TF-3243 Fix email without content

[dab246]

Issue

#3243

Root cause

• Because the function Uri.decodeFull(inputText) throws an exception FormatException: Invalid UTF-8 byte (at offset 11) during handle 3D Links in DOM.
• This error only occurs on the web

Solution

• Add try/catch blocks to all email transformer DOM handler functions

Resolved

• Web:

Screen.Recording.2024-10-29.at.19.29.14.mov

• Mobile:

demo-mobile.webm

[github-actions]

This PR has been deployed to https://linagora.github.io/tmail-flutter/3245.

[chibenwa]

Add try/catch blocks to all email transformer and sanitize handler functions

Does this means that if I send a broken base64 link then HTML sanitizing is bypassed and thus I could pass an XSS payload after the broken base64 link?

[dab246]

Add try/catch blocks to all email transformer and sanitize handler functions

Does this means that if I send a broken base64 link then HTML sanitizing is bypassed and thus I could pass an XSS payload after the broken base64 link?

No. We do HTML sanitization before DOM processing. This error does not try/catch function Uri.decodeFull(inputText) when processing 3D links during DOM processing. So we always block XSS from the start.