status-im
/
specs
mirror of https://github.com/status-im/specs.git
2
0
Fork 0
Code Issues Projects Releases Wiki Activity

fmt and todo

This commit is contained in:
Oskar Thoren 2019-08-29 13:51:30 +02:00
parent a4f3e4a918
commit c2c9599fc6
No known key found for this signature in database
GPG Key ID: B2ECCFD3BC2EF77E
1 changed files with 14 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
status-secure-transport-spec.md
View File

@ -276,29 +276,31 @@ message DirectMessageProtocol {
<!-- TODO: A lot of links to status-go, seems likely these should be updated to status-protocol-go --> <!-- TODO: A lot of links to status-go, seems likely these should be updated to status-protocol-go -->
# Session Management ## Session Management
This section describe how sessions are handled. This section describe how sessions are handled.
<!-- TODO: Clarify what we mean by a session -->
A peer is identified by two pieces of data: A peer is identified by two pieces of data:
1) An `installation-id` which is generated upon creating a new account in the `Status` application 1) An `installation-id` which is generated upon creating a new account in the `Status` application
2) Their identity whisper key 2) Their identity whisper key
## Initialization ### Initialization
A new session is initialized once a successful X3DH exchange has taken place. A new session is initialized once a successful X3DH exchange has taken place.
Subsequent messages will use the established session until re-keying is necessary. Subsequent messages will use the established session until re-keying is necessary.
## Concurrent sessions ### Concurrent sessions
If two sessions are created concurrently between two peers the one with the symmetric key first in byte order should be used, marking the other has expired. If two sessions are created concurrently between two peers the one with the symmetric key first in byte order should be used, marking the other has expired.
## Re-keying ### Re-keying
On receiving a bundle from a given peer with a higher version, the old bundle should be marked as expired and a new session should be established on the next message sent. On receiving a bundle from a given peer with a higher version, the old bundle should be marked as expired and a new session should be established on the next message sent.
## Multi-device support ### Multi-device support
Multi-device support is quite challenging as we don't have a central place where information on which and how many devices (identified by their respective `installation-id`) belongs to a whisper-identity. Multi-device support is quite challenging as we don't have a central place where information on which and how many devices (identified by their respective `installation-id`) belongs to a whisper-identity.
@ -310,7 +312,7 @@ This mean that every time a new device is paired, the bundle needs to be updated
The method is loosely based on https://signal.org/docs/specifications/sesame/ . The method is loosely based on https://signal.org/docs/specifications/sesame/ .
## Pairing ### Pairing
When a user adds a new account in the `Status` application, a new `installation-id` will be generated. The device should be paired as soon as possible if other devices are present. Once paired the contacts will be notified of the new device and it will be included in further communications. When a user adds a new account in the `Status` application, a new `installation-id` will be generated. The device should be paired as soon as possible if other devices are present. Once paired the contacts will be notified of the new device and it will be included in further communications.
@ -322,22 +324,22 @@ The bundle will be propagated to contacts through the usual channels.
Removal of paired devices is a manual step that needs to be applied on each device, and consist simply in disabling the device, at which point pairing information will not be propagated anymore. Removal of paired devices is a manual step that needs to be applied on each device, and consist simply in disabling the device, at which point pairing information will not be propagated anymore.
## Sending messages to a paired group ### Sending messages to a paired group
When sending a message, the peer will send a message to any `installation-id` that they have seen, using pairwise encryption, including their own devices. When sending a message, the peer will send a message to any `installation-id` that they have seen, using pairwise encryption, including their own devices.
The number of devices is capped to 3, ordered by last activity. The number of devices is capped to 3, ordered by last activity.
## Account recovery ### Account recovery
Account recovery is no different from adding a new device, and it is handled in exactly the same way. Account recovery is no different from adding a new device, and it is handled in exactly the same way.
## Partitioned devices ### Partitioned devices
In some cases (i.e. account recovery when no other pairing device is available, device not paired), it is possible that a device will receive a message that is not targeted to its own `installation-id`. In some cases (i.e. account recovery when no other pairing device is available, device not paired), it is possible that a device will receive a message that is not targeted to its own `installation-id`.
In this case an empty message containing bundle information is sent back, which will notify the receiving end of including this device in any further communication. In this case an empty message containing bundle information is sent back, which will notify the receiving end of including this device in any further communication.
## Trust establishment ### Trust establishment
#### Contact request #### Contact request
@ -355,12 +357,11 @@ If Bob's prekey bundle was not available to Alice, Perfect Forward Secrecy hasn'
If Bob accepts the contact request, a secure channel is created (if it wasn't already), and a visual indicator is displayed to signify that PFS has been established. Bob and Alice can then start exchanging messages, making use of the Double Ratchet algorithm as explained in more detail in [Double Ratchet](#double-ratchet) section. If Bob accepts the contact request, a secure channel is created (if it wasn't already), and a visual indicator is displayed to signify that PFS has been established. Bob and Alice can then start exchanging messages, making use of the Double Ratchet algorithm as explained in more detail in [Double Ratchet](#double-ratchet) section.
If Bob denies the request, Alice is not able to send messages and the only action available is resending the contact request. If Bob denies the request, Alice is not able to send messages and the only action available is resending the contact request.
### Expired session
## Expired session
Expired session should not be used for new messages and should be deleted after 14 days from the expiration date, in order to be able to decrypt out-of-order and mailserver messages. Expired session should not be used for new messages and should be deleted after 14 days from the expiration date, in order to be able to decrypt out-of-order and mailserver messages.
## Stale devices ### Stale devices
When a bundle is received from `IK` a timer is initiated on any `installation-id` belonging to `IK` not included in the bundle. If after 7 days no bundles are received from these devices they are marked as `stale` and no message will be sent to them. When a bundle is received from `IK` a timer is initiated on any `installation-id` belonging to `IK` not included in the bundle. If after 7 days no bundles are received from these devices they are marked as `stale` and no message will be sent to them.