package models import ( "crypto/rand" "errors" "fmt" "github.com/go-playground/validator/v10" "github.com/rs/zerolog/log" "gogs.mikescher.com/BlackForestBytes/goext/langext" "math/big" "reflect" "regexp" "strings" ) type EntityID interface { String() string Valid() error Prefix() string Raw() string CheckString() string Regex() *regexp.Regexp } const idlen = 24 const checklen = 1 const idCharset = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" const idCharsetLen = len(idCharset) var charSetReverseMap = generateCharsetMap() const ( prefixUserID = "USR" prefixChannelID = "CHA" prefixDeliveryID = "DEL" prefixMessageID = "MSG" prefixSubscriptionID = "SUB" prefixClientID = "CLN" prefixRequestID = "REQ" ) var ( regexUserID = generateRegex(prefixUserID) regexChannelID = generateRegex(prefixChannelID) regexDeliveryID = generateRegex(prefixDeliveryID) regexMessageID = generateRegex(prefixMessageID) regexSubscriptionID = generateRegex(prefixSubscriptionID) regexClientID = generateRegex(prefixClientID) regexRequestID = generateRegex(prefixRequestID) ) func generateRegex(prefix string) *regexp.Regexp { return regexp.MustCompile(fmt.Sprintf("^%s[%s]{%d}[%s]{%d}$", prefix, idCharset, idlen-len(prefix)-checklen, idCharset, checklen)) } func generateCharsetMap() []int { result := make([]int, 128) for i := 0; i < len(result); i++ { result[i] = -1 } for idx, chr := range idCharset { result[int(chr)] = idx } return result } func generateID(prefix string) string { k := "" max := big.NewInt(int64(idCharsetLen)) checksum := 0 for i := 0; i < idlen-len(prefix)-checklen; i++ { v, err := rand.Int(rand.Reader, max) if err != nil { panic(err) } v64 := v.Int64() k += string(idCharset[v64]) checksum = (checksum + int(v64)) % (idCharsetLen) } checkstr := string(idCharset[checksum%idCharsetLen]) return prefix + k + checkstr } func validateID(prefix string, value string) error { if len(value) != idlen { return errors.New("id has the wrong length") } if !strings.HasPrefix(value, prefix) { return errors.New("id is missing the correct prefix") } checksum := 0 for i := len(prefix); i < len(value)-checklen; i++ { ichr := int(value[i]) if ichr < 0 || ichr >= len(charSetReverseMap) || charSetReverseMap[ichr] == -1 { return errors.New("id contains invalid characters") } checksum = (checksum + charSetReverseMap[ichr]) % (idCharsetLen) } checkstr := string(idCharset[checksum%idCharsetLen]) if !strings.HasSuffix(value, checkstr) { return errors.New("id checkstring is invalid") } return nil } func getRawData(prefix string, value string) string { if len(value) != idlen { return "" } return value[len(prefix) : idlen-checklen] } func getCheckString(prefix string, value string) string { if len(value) != idlen { return "" } return value[idlen-checklen:] } func ValidateEntityID(vfl validator.FieldLevel) bool { if !vfl.Field().CanInterface() { log.Error().Msgf("Failed to validate EntityID (cannot interface ?!?)") return false } ifvalue := vfl.Field().Interface() if value1, ok := ifvalue.(EntityID); ok { if vfl.Field().Type().Kind() == reflect.Pointer && langext.IsNil(value1) { return true } if err := value1.Valid(); err != nil { log.Debug().Msgf("Failed to validate EntityID '%s' (%s)", value1.String(), err.Error()) return false } else { return true } } else { log.Error().Msgf("Failed to validate EntityID (wrong type: %T)", ifvalue) return false } } // ------------------------------------------------------------ type UserID string func NewUserID() UserID { return UserID(generateID(prefixUserID)) } func (id UserID) Valid() error { return validateID(prefixUserID, string(id)) } func (id UserID) String() string { return string(id) } func (id UserID) Prefix() string { return prefixUserID } func (id UserID) Raw() string { return getRawData(prefixUserID, string(id)) } func (id UserID) CheckString() string { return getCheckString(prefixUserID, string(id)) } func (id UserID) Regex() *regexp.Regexp { return regexUserID } // ------------------------------------------------------------ type ChannelID string func NewChannelID() ChannelID { return ChannelID(generateID(prefixChannelID)) } func (id ChannelID) Valid() error { return validateID(prefixChannelID, string(id)) } func (id ChannelID) String() string { return string(id) } func (id ChannelID) Prefix() string { return prefixChannelID } func (id ChannelID) Raw() string { return getRawData(prefixChannelID, string(id)) } func (id ChannelID) CheckString() string { return getCheckString(prefixChannelID, string(id)) } func (id ChannelID) Regex() *regexp.Regexp { return regexChannelID } // ------------------------------------------------------------ type DeliveryID string func NewDeliveryID() DeliveryID { return DeliveryID(generateID(prefixDeliveryID)) } func (id DeliveryID) Valid() error { return validateID(prefixDeliveryID, string(id)) } func (id DeliveryID) String() string { return string(id) } func (id DeliveryID) Prefix() string { return prefixDeliveryID } func (id DeliveryID) Raw() string { return getRawData(prefixDeliveryID, string(id)) } func (id DeliveryID) CheckString() string { return getCheckString(prefixDeliveryID, string(id)) } func (id DeliveryID) Regex() *regexp.Regexp { return regexDeliveryID } // ------------------------------------------------------------ type MessageID string func NewMessageID() MessageID { return MessageID(generateID(prefixMessageID)) } func (id MessageID) Valid() error { return validateID(prefixMessageID, string(id)) } func (id MessageID) String() string { return string(id) } func (id MessageID) Prefix() string { return prefixMessageID } func (id MessageID) Raw() string { return getRawData(prefixMessageID, string(id)) } func (id MessageID) CheckString() string { return getCheckString(prefixMessageID, string(id)) } func (id MessageID) Regex() *regexp.Regexp { return regexMessageID } // ------------------------------------------------------------ type SubscriptionID string func NewSubscriptionID() SubscriptionID { return SubscriptionID(generateID(prefixSubscriptionID)) } func (id SubscriptionID) Valid() error { return validateID(prefixSubscriptionID, string(id)) } func (id SubscriptionID) String() string { return string(id) } func (id SubscriptionID) Prefix() string { return prefixSubscriptionID } func (id SubscriptionID) Raw() string { return getRawData(prefixSubscriptionID, string(id)) } func (id SubscriptionID) CheckString() string { return getCheckString(prefixSubscriptionID, string(id)) } func (id SubscriptionID) Regex() *regexp.Regexp { return regexSubscriptionID } // ------------------------------------------------------------ type ClientID string func NewClientID() ClientID { return ClientID(generateID(prefixClientID)) } func (id ClientID) Valid() error { return validateID(prefixClientID, string(id)) } func (id ClientID) String() string { return string(id) } func (id ClientID) Prefix() string { return prefixClientID } func (id ClientID) Raw() string { return getRawData(prefixClientID, string(id)) } func (id ClientID) CheckString() string { return getCheckString(prefixClientID, string(id)) } func (id ClientID) Regex() *regexp.Regexp { return regexClientID } // ------------------------------------------------------------ type RequestID string func NewRequestID() RequestID { return RequestID(generateID(prefixRequestID)) } func (id RequestID) Valid() error { return validateID(prefixRequestID, string(id)) } func (id RequestID) String() string { return string(id) } func (id RequestID) Prefix() string { return prefixRequestID } func (id RequestID) Raw() string { return getRawData(prefixRequestID, string(id)) } func (id RequestID) CheckString() string { return getCheckString(prefixRequestID, string(id)) } func (id RequestID) Regex() *regexp.Regexp { return regexRequestID }