func validCert(domains []string, der [][]byte, key crypto.Signer) (*x509.Certificate, error) {
+ leaf, err := leafCertFromDER(der)
+ if err != nil {
+ return nil, err
+ }
+
+ // Verify the leaf is not expired.
+ if err := isCertExpired(leaf); err != nil {
+ return nil, err
+ }
+
+ // Verify that it matches the given domains.
+ if err := certMatchesDomains(leaf, domains); err != nil {
+ return nil, err
+ }
+
+ // Verify that it matches the private key.
+ if err := certMatchesPrivateKey(leaf, key); err != nil {
+ return nil, err
+ }
+
+ return leaf, nil
+}
+
+func leafCertFromDER(der [][]byte) (*x509.Certificate, error) {
+ x509Cert, err := x509.ParseCertificates(concatDER(der))
+ if err != nil {
+ return nil, err
+ }
+ if len(x509Cert) == 0 {
+ return nil, errors.New("no public key found")
+ }
+ return x509Cert[0], nil
+}
+
+func isCertExpired(cert *x509.Certificate) error {
+ now := time.Now()
+ if now.Before(cert.NotBefore) {
+ return errors.New("certificate isn't valid yet")
+ }
+ if now.After(cert.NotAfter) {
+ return errors.New("certificate expired")
+ }
+ return nil
+}
+
+func certMatchesDomains(cert *x509.Certificate, domains []string) error {
+ for _, domain := range domains {
+ if err := cert.VerifyHostname(domain); err != nil {
+ return fmt.Errorf("certificate does not match domain %q", domain)
+ }
+ }
+ return nil
+}
+
+func certMatchesPrivateKey(cert *x509.Certificate, key crypto.Signer) error {
+ switch pub := cert.PublicKey.(type) {
+ case *rsa.PublicKey:
+ prv, ok := key.(*rsa.PrivateKey)
+ if !ok {
+ return errors.New("private key type does not match public key type")
+ }
+ if pub.N.Cmp(prv.N) != 0 {
+ return errors.New("private key does not match public key")
+ }
+ case *ecdsa.PublicKey:
+ prv, ok := key.(*ecdsa.PrivateKey)
+ if !ok {
+ return errors.New("private key type does not match public key type")
+ }
+ if pub.X.Cmp(prv.X) != 0 || pub.Y.Cmp(prv.Y) != 0 {
+ return errors.New("private key does not match public key")
+ }
+ default:
+ return errors.New("unsupported public key algorithm")
+ }
+ return nil
+}
--
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