caddytls: Configurable OCSP stapling; global option (closes #3714)

Allows user to disable OCSP stapling (including support in the Caddyfile via the ocsp_stapling global option) or overriding responder URLs. Useful in environments where responders are not reachable due to firewalls.

caddyconfig/httpcaddyfile/options.go

@@ -43,6 +43,7 @@ func init() {
 	RegisterGlobalOption("key_type", parseOptSingleString)
 	RegisterGlobalOption("auto_https", parseOptAutoHTTPS)
 	RegisterGlobalOption("servers", parseServerOptions)
+	RegisterGlobalOption("ocsp_stapling", parseOCSPStaplingOptions)
 }
 
 func parseOptTrue(d *caddyfile.Dispenser, _ interface{}) (interface{}, error) { return true, nil }
@@ -370,3 +371,17 @@ func parseOptAutoHTTPS(d *caddyfile.Dispenser, _ interface{}) (interface{}, erro
 func parseServerOptions(d *caddyfile.Dispenser, _ interface{}) (interface{}, error) {
 	return unmarshalCaddyfileServerOptions(d)
 }
+
+func parseOCSPStaplingOptions(d *caddyfile.Dispenser, _ interface{}) (interface{}, error) {
+	d.Next() // consume option name
+	var val string
+	if !d.AllArgs(&val) {
+		return nil, d.ArgErr()
+	}
+	if val != "off" {
+		return nil, d.Errf("invalid argument '%s'", val)
+	}
+	return certmagic.OCSPConfig{
+		DisableStapling: val == "off",
+	}, nil
+}

caddyconfig/httpcaddyfile/tlsapp.go

@@ -417,8 +417,9 @@ func newBaseAutomationPolicy(options map[string]interface{}, warnings []caddycon
 	issuers, hasIssuers := options["cert_issuer"]
 	_, hasLocalCerts := options["local_certs"]
 	keyType, hasKeyType := options["key_type"]
+	ocspStapling, hasOCSPStapling := options["ocsp_stapling"]
 
-	hasGlobalAutomationOpts := hasIssuers || hasLocalCerts || hasKeyType
+	hasGlobalAutomationOpts := hasIssuers || hasLocalCerts || hasKeyType || hasOCSPStapling
 
 	// if there are no global options related to automation policies
 	// set, then we can just return right away
@@ -444,6 +445,12 @@ func newBaseAutomationPolicy(options map[string]interface{}, warnings []caddycon
 		ap.Issuers = []certmagic.Issuer{new(caddytls.InternalIssuer)}
 	}
 
+	if hasOCSPStapling {
+		ocspConfig := ocspStapling.(certmagic.OCSPConfig)
+		ap.DisableOCSPStapling = ocspConfig.DisableStapling
+		ap.OCSPOverrides = ocspConfig.ResponderOverrides
+	}
+
 	return ap, nil
 }
 

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/Masterminds/sprig/v3 v3.1.0
 	github.com/alecthomas/chroma v0.8.2
 	github.com/aryann/difflib v0.0.0-20170710044230-e206f873d14a
-	github.com/caddyserver/certmagic v0.12.1-0.20210104224249-7891c830824b
+	github.com/caddyserver/certmagic v0.12.1-0.20210107224522-725b69d53d57
 	github.com/dustin/go-humanize v1.0.1-0.20200219035652-afde56e7acac
 	github.com/go-chi/chi v4.1.2+incompatible
 	github.com/google/cel-go v0.6.0

go.sum

@@ -99,8 +99,8 @@ github.com/bombsimon/wsl/v2 v2.0.0/go.mod h1:mf25kr/SqFEPhhcxW1+7pxzGlW+hIl/hYTK
 github.com/boombuler/barcode v1.0.0/go.mod h1:paBWMcWSl3LHKBqUq+rly7CNSldXjb2rDl3JlRe0mD8=
 github.com/bradfitz/go-smtpd v0.0.0-20170404230938-deb6d6237625/go.mod h1:HYsPBTaaSFSlLx/70C2HPIMNZpVV8+vt/A+FMnYP11g=
 github.com/buger/jsonparser v0.0.0-20181115193947-bf1c66bbce23/go.mod h1:bbYlZJ7hK1yFx9hf58LP0zeX7UjIGs20ufpu3evjr+s=
-github.com/caddyserver/certmagic v0.12.1-0.20210104224249-7891c830824b h1:3sAfeMhRiv0CVLWvM+bTSVkZIf1KupsMjglpaOCAQjE=
+github.com/caddyserver/certmagic v0.12.1-0.20210107224522-725b69d53d57 h1:eslWGgoQlVAzOGMUfK3ncoHnONjCUVOPTGRD9JG3gAY=
-github.com/caddyserver/certmagic v0.12.1-0.20210104224249-7891c830824b/go.mod h1:yHMCSjG2eOFdI/Jx0+CCzr2DLw+UQu42KbaOVBx7LwA=
+github.com/caddyserver/certmagic v0.12.1-0.20210107224522-725b69d53d57/go.mod h1:yHMCSjG2eOFdI/Jx0+CCzr2DLw+UQu42KbaOVBx7LwA=
 github.com/casbin/casbin/v2 v2.1.2/go.mod h1:YcPU1XXisHhLzuxH9coDNf2FbKpjGlbCg3n9yuLkIJQ=
 github.com/cenkalti/backoff v2.2.1+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QHaoyV4aDUVVkXQJJJ3NXXM=
 github.com/census-instrumentation/opencensus-proto v0.2.0/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=

modules/caddytls/automation.go

@@ -107,6 +107,19 @@ type AutomationPolicy struct {
 	// load.
 	OnDemand bool `json:"on_demand,omitempty"`
 
+	// Disables OCSP stapling. Disabling OCSP stapling puts clients at
+	// greater risk, reduces their privacy, and usually lowers client
+	// performance. It is NOT recommended to disable this unless you
+	// are able to justify the costs.
+	// EXPERIMENTAL. Subject to change.
+	DisableOCSPStapling bool `json:"disable_ocsp_stapling,omitempty"`
+
+	// Overrides the URLs of OCSP responders embedded in certificates.
+	// Each key is a OCSP server URL to override, and its value is the
+	// replacement. An empty value will disable querying of that server.
+	// EXPERIMENTAL. Subject to change.
+	OCSPOverrides map[string]string `json:"ocsp_overrides,omitempty"`
+
 	// Issuers stores the decoded issuer parameters. This is only
 	// used to populate an underlying certmagic.Config's Issuers
 	// field; it is not referenced thereafter.
@@ -205,9 +218,13 @@ func (ap *AutomationPolicy) Provision(tlsApp *TLS) error {
 		RenewalWindowRatio: ap.RenewalWindowRatio,
 		KeySource:          keySource,
 		OnDemand:           ond,
-		Storage:            storage,
+		OCSP: certmagic.OCSPConfig{
-		Issuers:            issuers,
+			DisableStapling:    ap.DisableOCSPStapling,
-		Logger:             tlsApp.logger,
+			ResponderOverrides: ap.OCSPOverrides,
+		},
+		Storage: storage,
+		Issuers: issuers,
+		Logger:  tlsApp.logger,
 	}
 	ap.magic = certmagic.New(tlsApp.certCache, template)