Mark file:// and sftp:// links in messages as url in Riot chat log

[MurzNN]

Our company have private local file storage and very often exchange links to files and folders, for example file://mnt/share/project1/file2.odt.

Many messengers convert this links to url via <a href="file://mnt/share/project1/file2.odt"> and we can open those files directly via single click.

Same problem is with sftp links - url like sftp://user:pass@example.com/path/to/file.txt breaks to parts:
sftp://user:pass@example.com/path/to/file.txt
instead of:
sftp://user:pass@example.com/path/to/file.txt

Please add same behavior to Riot-web interface.

[lampholder]

It looks like Riot highlights file://stuff/stuff/stuff.txt as a link, but then clicking it doesn't follow the link.

@MurzNN are you just asking for following file:// links to be enabled?

[lampholder]

Are there any considerations here? Any reasons we wouldn't want to do this?

[lukebarnard1]

Chome blocks access to local files and other browsers probably do the same.

https://stackoverflow.com/a/39007324

[turt2live]

Browser security may play a factor into the link not working, or result in unreliable functionality.

Electron might be able to leverage OS things more easily, but still might be subject to security policies.

I'm not 100% sure though. Just seems like something Chrome would prevent at the least.

[MurzNN]

Here is screenshot of tests with file:// links from Riot.im website: http://i.imgur.com/OfHUqQy.png
So all other types of link are detected and converted to <a href=...> but file:// - not.
The problem can be solved via adding file:// scheme to url detection rules.

Problem with not-working file:// links in browsers easily solved via extensions or via pre-configured enterprise settings:

• Firefox settings: https://stackoverflow.com/a/13083926/1395757
• Firefox extension: https://addons.mozilla.org/en-US/firefox/addon/local-filesystem-links/?src=search
• Chrome extension: https://chrome.google.com/webstore/detail/local-explorer-file-manag/eokekhgpaakbkfkmjjcbffibkencdfkl

So from Riot side - we must only convert file://... links to <a href="file://...>file://...</a> html code - that's all.

[MurzNN]

@lampholder, can you point me to place in Riot code where plaintext message is converting to <a href> links? I'll try to add file:// detection in this function.

I have found similar place in pre-compiled bundles/406deb16788d2085050e/bundle.js file:

allowedSchemes:["http","https","ftp","mailto"]

But can't find this code in git sources.

[lukebarnard1]

@MurzNN a lot of logic for Riot lives in https://github.com/matrix-org/matrix-react-sdk. You're looking for HtmlUtils.js

Edit: Interestingly, it seems that the extra / is important. Riot will highlight if there are only two slashes //, but not three...

linkifyjs is the npm package we use to take plain text bodies and replace URLs with <a> tags. But http-sanitize is the library that might be disallowing links with file:/// as their protocol (and allowing file://)

Update: I've discovered that the difference is the number of / and the library causing the issue is linkify itself.:

> const lfy = require('linkifyjs');
undefined
...
> lfy.find('file:///test');
[]
> lfy.find('file://test');
[ { type: 'url', value: 'file://test', href: 'file://test' } ]

[MurzNN]

@lukebarnard1 thanks for the info, so seems the issue is in linkifyjs - Hypercontext/linkifyjs#171
Hope they will fix it

[MurzNN]

And from Riot side there are create them clickable in riot-web electron app. At now riot converts links like file://C:/windows_3.11/roadmap.txt to url - they works well in browser, but not clickable when I click in electron app. Can we fix this now, and make open file by link in riot-web electron app?

[lukebarnard1]

not clickable when I click in electron app

I'm guessing this is because your extensions aren't running in the context of electron (and they can't - electron/electron#1498)

[MurzNN]

Same problem is with sftp links - url like sftp://user:pass@example.com/path/to/file.txt breaks to parts:
sftp://user:pass@example.com/path/to/file.txt
instead of:
sftp://user:pass@example.com/path/to/file.txt
For ftp:// links all works well.
Fix for both problems will be the same, so I add this to issue title.

[MurzNN]

Here is solution how to fix open local files in Elecron app: https://stackoverflow.com/a/33425619, so typing in Riot app console on Linux commands:

const {shell} = require('electron');
shell.openItem('file:///etc/issue');

• successfully executes file opening process via default application for this file type.

[MurzNN]

Seems here https://github.com/matrix-org/matrix-react-sdk/blob/master/src/components/views/messages/TextualBody.js#L82 is the place where plain text converts to html with links.

[aaronraimist]

This is the current behavior (although #8720 wants to unlinkify them)

[t3chguy]

successfully executes file opening process via default application for this file type.

Sure but what if that default action would be executing an executable, or opening a virus, this has many security implications

[MurzNN]

If user want to execute a virus, he can download it and open via double click, what is the difference? At now, for open file://path/to/file.txt we need every day to do manually copy url to clipboard, and paste it into filemanager.

So Element-Web only need to linkify those links, all other job will be done in browser.

For example, Firefox works well for those links - it asks user what to do: open file directly, or download it to Downloads folder, and this is very useful feature! Did you think, that Firefox doesn't care about security, if still not disable this feature?

But Chromium family browsers historically miss this feature, and have many upvotes for implement it: https://bugs.chromium.org/p/chromium/issues/detail?id=333&q=open%20file%20download&can=2&sort=-stars

[MurzNN]

I checked this feature, at now Element-Web successfully linkify "file://" links, but linkify badly "sftp://" links: