From 8bb5b4a557f2a46f300b79745982788c59f765f7 Mon Sep 17 00:00:00 2001
From: Jason Williams <936006+jasonwilliams@users.noreply.github.com>
Date: Sun, 10 Jul 2022 14:54:31 +0100
Subject: [PATCH] Desktop: Resolves #164: Add support for proxy (#6537)

---
 cspell.json                     |  3 +-
 packages/lib/BaseApplication.ts | 12 +++++++
 packages/lib/models/Setting.ts  | 32 ++++++++++++++++++-
 packages/lib/package.json       |  1 +
 packages/lib/shim-init-node.js  | 56 +++++++++++++++++++++++++++++++--
 packages/lib/shim.ts            |  2 +-
 yarn.lock                       |  8 +++++
 7 files changed, 108 insertions(+), 6 deletions(-)

diff --git a/cspell.json b/cspell.json
index 2c79c27b1a..fb618b0fd4 100644
--- a/cspell.json
+++ b/cspell.json
@@ -325,6 +325,7 @@
 		"homenote",
 		"hotfolder",
 		"Howver",
+		"hpagent",
 		"Hrvatska",
 		"htmlentities",
 		"htmlfile",
@@ -950,4 +951,4 @@
 		"မြန်မာ",
 		"កម្ពុជា"
 	]
-}
\ No newline at end of file
+}
diff --git a/packages/lib/BaseApplication.ts b/packages/lib/BaseApplication.ts
index 2cb9763fe6..0297ec005e 100644
--- a/packages/lib/BaseApplication.ts
+++ b/packages/lib/BaseApplication.ts
@@ -1,6 +1,7 @@
 import Setting, { Env } from './models/Setting';
 import Logger, { TargetType, LoggerWrapper } from './Logger';
 import shim from './shim';
+const { setupProxySettings } = require('./shim-init-node');
 import BaseService from './services/BaseService';
 import reducer, { setStore } from './reducer';
 import KeychainServiceDriver from './services/keychain/KeychainServiceDriver.node';
@@ -456,6 +457,14 @@ export default class BaseApplication {
 					syswidecas.addCAs(f);
 				}
 			},
+			'net.proxyEnabled': async () => {
+				setupProxySettings({
+					maxConcurrentConnections: Setting.value('sync.maxConcurrentConnections'),
+					proxyTimeout: Setting.value('net.proxyTimeout'),
+					proxyEnabled: Setting.value('net.proxyEnabled'),
+					proxyUrl: Setting.value('net.proxyUrl'),
+				});
+			},
 
 			// Note: this used to run when "encryption.enabled" was changed, but
 			// now we run it anytime any property of the sync target info is
@@ -491,6 +500,9 @@ export default class BaseApplication {
 		sideEffects['locale'] = sideEffects['dateFormat'];
 		sideEffects['encryption.passwordCache'] = sideEffects['syncInfoCache'];
 		sideEffects['encryption.masterPassword'] = sideEffects['syncInfoCache'];
+		sideEffects['sync.maxConcurrentConnections'] = sideEffects['net.proxyEnabled'];
+		sideEffects['sync.proxyTimeout'] = sideEffects['net.proxyEnabled'];
+		sideEffects['sync.proxyUrl'] = sideEffects['net.proxyEnabled'];
 
 		if (action) {
 			const effect = sideEffects[action.key];
diff --git a/packages/lib/models/Setting.ts b/packages/lib/models/Setting.ts
index 4b511ca2ca..af48f1afa2 100644
--- a/packages/lib/models/Setting.ts
+++ b/packages/lib/models/Setting.ts
@@ -1384,7 +1384,37 @@ class Setting extends BaseModel {
 				label: () => _('Ignore TLS certificate errors'),
 				storage: SettingStorage.File,
 			},
-
+			'net.proxyEnabled': {
+				value: false,
+				type: SettingItemType.Bool,
+				advanced: true,
+				section: 'sync',
+				isGlobal: true,
+				public: true,
+				label: () => _('Proxy enabled (beta)'),
+				storage: SettingStorage.File,
+			},
+			'net.proxyUrl': {
+				value: '',
+				type: SettingItemType.String,
+				advanced: true,
+				section: 'sync',
+				isGlobal: true,
+				public: true,
+				label: () => _('Proxy URL (beta)'),
+				description: () => _('e.g "http://my.proxy.com:80". You can also set via environment variables'),
+				storage: SettingStorage.File,
+			},
+			'net.proxyTimeout': {
+				value: 1,
+				type: SettingItemType.Int,
+				advanced: true,
+				section: 'sync',
+				isGlobal: true,
+				public: true,
+				label: () => _('proxy timeout (seconds) (beta)'),
+				storage: SettingStorage.File,
+			},
 			'sync.wipeOutFailSafe': {
 				value: true,
 				type: SettingItemType.Bool,
diff --git a/packages/lib/package.json b/packages/lib/package.json
index fe719129f2..a5fb4e9828 100644
--- a/packages/lib/package.json
+++ b/packages/lib/package.json
@@ -53,6 +53,7 @@
     "follow-redirects": "^1.2.4",
     "form-data": "^2.1.4",
     "fs-extra": "^5.0.0",
+    "hpagent": "^1.0.0",
     "html-entities": "^1.2.1",
     "html-minifier": "^3.5.15",
     "image-data-uri": "^2.0.0",
diff --git a/packages/lib/shim-init-node.js b/packages/lib/shim-init-node.js
index 114c4f998c..895a1a1131 100644
--- a/packages/lib/shim-init-node.js
+++ b/packages/lib/shim-init-node.js
@@ -13,12 +13,15 @@ const urlValidator = require('valid-url');
 const { _ } = require('./locale');
 const http = require('http');
 const https = require('https');
+const { HttpProxyAgent, HttpsProxyAgent } = require('hpagent');
 const toRelative = require('relative');
 const timers = require('timers');
 const zlib = require('zlib');
 const dgram = require('dgram');
 const { basename, fileExtension, safeFileExtension } = require('./path-utils');
 
+const proxySettings = {};
+
 function fileExists(filePath) {
 	try {
 		return fs.statSync(filePath).isFile();
@@ -27,6 +30,20 @@ function fileExists(filePath) {
 	}
 }
 
+function isUrlHttps(url) {
+	return url.startsWith('https');
+}
+
+function resolveProxyUrl(proxyUrl) {
+	return (
+		proxyUrl ||
+		process.env['http_proxy'] ||
+		process.env['https_proxy'] ||
+		process.env['HTTP_PROXY'] ||
+		process.env['HTTPS_PROXY']
+	);
+}
+
 // https://github.com/sindresorhus/callsites/blob/main/index.js
 function callsites() {
 	const _prepareStackTrace = Error.prepareStackTrace;
@@ -64,6 +81,13 @@ const gunzipFile = function(source, destination) {
 	});
 };
 
+function setupProxySettings(options) {
+	proxySettings.maxConcurrentConnections = options.maxConcurrentConnections;
+	proxySettings.proxyTimeout = options.proxyTimeout;
+	proxySettings.proxyEnabled = options.proxyEnabled;
+	proxySettings.proxyUrl = options.proxyUrl;
+}
+
 function shimInit(options = null) {
 	options = {
 		sharp: null,
@@ -79,6 +103,7 @@ function shimInit(options = null) {
 	const keytar = (shim.isWindows() || shim.isMac()) && !shim.isPortable() ? options.keytar : null;
 	const appVersion = options.appVersion;
 
+
 	shim.setNodeSqlite(options.nodeSqlite);
 
 	shim.fsDriver = () => {
@@ -420,10 +445,11 @@ function shimInit(options = null) {
 		return new Buffer(data).toString('base64');
 	};
 
-	shim.fetch = async function(url, options = null) {
+	shim.fetch = async function(url, options = {}) {
 		const validatedUrl = urlValidator.isUri(url);
 		if (!validatedUrl) throw new Error(`Not a valid URL: ${url}`);
-
+		const resolvedProxyUrl = resolveProxyUrl(proxySettings.proxyUrl);
+		options.agent = (resolvedProxyUrl && proxySettings.proxyEnabled) ? shim.proxyAgent(url, resolvedProxyUrl) : null;
 		return shim.fetchWithRetry(() => {
 			return nodeFetch(url, options);
 		}, options);
@@ -466,6 +492,9 @@ function shimInit(options = null) {
 			headers: headers,
 		};
 
+		const resolvedProxyUrl = resolveProxyUrl(proxySettings.proxyUrl);
+		requestOptions.agent = (resolvedProxyUrl && proxySettings.proxyEnabled) ? shim.proxyAgent(url, resolvedProxyUrl) : null;
+
 		const doFetchOperation = async () => {
 			return new Promise((resolve, reject) => {
 				let file = null;
@@ -572,6 +601,27 @@ function shimInit(options = null) {
 		return url.startsWith('https') ? shim.httpAgent_.https : shim.httpAgent_.http;
 	};
 
+	shim.proxyAgent = (serverUrl, proxyUrl) => {
+		const proxyAgentConfig = {
+			keepAlive: true,
+			maxSockets: proxySettings.maxConcurrentConnections,
+			keepAliveMsecs: 5000,
+			proxy: proxyUrl,
+			timeout: proxySettings.proxyTimeout * 1000,
+		};
+
+		// Based on https://github.com/delvedor/hpagent#usage
+		if (!isUrlHttps(proxyUrl) && !isUrlHttps(serverUrl)) {
+			return new HttpProxyAgent(proxyAgentConfig);
+		} else if (isUrlHttps(proxyUrl) && !isUrlHttps(serverUrl)) {
+			return new HttpProxyAgent(proxyAgentConfig);
+		} else if (!isUrlHttps(proxyUrl) && isUrlHttps(serverUrl)) {
+			return new HttpsProxyAgent(proxyAgentConfig);
+		} else {
+			return new HttpsProxyAgent(proxyAgentConfig);
+		}
+	};
+
 	shim.openOrCreateFile = (filepath, defaultContents) => {
 		// If the file doesn't exist, create it
 		if (!fs.existsSync(filepath)) {
@@ -634,4 +684,4 @@ function shimInit(options = null) {
 	};
 }
 
-module.exports = { shimInit };
+module.exports = { shimInit, setupProxySettings };
diff --git a/packages/lib/shim.ts b/packages/lib/shim.ts
index a9495ad291..26dc7b1bf5 100644
--- a/packages/lib/shim.ts
+++ b/packages/lib/shim.ts
@@ -16,7 +16,7 @@ let isTestingEnv_ = false;
 // (app-desktop, app-mobile, etc.) since we are sure they won't be dependency to
 // other packages (unlike the lib which can be included anywhere).
 //
-// Regarding the type - althought we import React, we only use it as a type
+// Regarding the type - although we import React, we only use it as a type
 // using `typeof React`. This is just to get types in hooks.
 //
 // https://stackoverflow.com/a/42816077/561309
diff --git a/yarn.lock b/yarn.lock
index 722a43a66a..4d92927990 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3436,6 +3436,7 @@ __metadata:
     follow-redirects: ^1.2.4
     form-data: ^2.1.4
     fs-extra: ^5.0.0
+    hpagent: ^1.0.0
     html-entities: ^1.2.1
     html-minifier: ^3.5.15
     image-data-uri: ^2.0.0
@@ -16672,6 +16673,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"hpagent@npm:^1.0.0":
+  version: 1.0.0
+  resolution: "hpagent@npm:1.0.0"
+  checksum: 911a9ba612747f5c9403fb60c1abd0c47a27fa634826caad9aecad41b899533489da36c92758b5cd83576e2bf9e84e23a4374a40aa513106d5450f62856c4b2d
+  languageName: node
+  linkType: hard
+
 "html-encoding-sniffer@npm:^1.0.2":
   version: 1.0.2
   resolution: "html-encoding-sniffer@npm:1.0.2"