chore: directory migration - gateway→server, web→client/electron

server/internal/handler/ratelimit.go

@@ -0,0 +1,75 @@
+package handler
+
+import (
+	"context"
+	"time"
+
+	"github.com/agentmail/gateway/internal/db"
+)
+
+// 登录失败限速：同一用户名连续 N 次失败后锁定一段时间。
+// 用 DB 而非进程内内存计数器，多实例部署时各实例共享同一份计数。
+const (
+	maxLoginFailures = 5
+	lockoutDuration  = 5 * time.Minute
+	failureWindow    = 15 * time.Minute
+)
+
+// LoginLimiter 通过 DB 实现的登录失败限速器。
+type LoginLimiter struct{}
+
+var limiter = &LoginLimiter{}
+
+// Locked 返回该用户名是否处于锁定期，以及剩余秒数。
+// 不记账，只读。
+func (l *LoginLimiter) Locked(ctx context.Context, name string) (bool, int) {
+	bucket := "login:" + name
+	cutoff := time.Now().Add(-failureWindow)
+
+	var count int
+	err := db.DB.QueryRowContext(ctx,
+		`SELECT COUNT(*) FROM rate_limits WHERE bucket = $1 AND ts >= $2`,
+		bucket, cutoff).Scan(&count)
+	if err != nil || count < maxLoginFailures {
+		return false, 0
+	}
+
+	// 找到最早那条记录 + lockoutDuration = 解锁时间
+	var earliest time.Time
+	err = db.DB.QueryRowContext(ctx,
+		`SELECT MIN(ts) FROM rate_limits WHERE bucket = $1 AND ts >= $2`,
+		bucket, cutoff).Scan(&earliest)
+	if err != nil || earliest.IsZero() {
+		return false, 0
+	}
+
+	unlockAt := earliest.Add(lockoutDuration)
+	now := time.Now()
+	if now.Before(unlockAt) {
+		remain := int(unlockAt.Sub(now).Seconds()) + 1
+		if remain < 1 {
+			remain = 1
+		}
+		return true, remain
+	}
+
+	// 锁定期已过，清理旧记录
+	db.DB.ExecContext(ctx, `DELETE FROM rate_limits WHERE bucket = $1 AND ts < $2`,
+		bucket, unlockAt)
+	return false, 0
+}
+
+// Fail 记录一次登录失败。达到阈值时不额外标记 ——
+// Locked() 用 COUNT >= maxLoginFailures 自然判定锁定。
+func (l *LoginLimiter) Fail(ctx context.Context, name string) {
+	bucket := "login:" + name
+	db.DB.ExecContext(ctx,
+		`INSERT INTO rate_limits (bucket, ts) VALUES ($1, $2)`,
+		bucket, time.Now())
+}
+
+// Reset 登录成功后清除失败计数。
+func (l *LoginLimiter) Reset(ctx context.Context, name string) {
+	bucket := "login:" + name
+	db.DB.ExecContext(ctx, `DELETE FROM rate_limits WHERE bucket = $1`, bucket)
+}