diff options
| -rw-r--r-- | modules/caddytls/automation.go | 23 | ||||
| -rw-r--r-- | modules/caddytls/tls.go | 15 |
2 files changed, 23 insertions, 15 deletions
diff --git a/modules/caddytls/automation.go b/modules/caddytls/automation.go index fffc0a3..1cfb28c 100644 --- a/modules/caddytls/automation.go +++ b/modules/caddytls/automation.go @@ -19,6 +19,7 @@ import ( "errors" "fmt" "net/http" + "strings" "time" "github.com/caddyserver/caddy/v2" @@ -224,8 +225,10 @@ func (ap *AutomationPolicy) Provision(tlsApp *TLS) error { // on-demand TLS var ond *certmagic.OnDemandConfig if ap.OnDemand { - // ask endpoint is now required after a number of negligence cases causing abuse - if !ap.onlyInternalIssuer() && (tlsApp.Automation == nil || tlsApp.Automation.OnDemand == nil || tlsApp.Automation.OnDemand.Ask == "") { + // ask endpoint is now required after a number of negligence cases causing abuse; + // but is still allowed for explicit subjects (non-wildcard, non-unbounded), + // and for the internal issuer since it doesn't cause ACME issuer pressure + if ap.isWildcardOrDefault() && !ap.onlyInternalIssuer() && (tlsApp.Automation == nil || tlsApp.Automation.OnDemand == nil || tlsApp.Automation.OnDemand.Ask == "") { return fmt.Errorf("on-demand TLS cannot be enabled without an 'ask' endpoint to prevent abuse; please refer to documentation for details") } ond = &certmagic.OnDemandConfig{ @@ -294,6 +297,22 @@ func (ap *AutomationPolicy) onlyInternalIssuer() bool { return ok } +// isWildcardOrDefault determines if the subjects include any wildcard domains, +// or is the "default" policy (i.e. no subjects) which is unbounded. +func (ap *AutomationPolicy) isWildcardOrDefault() bool { + isWildcardOrDefault := false + if len(ap.Subjects) == 0 { + isWildcardOrDefault = true + } + for _, sub := range ap.Subjects { + if strings.HasPrefix(sub, "*") { + isWildcardOrDefault = true + break + } + } + return isWildcardOrDefault +} + // DefaultIssuers returns empty Issuers (not provisioned) to be used as defaults. // This function is experimental and has no compatibility promises. func DefaultIssuers() []certmagic.Issuer { diff --git a/modules/caddytls/tls.go b/modules/caddytls/tls.go index 92004b8..486a58c 100644 --- a/modules/caddytls/tls.go +++ b/modules/caddytls/tls.go @@ -22,7 +22,6 @@ import ( "log" "net/http" "runtime/debug" - "strings" "sync" "time" @@ -182,8 +181,8 @@ func (t *TLS) Provision(ctx caddy.Context) error { onDemandRateLimiter.SetWindow(time.Duration(t.Automation.OnDemand.RateLimit.Interval)) } else { // remove any existing rate limiter - onDemandRateLimiter.SetMaxEvents(0) onDemandRateLimiter.SetWindow(0) + onDemandRateLimiter.SetMaxEvents(0) } // run replacer on ask URL (for environment variables) -- return errors to prevent surprises (#5036) @@ -260,17 +259,7 @@ func (t *TLS) Start() error { if t.Automation.OnDemand == nil || (t.Automation.OnDemand.Ask == "" && t.Automation.OnDemand.RateLimit == nil) { for _, ap := range t.Automation.Policies { - isWildcardOrDefault := false - if len(ap.Subjects) == 0 { - isWildcardOrDefault = true - } - for _, sub := range ap.Subjects { - if strings.HasPrefix(sub, "*") { - isWildcardOrDefault = true - break - } - } - if ap.OnDemand && isWildcardOrDefault { + if ap.OnDemand && ap.isWildcardOrDefault() { t.logger.Warn("YOUR SERVER MAY BE VULNERABLE TO ABUSE: on-demand TLS is enabled, but no protections are in place", zap.String("docs", "https://caddyserver.com/docs/automatic-https#on-demand-tls")) break |