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Move CSP logic to new file, Fix boolean config examples

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Not sure why I was quoting these in the first place
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Literallie 2017-10-22 01:22:48 +02:00
parent e5f03fe135
commit 04f5e3a341
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5 changed files with 91 additions and 81 deletions
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4
README.md
View file

@ -171,8 +171,8 @@ Application settings `config.json`
| port | `80` | web app port |
| alloworigin | `['localhost']` | domain name whitelist |
| usessl | `true` or `false` | set to use ssl server (if true will auto turn on `protocolusessl`) |
| hsts | `{"enable": "true", "maxAgeSeconds": "31536000", "includeSubdomains": "true", "preload": "true"}` | [HSTS](https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security) options to use with HTTPS (default is the example value, max age is a year) |
| csp | `{"enable": "true", "directives": {"scriptSrc": "trustwodthy-scripts.example.com"}, "upgradeInsecureRequests": "auto", "addDefaults": "true"}` | Configures [Content Security Policy](https://helmetjs.github.io/docs/csp/). Directives are directly passed to Helmet, so [their format](https://helmetjs.github.io/docs/csp/) applies. Further, some defaults are added so that the application doesn't break. To disable adding these defaults, set `addDefaults` to `false`. If `usecdn` is on, default CDN locations are allowed too. By default (`auto`), insecure (HTTP) requests are upgraded to HTTPS via CSP if `usessl` is on. To change this behaviour, set `upgradeInsecureRequests` to either `true` or `false`. |
| hsts | `{"enable": true, "maxAgeSeconds": 31536000, "includeSubdomains": true, "preload": true}` | [HSTS](https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security) options to use with HTTPS (default is the example value, max age is a year) |
| csp | `{"enable": true, "directives": {"scriptSrc": "trustworthy-scripts.example.com"}, "upgradeInsecureRequests": "auto", "addDefaults": true}` | Configures [Content Security Policy](https://helmetjs.github.io/docs/csp/). Directives are passed to Helmet - see [their documentation](https://helmetjs.github.io/docs/csp/) for more information on the format. Some defaults are added to the configured values so that the application doesn't break. To disable this behaviour, set `addDefaults` to `false`. Further, if `usecdn` is on, some CDN locations are allowed too. By default (`auto`), insecure (HTTP) requests are upgraded to HTTPS via CSP if `usessl` is on. To change this behaviour, set `upgradeInsecureRequests` to either `true` or `false`. |
| protocolusessl | `true` or `false` | set to use ssl protocol for resources path (only applied when domain is set) |
| urladdport | `true` or `false` | set to add port on callback url (port 80 or 443 won't applied) (only applied when domain is set) |
| usecdn | `true` or `false` | set to use CDN resources or not (default is `true`) |

77
app.js
View file

@ -12,7 +12,6 @@ var session = require('express-session')
var SequelizeStore = require('connect-session-sequelize')(session.Store)
var fs = require('fs')
var path = require('path')
var uuid = require('uuid')
var morgan = require('morgan')
var passportSocketIo = require('passport.socketio')
@ -25,6 +24,7 @@ var config = require('./lib/config')
var logger = require('./lib/logger')
var response = require('./lib/response')
var models = require('./lib/models')
var csp = require('./lib/csp')
// generate front-end constants by template
var constpath = path.join(__dirname, './public/js/lib/common/constant.ejs')
@ -109,83 +109,14 @@ if (config.hsts.enable) {
logger.info('https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security')
}
app.use((req, res, next) => {
res.locals.nonce = uuid.v4()
next()
})
// Generate a random nonce per request, for CSP with inline scripts
app.use(csp.addNonceToLocals)
// use Content-Security-Policy to limit XSS, dangerous plugins, etc.
// https://helmetjs.github.io/docs/csp/
function getCspNonce (req, res) {
return "'nonce-" + res.locals.nonce + "'"
}
function getCspWebSocketUrl (req, res) {
// wss: is included in 'self', but 'ws:' is not
return (req.protocol === 'http' ? 'ws:' : 'wss:') + config.serverurl.replace(/https?:/, "")
}
function mergeWithDefaults(configured, defaultDirective, cdnDirective) {
var directive = [].concat(configured)
if (config.csp.addDefaults && defaultDirective) {
directive = directive.concat(defaultDirective)
}
if (config.usecdn && cdnDirective) {
directive = directive.concat(cdnDirective)
}
return directive
}
if (config.csp.enable) {
var defaultDirectives = {
defaultSrc: ['\'self\''],
scriptSrc: ['\'self\'', 'vimeo.com', 'https://gist.github.com', 'www.slideshare.net', 'https://query.yahooapis.com', 'https://*.disqus.com', '\'unsafe-eval\''], // TODO: Remove unsafe-eval - webpack script-loader issues
imgSrc: ['*'],
styleSrc: ['\'self\'', '\'unsafe-inline\'', 'https://assets-cdn.github.com'], // unsafe-inline is required for some libs, plus used in views
fontSrc: ['\'self\'', 'https://public.slidesharecdn.com'],
objectSrc: ['*'], // Chrome PDF viewer treats PDFs as objects :/
childSrc: ['*'],
connectSrc: ['*']
};
var cdnDirectives = {
scriptSrc: ['https://cdnjs.cloudflare.com', 'https://cdn.mathjax.org'],
styleSrc: ['https://cdnjs.cloudflare.com', 'https://fonts.googleapis.com'],
fontSrc: ['https://cdnjs.cloudflare.com', 'https://fonts.gstatic.com']
}
var directives = {}
for (var propertyName in config.csp.directives) {
if (config.csp.directives.hasOwnProperty(propertyName)) {
directives[propertyName] = mergeWithDefaults(
config.csp.directives[propertyName],
defaultDirectives[propertyName],
cdnDirectives[propertyName]
)
}
}
for (var propertyName in defaultDirectives) {
if (!directives[propertyName]) {
directives[propertyName] = mergeWithDefaults(
[],
defaultDirectives[propertyName],
cdnDirectives[propertyName]
)
}
}
if (directives.scriptSrc.indexOf('\'unsafe-inline\'') === -1) {
directives.scriptSrc.push(getCspNonce)
// TODO: This is the SHA-256 hash of the inline script in
// build/reveal.js/plugins/notes/notes.html . Any cleaner
// solution appreciated.
directives.scriptSrc.push('\'sha256-EtvSSxRwce5cLeFBZbvZvDrTiRoyoXbWWwvEVciM5Ag=\'')
}
directives.connectSrc.push(getCspWebSocketUrl)
if (config.csp.upgradeInsecureRequests === 'auto') {
directives.upgradeInsecureRequests = config.usessl === 'true'
} else {
directives.upgradeInsecureRequests = config.csp.upgradeInsecureRequests === 'true'
}
app.use(helmet.contentSecurityPolicy({
directives: directives
directives: csp.computeDirectives()
}))
} else {
logger.info('Content-Security-Policy is disabled. This may be a security risk.')

10
config.json.example
View file

@ -17,17 +17,17 @@
"production": {
"domain": "localhost",
"hsts": {
"enable": "true",
"enable": true,
"maxAgeSeconds": "31536000",
"includeSubdomains": "true",
"preload": "true"
"includeSubdomains": true,
"preload": true
},
csp: {
"enable": "true",
"enable": true,
"directives": {
},
"upgradeInsecureRequests": "auto"
"addDefaults": "true"
"addDefaults": true
},
"db": {
"username": "",

80
lib/csp.js Normal file
View file

@ -0,0 +1,80 @@
var config = require('./config')
var uuid = require('uuid')
var CspStrategy = {}
var defaultDirectives = {
defaultSrc: ['\'self\''],
scriptSrc: ['\'self\'', 'vimeo.com', 'https://gist.github.com', 'www.slideshare.net', 'https://query.yahooapis.com', 'https://*.disqus.com', '\'unsafe-eval\''],
// ^ TODO: Remove unsafe-eval - webpack script-loader issues https://github.com/hackmdio/hackmd/issues/594
imgSrc: ['*'],
styleSrc: ['\'self\'', '\'unsafe-inline\'', 'https://assets-cdn.github.com'], // unsafe-inline is required for some libs, plus used in views
fontSrc: ['\'self\'', 'https://public.slidesharecdn.com'],
objectSrc: ['*'], // Chrome PDF viewer treats PDFs as objects :/
childSrc: ['*'],
connectSrc: ['*']
}
var cdnDirectives = {
scriptSrc: ['https://cdnjs.cloudflare.com', 'https://cdn.mathjax.org'],
styleSrc: ['https://cdnjs.cloudflare.com', 'https://fonts.googleapis.com'],
fontSrc: ['https://cdnjs.cloudflare.com', 'https://fonts.gstatic.com']
}
CspStrategy.computeDirectives = function () {
var directives = {}
mergeDirectives(directives, config.csp.directives)
mergeDirectivesIf(config.csp.addDefaults, directives, defaultDirectives)
mergeDirectivesIf(config.usecdn, directives, cdnDirectives)
if (!areAllInlineScriptsAllowed(directives)) {
addInlineScriptExceptions(directives)
}
addUpgradeUnsafeRequestsOptionTo(directives)
return directives
}
function mergeDirectives (existingDirectives, newDirectives) {
for (var propertyName in newDirectives) {
var newDirective = newDirectives[propertyName]
if (newDirective) {
var existingDirective = existingDirectives[propertyName] || []
existingDirectives[propertyName] = existingDirective.concat(newDirective)
}
}
}
function mergeDirectivesIf (condition, existingDirectives, newDirectives) {
if (condition) {
mergeDirectives(existingDirectives, newDirectives)
}
}
function areAllInlineScriptsAllowed (directives) {
return directives.scriptSrc.indexOf('\'unsafe-inline\'') !== -1
}
function addInlineScriptExceptions (directives) {
directives.scriptSrc.push(getCspNonce)
// TODO: This is the SHA-256 hash of the inline script in build/reveal.js/plugins/notes/notes.html
// Any more clean solution appreciated.
directives.scriptSrc.push('\'sha256-EtvSSxRwce5cLeFBZbvZvDrTiRoyoXbWWwvEVciM5Ag=\'')
}
function getCspNonce (req, res) {
return "'nonce-" + res.locals.nonce + "'"
}
function addUpgradeUnsafeRequestsOptionTo (directives) {
if (config.csp.upgradeInsecureRequests === 'auto' && config.usessl) {
directives.upgradeInsecureRequests = true
} else if (config.csp.upgradeInsecureRequests === true) {
directives.upgradeInsecureRequests = true
}
}
CspStrategy.addNonceToLocals = function (req, res, next) {
res.locals.nonce = uuid.v4()
next()
}
module.exports = CspStrategy

1
public/js/index.js
View file

@ -3,7 +3,6 @@
modeType, Idle, serverurl, key, gapi, Dropbox, FilePicker
ot, MediaUploader, hex2rgb, num_loaded, Visibility */
require('../vendor/showup/showup')
require('../css/index.css')