allow private IP ranges to specify allowed ports

3 files changed, 161 insertions, 43 deletions

diff --git a/packages/backend/src/config.ts b/packages/backend/src/config.ts
index 92fc2b8a13..2a3184f9b4 100644
--- a/packages/backend/src/config.ts
+++ b/packages/backend/src/config.ts
@@ -8,9 +8,11 @@ import { fileURLToPath } from 'node:url';
 import { dirname, resolve } from 'node:path';
 import * as yaml from 'js-yaml';
 import { globSync } from 'glob';
+import ipaddr from 'ipaddr.js';
 import type * as Sentry from '@sentry/node';
 import type * as SentryVue from '@sentry/vue';
 import type { RedisOptions } from 'ioredis';
+import type { IPv4, IPv6 } from 'ipaddr.js';
 
 type RedisOptionsSource = Partial<RedisOptions> & {
 	host?: string;
@@ -152,6 +154,33 @@ type Source = {
 	}
 };
 
+export type PrivateNetwork = {
+	/**
+	 * CIDR IP/netmask definition of the IP range to match.
+	 */
+	cidr: [ip: IPv4 | IPv6, mask: number];
+
+	/**
+	 * List of ports to match.
+	 * If undefined, then all ports match.
+	 * If empty, then NO ports match.
+	 */
+	ports?: number[];
+};
+
+export function parsePrivateNetworks(patterns: string[]): PrivateNetwork[];
+export function parsePrivateNetworks(patterns: undefined): undefined;
+export function parsePrivateNetworks(patterns: string[] | undefined): PrivateNetwork[] | undefined;
+export function parsePrivateNetworks(patterns: string[] | undefined): PrivateNetwork[] | undefined {
+	return patterns?.map(e => {
+		const [ip, ports] = e.split('#') as [string, ...(string | undefined)[]];
+		return {
+			cidr: ipaddr.parseCIDR(ip),
+			ports: ports?.split(',').map(p => parseInt(p)),
+		};
+	});
+}
+
 export type Config = {
 	url: string;
 	port: number;
@@ -190,7 +219,7 @@ export type Config = {
 	proxy: string | undefined;
 	proxySmtp: string | undefined;
 	proxyBypassHosts: string[] | undefined;
-	allowedPrivateNetworks: string[] | undefined;
+	allowedPrivateNetworks: PrivateNetwork[] | undefined;
 	disallowExternalApRedirect: boolean;
 	maxFileSize: number;
 	maxNoteLength: number;
@@ -382,7 +411,7 @@ export function loadConfig(): Config {
 		proxy: config.proxy,
 		proxySmtp: config.proxySmtp,
 		proxyBypassHosts: config.proxyBypassHosts,
-		allowedPrivateNetworks: config.allowedPrivateNetworks,
+		allowedPrivateNetworks: parsePrivateNetworks(config.allowedPrivateNetworks),
 		disallowExternalApRedirect: config.disallowExternalApRedirect ?? false,
 		maxFileSize: config.maxFileSize ?? 262144000,
 		maxNoteLength: config.maxNoteLength ?? 3000,
diff --git a/packages/backend/src/core/HttpRequestService.ts b/packages/backend/src/core/HttpRequestService.ts
index 12047346fb..7c086c9976 100644
--- a/packages/backend/src/core/HttpRequestService.ts
+++ b/packages/backend/src/core/HttpRequestService.ts
@@ -12,7 +12,7 @@ import fetch from 'node-fetch';
 import { HttpProxyAgent, HttpsProxyAgent } from 'hpagent';
 import { Inject, Injectable } from '@nestjs/common';
 import { DI } from '@/di-symbols.js';
-import type { Config } from '@/config.js';
+import type { Config, PrivateNetwork } from '@/config.js';
 import { StatusError } from '@/misc/status-error.js';
 import { bindThis } from '@/decorators.js';
 import { validateContentTypeSetAsActivityPub } from '@/core/activitypub/misc/validator.js';
@@ -20,12 +20,36 @@ import type { IObject, IObjectWithId } from '@/core/activitypub/type.js';
 import { ApUtilityService } from './activitypub/ApUtilityService.js';
 import type { Response } from 'node-fetch';
 import type { URL } from 'node:url';
+import type { Socket } from 'node:net';
 
 export type HttpRequestSendOptions = {
 	throwErrorWhenResponseNotOk: boolean;
 	validators?: ((res: Response) => void)[];
 };
 
+export function isPrivateIp(allowedPrivateNetworks: PrivateNetwork[] | undefined, ip: string, port?: number): boolean {
+	const parsedIp = ipaddr.parse(ip);
+
+	for (const { cidr, ports } of allowedPrivateNetworks ?? []) {
+		if (cidr[0].kind() === parsedIp.kind() && parsedIp.match(cidr)) {
+			if (port == null || ports == null || ports.includes(port)) {
+				return false;
+			}
+		}
+	}
+
+	return parsedIp.range() !== 'unicast';
+}
+
+export function validateSocketConnect(allowedPrivateNetworks: PrivateNetwork[] | undefined, socket: Socket): void {
+	const address = socket.remoteAddress;
+	if (address && ipaddr.isValid(address)) {
+		if (isPrivateIp(allowedPrivateNetworks, address, socket.remotePort)) {
+			socket.destroy(new Error(`Blocked address: ${address}`));
+		}
+	}
+}
+
 declare module 'node:http' {
 	interface Agent {
 		createConnection(options: net.NetConnectOpts, callback?: (err: unknown, stream: net.Socket) => void): net.Socket;
@@ -44,31 +68,12 @@ class HttpRequestServiceAgent extends http.Agent {
 	public createConnection(options: net.NetConnectOpts, callback?: (err: unknown, stream: net.Socket) => void): net.Socket {
 		const socket = super.createConnection(options, callback)
 			.on('connect', () => {
-				const address = socket.remoteAddress;
 				if (process.env.NODE_ENV === 'production') {
-					if (address && ipaddr.isValid(address)) {
-						if (this.isPrivateIp(address)) {
-							socket.destroy(new Error(`Blocked address: ${address}`));
-						}
-					}
+					validateSocketConnect(this.config.allowedPrivateNetworks, socket);
 				}
 			});
 		return socket;
 	}
-
-	@bindThis
-	private isPrivateIp(ip: string): boolean {
-		const parsedIp = ipaddr.parse(ip);
-
-		for (const net of this.config.allowedPrivateNetworks ?? []) {
-			const cidr = ipaddr.parseCIDR(net);
-			if (cidr[0].kind() === parsedIp.kind() && parsedIp.match(ipaddr.parseCIDR(net))) {
-				return false;
-			}
-		}
-
-		return parsedIp.range() !== 'unicast';
-	}
 }
 
 class HttpsRequestServiceAgent extends https.Agent {
@@ -83,31 +88,12 @@ class HttpsRequestServiceAgent extends https.Agent {
 	public createConnection(options: net.NetConnectOpts, callback?: (err: unknown, stream: net.Socket) => void): net.Socket {
 		const socket = super.createConnection(options, callback)
 			.on('connect', () => {
-				const address = socket.remoteAddress;
 				if (process.env.NODE_ENV === 'production') {
-					if (address && ipaddr.isValid(address)) {
-						if (this.isPrivateIp(address)) {
-							socket.destroy(new Error(`Blocked address: ${address}`));
-						}
-					}
+					validateSocketConnect(this.config.allowedPrivateNetworks, socket);
 				}
 			});
 		return socket;
 	}
-
-	@bindThis
-	private isPrivateIp(ip: string): boolean {
-		const parsedIp = ipaddr.parse(ip);
-
-		for (const net of this.config.allowedPrivateNetworks ?? []) {
-			const cidr = ipaddr.parseCIDR(net);
-			if (cidr[0].kind() === parsedIp.kind() && parsedIp.match(ipaddr.parseCIDR(net))) {
-				return false;
-			}
-		}
-
-		return parsedIp.range() !== 'unicast';
-	}
 }
 
 @Injectable()
diff --git a/packages/backend/test/unit/core/HttpRequestService.ts b/packages/backend/test/unit/core/HttpRequestService.ts
new file mode 100644
index 0000000000..3185b91567
--- /dev/null
+++ b/packages/backend/test/unit/core/HttpRequestService.ts
@@ -0,0 +1,103 @@
+/*
+ * SPDX-FileCopyrightText: hazelnoot and other Sharkey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { jest } from '@jest/globals';
+import type { Mock } from 'jest-mock';
+import type { PrivateNetwork } from '@/config.js';
+import type { Socket } from 'net';
+import { HttpRequestService, isPrivateIp, validateSocketConnect } from '@/core/HttpRequestService.js';
+import { parsePrivateNetworks } from '@/config.js';
+
+describe(HttpRequestService, () => {
+	let allowedPrivateNetworks: PrivateNetwork[] | undefined;
+
+	beforeEach(() => {
+		allowedPrivateNetworks = parsePrivateNetworks([
+			'10.0.0.1/32',
+			'127.0.0.1/32#1',
+			'127.0.0.1/32#3,4,5',
+		]);
+	});
+
+	describe('isPrivateIp', () => {
+		it('should return false when ip public', () => {
+			const result = isPrivateIp(allowedPrivateNetworks, '74.125.127.100', 80);
+			expect(result).toBeFalsy();
+		});
+
+		it('should return false when ip private and port matches', () => {
+			const result = isPrivateIp(allowedPrivateNetworks, '127.0.0.1', 1);
+			expect(result).toBeFalsy();
+		});
+
+		it('should return true when ip private and no ports specified', () => {
+			const result = isPrivateIp(allowedPrivateNetworks, '10.0.0.2', 80);
+			expect(result).toBeTruthy();
+		});
+
+		it('should return true when ip private and port does not match', () => {
+			const result = isPrivateIp(allowedPrivateNetworks, '127.0.0.1', 80);
+			expect(result).toBeTruthy();
+		});
+	});
+
+	describe('validateSocketConnect', () => {
+		let fakeSocket: Socket;
+		let fakeSocketMutable: {
+			remoteAddress: string | undefined;
+			remotePort: number | undefined;
+			destroy: Mock<(error?: Error) => void>;
+		};
+
+		beforeEach(() => {
+			fakeSocketMutable = {
+				remoteAddress: '74.125.127.100',
+				remotePort: 80,
+				destroy: jest.fn<(error?: Error) => void>(),
+			};
+			fakeSocket = fakeSocketMutable as unknown as Socket;
+		});
+
+		it('should accept when IP is empty', () => {
+			fakeSocketMutable.remoteAddress = undefined;
+
+			validateSocketConnect(allowedPrivateNetworks, fakeSocket);
+
+			expect(fakeSocket.destroy).not.toHaveBeenCalled();
+		});
+
+		it('should accept when IP is invalid', () => {
+			fakeSocketMutable.remoteAddress = 'AB939ajd9jdajsdja8jj';
+
+			validateSocketConnect(allowedPrivateNetworks, fakeSocket);
+
+			expect(fakeSocket.destroy).not.toHaveBeenCalled();
+		});
+
+		it('should accept when IP is valid', () => {
+			validateSocketConnect(allowedPrivateNetworks, fakeSocket);
+
+			expect(fakeSocket.destroy).not.toHaveBeenCalled();
+		});
+
+		it('should accept when IP is private and port match', () => {
+			fakeSocketMutable.remoteAddress = '127.0.0.1';
+			fakeSocketMutable.remotePort = 1;
+
+			validateSocketConnect(allowedPrivateNetworks, fakeSocket);
+
+			expect(fakeSocket.destroy).not.toHaveBeenCalled();
+		});
+
+		it('should reject when IP is private and port no match', () => {
+			fakeSocketMutable.remoteAddress = '127.0.0.1';
+			fakeSocketMutable.remotePort = 2;
+
+			validateSocketConnect(allowedPrivateNetworks, fakeSocket);
+
+			expect(fakeSocket.destroy).toHaveBeenCalled();
+		});
+	});
+});