/chat/downloadimage fails for images from Channels with "invalid media hmac" (500 Internal Server Error) #241
Description
When trying to download images from public Channels via the /chat/downloadimage endpoint, WuzAPI returns a 500 error with invalid media hmac.
The same image download works correctly for normal chats, and the issue appears to affect only images coming from Channels.
Logs:
2025-12-09 15:12:48.090 +01:00 [DBG] Manual attachment download
2025-12-09 15:12:48.117 +01:00 [WRN] Wuz API return unsucces status code: "InternalServerError". Response:
{"code":500,"error":"failed to download image failed to download media from last host: invalid media hmac","success":false}
2025-12-09 15:12:48.120 +01:00 [WRN] Wuz API /chat/downloadimage return unsucces status
It looks like:
- Images from public Channels are not encrypted
- The /chat/downloadimage handler seems to expect encrypted media
- As a result, it attempts HMAC validation and fails
The download logic likely assumes encryption for all media, but Channel images appear to be delivered unencrypted, causing HMAC validation to fail.