README.md

@@ -58,14 +58,22 @@ pass-through view of the zone-side CAA records:
 - `caa_issuer_unknown`: CCADB has no mapping for the observed issuer
   (AKI + DN). Reported `INFO`; action is to file a CCADB update.
 
-## Issuer → CAA domain mapping (CCADB)
+## Issuer -> CAA domain mapping (CCADB)
 
 The file `checker/AllCAAIdentifiersReport.csv` is an unmodified
 snapshot of the "CAA Identifiers (V2)" report from the Common CA
 Database (https://www.ccadb.org/resources). It is embedded into the
-binary via `//go:embed`. To refresh it, download the CSV from CCADB
+binary via `//go:embed` but is **not committed to the repository**.
-and replace the file; no code changes needed. A future `make
+To fetch or refresh it, run:
-update-ccadb` target will automate this.
+
+```bash
+go generate ./checker/
+```
+
+This downloads the current CSV from CCADB. No code changes are needed
+to pick up a new snapshot: only a re-embed (recompile) is required
+after the file is refreshed. Note that the download depends on CCADB
+being reachable; `go build` itself has no network dependency.
 
 The lookup key is:
 
@@ -78,9 +86,9 @@ The lookup key is:
 ## Options
 
 | Id        | Type   | Default | Description                        |
-| --------- | ------ | ------- | ---------------------------------- |
+|-----------|--------|---------|------------------------------------|
 | `domain`  | string | (auto)  | Domain being checked (`AutoFill`). |
-| `service` | (n/a)   | (auto)  | `svcs.CAAPolicy` service body.     |
+| `service` | (n/a)  | (auto)  | `svcs.CAAPolicy` service body.     |
 
 ## Running
 
@@ -91,11 +99,3 @@ make plugin
 # Standalone HTTP server
 make && ./checker-caa -listen :8080
 ```
-
-## Out of scope for v1
-
-- CAA parameter matching (`;account=…`, `;validationmethods=…`): only
-  the base issuer domain name is compared.
-- `issuemail` / `issuevmc` policies: the consumed TLS observations are
-  for web-PKI endpoints only.
-- HTML report page.

checker/ccadb.go

@@ -130,7 +130,7 @@ func Lookup(aki, dn string) ([]string, bool) {
 // is lowercased because CAA identifiers are case-insensitive.
 func splitCAADomains(raw string) []string {
 	var out []string
-	for _, d := range strings.Split(raw, ",") {
+	for d := range strings.SplitSeq(raw, ",") {
 		d = strings.TrimSpace(strings.ToLower(d))
 		if d != "" {
 			out = append(out, d)

checker/interactive.go

@@ -0,0 +1,118 @@
+package checker
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net"
+	"net/http"
+	"strings"
+
+	sdk "git.happydns.org/checker-sdk-go/checker"
+	"github.com/miekg/dns"
+)
+
+// RenderForm describes the minimal input the standalone /check route
+// accepts: just a domain name to resolve CAA records for.
+func (p *caaProvider) RenderForm() []sdk.CheckerOptionField {
+	return []sdk.CheckerOptionField{
+		{
+			Id:          "domain",
+			Type:        "string",
+			Label:       "Domain name",
+			Placeholder: "example.com",
+			Required:    true,
+		},
+	}
+}
+
+// ParseForm resolves CAA records for the submitted domain via direct
+// DNS queries and packages them into the CheckerOptions shape Collect
+// expects. TLS probes are not gathered here; the rule will report
+// StatusUnknown for the TLS cross-check when used standalone.
+func (p *caaProvider) ParseForm(r *http.Request) (sdk.CheckerOptions, error) {
+	domain := strings.TrimSpace(r.FormValue("domain"))
+	if domain == "" {
+		return nil, errors.New("domain is required")
+	}
+	domain = dns.Fqdn(domain)
+
+	records, err := lookupCAA(domain)
+	if err != nil {
+		return nil, fmt.Errorf("CAA lookup for %s: %w", domain, err)
+	}
+
+	payload := caaPolicyPayload{Records: make([]caaRecordPayload, 0, len(records))}
+	for _, rec := range records {
+		payload.Records = append(payload.Records, caaRecordPayload{
+			Flag: rec.Flag, Tag: rec.Tag, Value: rec.Value,
+		})
+	}
+	svcBody, err := json.Marshal(payload)
+	if err != nil {
+		return nil, fmt.Errorf("marshal CAA payload: %w", err)
+	}
+
+	svc := serviceMessage{
+		Type:    serviceType,
+		Domain:  strings.TrimSuffix(domain, "."),
+		Service: svcBody,
+	}
+
+	return sdk.CheckerOptions{
+		"domain":  strings.TrimSuffix(domain, "."),
+		"service": svc,
+	}, nil
+}
+
+// lookupCAA queries CAA records for fqdn using the system resolver.
+// Walks up the label tree per RFC 8659 §3 until a record set is found
+// or the zone apex is reached; returns an empty slice when none exist.
+func lookupCAA(fqdn string) ([]CAARecord, error) {
+	resolver, err := systemResolver()
+	if err != nil {
+		return nil, err
+	}
+
+	for name := fqdn; name != "" && name != "."; {
+		msg := new(dns.Msg)
+		msg.SetQuestion(name, dns.TypeCAA)
+		msg.RecursionDesired = true
+
+		c := new(dns.Client)
+		in, _, err := c.Exchange(msg, resolver)
+		if err != nil {
+			return nil, err
+		}
+		if in.Rcode != dns.RcodeSuccess && in.Rcode != dns.RcodeNameError {
+			return nil, fmt.Errorf("rcode %s", dns.RcodeToString[in.Rcode])
+		}
+
+		var out []CAARecord
+		for _, rr := range in.Answer {
+			if caa, ok := rr.(*dns.CAA); ok {
+				out = append(out, CAARecord{Flag: caa.Flag, Tag: caa.Tag, Value: caa.Value})
+			}
+		}
+		if len(out) > 0 {
+			return out, nil
+		}
+
+		i := strings.IndexByte(name, '.')
+		if i < 0 || i >= len(name)-1 {
+			break
+		}
+		name = name[i+1:]
+	}
+	return nil, nil
+}
+
+// systemResolver returns the first nameserver in /etc/resolv.conf as a
+// host:port string suitable for dns.Client.Exchange.
+func systemResolver() (string, error) {
+	cfg, err := dns.ClientConfigFromFile("/etc/resolv.conf")
+	if err != nil || len(cfg.Servers) == 0 {
+		return net.JoinHostPort("1.1.1.1", "53"), nil
+	}
+	return net.JoinHostPort(cfg.Servers[0], cfg.Port), nil
+}

checker/rule.go

@@ -88,25 +88,25 @@ func issuerFromValue(v string) string {
 }
 
 // Evaluate runs the compliance rule.
-func (r *caaRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, opts sdk.CheckerOptions) sdk.CheckState {
+func (r *caaRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, opts sdk.CheckerOptions) []sdk.CheckState {
 	var data CAAData
 	if err := obs.Get(ctx, ObservationKeyCAA, &data); err != nil {
-		return sdk.CheckState{
+		return []sdk.CheckState{{
 			Status:  sdk.StatusError,
 			Message: fmt.Sprintf("Failed to read caa_policy: %v", err),
 			Code:    CodeObservationError,
-		}
+		}}
 	}
 
 	related, _ := obs.GetRelated(ctx, TLSRelatedKey)
 	probes := parseAllTLSRelated(related)
 
 	if len(probes) == 0 {
-		return sdk.CheckState{
+		return []sdk.CheckState{{
 			Status:  sdk.StatusUnknown,
 			Message: "No TLS probes have been observed for this target yet",
 			Code:    CodeNoTLS,
-		}
+		}}
 	}
 
 	al := buildAllowList(data.Records)
@@ -175,94 +175,53 @@ func (r *caaRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, opts
 		issue(p, "", "", "", "")
 	}
 
-	// Materialize issues in a deterministic order (keys sorted) so test
+	// Emit one CheckState per distinct issuer, keyed deterministically so
-	// output is stable and the "first" critical/warn message is not
+	// state ordering does not depend on map iteration.
-	// map-iteration-dependent.
 	keys := make([]string, 0, len(agg))
 	for k := range agg {
 		keys = append(keys, k)
 	}
 	sort.Strings(keys)
 
-	var critCount, warnCount, infoCount, okIssuerCount int
+	out := make([]sdk.CheckState, 0, len(keys))
-	var firstCrit, firstWarn, firstInfo string
 	for _, k := range keys {
 		a := agg[k]
+		subject := issuerLabel(a.sample)
+		endpoints := make([]string, 0, len(a.endpoints))
+		for ep := range a.endpoints {
+			endpoints = append(endpoints, ep)
+		}
+		sort.Strings(endpoints)
+		meta := map[string]any{"endpoints": endpoints}
+
 		switch a.severity {
 		case SeverityCrit:
-			critCount++
+			out = append(out, sdk.CheckState{
-			if firstCrit == "" {
+				Status: sdk.StatusCrit, Message: a.msg, Code: a.code,
-				firstCrit = a.msg
+				Subject: subject, Meta: meta,
-			}
+			})
 		case SeverityWarn:
-			warnCount++
+			out = append(out, sdk.CheckState{
-			if firstWarn == "" {
+				Status: sdk.StatusWarn, Message: a.msg, Code: a.code,
-				firstWarn = a.msg
+				Subject: subject, Meta: meta,
-			}
+			})
 		case SeverityInfo:
-			infoCount++
+			out = append(out, sdk.CheckState{
-			if firstInfo == "" {
+				Status: sdk.StatusInfo, Message: a.msg, Code: a.code,
-				firstInfo = a.msg
+				Subject: subject, Meta: meta,
-			}
+			})
 		default:
-			okIssuerCount++
+			msg := "Certificate authorized by CAA policy"
-		}
+			if !hasPolicy {
-	}
+				msg = "Certificate observed; no CAA records published"
-
+			}
-	meta := map[string]any{
+			out = append(out, sdk.CheckState{
-		"probes":           len(probes),
+				Status: sdk.StatusOK, Message: msg, Code: CodeOK,
-		"distinct_issuers": len(agg),
+				Subject: subject, Meta: meta,
-		"authorized":       okIssuerCount,
+			})
-		"unauthorized":     critCount,
-		"info":             infoCount,
-		"caa_records":      len(data.Records),
-	}
-
-	switch {
-	case critCount > 0:
-		code := CodeNotAuthorized
-		if al.disallowIssue {
-			code = CodeIssuanceDisallowed
-		}
-		return sdk.CheckState{
-			Status:  sdk.StatusCrit,
-			Message: fmt.Sprintf("%d issuer(s) violate the zone's CAA policy: %s", critCount, firstCrit),
-			Code:    code,
-			Meta:    meta,
-		}
-	case warnCount > 0:
-		return sdk.CheckState{
-			Status:  sdk.StatusWarn,
-			Message: firstWarn,
-			Code:    CodeNotAuthorized,
-			Meta:    meta,
-		}
-	case infoCount > 0 && okIssuerCount == 0:
-		// Only info-level findings. When a policy exists this is a data
-		// gap (CCADB didn't know the issuer); without a policy it's the
-		// "publish CAA" nudge, which is fine; OK code.
-		code := CodeIssuerUnknown
-		if !hasPolicy {
-			code = CodeOK
-		}
-		return sdk.CheckState{
-			Status:  sdk.StatusInfo,
-			Message: firstInfo,
-			Code:    code,
-			Meta:    meta,
-		}
-	default:
-		msg := fmt.Sprintf("%d TLS issuer(s) authorized by CAA policy", okIssuerCount)
-		if !hasPolicy {
-			msg = fmt.Sprintf("%d TLS issuer(s) observed; no CAA records published", okIssuerCount)
-		}
-		return sdk.CheckState{
-			Status:  sdk.StatusOK,
-			Message: msg,
-			Code:    CodeOK,
-			Meta:    meta,
 		}
 	}
+	return out
 }
 
 // severityRank turns a severity string into a comparable integer so

checker/rule_test.go

@@ -69,7 +69,11 @@ func TestRule_OK(t *testing.T) {
 			}),
 		},
 	}
-	state := Rule().Evaluate(context.Background(), obs, nil)
+	states := Rule().Evaluate(context.Background(), obs, nil)
+	if len(states) != 1 {
+		t.Fatalf("expected 1 state, got %d", len(states))
+	}
+	state := states[0]
 	if state.Status != sdk.StatusOK {
 		t.Fatalf("expected StatusOK, got %s: %s", state.Status, state.Message)
 	}
@@ -96,7 +100,11 @@ func TestRule_NotAuthorized(t *testing.T) {
 			}),
 		},
 	}
-	state := Rule().Evaluate(context.Background(), obs, nil)
+	states := Rule().Evaluate(context.Background(), obs, nil)
+	if len(states) != 1 {
+		t.Fatalf("expected 1 state, got %d", len(states))
+	}
+	state := states[0]
 	if state.Status != sdk.StatusCrit {
 		t.Fatalf("expected StatusCrit, got %s: %s", state.Status, state.Message)
 	}
@@ -126,7 +134,11 @@ func TestRule_IssuanceDisallowed(t *testing.T) {
 			}),
 		},
 	}
-	state := Rule().Evaluate(context.Background(), obs, nil)
+	states := Rule().Evaluate(context.Background(), obs, nil)
+	if len(states) != 1 {
+		t.Fatalf("expected 1 state, got %d", len(states))
+	}
+	state := states[0]
 	if state.Status != sdk.StatusCrit {
 		t.Fatalf("expected StatusCrit, got %s: %s", state.Status, state.Message)
 	}
@@ -153,7 +165,11 @@ func TestRule_IssuerUnknown(t *testing.T) {
 			}),
 		},
 	}
-	state := Rule().Evaluate(context.Background(), obs, nil)
+	states := Rule().Evaluate(context.Background(), obs, nil)
+	if len(states) != 1 {
+		t.Fatalf("expected 1 state, got %d", len(states))
+	}
+	state := states[0]
 	if state.Status != sdk.StatusInfo {
 		t.Fatalf("expected StatusInfo, got %s: %s", state.Status, state.Message)
 	}
@@ -172,7 +188,11 @@ func TestRule_NoTLS(t *testing.T) {
 		},
 		related: nil,
 	}
-	state := Rule().Evaluate(context.Background(), obs, nil)
+	states := Rule().Evaluate(context.Background(), obs, nil)
+	if len(states) != 1 {
+		t.Fatalf("expected 1 state, got %d", len(states))
+	}
+	state := states[0]
 	if state.Status != sdk.StatusUnknown {
 		t.Fatalf("expected StatusUnknown, got %s: %s", state.Status, state.Message)
 	}
@@ -197,7 +217,11 @@ func TestRule_NoCAAPublished(t *testing.T) {
 			}),
 		},
 	}
-	state := Rule().Evaluate(context.Background(), obs, nil)
+	states := Rule().Evaluate(context.Background(), obs, nil)
+	if len(states) != 1 {
+		t.Fatalf("expected 1 state, got %d", len(states))
+	}
+	state := states[0]
 	if state.Status != sdk.StatusInfo {
 		t.Fatalf("expected StatusInfo (no policy), got %s: %s", state.Status, state.Message)
 	}

go.mod

@@ -3,3 +3,12 @@ module git.happydns.org/checker-caa
 go 1.25.0
 
 require git.happydns.org/checker-sdk-go v1.1.0
+
+require (
+	github.com/miekg/dns v1.1.72 // indirect
+	golang.org/x/mod v0.31.0 // indirect
+	golang.org/x/net v0.48.0 // indirect
+	golang.org/x/sync v0.19.0 // indirect
+	golang.org/x/sys v0.39.0 // indirect
+	golang.org/x/tools v0.40.0 // indirect
+)

go.sum

@@ -1,2 +1,13 @@
-git.happydns.org/checker-sdk-go v1.1.0 h1:xgR39X1Mh+v481BHTDYHtGYFL1qRwldTsehazwSc67Y=
 git.happydns.org/checker-sdk-go v1.1.0/go.mod h1:aNAcfYFfbhvH9kJhE0Njp5GX0dQbxdRB0rJ0KvSC5nI=
+github.com/miekg/dns v1.1.72 h1:vhmr+TF2A3tuoGNkLDFK9zi36F2LS+hKTRW0Uf8kbzI=
+github.com/miekg/dns v1.1.72/go.mod h1:+EuEPhdHOsfk6Wk5TT2CzssZdqkmFhf8r+aVyDEToIs=
+golang.org/x/mod v0.31.0 h1:HaW9xtz0+kOcWKwli0ZXy79Ix+UW/vOfmWI5QVd2tgI=
+golang.org/x/mod v0.31.0/go.mod h1:43JraMp9cGx1Rx3AqioxrbrhNsLl2l/iNAvuBkrezpg=
+golang.org/x/net v0.48.0 h1:zyQRTTrjc33Lhh0fBgT/H3oZq9WuvRR5gPC70xpDiQU=
+golang.org/x/net v0.48.0/go.mod h1:+ndRgGjkh8FGtu1w1FGbEC31if4VrNVMuKTgcAAnQRY=
+golang.org/x/sync v0.19.0 h1:vV+1eWNmZ5geRlYjzm2adRgW2/mcpevXNg50YZtPCE4=
+golang.org/x/sync v0.19.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
+golang.org/x/sys v0.39.0 h1:CvCKL8MeisomCi6qNZ+wbb0DN9E5AATixKsvNtMoMFk=
+golang.org/x/sys v0.39.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/tools v0.40.0 h1:yLkxfA+Qnul4cs9QA3KnlFu0lVmd8JJfoq+E41uSutA=
+golang.org/x/tools v0.40.0/go.mod h1:Ik/tzLRlbscWpqqMRjyWYDisX8bG13FrdXp3o4Sr9lc=