Access Control & Resource Sharing

Access tokens are used to authenticate and authorize requests to the API. They are usually bound to a resource, which can reside on any node within the Cloudillo network.

Requesting an Access Token

When a user wants to access a resource, they follow this process:

1. The user’s node requests an access token.
2. If the resource is local, the node issues the token directly.
3. If the resource is remote, the node authenticates with the remote node and requests a token on behalf of the user.
4. The access token is returned to the user, allowing them to interact with the resource directly on its home node.

Security & Trust Model

• Access tokens are cryptographically signed to prevent tampering.
• Tokens have expiration times and scopes to limit misuse.
• Nodes validate access tokens before granting access to a resource.

Example 1: Request access to own resource

sequenceDiagram
    box Alice frontend
        participant Alice shell
        participant Alice app
    end
    participant Alice node
    Alice shell ->>+Alice node: Initiate access token request
    Note right of Alice node: Create access token
    Alice node ->>+Alice shell: Access token granted
    deactivate Alice node
    Alice shell ->>+Alice app: Open resource with this token
    deactivate Alice shell
    Alice app ->+Alice node: Use access token
    loop Edit resource
        Alice app --> Alice node: Edit resource
    end
    deactivate Alice app

• Alice opens a resource using her Cloudillo Shell
• Her shell initiates an access token request at her node
• Her node creates an access token and sends it to her shell
• Her shell gives the access token to the App Alice uses to open the resource
• The App uses the access token to edit the resource

Example 2: Request access to resource of an other identity

sequenceDiagram
    box Alice frontend
        participant Alice shell
        participant Alice app
    end
    participant Alice node
    participant Bob node
    Alice shell ->>+Alice node: Initiate access token request
    Note right of Alice node: Create signed request
    Alice node ->>+Bob node: Request access token
    Note right of Bob node: Verify signed request
    Note right of Bob node: Create access token
    deactivate Alice node
    Bob node ->>+Alice node: Grant access token
    deactivate Bob node
    Alice node ->>+Alice shell: Access token granted
    deactivate Alice node
    Alice shell ->>+Alice app: Open resource with this token
    deactivate Alice shell
    Alice app ->+Bob node: Use access token
    loop Edit resource
        Alice app --> Bob node: Edit resource
    end
    deactivate Alice app
    deactivate Bob node

• Alice opens a resource using her Cloudillo Shell
• Her shell initiates an access token request through her node
• Her node creates a signed request and sends it to Bob’s node
• Bob’s node creates an access token and sends it back to Alice’s node
• Alice’s node sends the access token to her shell
• Her shell gives the access token to the App Alice uses to open the resource
• The App uses the access token to edit the resource