Module extensions

Extensions

In MLS, extensions appear in the following places:

• In KeyPackages, to describe client capabilities and aspects of their participation in the group.
• In the GroupInfo, to tell new members of a group what parameters are being used by the group, and to provide any additional details required to join the group.
• In the GroupContext object, to ensure that all members of the group have the same view of the parameters in use.

Note that GroupInfo and GroupContext are not exposed in OpenMLS’ public API.

OpenMLS supports the following extensions:

• ApplicationIdExtension (KeyPackage extension)
• RatchetTreeExtension (GroupInfo extension)
• RequiredCapabilitiesExtension (GroupContext extension)
• ExternalPubExtension (GroupInfo extension)

Modules

• errors
  Extension errors.

Structs

• ApplicationIdExtension
  Application Identifiers
• Extensions
  A list of extensions with unique extension types.
• ExternalPubExtension
• ExternalSender
  ExternalSender
• LastResortExtension
• RatchetTreeExtension
  Ratchet Tree Extension.
• RequiredCapabilitiesExtension
  Required Capabilities Extension.
• SenderExtensionIndex
  Identifies an external sender in the ExternalSendersExtension.
• UnknownExtension
  A unknown/unparsed extension represented by raw bytes.

Enums

• Extension
  Extension
• ExtensionType
  MLS Extension Types

Type Aliases

• ExternalSendersExtension
  ExternalSender (extension data)