feat: expose signed platform health status

internal/httpapi/platform_health_callbacks.go

@@ -0,0 +1,93 @@
+package httpapi
+
+import (
+	"bytes"
+	"context"
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"io"
+	"log/slog"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	"data-terminal-cloud/internal/diagnostics"
+)
+
+const (
+	HeaderPlatformTimestamp = "X-Platform-Timestamp"
+	HeaderPlatformSignature = "X-Platform-Signature"
+)
+
+type PlatformHealthProcessor interface {
+	IngestPlatformHealth(context.Context, diagnostics.PlatformHealthInput, []byte, time.Time) (diagnostics.PlatformHealthReceipt, error)
+}
+
+func PlatformHealthCallbackHandler(secret []byte, maxSkew time.Duration, processor PlatformHealthProcessor) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		r.Body = http.MaxBytesReader(w, r.Body, 64*1024)
+		rawBody, err := io.ReadAll(r.Body)
+		if err != nil {
+			WriteError(w, r, http.StatusBadRequest, "INVALID_PLATFORM_HEALTH_REPORT", "服务器健康报告无法读取")
+			return
+		}
+		now := time.Now().UTC()
+		if !verifyPlatformHealthSignature(secret, r.Header.Get(HeaderPlatformTimestamp), r.Header.Get(HeaderPlatformSignature), rawBody, now, maxSkew) {
+			WriteError(w, r, http.StatusUnauthorized, "PLATFORM_HEALTH_AUTHENTICATION_FAILED", "服务器健康报告身份验证失败")
+			return
+		}
+		decoder := json.NewDecoder(bytes.NewReader(rawBody))
+		decoder.DisallowUnknownFields()
+		var input diagnostics.PlatformHealthInput
+		if err = decoder.Decode(&input); err != nil || ensureJSONEOF(decoder) != nil {
+			WriteError(w, r, http.StatusBadRequest, "INVALID_PLATFORM_HEALTH_REPORT", "服务器健康报告字段不正确")
+			return
+		}
+		receipt, err := processor.IngestPlatformHealth(r.Context(), input, rawBody, now)
+		if err != nil {
+			if errors.Is(err, diagnostics.ErrInvalid) {
+				WriteError(w, r, http.StatusBadRequest, "INVALID_PLATFORM_HEALTH_REPORT", "服务器健康报告字段不正确")
+				return
+			}
+			slog.ErrorContext(r.Context(), "platform health callback processing failed", "error", err)
+			WriteAPIError(w, r, http.StatusServiceUnavailable, Error{Code: "PLATFORM_HEALTH_UNAVAILABLE", Message: "服务器健康报告暂时无法处理", Retryable: true})
+			return
+		}
+		status := http.StatusCreated
+		if receipt.Duplicate {
+			status = http.StatusOK
+		}
+		w.Header().Set("Cache-Control", "no-store")
+		WriteJSON(w, r, status, receipt)
+	})
+}
+
+func verifyPlatformHealthSignature(secret []byte, timestamp, signature string, body []byte, now time.Time, maxSkew time.Duration) bool {
+	if len(secret) < 32 || maxSkew <= 0 || timestamp == "" || !strings.HasPrefix(signature, "sha256=") {
+		return false
+	}
+	epoch, err := strconv.ParseInt(timestamp, 10, 64)
+	if err != nil || absDuration(now.Sub(time.Unix(epoch, 0))) > maxSkew {
+		return false
+	}
+	provided, err := hex.DecodeString(strings.TrimPrefix(signature, "sha256="))
+	if err != nil {
+		return false
+	}
+	mac := hmac.New(sha256.New, secret)
+	_, _ = mac.Write([]byte(timestamp))
+	_, _ = mac.Write([]byte("."))
+	_, _ = mac.Write(body)
+	return hmac.Equal(provided, mac.Sum(nil))
+}
+
+func absDuration(value time.Duration) time.Duration {
+	if value < 0 {
+		return -value
+	}
+	return value
+}