feat: sync durable moderation and appeals

internal/domain/auth_delivery_report.go

@@ -0,0 +1,114 @@
+package domain
+
+import (
+	"crypto/sha256"
+	"encoding/json"
+	"errors"
+	"time"
+	"unicode/utf8"
+)
+
+const (
+	MaxAuthDeliveryMNCBytes           = 8
+	MaxAuthDeliveryClientTypeBytes    = 32
+	MaxAuthDeliveryIDBytes            = 128
+	MaxAuthDeliveryReportsPerHour     = 10
+	MaxAuthDeliveryReportsPerPhoneDay = 20
+)
+
+var (
+	ErrAuthDeliveryReportInvalid = errors.New("auth delivery report invalid")
+	ErrAuthDeliveryRateLimited   = errors.New("auth delivery report rate limited")
+)
+
+// AuthDeliveryReport is operational delivery telemetry, not an abuse report.
+// It deliberately stores only hashes of the phone and phone_code_hash and
+// never stores the authentication code.
+type AuthDeliveryReport struct {
+	ID           int64
+	AuthKeyID    [8]byte
+	SessionID    int64
+	ClientType   string
+	PhoneHash    [sha256.Size]byte
+	CodeHash     [sha256.Size]byte
+	IssuedUserID int64
+	DeliveryID   string
+	Channel      AuthCodeDeliveryKind
+	MNC          string
+	Fingerprint  [sha256.Size]byte
+	CreatedAt    time.Time
+}
+
+type AuthMissingCodeReportRequest struct {
+	AuthKeyID     [8]byte
+	SessionID     int64
+	ClientType    string
+	Phone         string
+	PhoneCodeHash string
+	MNC           string
+	CreatedAt     time.Time
+}
+
+func NewAuthDeliveryReport(authKeyID [8]byte, sessionID int64, clientType, phone, phoneCodeHash string, issuedUserID int64, deliveryID string, channel AuthCodeDeliveryKind, mnc string, createdAt time.Time) (AuthDeliveryReport, error) {
+	report := AuthDeliveryReport{
+		AuthKeyID: authKeyID, SessionID: sessionID, ClientType: clientType,
+		PhoneHash: sha256.Sum256([]byte(phone)), CodeHash: sha256.Sum256([]byte(phoneCodeHash)),
+		IssuedUserID: issuedUserID, DeliveryID: deliveryID,
+		Channel: channel, MNC: mnc, CreatedAt: createdAt,
+	}
+	raw, err := json.Marshal(struct {
+		Version    int
+		AuthKeyID  [8]byte
+		SessionID  int64
+		PhoneHash  [sha256.Size]byte
+		CodeHash   [sha256.Size]byte
+		DeliveryID string
+		Channel    AuthCodeDeliveryKind
+		MNC        string
+	}{
+		Version: 1, AuthKeyID: authKeyID, SessionID: sessionID,
+		PhoneHash: report.PhoneHash, CodeHash: report.CodeHash,
+		DeliveryID: deliveryID, Channel: channel, MNC: mnc,
+	})
+	if err != nil {
+		return AuthDeliveryReport{}, ErrAuthDeliveryReportInvalid
+	}
+	report.Fingerprint = sha256.Sum256(raw)
+	if err := report.Validate(); err != nil {
+		return AuthDeliveryReport{}, err
+	}
+	return report, nil
+}
+
+func (r AuthDeliveryReport) Validate() error {
+	if r.ID < 0 || r.AuthKeyID == ([8]byte{}) || r.SessionID == 0 ||
+		r.PhoneHash == ([sha256.Size]byte{}) || r.CodeHash == ([sha256.Size]byte{}) ||
+		r.Fingerprint == ([sha256.Size]byte{}) || r.IssuedUserID < 0 ||
+		len(r.ClientType) > MaxAuthDeliveryClientTypeBytes || !utf8.ValidString(r.ClientType) ||
+		len(r.DeliveryID) > MaxAuthDeliveryIDBytes || !utf8.ValidString(r.DeliveryID) ||
+		!validAuthDeliveryChannel(r.Channel) || !validMNC(r.MNC) || r.CreatedAt.IsZero() {
+		return ErrAuthDeliveryReportInvalid
+	}
+	return nil
+}
+
+func validAuthDeliveryChannel(channel AuthCodeDeliveryKind) bool {
+	switch channel {
+	case AuthCodeDeliveryPhone, AuthCodeDeliverySMS:
+		return true
+	default:
+		return false
+	}
+}
+
+func validMNC(mnc string) bool {
+	if len(mnc) > MaxAuthDeliveryMNCBytes {
+		return false
+	}
+	for _, r := range mnc {
+		if r < '0' || r > '9' {
+			return false
+		}
+	}
+	return true
+}