From b31b232edfcc7f04acf828bf6829ab716b290692 Mon Sep 17 00:00:00 2001 From: ThibG Date: Tue, 30 Jul 2019 12:13:29 +0200 Subject: [PATCH] Change links in webUI to rewrite misleading links (#11426) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * [WiP] Show host for “misleading” links * Disallow misleading targets which domain names are prefixes of link text * Move decodeIDNA to app/javascript/mastodon/utils * Add support for international domain names * Change link origin tag color to darker text color * Handle links to domains starting with www. as shortened by Mastodon * [WiP] Ignore links that cannot be misread as URLs, rewrite other links --- .../mastodon/components/status_content.js | 90 +++++++++++++++++++ .../features/status/components/card.js | 11 +-- app/javascript/mastodon/utils/idna.js | 10 +++ 3 files changed, 101 insertions(+), 10 deletions(-) create mode 100644 app/javascript/mastodon/utils/idna.js diff --git a/app/javascript/mastodon/components/status_content.js b/app/javascript/mastodon/components/status_content.js index 549de95fc..e717934fa 100644 --- a/app/javascript/mastodon/components/status_content.js +++ b/app/javascript/mastodon/components/status_content.js @@ -8,9 +8,71 @@ import classnames from 'classnames'; import PollContainer from 'mastodon/containers/poll_container'; import Icon from 'mastodon/components/icon'; import { autoPlayGif } from 'mastodon/initial_state'; +import { decode as decodeIDNA } from 'mastodon/utils/idna'; const MAX_HEIGHT = 642; // 20px * 32 (+ 2px padding at the top) +// Regex matching what "looks like a link", that is, something that starts with +// an optional "http://" or "https://" scheme and then what could look like a +// domain main, that is, at least two sequences of characters not including spaces +// and separated by "." or an homoglyph. The idea is not to match valid URLs or +// domain names, but what could be confused for a valid URL or domain name, +// especially to the untrained eye. + +const h_confusables = 'h\u13c2\u1d58d\u1d4f1\u1d691\u0068\uff48\u1d525\u210e\u1d489\u1d629\u0570\u1d4bd\u1d65d\u1d421\u1d5c1\u1d5f5\u04bb\u1d559'; +const t_confusables = 't\u1d42d\u1d5cd\u1d531\u1d565\u1d4c9\u1d669\u1d4fd\u1d69d\u0074\u1d461\u1d601\u1d495\u1d635\u1d599'; +const p_confusables = 'p\u0440\u03c1\u1d52d\u1d631\u1d665\u1d429\uff50\u1d6e0\u1d45d\u1d561\u1d595\u1d71a\u1d699\u1d78e\u2ca3\u1d754\u1d6d2\u1d491\u1d7c8\u1d746\u1d4c5\u1d70c\u1d5c9\u0070\u1d780\u03f1\u1d5fd\u2374\u1d7ba\u1d4f9'; +const s_confusables = 's\u1d530\u118c1\u1d494\u1d634\u1d4c8\u1d668\uabaa\u1d42c\u1d5cc\u1d460\u1d600\ua731\u0073\uff53\u1d564\u0455\u1d598\u1d4fc\u1d69c\u10448\u01bd'; +const column_confusables = ':\u0903\u0a83\u0703\u1803\u05c3\u0704\u0589\u1809\ua789\u16ec\ufe30\u02d0\u2236\u02f8\u003a\uff1a\u205a\ua4fd'; +const slash_confusables = '/\u2041\u2f03\u2044\u2cc6\u27cb\u30ce\u002f\u2571\u31d3\u3033\u1735\u2215\u29f8\u1d23a\u4e3f'; +const dot_confusables = '.\u002e\u0660\u06f0\u0701\u0702\u2024\ua4f8\ua60e\u10a50\u1d16d'; + +const linkRegex = new RegExp(`^\\s*(([${h_confusables}][${t_confusables}][${t_confusables}][${p_confusables}][${s_confusables}]?[${column_confusables}][${slash_confusables}][${slash_confusables}]))?[^:/\\n ]+([${dot_confusables}][^:/\\n ]+)+`); + +const isLinkMisleading = (link) => { + let linkTextParts = []; + + // Reconstruct visible text, as we do not have much control over how links + // from remote software look, and we can't rely on `innerText` because the + // `invisible` class does not set `display` to `none`. + + const walk = (node) => { + switch (node.nodeType) { + case Node.TEXT_NODE: + linkTextParts.push(node.textContent); + break; + case Node.ELEMENT_NODE: + if (node.classList.contains('invisible')) return; + const children = node.childNodes; + for (let i = 0; i < children.length; i++) { + walk(children[i]); + } + break; + } + }; + + walk(link); + + const linkText = linkTextParts.join(''); + const targetURL = new URL(link.href); + + // The following may not work with international domain names + if (linkText === targetURL.origin || linkText === targetURL.host || 'www.' + linkText === targetURL.host || linkText.startsWith(targetURL.origin + '/') || linkText.startsWith(targetURL.host + '/')) { + return false; + } + + // The link hasn't been recognized, maybe it features an international domain name + const hostname = decodeIDNA(targetURL.hostname); + const host = targetURL.host.replace(targetURL.hostname, hostname); + const origin = targetURL.origin.replace(targetURL.host, host); + if (linkText === origin || linkText === host || linkText.startsWith(origin + '/') || linkText.startsWith(host + '/')) { + return false; + } + + // If the link text looks like an URL or auto-generated link, it is misleading + return linkRegex.test(linkText); +}; + export default class StatusContent extends React.PureComponent { static contextTypes = { @@ -56,6 +118,34 @@ export default class StatusContent extends React.PureComponent { } else { link.setAttribute('title', link.href); link.classList.add('unhandled-link'); + + if (isLinkMisleading(link)) { + while (link.firstChild) { + link.removeChild(link.firstChild); + } + + const prefix = (link.href.match(/https?:\/\/(www\.)?/) || [''])[0]; + const text = link.href.substr(prefix.length, 30); + const suffix = link.href.substr(prefix.length + 30); + const cutoff = !!suffix; + + const prefixTag = document.createElement('span'); + prefixTag.classList.add('invisible'); + prefixTag.textContent = prefix; + link.appendChild(prefixTag); + + const textTag = document.createElement('span'); + if (cutoff) { + textTag.classList.add('ellipsis'); + } + textTag.textContent = text; + link.appendChild(textTag); + + const suffixTag = document.createElement('span'); + suffixTag.classList.add('invisible'); + suffixTag.textContent = suffix; + link.appendChild(suffixTag); + } } link.setAttribute('target', '_blank'); diff --git a/app/javascript/mastodon/features/status/components/card.js b/app/javascript/mastodon/features/status/components/card.js index 0eff54411..012542843 100644 --- a/app/javascript/mastodon/features/status/components/card.js +++ b/app/javascript/mastodon/features/status/components/card.js @@ -2,18 +2,9 @@ import React from 'react'; import PropTypes from 'prop-types'; import Immutable from 'immutable'; import ImmutablePropTypes from 'react-immutable-proptypes'; -import punycode from 'punycode'; import classnames from 'classnames'; import Icon from 'mastodon/components/icon'; - -const IDNA_PREFIX = 'xn--'; - -const decodeIDNA = domain => { - return domain - .split('.') - .map(part => part.indexOf(IDNA_PREFIX) === 0 ? punycode.decode(part.slice(IDNA_PREFIX.length)) : part) - .join('.'); -}; +import { decode as decodeIDNA } from 'mastodon/utils/idna'; const getHostname = url => { const parser = document.createElement('a'); diff --git a/app/javascript/mastodon/utils/idna.js b/app/javascript/mastodon/utils/idna.js new file mode 100644 index 000000000..efab5bacf --- /dev/null +++ b/app/javascript/mastodon/utils/idna.js @@ -0,0 +1,10 @@ +import punycode from 'punycode'; + +const IDNA_PREFIX = 'xn--'; + +export const decode = domain => { + return domain + .split('.') + .map(part => part.indexOf(IDNA_PREFIX) === 0 ? punycode.decode(part.slice(IDNA_PREFIX.length)) : part) + .join('.'); +};