Concepts

Capabilities

Capabilities are multi-owner. A scoped keeper can create a capability via NewCapability which creates a new unique, unforgeable object-capability reference. The newly created capability is automatically persisted; the calling module need not call ClaimCapability. Calling NewCapability will create the capability with the calling module and name as a tuple to be treated the capabilities first owner.

Capabilities can be claimed by other modules which add them as owners. ClaimCapability allows a module to claim a capability key which it has received from another module so that future GetCapability calls will succeed. ClaimCapability MUST be called if a module which receives a capability wishes to access it by name in the future. Again, capabilities are multi-owner, so if multiple modules have a single Capability reference, they will all own it. If a module receives a capability from another module but does not call ClaimCapability, it may use it in the executing transaction but will not be able to access it afterwards.

AuthenticateCapability can be called by any module to check that a capability does in fact correspond to a particular name (the name can be un-trusted user input) with which the calling module previously associated it.

GetCapability allows a module to fetch a capability which it has previously claimed by name. The module is not allowed to retrieve capabilities which it does not own.

Stores

• MemStore
• KeyStore