Citrix Workspace App For Html5

30-04-2021
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A list containing the majority of Citrix Workspace app for HTML5 (formerly Receiver for HTML5) support articles collated to make this page a one stop place for you to search for and find information regarding any issues you have with the product and its related dependencies. The page is updated daily with new support articles and information. With an HTML5 connection method, the end-user device does not need a locally installed Workspace app client to be available. Instead, the end-user connects to their Virtual Apps and Desktops directly from their HTML5 capable browser such as Chrome, Internet Explorer or Firefox.

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  • Citrix Workspace App

Symptoms or Error

This article is intended for Citrix administrators and technical teams only.
Non-admin users must contact their company’s Help Desk/IT support team and can refer to CTX297149 for more information.
When using StoreFront with or without Workspace App for HTML5 through an HTTPS URL, applications and desktops cannot be started. The following error message is displayed:

“Cannot create a secure connection in this browser. Refer to the Citrix Knowledge Center article CTX134123.”

Solution

Recommended Solution(s) for All Browsers

  • Connect via Citrix Gateway even for internal connections. This would ensure connections work fine regardless of Virtual Apps or Desktops versions.
    Deploying SSL/TLS for each Virtual Delivery Agent (VDA) for direct connections. Workspace App for HTML5 supports secure direct SSL/TLS connections with XenApp/XenDesktop 7.6

Read the following articles from the Citrix Blog for more information:

Mozilla Firefox

There is a possible workaround for Mozilla Firefox browser.

Note: This workaround has security implications; consult the security specialist of your organization to consider the following configuration.

  1. Enforce secure communications between Workspace App for HTML5 and applications or desktops (for example, using IPSec).

  2. Use Mozilla Firefox only for Citrix Receiver for HTML5 (not for general website use).

  3. Enforce a secure configuration for Firefox.

  4. Enable the Firefox network.websocket.allowInsecureFromHTTPS option.

If the preceding configuration is consistent with the security policy of your organization, an administrator can enable launching applications or desktop using the following steps:

  1. Open a new tab in the Firefox browser.

  2. Type about:config in the address bar.

  3. Double-click network.websocket.allowInsecureFromHTTPS and set the value to true.

Citrix Workspace App For Html5 Microphone

Note: This Firefox option might not be supported in Citrix Receiver for HTML5 future versions.

WARNING! This option on Firefox affects the operation of entire Firefox, not just Citrix Receiver for HTML5.

Important Note

As of version 9, Safari browser allows insecure web socket connections. Internet Explorer never allowed non SSL/TLS web socket connections from HTTPS websites. Chrome used to allow it behind a flag, but after the Chrome 44 update, this is no longer supported. Firefox allows it behind a flag (as explained earlier in this article), but it is not recommended. Going forward, only secure (SSL/TLS) web socket connections can be made from Receiver for HTML5.

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Problem Cause

When Workspace App for HTML5 is hosted on a https site (default and recommended), non SSL/TLS websocket connections are prohibited by browsers.
In explaining the technical reason behind this it is important to understand the following two principles:
1. As opposed to existing as a separate process, Citrix Workspace App for HTML5 operates within the frame and process space of the browser itself. As such the browser has the ability to enforce certain security parameters.

2. Additionally, when any Workspace App for Windows makes a connection to a VDA for either a published desktop or app, the underlying connection is made to the VDA and not the Storefront server as any kind of intermediate proxy.


This second point is less obvious in the case of Citrix Workspace App for HTML5 because the published desktop or application displays within the browser frame and “appears” to be connected via the Storefront server. Despite this appearance though, the underlying TCP/UDP connection is still between the client and the VDA. If the Storefront base URL is SSL enabled (where it begins with https as is best practice) and the VDA is not SSL enabled (which it is not by default) the browser in this case will prevent the connection due to what it sees as an underlying inconsistency. The inconsistency is that while the URL shown in the browser frame is prefixed with https, the actual underlying connection is not https even though it is not obvious to the user.
There are two solutions for this.
Solution 1 is to enable SSL on the VDA using the following guide:

https://docs.citrix.com/en-us/citrix-virtual-apps-desktops/secure/tls.html
This will ensure that the connection path is SSL enabled between the internal client and the VDA.Citrix workspace app for html5

Citrix Workspace App For Html5 Desktop

Solution 2 is to have your connections from the clients first go through a Citrix Gateway. Citrix Gateway will proxy the connections and perform a SSL handshake between the client and the Citrix Gateway. In this scenario there is no inconsistency and connections via HTML5 Receiver will succeed.Citrix workspace app for html5

Additional Resources

Citrix Workspace Use Html5

Citrix workspace app for html5 extension
You can now use the Application probing feature to proactively monitor the health of applications enabling you to fix issues before the user actually experiences them. For more information refer to Citrix Documentation - Application probing.

Recommended solution: Update the certificates.

Citrix Workspace App For Html5

Alternatively, you can try this workaround:

  1. Close the Citrix Workspace app for Chrome / Citrix Receiver for Chrome.

  2. Open Chrome browser in your Chromebook.

  3. Visit your site.

  4. It will show some error as below.

Now, open the Citrix Workspace app for Chrome or Citrix Receiver for Chrome and it might allow you to access your StoreFront/VDA.

Other possible workaround for specific certificate error:

  1. NET::ERR_CERT_WEAK_SIGNATURE_ALGORITHM error
    Latest Firefox and Chrome browsers do not support SHA-1 certificate and StoreFront connection fails with error: NET::ERR_CERT_WEAK_SIGNATURE_ALGORITHM
    Citrix Receiver for Chrome/HTML5 or Citrix Workspace app for Chrome/HTML5 cannot establish secure connection and session launch will fail

  2. NET::ERR_CERT_COMMON_NAME_INVALID error
    Chrome requires Subject Alternative Name for SHA-2 certificate, without SAN (Subject Alternative Name) in the SHA-2 certificate, the connection will fail with error NET::ERR_CERT_COMMON_NAME_INVALID
    Session launch fails with CERT_COMMON_NAME_INVALID(-200) error dialog
    Workaround for NET::ERR_CERT_WEAK_SIGNATURE_ALGORITHM and
    NET::ERR_CERT_COMMON_NAME_INVALID:

    • Mozilla:

      Enable network.websocket.allowInsecureFormHTTPS from about:config

    • Chrome:
      Chrome by default requires SHA2 Certificate with Subject Alternative Names (SAN)
      Add the following registry keys at : SoftwarePoliciesGoogleChrome

    • EnableCommonNameFallbackForLocalAnchors – true
      (Note: Chrome need SAN by default)

    • EnableSha1ForLocalAnchors – true
      (Note: SHA1 is not supported)
      Recommended Solution: Use SHA2 certificates with Subject Alternative Names (SAN).

      Problem Cause:

    • CTX134123 - Receiver for HTML5 - Unable to Launch Apps Using HTTPS URL

    • CTX217352 - How to Collect Logs in Receiver for Chrome and Receiver for HTML5

  3. NET::ERR_CERT_SYMANTEC_LEGACY
    From Chrome OS version 66 onwards the SSL certificate from Symantec is distrusted. You can go through https://security.googleblog.com/2018/03/distrust-of-symantec-pki-immediate.html to know more about it.
    Workaround: Try general workaround mention above.
    Recommended Solution: Update SSL certificates.