Redesigning permissions and sharing

Module 6: Files and documents · Reading time: 10 minutes

Learning objective: After this lesson, you'll be able to design a new sharing structure with a permissions matrix, team folders and secure public links, instead of rebuilding the old shares one to one.

Key concepts: owner, shared folder, team folder (group folder), sharing with a user, group or team, read permission, edit permission, public link, password, expiry date, download limit, sharing by email, federated sharing, file request, permissions matrix, transferring ownership

Shares don't come along

In almost every switch, this is the biggest surprise: the files come along, the shares don't. If you shared a folder with a colleague on Google or Microsoft, sent a public link to a customer or let a supplier look along, you'll need to do that again in the new cloud. A migration tool doesn't know the people in your new cloud, and a public link on Google has a Google address that stops working after you cancel.

That feels like extra work, but it's also an opportunity. After years of sharing, the old situation is often a tangle: folders shared with former employees, links without a password that have been open for three years, and nobody knows any more who's allowed what. At Bakkerij De Korrel, the "Staff" folder, containing contracts and payslips, turned out to still be shared with an intern from two years ago. The switch is the moment to put that right.

Who owns a folder?

In every cloud, a file or folder belongs to someone: the owner. Sharing means the owner gives others access. That has two consequences:

1. If the owner leaves, the folder is at risk. If their account is deleted, their files disappear too, even if a hundred colleagues worked with them. Transferring ownership first is then essential.
2. Storage counts towards the owner. What colleagues put in your shared folder counts against your storage.

For anything that belongs to the organisation rather than to one person, use a team folder (also called a group folder, shared drive or project space with other services). That belongs to the team. People come and go, the folder stays.

Design first: the permissions matrix

Don't blindly rebuild what was there before. First create a permissions matrix: a table with the organisation's folders in the rows, the groups in the columns, and in each cell what that group is allowed to do. Work with groups or teams, not individual names. That way, when a new colleague joins, you only need to update the group.

Bakkerij De Korrel's matrix:

Three rules:

• As few permissions as possible. Read is the default; edit only for those who really need it. This also limits the damage if an account is compromised or someone accidentally empties a folder.
• Keep sensitive folders separate. Personnel files, health data and the administration belong in their own folders with a small group.
• One owner per folder. Agree who manages a folder and who decides who gets access, even for a team folder.

Sharing within and outside the organisation

Within the new cloud, you share with a user, a group or a team. You choose read or edit permission, and often further details such as whether they can delete or re-share.

For people outside the organisation, there are more options:

• Public link. Anyone with the link can access it, even if it's forwarded on. For anything that isn't genuinely public, add a password and send it through a different channel (link by email, password by text message or phone). Set an expiry date and, if possible, a download limit.
• Sharing by email. The recipient gets a personal link by email, without needing an account. Handy for an accountant or a customer.
• File request (also called a file drop or upload link). The other person can only drop files, not see what's already there. Ideal for having a customer supply documents.
• Federated sharing. With Nextcloud and other services that follow the open Open Cloud Mesh standard, you share directly with someone on another server, without a public link. The other person sees the folder in their own cloud.

A link with "hide download" looks secure, but it doesn't actually stop anything: viewing is still possible, and so is taking a screenshot. Don't rely on it for confidential documents.

Letting external parties know something is changing

Don't forget the people outside your organisation. At Bakkerij De Korrel, this involved the accountant (invoices folder), the printer (designs folder) and two regular customers with an order list. Their old Google links stop working after cancellation.

1. Find all public links and external shares in your old service. Google Drive and OneDrive have an overview for this (also in the admin area for an organisation).
2. Decide for each link whether it's still needed. Often the answer is no.
3. Recreate the necessary links in the new cloud, this time with a password and an expiry date.
4. Send the external party the new link, with a brief explanation and the date on which the old one stops working.

Departure and handover

Permissions only stay in good shape if you keep them up to date. Record this in your offboarding routine (lesson 7.3):

• Personal folders that are still needed: transfer ownership to a successor, before the account is disabled.
• Disable the account first, and only delete it after checking. A deleted account disappears along with all its files.
• Remove the person leaving from all groups and teams, and revoke their public links.

Do a quick check every six months: is the matrix still accurate, and which public links are still open?

In practice: what this looks like with a provider

In a WebOké Nextcloud, you share from the Share tab in a file's or folder's details. There you can search for a user, group or team, or create a public link using the plus button next to Create public link. Under Customise link and Advanced settings, you set a password, an expiry date and a download limit. Team folders appear on the left in the Files menu; you request a team folder from WebOké via support, and link it to a team from the Teams app. The owner transfers ownership themselves under Settings, Sharing.

With other Nextcloud providers, an administrator can often create group folders themselves. Other European clouds use different names (shared space, project folder), but the choices are the same: who owns the folder, who's allowed to do what, and how secure the link is.

Summary

• Shares and public links don't carry over in a switch. Rebuild them deliberately.
• First create a permissions matrix with groups and as few permissions as possible.
• Everything belonging to the organisation belongs in a team folder, not in one employee's personal folder.
• Public links: password via a different channel, an expiry date and a download limit where possible.
• Let external parties know their link is changing, and keep permissions up to date with a fixed offboarding routine.

Quiz

Exercise

Exercise A6.2: Checking a secure share link. In your new cloud, create a public test link to a harmless test file, with a password and an expiry date. Paste the link (not the password). The program will check whether the link works over https and whether the file can't be viewed or downloaded without the password.

Exercise E6.2: Your permissions matrix. Create the permissions matrix for your own organisation (folders, groups, permissions), assign an owner to each folder, and make a list of external parties who need to receive a new link.

Further reading

The steps in these articles apply to WebOké's services; with other providers, it works in a similar way.

• Nextcloud manual 5.1: Sharing with a user from your own Nextcloud
• Nextcloud manual 5.2: Creating a public link: viewing, editing, password, expiration date and download limit
• Nextcloud manual 5.3: Having files sent to you: file drop and file request
• Nextcloud manual 5.5: Creating teams and sharing a folder with your whole team
• Nextcloud manual 5.6: Team folders: a shared folder that belongs to the team
• Nextcloud manual 5.7: Sharing with someone on another Nextcloud (federated sharing)
• Nextcloud manual 5.10: Transferring ownership when a colleague leaves
• Nextcloud manual 16.7: Colleague leaving: safely taking over files, calendar and shared folders