opnsense: add initial api to create new clients

src/routes/api/clients/+server.ts

@@ -1,7 +1,17 @@
-import { error, type RequestHandler } from '@sveltejs/kit';
-import { wgClients } from '$lib/server/db/schema';
+import { error } from '@sveltejs/kit';
+import { ipAllocations, wgClients } from '$lib/server/db/schema';
 import { db } from '$lib/server/db';
-import { eq } from 'drizzle-orm';
+import { eq, isNull } from 'drizzle-orm';
+import {
+	IP_MAX_INDEX,
+	IPV4_STARTING_ADDR,
+	IPV6_CLIENT_PREFIX_SIZE,
+	IPV6_STARTING_ADDR,
+	VPN_ENDPOINT,
+} from '$env/static/private';
+import { opnsenseAuth, opnsenseUrl, serverUuid } from '$lib/server/opnsense';
+import type { RequestHandler } from './$types';
+import { Address4, Address6 } from 'ip-address';
 
 export const GET: RequestHandler = async (event) => {
 	if (!event.locals.user) {
@@ -12,7 +22,7 @@ export const GET: RequestHandler = async (event) => {
 	return new Response(
 		JSON.stringify({
 			clients,
-		})
+		}),
 	);
 };
 
@@ -20,9 +30,161 @@ async function findClients(userId: string) {
 	return db.query.wgClients.findMany({
 		where: eq(wgClients.userId, userId),
 		with: {
-			ipAllocation: true
-		}
+			ipAllocation: true,
+		},
 	});
 }
 
 export type Clients = Awaited<ReturnType<typeof findClients>>;
+
+export const POST: RequestHandler = async (event) => {
+	if (!event.locals.user) {
+		return error(401, 'Unauthorized');
+	}
+	// this is going to be quite long
+	// 1. fetch params for new client from opnsense api
+	// 2.1 get an allocation for the client
+	// 2.2. insert new client into db
+	// 2.3. update the allocation with the client id
+	// 3. create the client in opnsense
+	// 4. reconfigure opnsense to enable the new client
+	const err: ReturnType<typeof error> | undefined = await db.transaction(async (tx) => {
+		// fetch params for new client from opnsense api
+		const keys = await getKeys();
+
+		// find first unallocated IP
+		const availableAllocation = await tx.query.ipAllocations.findFirst({
+			columns: {
+				id: true,
+			},
+			where: isNull(ipAllocations.clientId),
+		});
+		// find last allocation to check if we have any IPs left
+		const lastAllocation = await tx.query.ipAllocations.findFirst({
+			columns: {
+				id: true,
+			},
+			orderBy: (ipAllocations, { desc }) => desc(ipAllocations.id),
+		});
+		// check for existing allocation or if we have any IPs left
+		if (!availableAllocation && lastAllocation && lastAllocation.id >= parseInt(IP_MAX_INDEX)) {
+			return error(500, 'No more IP addresses available');
+		}
+
+		// use existing allocation or create a new one
+		const ipAllocationId =
+			availableAllocation?.id ??
+			(await tx.insert(ipAllocations).values({}).returning({ id: ipAllocations.id }))[0].id;
+
+		// transaction savepoint after creating a new IP allocation
+		// TODO: not sure if this is needed
+		return await tx.transaction(async (tx2) => {
+			// create client in opnsense
+			const opnsenseRes = await opnsenseCreateClient({
+				// @ts-expect-error event.locals.user is checked at the beginning of the function
+				username: event.locals.user.username,
+				pubkey: keys.pubkey,
+				psk: keys.psk,
+				allowedIps: getAllowedIps(ipAllocationId - 1),
+			});
+			const opnsenseResJson = await opnsenseRes.json();
+			if (opnsenseResJson['result'] !== 'saved') {
+				tx2.rollback();
+				console.error(`Error creating client in OPNsense: \n${opnsenseResJson}`);
+				return error(500, 'Error creating client in OPNsense');
+			}
+
+			// create new client in db
+			const [newClient] = await tx2
+				.insert(wgClients)
+				.values({
+					// @ts-expect-error event.locals.user is checked at the beginning of the function
+					userId: event.locals.user.id,
+					name: 'New Client',
+					publicKey: keys.pubkey,
+					privateKey: keys.privkey,
+					preSharedKey: keys.psk,
+				})
+				.returning({ id: wgClients.id });
+
+			// update IP allocation with client ID
+			await tx2
+				.update(ipAllocations)
+				.set({ clientId: newClient.id })
+				.where(eq(ipAllocations.id, ipAllocationId));
+
+			// reconfigure opnsense
+			await opnsenseReconfigure();
+		});
+
+	});
+	return err?? new Response(null, { status: 201 });
+};
+
+async function getKeys() {
+	// fetch key pair from opnsense
+	const options: RequestInit = {
+		method: 'GET',
+		headers: {
+			Authorization: opnsenseAuth,
+			Accept: 'application/json',
+		},
+	};
+	const resKeyPair = await fetch(`${opnsenseUrl}/api/wireguard/server/key_pair`, options);
+	const resPsk = await fetch(`${opnsenseUrl}/api/wireguard/client/psk`, options);
+	const keyPair = await resKeyPair.json();
+	const psk = await resPsk.json();
+	return {
+		pubkey: keyPair['pubkey'] as string,
+		privkey: keyPair['privkey'] as string,
+		psk: psk['psk'] as string,
+	};
+}
+
+function getAllowedIps(ipIndex: number) {
+	const v4StartingAddr = new Address4(IPV4_STARTING_ADDR);
+	const v6StartingAddr = new Address6(IPV6_STARTING_ADDR);
+	const v4Allowed = Address4.fromBigInt(v4StartingAddr.bigInt() + BigInt(ipIndex));
+	const v6Offset = BigInt(ipIndex) << (128n - BigInt(IPV6_CLIENT_PREFIX_SIZE));
+	const v6Allowed = Address6.fromBigInt(v6StartingAddr.bigInt() + v6Offset);
+	const v6AllowedShort = v6Allowed.parsedAddress.join(':');
+
+	return `${v4Allowed.address}/32,${v6AllowedShort}/${IPV6_CLIENT_PREFIX_SIZE}`;
+}
+
+async function opnsenseCreateClient(params: {
+	username: string;
+	pubkey: string;
+	psk: string;
+	allowedIps: string;
+}) {
+	return fetch(`${opnsenseUrl}/api/wireguard/client/addClientBuilder`, {
+		method: 'POST',
+		headers: {
+			Authorization: opnsenseAuth,
+			Accept: 'application/json',
+			'Content-Type': 'application/json',
+		},
+		body: JSON.stringify({
+			configbuilder: {
+				enabled: '1',
+				name: `vpgen-${params.username}`,
+				pubkey: params.pubkey,
+				psk: params.psk,
+				tunneladdress: params.allowedIps,
+				server: serverUuid,
+				endpoint: VPN_ENDPOINT,
+			},
+		}),
+	});
+}
+
+async function opnsenseReconfigure() {
+	return fetch(`${opnsenseUrl}/api/wireguard/service/reconfigure`, {
+		method: 'POST',
+		headers: {
+			Authorization: opnsenseAuth,
+			Accept: 'application/json',
+		},
+	});
+}