Proposal for OpenID information exchange with widgets
Travis Ralston
6 years ago
parent
b12e92440e
commit
e8de1423b1
@ -0,0 +1,83 @@
|
||||
# MSC0000: OpenID information exchange for widgets
|
||||
|
||||
With the various integrations API proposals, widgets are left with no options to verify the
|
||||
requesting user's ID if they need it. Widgets like the sticker picker must know who is making
|
||||
the request and as such need a way to get accurate information about who is contacting them.
|
||||
|
||||
This proposal introduces a way for widgets (room and account) to do so over the `fromWidget`
|
||||
API proposed by [MSC1236](https://github.com/matrix-org/matrix-doc/issues/1236).
|
||||
|
||||
|
||||
## Proposal
|
||||
|
||||
Room and account widgets may request a new OpenID object from the user so they can log in/register with
|
||||
the backing integration manager or other application. This is largely based on the prior art available
|
||||
[here (riot-web#7153)](https://github.com/vector-im/riot-web/issues/7153). The rationale for such an
|
||||
API is so that widgets can load things like a user's sticker packs or other information without having
|
||||
to rely on secret strings. For example, a room could be used to let a user create custom sticker packs
|
||||
via a common widget - it would be nice if that widget could auth the user without asking them to enter
|
||||
their username and password into an iframe.
|
||||
|
||||
Widgets can request OpenID credentials from the user by sending a `fromWidget` action of `get_openid`
|
||||
to intiate the token exchange process. The client should respond with an acknowledgement of
|
||||
`{"state":"request"}` (or `{"state":"blocked"}` if the client/user doesn't think the widget is safe).
|
||||
The client should then prompt the user if the widget should be allowed to get details about the user,
|
||||
optionally providing a way for the user to always accept/deny the widget. If the user agrees, the
|
||||
client sends a `toWidget` action of `openid_credentials` with `data` holding the raw OpenID credentials
|
||||
object returned from the homeserver, and a `success: true` parameter. If the user denies the widget,
|
||||
just `success: false` is returned in the `data` property. To lessen the number of requests, a client may
|
||||
also respond to the original `get_openid` request with a `state` of `"allowed"`, `success: true`, and
|
||||
the OpenID object (just like in the data for `openid_credentials`). The widget should not request OpenID
|
||||
credentials until after it has exchanged capabilities with the client, however this is not required. The
|
||||
widget should acknowledge the `openid_credentials` request with an empty response object.
|
||||
|
||||
A full sequence diagram for this flow is as follows:
|
||||
|
||||
```
|
||||
+-------+ +---------+ +---------+
|
||||
| User | | Client | | Widget |
|
||||
+-------+ +---------+ +---------+
|
||||
| | |
|
||||
| | Capabilities negotiation |
|
||||
| |<-----------------------------------------|
|
||||
| | |
|
||||
| | Capabilities negotiation |
|
||||
| |----------------------------------------->|
|
||||
| | |
|
||||
| | fromWidget get_openid request |
|
||||
| |<-----------------------------------------|
|
||||
| | |
|
||||
| | ack with state "request" |
|
||||
| |----------------------------------------->|
|
||||
| | |
|
||||
| Ask if the widget can have information | |
|
||||
|<--------------------------------------------| |
|
||||
| | |
|
||||
| Approve | |
|
||||
|-------------------------------------------->| |
|
||||
| | |
|
||||
| | toWidget openid_credentials request |
|
||||
| |----------------------------------------->|
|
||||
| | |
|
||||
| | acknowledge request (empty response) |
|
||||
| |<-----------------------------------------|
|
||||
```
|
||||
|
||||
Prior to this proposal, widgets could use an undocumented `scalar_token` parameter if the client chose to
|
||||
send it to the widget. Clients typically chose to send it if the widget's URL matched a whitelist for URLs
|
||||
the client trusts. Widgets are now not able to rely on this behaviour with this proposal, although clients
|
||||
may wish to still support it until adoption is complete. Widgets may wish to look into cookies and other
|
||||
storage techniques to avoid continously requesting credentials.
|
||||
|
||||
A proof of concept for this system is demonstrated [here](https://github.com/matrix-org/matrix-react-sdk/pull/2781).
|
||||
|
||||
The widget is left responsible for dealing with the OpenID object it receives, likely handing it off to
|
||||
the integration manager it is backed by to exchange it for a long-lived Bearer token.
|
||||
|
||||
## Security considerations
|
||||
|
||||
The user is explicitly kept in the loop to avoid automatic and silent harvesting of private information.
|
||||
Clients must ask the user for permission to send OpenID information to a widget, but may optionally allow
|
||||
the user to always allow/deny the widget access. Clients are encouraged to notify the user when future
|
||||
requests are automatically handled due to the user's prior selection (eg: an unobtrusive popup saying
|
||||
"hey, your sticker picker asked for your information. [Block future requests]").
|
||||
Loading…
Reference in New Issue