Merge pull request #1066 from binwiederhier/templating-disallow

Disallow certain templates
This commit is contained in:
Philipp C. Heckel 2024-03-25 09:38:33 -04:00 committed by GitHub
commit d90b290cd2
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3 changed files with 50 additions and 17 deletions

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@ -89,7 +89,7 @@ var (
errHTTPBadRequestSinceInvalid = &errHTTP{40008, http.StatusBadRequest, "invalid since parameter", "https://ntfy.sh/docs/subscribe/api/#fetch-cached-messages", nil}
errHTTPBadRequestTopicInvalid = &errHTTP{40009, http.StatusBadRequest, "invalid request: topic invalid", "", nil}
errHTTPBadRequestTopicDisallowed = &errHTTP{40010, http.StatusBadRequest, "invalid request: topic name is not allowed", "", nil}
errHTTPBadRequestMessageNotUTF8 = &errHTTP{40011, http.StatusBadRequest, "invalid message: message must be UTF-8 encoded", "", nil}
errHTTPBadRequestMessageNotUTF8 = &errHTTP{40011, http.StatusBadRequest, "invalid request: message must be UTF-8 encoded", "", nil}
errHTTPBadRequestAttachmentURLInvalid = &errHTTP{40013, http.StatusBadRequest, "invalid request: attachment URL is invalid", "https://ntfy.sh/docs/publish/#attachments", nil}
errHTTPBadRequestAttachmentsDisallowed = &errHTTP{40014, http.StatusBadRequest, "invalid request: attachments not allowed", "https://ntfy.sh/docs/config/#attachments", nil}
errHTTPBadRequestAttachmentsExpiryBeforeDelivery = &errHTTP{40015, http.StatusBadRequest, "invalid request: attachment expiry before delayed delivery date", "https://ntfy.sh/docs/publish/#scheduled-delivery", nil}
@ -113,14 +113,15 @@ var (
errHTTPBadRequestPhoneNumberNotVerified = &errHTTP{40034, http.StatusBadRequest, "invalid request: phone number not verified, or no matching verified numbers found", "https://ntfy.sh/docs/publish/#phone-calls", nil}
errHTTPBadRequestAnonymousCallsNotAllowed = &errHTTP{40035, http.StatusBadRequest, "invalid request: anonymous phone calls are not allowed", "https://ntfy.sh/docs/publish/#phone-calls", nil}
errHTTPBadRequestPhoneNumberVerifyChannelInvalid = &errHTTP{40036, http.StatusBadRequest, "invalid request: verification channel must be 'sms' or 'call'", "https://ntfy.sh/docs/publish/#phone-calls", nil}
errHTTPBadRequestDelayNoCall = &errHTTP{40037, http.StatusBadRequest, "delayed call notifications are not supported", "", nil}
errHTTPBadRequestDelayNoCall = &errHTTP{40037, http.StatusBadRequest, "invalid request: delayed call notifications are not supported", "", nil}
errHTTPBadRequestWebPushSubscriptionInvalid = &errHTTP{40038, http.StatusBadRequest, "invalid request: web push payload malformed", "", nil}
errHTTPBadRequestWebPushEndpointUnknown = &errHTTP{40039, http.StatusBadRequest, "invalid request: web push endpoint unknown", "", nil}
errHTTPBadRequestWebPushTopicCountTooHigh = &errHTTP{40040, http.StatusBadRequest, "invalid request: too many web push topic subscriptions", "", nil}
errHTTPBadRequestTemplatedMessageTooLarge = &errHTTP{40041, http.StatusBadRequest, "invalid request: message or title is too large after replacing template", "", nil}
errHTTPBadRequestTemplatedMessageNotJSON = &errHTTP{40042, http.StatusBadRequest, "invalid request: message body must be JSON if templating is enabled", "", nil}
errHTTPBadRequestTemplateInvalid = &errHTTP{40043, http.StatusBadRequest, "invalid request: could not parse template", "", nil}
errHTTPBadRequestTemplateExecutionFailed = &errHTTP{40044, http.StatusBadRequest, "invalid request: template execution failed", "", nil}
errHTTPBadRequestTemplateMessageTooLarge = &errHTTP{40041, http.StatusBadRequest, "invalid request: message or title is too large after replacing template", "https://ntfy.sh/docs/publish/#message-templating", nil}
errHTTPBadRequestTemplateMessageNotJSON = &errHTTP{40042, http.StatusBadRequest, "invalid request: message body must be JSON if templating is enabled", "https://ntfy.sh/docs/publish/#message-templating", nil}
errHTTPBadRequestTemplateInvalid = &errHTTP{40043, http.StatusBadRequest, "invalid request: could not parse template", "https://ntfy.sh/docs/publish/#message-templating", nil}
errHTTPBadRequestTemplateDisallowedFunctionCalls = &errHTTP{40044, http.StatusBadRequest, "invalid request: template contains disallowed function calls, e.g. template, call, or define", "https://ntfy.sh/docs/publish/#message-templating", nil}
errHTTPBadRequestTemplateExecuteFailed = &errHTTP{40045, http.StatusBadRequest, "invalid request: template execution failed", "https://ntfy.sh/docs/publish/#message-templating", nil}
errHTTPNotFound = &errHTTP{40401, http.StatusNotFound, "page not found", "", nil}
errHTTPUnauthorized = &errHTTP{40101, http.StatusUnauthorized, "unauthorized", "https://ntfy.sh/docs/publish/#authentication", nil}
errHTTPForbidden = &errHTTP{40301, http.StatusForbidden, "forbidden", "https://ntfy.sh/docs/publish/#authentication", nil}

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@ -136,6 +136,12 @@ const (
templateMaxExecutionTime = 100 * time.Millisecond
)
var (
// templateDisallowedRegex tests a template for disallowed expressions. While not really dangerous, they
// are not useful, and seem potentially troublesome.
templateDisallowedRegex = regexp.MustCompile(`(?m)\{\{-?\s*(call|template|define)\b`)
)
// WebSocket constants
const (
wsWriteWait = 2 * time.Second
@ -1108,15 +1114,18 @@ func (s *Server) handleBodyAsTemplatedTextMessage(m *message, body *util.PeekedR
return err
}
if len(m.Message) > s.config.MessageSizeLimit {
return errHTTPBadRequestTemplatedMessageTooLarge
return errHTTPBadRequestTemplateMessageTooLarge
}
return nil
}
func replaceTemplate(tpl string, source string) (string, error) {
if templateDisallowedRegex.MatchString(tpl) {
return "", errHTTPBadRequestTemplateDisallowedFunctionCalls
}
var data any
if err := json.Unmarshal([]byte(source), &data); err != nil {
return "", errHTTPBadRequestTemplatedMessageNotJSON
return "", errHTTPBadRequestTemplateMessageNotJSON
}
t, err := template.New("").Parse(tpl)
if err != nil {
@ -1124,7 +1133,7 @@ func replaceTemplate(tpl string, source string) (string, error) {
}
var buf bytes.Buffer
if err := t.Execute(util.NewTimeoutWriter(&buf, templateMaxExecutionTime), data); err != nil {
return "", errHTTPBadRequestTemplateExecutionFailed
return "", errHTTPBadRequestTemplateExecuteFailed
}
return buf.String(), nil
}

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