Class DeviceKeyService

The server's part of end-to-end encryption: device keys, one-time and fallback keys, cross-signing keys and signatures.

Inheritance

object

DeviceKeyService

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Uniform.Matrix.Server.Encryption

Assembly: Uniform.Matrix.Server.dll

Syntax

public sealed class DeviceKeyService

Remarks

The server never sees private keys. It checks that uploaded keys are signed as the spec requires, hands out one-time keys once, and records each change of a user's keys so other users' syncs list them in device_lists.changed.

Constructors

DeviceKeyService(IDbContextFactory<ServerDbContext>, ServerStream)

Create the service.

Declaration

public DeviceKeyService(IDbContextFactory<ServerDbContext> contexts, ServerStream stream)

Parameters

Type	Name	Description
IDbContextFactory<ServerDbContext>	contexts
ServerStream	stream

Fields

Master

Usage of the master cross-signing key.

Declaration

public const string Master = "master"

Field Value

Type	Description
string

SelfSigning

Usage of the key that signs the user's own devices.

Declaration

public const string SelfSigning = "self_signing"

Field Value

Type	Description
string

UserSigning

Usage of the key that signs other users' master keys.

Declaration

public const string UserSigning = "user_signing"

Field Value

Type	Description
string

Methods

ClaimAsync(JsonObject, CancellationToken)

Claims one key per requested device: a one-time key, which is then removed, else the fallback key.

Declaration

public Task<JsonObject> ClaimAsync(JsonObject request, CancellationToken cancellationToken)

Parameters

Type	Name	Description
JsonObject	request
CancellationToken	cancellationToken

Returns

Type	Description
Task<JsonObject>

CountOneTimeKeysAsync(ServerDbContext, string, string, CancellationToken)

Return the counts of a device's unclaimed one-time keys by algorithm.

Declaration

public static Task<JsonObject> CountOneTimeKeysAsync(ServerDbContext dbContext, string userId, string deviceId, CancellationToken cancellationToken)

Parameters

Type	Name	Description
ServerDbContext	dbContext
string	userId
string	deviceId
CancellationToken	cancellationToken

Returns

Type	Description
Task<JsonObject>

DeleteDevicesAsync(string, IReadOnlyCollection<string>, CancellationToken)

Remove the keys and signatures of deleted devices, and tell others.

Declaration

public Task DeleteDevicesAsync(string userId, IReadOnlyCollection<string> deviceIds, CancellationToken cancellationToken)

Parameters

Type	Name	Description
string	userId
IReadOnlyCollection<string>	deviceIds
CancellationToken	cancellationToken

Returns

Type	Description
Task

MarkChangedAsync(IEnumerable<string>, CancellationToken)

Record a change of the users' keys at a new stream position.

Declaration

public Task MarkChangedAsync(IEnumerable<string> userIds, CancellationToken cancellationToken)

Parameters

Type	Name	Description
IEnumerable<string>	userIds
CancellationToken	cancellationToken

Returns

Type	Description
Task

QueryAsync(string, JsonObject, CancellationToken)

Return the device and cross-signing keys of queried users: all devices, or the listed ones.

Declaration

public Task<JsonObject> QueryAsync(string requesterId, JsonObject query, CancellationToken cancellationToken)

Parameters

Type	Name	Description
string	requesterId
JsonObject	query
CancellationToken	cancellationToken

Returns

Type	Description
Task<JsonObject>

Remarks

Signatures uploaded later are added from their owners and from the requester only; user-signing keys are returned only for the requester.

UnusedFallbackKeyTypesAsync(ServerDbContext, string, string, CancellationToken)

Return the algorithms of a device's fallback keys that were not claimed yet.

Declaration

public static Task<JsonArray> UnusedFallbackKeyTypesAsync(ServerDbContext dbContext, string userId, string deviceId, CancellationToken cancellationToken)

Parameters

Type	Name	Description
ServerDbContext	dbContext
string	userId
string	deviceId
CancellationToken	cancellationToken

Returns

Type	Description
Task<JsonArray>

UploadAsync(Requester, JsonObject?, JsonObject?, JsonObject?, CancellationToken)

Store uploaded keys of the requester's device; return the counts of its unclaimed one-time keys by algorithm.

Declaration

public Task<JsonObject> UploadAsync(Requester requester, JsonObject? deviceKeys, JsonObject? oneTimeKeys, JsonObject? fallbackKeys, CancellationToken cancellationToken)

Parameters

Type	Name	Description
Requester	requester
JsonObject	deviceKeys
JsonObject	oneTimeKeys
JsonObject	fallbackKeys
CancellationToken	cancellationToken

Returns

Type	Description
Task<JsonObject>

UploadCrossSigningKeysAsync(string, JsonObject?, JsonObject?, JsonObject?, Func<Task>, CancellationToken)

Stores cross-signing keys; replacing an existing master key needs authorize, which asks for the password.

Declaration

public Task UploadCrossSigningKeysAsync(string userId, JsonObject? master, JsonObject? selfSigning, JsonObject? userSigning, Func<Task> authorize, CancellationToken cancellationToken)

Parameters

Type	Name	Description
string	userId
JsonObject	master
JsonObject	selfSigning
JsonObject	userSigning
Func<Task>	authorize
CancellationToken	cancellationToken

Returns

Type	Description
Task

UploadSignaturesAsync(string, JsonObject, CancellationToken)

Stores signatures of devices and master keys after checking them; returns the failures by user and key.

Declaration

public Task<JsonObject> UploadSignaturesAsync(string requesterId, JsonObject body, CancellationToken cancellationToken)

Parameters

Type	Name	Description
string	requesterId
JsonObject	body
CancellationToken	cancellationToken

Returns

Type	Description
Task<JsonObject>

Remarks

Accepted: the requester's devices signed by their self-signing key, their master key signed by one of their devices, and other users' master keys signed by the requester's user-signing key. The uploaded object must be the stored key.