security: address medium risks in jwt, redis ordering and body limit

app/persistence/redis.go

@@ -12,6 +12,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"sync"
 	"time"
 
 	"github.com/redis/go-redis/v9"
@@ -24,6 +25,12 @@ import (
 // nil означает режим "только память" — все функции тихо no-op.
 var Client *redis.Client
 
+var (
+	seqMu          sync.Mutex
+	queueWriteSeq  = map[string]uint64{}
+	tenantWriteSeq = map[string]uint64{}
+)
+
 const (
 	// redisHashTenants — HASH: tenantID → JSON тенанта
 	redisHashTenants = "ssq:tenants"
@@ -85,7 +92,11 @@ func SaveQueue(key string, queue *models.Queue) {
 		log.Warnf("persistence: queue %q too large for Redis (%d bytes), skipping", key, len(data))
 		return
 	}
+	writeSeq := nextQueueWriteSeq(key)
 	asyncWrite(func() {
+		if !isLatestQueueWriteSeq(key, writeSeq) {
+			return
+		}
 		ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
 		defer cancel()
 		if err := Client.HSet(ctx, redisHashQueues, key, string(data)).Err(); err != nil {
@@ -99,7 +110,11 @@ func DeleteQueue(key string) {
 	if Client == nil {
 		return
 	}
+	writeSeq := nextQueueWriteSeq(key)
 	asyncWrite(func() {
+		if !isLatestQueueWriteSeq(key, writeSeq) {
+			return
+		}
 		ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
 		defer cancel()
 		if err := Client.HDel(ctx, redisHashQueues, key).Err(); err != nil {
@@ -153,7 +168,11 @@ func SaveTenantRaw(id string, jsonData []byte) {
 	// Копируем bytes — вызывающий может переиспользовать буфер
 	dataCopy := make([]byte, len(jsonData))
 	copy(dataCopy, jsonData)
+	writeSeq := nextTenantWriteSeq(id)
 	asyncWrite(func() {
+		if !isLatestTenantWriteSeq(id, writeSeq) {
+			return
+		}
 		ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
 		defer cancel()
 		if err := Client.HSet(ctx, redisHashTenants, id, string(dataCopy)).Err(); err != nil {
@@ -167,7 +186,11 @@ func DeleteTenant(id string) {
 	if Client == nil {
 		return
 	}
+	writeSeq := nextTenantWriteSeq(id)
 	asyncWrite(func() {
+		if !isLatestTenantWriteSeq(id, writeSeq) {
+			return
+		}
 		ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
 		defer cancel()
 		if err := Client.HDel(ctx, redisHashTenants, id).Err(); err != nil {
@@ -176,6 +199,32 @@ func DeleteTenant(id string) {
 	})
 }
 
+func nextQueueWriteSeq(key string) uint64 {
+	seqMu.Lock()
+	defer seqMu.Unlock()
+	queueWriteSeq[key]++
+	return queueWriteSeq[key]
+}
+
+func isLatestQueueWriteSeq(key string, seq uint64) bool {
+	seqMu.Lock()
+	defer seqMu.Unlock()
+	return queueWriteSeq[key] == seq
+}
+
+func nextTenantWriteSeq(id string) uint64 {
+	seqMu.Lock()
+	defer seqMu.Unlock()
+	tenantWriteSeq[id]++
+	return tenantWriteSeq[id]
+}
+
+func isLatestTenantWriteSeq(id string, seq uint64) bool {
+	seqMu.Lock()
+	defer seqMu.Unlock()
+	return tenantWriteSeq[id] == seq
+}
+
 // LoadAllTenantsRaw — загружает всех тенантов из Redis при старте.
 // Возвращает map[tenantID]rawJSON — десериализацию делает tenant_store.go.
 func LoadAllTenantsRaw() (map[string][]byte, error) {