feat: expose signed platform health status

internal/httpapi/platform_health_callbacks_test.go

@@ -0,0 +1,78 @@
+package httpapi
+
+import (
+	"context"
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"data-terminal-cloud/internal/diagnostics"
+)
+
+type fakePlatformHealthProcessor struct {
+	calls     int
+	receipt   diagnostics.PlatformHealthReceipt
+	err       error
+	lastInput diagnostics.PlatformHealthInput
+}
+
+func (p *fakePlatformHealthProcessor) IngestPlatformHealth(_ context.Context, input diagnostics.PlatformHealthInput, _ []byte, _ time.Time) (diagnostics.PlatformHealthReceipt, error) {
+	p.calls++
+	p.lastInput = input
+	return p.receipt, p.err
+}
+
+func TestPlatformHealthCallbackRequiresSignatureAndAcceptsReport(t *testing.T) {
+	secret := []byte("01234567890123456789012345678901")
+	now := time.Now().UTC().Truncate(time.Second)
+	body, _ := json.Marshal(diagnostics.PlatformHealthInput{
+		Schema: diagnostics.PlatformHealthSchema, Status: "healthy", ObservedAt: now,
+		Checks: []diagnostics.PlatformHealthCheck{{Name: "public_https", Status: "healthy", Value: "http_200"}},
+	})
+	processor := &fakePlatformHealthProcessor{receipt: diagnostics.PlatformHealthReceipt{ID: "10000000-0000-0000-0000-000000000999", Status: "healthy"}}
+	handler := PlatformHealthCallbackHandler(secret, time.Minute, processor)
+
+	unsigned := httptest.NewRequest(http.MethodPost, "/callbacks/v1/platform-health", strings.NewReader(string(body)))
+	unsignedRecorder := httptest.NewRecorder()
+	handler.ServeHTTP(unsignedRecorder, unsigned)
+	if unsignedRecorder.Code != http.StatusUnauthorized || processor.calls != 0 {
+		t.Fatalf("unsigned status=%d calls=%d", unsignedRecorder.Code, processor.calls)
+	}
+
+	timestamp := strconv.FormatInt(now.Unix(), 10)
+	signed := httptest.NewRequest(http.MethodPost, "/callbacks/v1/platform-health", strings.NewReader(string(body)))
+	signed.Header.Set(HeaderPlatformTimestamp, timestamp)
+	signed.Header.Set(HeaderPlatformSignature, signPlatformHealth(secret, timestamp, body))
+	recorder := httptest.NewRecorder()
+	handler.ServeHTTP(recorder, signed)
+	if recorder.Code != http.StatusCreated || processor.calls != 1 || processor.lastInput.Schema != diagnostics.PlatformHealthSchema {
+		t.Fatalf("status=%d calls=%d input=%+v body=%s", recorder.Code, processor.calls, processor.lastInput, recorder.Body.String())
+	}
+}
+
+func TestPlatformHealthCallbackRejectsStaleAndMalformedSignature(t *testing.T) {
+	secret := []byte("01234567890123456789012345678901")
+	body := []byte(`{"schema":"platform-server-health-v1","status":"healthy","observed_at":"2026-08-26T00:00:00Z","checks":[]}`)
+	now := time.Now().UTC()
+	staleTimestamp := strconv.FormatInt(now.Add(-10*time.Minute).Unix(), 10)
+	if verifyPlatformHealthSignature(secret, staleTimestamp, signPlatformHealth(secret, staleTimestamp, body), body, now, time.Minute) {
+		t.Fatal("stale signature accepted")
+	}
+	if verifyPlatformHealthSignature(secret, strconv.FormatInt(now.Unix(), 10), "sha256=broken", body, now, time.Minute) {
+		t.Fatal("malformed signature accepted")
+	}
+}
+
+func signPlatformHealth(secret []byte, timestamp string, body []byte) string {
+	mac := hmac.New(sha256.New, secret)
+	_, _ = mac.Write([]byte(timestamp + "."))
+	_, _ = mac.Write(body)
+	return "sha256=" + hex.EncodeToString(mac.Sum(nil))
+}