Nodes without MD5 checksum cannot be downloaded from remote locations

[wilke]

Summary

When downloading a node from a remote location, if the node has no MD5 checksum stored, the download fails with an error that acknowledges the issue needs fixing.

Location

shock-server/node/util.go:163-174

Current Code

if nodeInstance.File.Checksum["md5"] == "" {
    err = errors.New("(FMOpen) node has no md5 sum, needs to be fixed")
    return
}

Impact

• Nodes uploaded without MD5 verification cannot be retrieved from remote storage
• No fallback mechanism (e.g., compute MD5 after download)
• Error message indicates this is a known issue: "needs to be fixed"

Expected Behavior

Options:

1. Allow download without MD5 verification (with warning)
2. Compute MD5 after download and update node
3. Require MD5 at upload time to prevent this state

Priority

Medium - data accessibility issue