Rework authentication system

src/auth/context/SecurityContext.ts

@@ -0,0 +1,104 @@
+import {Inject, Injectable} from '../../di'
+import {EventBus} from '../../event/EventBus'
+import {Awaitable, Maybe} from '../../util'
+import {Authenticatable, AuthenticatableRepository} from '../types'
+import {Logging} from '../../service/Logging'
+import {UserAuthenticatedEvent} from '../event/UserAuthenticatedEvent'
+import {UserFlushedEvent} from '../event/UserFlushedEvent'
+
+/**
+ * Base-class for a context that authenticates users and manages security.
+ */
+@Injectable()
+export abstract class SecurityContext {
+    @Inject()
+    protected readonly bus!: EventBus
+
+    @Inject()
+    protected readonly logging!: Logging
+
+    /** The currently authenticated user, if one exists. */
+    protected authenticatedUser?: Authenticatable
+
+    constructor(
+        /** The repository where users are persisted. */
+        public readonly repository: AuthenticatableRepository,
+
+        /** The name of this context. */
+        public readonly name: string,
+    ) { }
+
+    /**
+     * Called when the context is created. Can be used by child-classes to do setup work.
+     */
+    initialize(): Awaitable<void> {}  // eslint-disable-line @typescript-eslint/no-empty-function
+
+    /**
+     * Authenticate the given user, without persisting the authentication.
+     * That is, when the lifecycle ends, the user will be unauthenticated implicitly.
+     * @param user
+     */
+    async authenticateOnce(user: Authenticatable): Promise<void> {
+        this.authenticatedUser = user
+        await this.bus.dispatch(new UserAuthenticatedEvent(user, this))
+    }
+
+    /**
+     * Authenticate the given user and persist the authentication.
+     * @param user
+     */
+    async authenticate(user: Authenticatable): Promise<void> {
+        this.authenticatedUser = user
+        await this.persist()
+        await this.bus.dispatch(new UserAuthenticatedEvent(user, this))
+    }
+
+    /**
+     * Unauthenticate the current user, if one exists, but do not persist the change.
+     */
+    async flushOnce(): Promise<void> {
+        const user = this.authenticatedUser
+        if ( user ) {
+            this.authenticatedUser = undefined
+            await this.bus.dispatch(new UserFlushedEvent(user, this))
+        }
+    }
+
+    /**
+     * Unauthenticate the current user, if one exists, and persist the change.
+     */
+    async flush(): Promise<void> {
+        const user = this.authenticatedUser
+        if ( user ) {
+            this.authenticatedUser = undefined
+            await this.persist()
+            await this.bus.dispatch(new UserFlushedEvent(user, this))
+        }
+    }
+
+    /**
+     * Assuming a user is still authenticated in the context,
+     * try to look up and fill in the user.
+     */
+    abstract resume(): Awaitable<void>
+
+    /**
+     * Write the current state of the security context to whatever storage
+     * medium the context's host provides.
+     */
+    abstract persist(): Awaitable<void>
+
+    /**
+     * Get the currently authenticated user, if one exists.
+     */
+    getUser(): Maybe<Authenticatable> {
+        return this.authenticatedUser
+    }
+
+    /**
+     * Returns true if there is a currently authenticated user.
+     */
+    hasUser(): boolean {
+        return Boolean(this.authenticatedUser)
+    }
+}

src/auth/context/SessionSecurityContext.ts

@@ -0,0 +1,39 @@
+import {SecurityContext} from './SecurityContext'
+import {Inject, Injectable} from '../../di'
+import {Session} from '../../http/session/Session'
+import {Awaitable} from '../../util'
+import {AuthenticatableRepository} from '../types'
+import {UserAuthenticationResumedEvent} from '../event/UserAuthenticationResumedEvent'
+
+export const EXTOLLO_AUTH_SESSION_KEY = '@extollo:auth.securityIdentifier'
+
+/**
+ * Security context implementation that uses the session as storage.
+ */
+@Injectable()
+export class SessionSecurityContext extends SecurityContext {
+    @Inject()
+    protected readonly session!: Session
+
+    constructor(
+        /** The repository from which to draw users. */
+        public readonly repository: AuthenticatableRepository,
+    ) {
+        super(repository, 'session')
+    }
+
+    persist(): Awaitable<void> {
+        this.session.set(EXTOLLO_AUTH_SESSION_KEY, this.getUser()?.getIdentifier())
+    }
+
+    async resume(): Promise<void> {
+        const identifier = this.session.get(EXTOLLO_AUTH_SESSION_KEY)
+        if ( identifier ) {
+            const user = await this.repository.getByIdentifier(identifier)
+            if ( user ) {
+                this.authenticatedUser = user
+                await this.bus.dispatch(new UserAuthenticationResumedEvent(user, this))
+            }
+        }
+    }
+}