Files

265 lines
9.4 KiB
TypeScript

// NOTE: Replace this with libauth sha256
import { toExtendedJson } from '@xo-cash/utils';
import { z } from 'zod';
import { HTTP_STATUS_CODE_NOT_ACCEPTED } from '../constants.ts';
import type{ AuthSecp256k1 } from '../auth/auth.ts';
import type { BaseBroadcaster } from '../services/broadcaster.ts';
import { ApplicationError, UnauthorizedError } from '../errors/index.ts';
import type { Database } from '../services/storage/database.ts';
import type { RouteDefinition, RouteModule, RouteStream } from './types.ts';
import type { Accounts } from '../auth/accounts.ts';
/**
* Schema to validate a single write resource.
*
* Each write targets one resource slot identified by (id, publicKey).
* The publicKey owner signs the payload to prove write authority.
*/
const writeResource = z.object({
id: z.string().min(1),
publicKey: z.string().min(1),
timestamp: z.number().positive(),
signature: z.string().min(1),
value: z.instanceof(Uint8Array),
});
/**
* Schema to validate the write body.
*
* The body contains an array of write resources.
*/
const writeBody = z.object({
resources: z.array(writeResource).min(1),
});
/**
* Schema to validate and deduplicate resource IDs supplied in an application body.
*
* The body contains an array of resource IDs.
*/
const resourceIdsSchema = z.object({
resourceId: z
.array(z.string().min(1))
.min(1, 'At least one resourceId is required')
.transform((ids) => [ ...new Set(ids) ]),
});
type WriteResource = z.infer<typeof writeResource>;
/**
* Resource data domain routes.
*
* A "resource" is a shared document identified by id. Multiple instances
* (one per publicKey) can coexist within the same resource. Clients read,
* write, subscribe to changes, and unsubscribe over the transport-neutral
* RouteStream API.
*/
export class DataRoute implements RouteModule {
constructor(
private readonly database: Database,
private readonly broadcaster: BaseBroadcaster,
private readonly auth: AuthSecp256k1,
private readonly accounts: Accounts,
) {}
/** Declare exact routes; each handler owns its stream behavior. */
async getRoutes(): Promise<Array<RouteDefinition>> {
return [
{
url: '/data/get',
handler: this.getData.bind(this),
},
{
url: '/data/write',
handler: this.writeData.bind(this),
},
{
url: '/data/subscribe',
handler: this.subscribeData.bind(this),
},
{
url: '/data/unsubscribe',
handler: this.unsubscribeData.bind(this),
},
];
}
/** Reads the requested resources from the database, returning all instances for each resource */
async getData(stream: RouteStream): Promise<void> {
const resourceIds = resourceIdsSchema.parse(stream.body).resourceId;
// Remove duplicates.
const uniqueIds = [ ...new Set(resourceIds) ];
// If there are no resource ids, return an empty array.
if (uniqueIds.length === 0) {
await stream.send([]);
return;
}
// Read the data from the database.
const rows = await this.database.db
.selectFrom('resource_data')
.select([ 'resource_id', 'public_key', 'blob', 'timestamp', 'signature' ])
.where('resource_id', 'in', uniqueIds)
.orderBy('timestamp', 'asc')
.execute();
// Format the rows into the read resource responses.
const formattedRows = rows.map((row) => ({
resourceId: row.resource_id,
publicKey: row.public_key,
blob: new Uint8Array(row.blob),
timestamp: row.timestamp,
signature: row.signature,
}));
await stream.send(formattedRows);
}
/**
* Authenticated batch write.
*
* Each resource in the batch is verified independently, then persisted and
* broadcast to any subscribers listening on that resource's topic.
*/
async writeData(stream: RouteStream): Promise<void> {
const { resources } = writeBody.parse(stream.body);
// temporarily disable the signature verification for testing
// const publicKey = stream.headers?.['x-public-key']
const publicKey = 'public-key';
// Authenticate the whole batch before producing any storage side effects.
// A single bad signature rejects the entire write — no partial commits.
await Promise.all(resources.map((resource) => this.verifyWriteResource(resource)));
const timestamp = Date.now();
const rows = resources.map((resource) => ({
resourceId: resource.id,
publicKey: resource.publicKey,
blob: Buffer.from(resource.value),
signature: resource.signature,
}));
// Get the total size of the bytes being written
const totalSize = rows.reduce((acc, row) => acc + row.blob.length, 0);
if (!await this.accounts.hasSufficientBalance(publicKey, totalSize)) {
throw new ApplicationError(203, 'Insufficient balance');
}
// Set the balance of the public key
await this.accounts.deductBalance(publicKey, totalSize);
// Upsert every row atomically; conflicts update blob and timestamp only.
await this.database.db.transaction().execute(async (trx) => {
for (const { resourceId, publicKey, blob, signature } of rows) {
await trx
.insertInto('resource_data')
.values({
resource_id: resourceId,
public_key: publicKey,
blob,
timestamp,
signature,
})
.onConflict((oc) =>
oc.columns([ 'resource_id', 'public_key' ]).doUpdateSet({
blob,
timestamp,
}))
.execute();
}
});
// Format the rows into the written resource responses.
const written = rows.map(({ resourceId, publicKey, blob, signature }) => ({
instance: {
resourceId,
publicKey,
blob: new Uint8Array(blob),
timestamp,
signature,
},
}));
// Notify subscribers on each changed resource. Topic names are scoped per
// resource id so clients only receive events for resources they joined.
for (const { instance } of written) {
await this.broadcaster.publish(DataRoute.resourceTopic(instance.resourceId), {
type: 'instance-changed',
data: instance,
});
}
// Return the persisted instances so the writer can confirm what was stored.
await stream.send({
resources: written.map(({ instance }) => ({
id: instance.resourceId,
...instance,
})),
balance: await this.accounts.getBalance(publicKey),
});
}
/** Subscribe this connection to future changes for the requested resources. */
async subscribeData(stream: RouteStream): Promise<void> {
const resourceIds = resourceIdsSchema.parse(stream.body).resourceId;
const topics = resourceIds.map((resourceId) => DataRoute.resourceTopic(resourceId));
// Subscribe registers the topics synchronously, then keeps this route
// active until those topics are removed or the connection closes.
await this.broadcaster.subscribe(stream, topics);
}
/**
* Leave resource topics without closing the connection.
*
* Only available on bidirectional transports (WebSocket). SSE clients
* unsubscribe implicitly by aborting the HTTP request.
*/
async unsubscribeData(stream: RouteStream): Promise<void> {
const resourceIds = resourceIdsSchema.parse(stream.body).resourceId;
// If the stream is not bidirectional, throw an error.
if (!stream.bidirectional) {
throw new ApplicationError(HTTP_STATUS_CODE_NOT_ACCEPTED, 'This route requires an existing bidirectional stream');
}
// Unsubscribe from the resource topics.
await this.broadcaster.unsubscribe(
stream,
resourceIds.map((resourceId) => DataRoute.resourceTopic(resourceId)),
);
await stream.send({});
}
/**
* Verify one write's timestamp freshness and secp256k1 signature.
*
* The client must sign the canonical payload built from timestamp, resource
* id, and value — not the raw HTTP/WebSocket envelope.
*/
private async verifyWriteResource(resource: WriteResource): Promise<void> {
this.auth.assertTimestampFreshness(resource.timestamp);
// Compile the signature payload as `Timestamp:ID:Value`
const signaturePayload = `${resource.timestamp}:${resource.id}:${toExtendedJson(resource.value)}`;
if (!(await this.auth.verifySignature(resource.publicKey, resource.signature, signaturePayload))) {
throw new UnauthorizedError('Invalid resource signature');
}
}
/** Broadcaster topic for a single resource's instance-changed events. */
private static resourceTopic(resourceId: string): string {
return `resource:${resourceId}`;
}
}