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The HTML Macro for Confluence app allows you to incorporate snippets of HTML into your page. These can include HTML, JavaScript, and CSS, which will run runs inside the macro itself but will does not affect the rest of the page.

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Table of Contents

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Table of Contents

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Features 

  • Ability to seamlessly incorporate HTML elements, custom styling (CSS) and JavaScript without affecting the rest of the page 

  • Allows for previews to prevent tedious page reloading

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Quick Start 

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Installation & Setup

  1. The app installation is a standard one for Confluence MarketPlace apps.

minLevel2
maxLevel6
outlinefalse
styledefault
typelist
printabletrue

Quick start 

  1. Insert the HTML Macro into your page and click Insert.

  2. (warning) The Sanitize box should be unchecked if you're inserting JavaScript. 

    See the

    Deselect the Sanitize checkbox to insert JavaScript. See the Security Considerations section for more information.

    the

    The macro is rendered in one or two levels of

    IFrames

    iframes. Therefore, you cannot interact with the DOM of the parent and

    should

    must be familiar with the same-origin policy if you are using advanced client-side code.

  3. Specify the height for your macro

    . You

    or you can leave it blank

    and adjust it later by editing the macro after you've previewed the page

    .
    Image Modified

  4. Add your HTML to the box that's now inserted on your page.

  5. Review the macro by viewing the Confluence page or use the "Preview" window in the macro editor.

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Security considerations

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Security Considerations

Sanitize HTML option

When using the Sanitize option (in the app’s configuration page and the Sanitize box in the macro is checked), only " safe " HTML is allowed (i.e., no JavaScript is allowed). This option will load slightly faster. 

Note

Unchecking Deselecting the Sanitize option Sanitize option allows JavaScript in the body of the HTML macroMacro. However, in this case, a second or double iFrame iframe is used from a different domain. This sandboxing insulates the content from the parent Confluence page, which prevents interaction with the parent page DOM and increases safety.  Any Cloud app that does not operate in this sandboxed manner would is not be inherently safe as JavaScript could make REST calls back to Confluence as the present user. Using This is prevented from occurring with the sandbox double iFrame iframe and a different domain adds security by preventing this from occurringto add more security.

Sandboxing helps to mitigate the most dangerous aspects of JavaScript running in your macro but you need to be aware that unchecking "Sanitize" adds risk.  Despite the insulation of the extra iframe, this enables certain classes of stored XSS attacks (for example, phishing for credentials in a fake login panel), so, you need to trust your site users to use the macro responsibly.

When sanitized Sanitize is uncheckeddeselected, the macro can execute JavaScript, and AJAX requests can be executed by your macro, and you can make AJAX requests made from your code in the body of the HTML macro body. The sandbox iFrame iframe does not add any CORS-related headers. However, AJAX requests to services you do not control may contain CORS response headers that prevent you from using them within the sandbox iFrame.

An administrator can use the "Configure" button for the HTML Macro in the "Manage apps" page to allow or prevent users from creating and viewing unsanitized HTML macros:

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The Javascript iframe.

The JavaScript is limited as to what it can do because we “sandbox” the unsanitized macro in an extra iframe. It cannot spoof the target user to obtain their Confluence access token or make changes to any content outside the sandboxed macro. There are still some potential attacks. It would be impossible to list all of these, but examples would be a user adding a pop-up or phishing for user information. Because of how Javascript works, there is no way to prevent these attacks by a malicious user already in the system. Therefore, unsanitized mode should only be enabled when users are trusted not to exploit it. If you are concerned about protecting your instance from these attacks you can limit the users that can access/edit the page to Admins or other trusted groups. 

X-Frame-Options Response Header

If you try to include an iFrame iframe in an HTML macro, it will not work if the server for the source (src) of the iframe sets the X-Frame-Options response header to DENY or SAMEORIGIN (https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Frame-Options). The browser console may say, display: "Refused to display 'https://www.mysite.com' in a frame because it set 'X-Frame-Options' to 'SAMEORIGIN."  

The X-Frame-Options header value of SAMEORIGIN only allows content to be embedded in an iFrame iframe if the content is from the same origin as the page containing the iframe. The DENY value will disallow it from any origin.

When a server returns the X-Frame-Options response header, the server has explicitly set a content security policy that limits its content rendering in an iFrameiframe, which the browser is honoring.  It is a browser security issue that Artemis Appfire cannot control or bypass.  

If you control the remote domain that is serving the src source of the iframe, you can disable this setting on that server or you could build a proxy for that domain that strips the header.  Many sites do not want to show up in iFrames iframes for Intellectual Property (IP) or security reasons. AnchorDevelopment

Development

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Considerations 

When developing JavaScript or other code to add to this app, please note that it is running in an iFrame iframe inside the macro AND an iFrame iframe on the Confluence page. The innermost iFrame iframe is served from our app domain and not from Atlassian. For instance, if you create an HTML form and submit it, you will likely get a response from our domain indicating that it is "Not authenticated."  AnchorExampleExample

Examples 

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anchorArticlesArticles

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Filter by label (Content by label)
showLabelsfalse
max50
showSpacefalse
sorttitle
cqllabel in ( "html-macro-cloud" , "html-macro" ) and space = currentSpace ( )

Additional references

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