diff --git a/lib/index.js b/lib/index.js index abc1525..320b983 100644 --- a/lib/index.js +++ b/lib/index.js @@ -20,20 +20,41 @@ var config = { commonmark: require('./presets/commonmark') }; - -var BAD_PROTOCOLS = [ 'vbscript', 'javascript', 'file' ]; +//////////////////////////////////////////////////////////////////////////////// +// +// This validator does not pretent to functionality of full weight sanitizers. +// It's a tradeoff between default security, simplicity and usability. +// If you need different setup - override validator method as you wish. Or +// replace it with dummy function and use external sanitizer. +// + +var BAD_PROTOCOLS = [ 'vbscript', 'javascript', 'file', 'data' ]; +var ALLOWED_DATA_MIMES = [ + 'data:image/gif', + 'data:image/png', + 'data:image/jpeg', + 'data:image/webp' +]; function validateLink(url) { // url should be normalized at this point, and existing entities are decoded - // - var str = url.trim().toLowerCase(); - if (str.indexOf(':') >= 0 && BAD_PROTOCOLS.indexOf(str.split(':')[0]) >= 0) { + var str = url.trim().toLowerCase(), + protocol = str.split(':')[0]; + + if (str.indexOf(':') >= 0 && BAD_PROTOCOLS.indexOf(protocol) >= 0) { + if (protocol === 'data' && ALLOWED_DATA_MIMES.indexOf(str.split(';')[0]) >= 0) { + return true; + } return false; } + return true; } +//////////////////////////////////////////////////////////////////////////////// + + var RECODE_HOSTNAME_FOR = [ 'http:', 'https:', 'mailto:' ]; function normalizeLink(url) { diff --git a/test/fixtures/markdown-it/xss.txt b/test/fixtures/markdown-it/xss.txt index 25eb361..99bfa42 100644 --- a/test/fixtures/markdown-it/xss.txt +++ b/test/fixtures/markdown-it/xss.txt @@ -53,6 +53,21 @@ Should not allow some protocols in links and images . +Should not allow data-uri except some whitelisted mimes +. +![](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7) +. +
+. + +. +[xss link](data:text/html;base64,PHNjcmlwdD5hbGVydCgnWFNTJyk8L3NjcmlwdD4K) +. +[xss link](data:text/html;base64,PHNjcmlwdD5hbGVydCgnWFNTJyk8L3NjcmlwdD4K)
+. + + + Image parser use the same code base. . ![xss link](javascript:alert(1))