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security: replace vulnerable regex with parser #1223

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Merged
merged 5 commits into from
Apr 17, 2018
Merged

security: replace vulnerable regex with parser #1223

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4717be9
security: replace vulnerable regex with parser
davisjam Apr 15, 2018
1ad9ca0
Travis failure: use backwards-compatible JS
davisjam Apr 15, 2018
fbf93a8
address review comments
davisjam Apr 16, 2018
ba2fc13
address review comments
davisjam Apr 16, 2018
47f4388
address review comments
davisjam Apr 16, 2018
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45 changes: 42 additions & 3 deletions lib/marked.js
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Original file line number Diff line number Diff line change
Expand Up @@ -554,9 +554,48 @@ inline.normal = merge({}, inline);
inline.pedantic = merge({}, inline.normal, {
strong: /^__(?=\S)([\s\S]*?\S)__(?!_)|^\*\*(?=\S)([\s\S]*?\S)\*\*(?!\*)/,
em: /^_(?=\S)([\s\S]*?\S)_(?!_)|^\*(?=\S)([\s\S]*?\S)\*(?!\*)/,
link: edit(/^!?\[(label)\]\(\s*<?([\s\S]*?)>?(?:\s+(['"][\s\S]*?['"]))?\s*\)/)
.replace('label', inline._label)
.getRegex(),
link: {
exec: function (s) {
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@joshbruce joshbruce Apr 16, 2018 •
edited
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Might be worth adding some doc blocks to introduce the why behind some of this...nothing too major, just to help those new to the code.

// [TEXT](DESTINATION)
var generalLinkRe = edit(/^!?\[(label)\]\((.*?)\)/)
.replace('label', inline._label)
.getRegex();

function unwrapCarats (str) {
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@joshbruce joshbruce Apr 16, 2018

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Carets?? Carat and carrot are different. :)

Angle brackets might be most appropriate if I'm reading the regex correctly.

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@davisjam davisjam Apr 16, 2018

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Haha I was wondering if I was spelling that right. I'll switch to AngleBrackets anyway.

if (str.match(/^<.*>$/)) {
str = str.substr(1, str.length - 1);
}
return str;
}

var fullMatch = generalLinkRe.exec(s);
if (fullMatch) {
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@styfle styfle Apr 16, 2018

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Can you flip this so that the if statement is smaller:

if (!fullMatch) {
  return null;
}
// ... split and such here
return [fullMatch[0], text, destinationAndTitle[0], destinationAndTitle[1]];

var text = fullMatch[1];
var destination = fullMatch[2];

var m;

var destinationAndTitleRe = /^([^'"(]*[^\s])\s+(['"(].*['")])/;
if (m = destinationAndTitleRe.exec(destination)) {
// <destination> -> destination
var dest1 = m[1].trim();
dest1 = unwrapCarats(dest1);
var title1 = m[2];
return [fullMatch[0], text, dest1, title1];
}

var destinationRe = /^(<?[\s\S]*>?)/;
if (m = destinationRe.exec(destination)) {
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@styfle styfle Apr 16, 2018 •
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The two if blocks are nearly identical. Can you make a common function for those? Something like this:

function getMatch(r, fullMatch) {
  var m = r.exec(fullMatch[2]);
  if (m) {
    var dest = unwrapAngleBrackets(m[1].trim());
    var title = m[2];
    return [fullMatch[0], fullMatch[1], dest, title];
  }
}

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@joshbruce joshbruce Apr 16, 2018

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Agree, but not a deal breaker for my review.

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@davisjam davisjam Apr 16, 2018

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Will do.

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@davisjam davisjam Apr 16, 2018

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@styfle See ba2fc13

// <destination> -> destination
var dest2 = m[1].trim();
destination = unwrapCarats(dest2);
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@styfle styfle Apr 16, 2018

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destination is assigned but never used. Is this intentional?

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@davisjam davisjam Apr 16, 2018

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Nope. Will fix.

var title2 = '';
return [fullMatch[0], text, dest2, title2];
}
}
return null;
}
},
reflink: edit(/^!?\[(label)\]\s*\[([^\]]*)\]/)
.replace('label', inline._label)
.getRegex()
Expand Down