Virus scanning

Uploads can be checked by an outside scanner before they are handed out. Off by default; it turns on when scan.url is set.

clamd://clamav:3310
https://scanner.example.com/scan

A clamd:// address talks to ClamAV directly. An http(s):// address is any service you put in front of a scanner; its authorization header, if it needs one, is a sealed credential like the rest.

What a visitor sees

Until the scan finishes, the share can be opened but not collected, and nothing is spent by trying. The command-line client waits on its own, for up to five minutes.

A file found infected disables the whole share, exactly as if an administrator had. The threat's name is kept and shown in the admin panel's share list.

The person who uploaded sees the scan's progress and result on the page shown after uploading and in their list of shares. A share disabled for a threat says so there, rather than looking expired.

When the scanner is down

The admin panel shows whether the scanner answered the last time it was called, why not when it failed, and how many files are waiting or were let through unscanned. An idle scanner is sent an empty file every fifteen minutes and a failing one every five, so this stays current when nobody uploads.

Turning scanning off releases everything still waiting.

What is not scanned

• End-to-end encrypted shares. The scanner could only see sealed bytes.
• Files larger than the scanner accepts. ClamAV has its own size limit; a file over it is let through and marked as too large rather than refused.
• Link shares, which hold an address and no file.

Writing an HTTP adapter

For a scanner that is not ClamAV, the HTTP service receives the file as the body of a POST, streamed, and answers:

Four files are scanned at a time.

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