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AppStream Domain Joined SAML Fleet not authenticating after AD domain prompt

Scenario:

A customer had an AD Domain joined fleet and configured through SAML (the only way you CAN log into an AD joined fleet) and after the password prompt the session was looping and asking for their domain credentials over and over again.

Troubleshooting:

After investigating the provided troubleshooting steps something was still blocking the AD joined fleet from logging in at the domain password prompt, though authentication was fine for the Image builders.

https://docs.aws.amazon.com/appstream2/latest/developerguide/troubleshooting-active-directory.html

 

Solution:

https://docs.aws.amazon.com/appstream2/latest/developerguide/active-directory-prerequisites.html

As a prerequisite for AD Domain joined fleets you cannot have an AD Logon banner displayed as it prevents the AppStream service from connecting into / accessing the streamed desktop.

In some scenarions customers will have the logon banner only display for Users and not Administrators (so you never see the prompt on an Image builder for example even if its in the same OU and of course the GPOs dont apply when accessing the Image builder with the built in AppStream administrator/template user/test users.

Snippet from the Prerequisites Page specific to this scenario: (please use the above URL for the most up to date information)

Group Policy Settings

  • Computer Configuration > Administrative Templates > Windows Components > Windows Logon Options > Disable or Enable software Secure Attention Sequence — Set this to Enabled for Services.
  • Computer Configuration > Administrative Templates > System > Logon > Exclude credential providers — Ensure that the following CLSID is not listed: e7c1bab5-4b49-4e64-a966-8d99686f8c7c
  • Computer Configuration > Policies > Windows Settings > Security Settings > Local Policies > Security Options > Interactive Logon > Interactive Logon: Message text for users attempting to log on — Set this to Not defined.
  • Computer Configuration > Policies > Windows Settings > Security Settings > Local Policies > Security Options > Interactive Logon > Interactive Logon: Message title for users attempting to log on — Set this to Not defined.

As part of a simple deployment or for your simple proof of concepts we recommend you simply ensure the OU your AppStream computer objects are being created under has GPO inheritance blocked and there are no higher level GPOS forced to apply. Get the service running and confirmed as accessible and then slowly start applying the company requried GPOS for look feel and security.

CloudReady Not Playing Audio from MP4 Video Files

When using CloudReady OS it was noticed that downloaded (files saved directly on the device) mp4 and other video files were not playing audio when using the local ChromeOS player / default video player and the sound icon is greyed out. This also included previewing the same files direct from Google Drive.

(Update, another reader advised this is due to the retirement of Adobe Flash- TBC)

Solution

Install the proprietary Media Components now available from CloudReady

Actual solution available from cloudready

You may automatically see this prompt

If you dont see the prompt above simply click the bottom right hand side taskbar and then the settings Cog
Click ‘Install’ next to Proprietary Media Compoments
Read the Licence Agreement then click ‘Accept License’
Reboot your cloudready device

WorkArounds / Alternatives

If for whatever reason the proprietary media components don’t work you could alternatively install VLC as below. Note: This will not work with the native Browser / File integration you would need to browser for and open the video file from within VLC at all times in order for it to work.

 

Downloaded VLC for Chrome OS HERE
Click ‘add to chrome’ button
Click ‘Add App’
Click Launch App
VLC will prompt for a folder to browse, I selected Downloads directory and clicked open:
VLC will open the directory previously selected (in this example ‘Downloads’ and the video file(s) can be selected and opened inside VLC:
When opening any downloaded videos VLC should be accessed first from the Chrome ‘Start’ Menu. At the time of writing there wasn’t a way to replace the default local video player.
Newly added videos to the downloads directory will automatically appear in the ‘Video’ section of VLC

 

Lesson Learned From Enabling AWS GuardDuty Across Multi Accounts and All Regions

Summary

AWS Guard Duty offers an enhanced security scan of all AWS services and how to better protect them based on your usage patters and well known vulnerabilities.

General Observations

  1. GD Analyzes VPC Flow Logs, AWS CloudTrail events and AWS DNS logs.
  2. Console Notification for new findings – as they are analysed and discovered.
  3. Notification frequency of new findings (to CloudWatch) every 5 minutes.
  4. Notification configurable frequency of 15ins, 60mins or 6 hours (to CloudWatch) for updates to existing findings (counts for the same finding / vulnerability)
  5. 1000 member accounts supported.
  6. Definitions for trusted IPs and cloudwatch notification time / period are set and enforced at master only to flow down to sub accounts.
  7. Max 2000 trusted IPs in single list.
  8. Max 250,000 threat IPs in single list.
  9. Master accounts cannot be member of any other account.
  10. Sub accounts can view findings related to their own account, but are unable to archive them. Master account can view all findings for all accounts and archive them, which removes them from the sub accounts findings view also.
  11. Guard Duty can be suspended on master and on slave accounts (from master) slaves can manage and re-enable suspension on themselves only.
  12. GD detectors are region specific and need to be enabled on a per region basis including any regional master/sub collector services
    • Regional Master accounts are required for aggregation from sub accounts in the same region
      • e.g you cannot have one master Guard Duty collector in EU-WEST-1 and have AWS EU-WEST-2 regions send their Guard Duty findings to it.
      • You must have a Guard Duty master enabled in the EU-WEST-2 region and invite the sub account again for every region you want to enable Guard Duty
  13. In master, sub account the trusted and threat lists are applied at the master as a single list only.
  14. Log data from CloudTrail. VPC DNS are all encrypted when in transit to GuardDuty, after analysis the logs are discarded.
  15. Immediate analysis of flow logs starts from the service being enabled, it consumes events directly as a duplicate stream of flow logs. This does not modify any existing flow log configurations.
  16. DNS analysis will only work if using AWS DNS Resolvers. Other DNS services will not be ‘captured’ or analysed.

 

Rollout

AWS documentation points to a Cloud Formation template for enabling Guard Duty. Its only available as a template in us-east-1 region, so be sure to select this region.

CloudFormation

If you just want to setup Guard Duty services in your accounts via an AWS CloudForation StackSet – use this AWS Provided CT template ‘Enable Amazon GuardDuty’

https://console.aws.amazon.com/cloudformation/stacksets/home?region=us-east-1#/stacksets/new

Caveats

If you dont specify a master ID. The CF template simply enables GuardDuty in the stackset accounts and regions only.

You have to manually invite all your ‘sub accounts’ from all regions first before this stackset will work with the ‘masterId’ (as each sub account has to have an invitation waiting from the master)

CF Message:

The Amazon GuardDuty master account ID. If you specify the master account ID, this stack set creates a GuardDuty detector in each specified account and accepts the GuardDuty membership invitation sent to each of the specified accounts by this master account. If this value is specified, before you can create this stack set, all accounts in all regions to which this stack set template is to be applied must already have an invitation from this master GuardDuty account and must NOT have a detector already created.

Python

If you want a full cross account multi region master subscriber setup, from scratch – use the AWS provided python script.]=]#=[

It creates a master detector in your specified master account, and subscribes each sub account and even every sub account region to the master, accepts the invite and links the accounts.

The script can even be run from an unrelated ‘build or deploy’ account. Perfect!

https://github.com/aws-samples/amazon-guardduty-multiaccount-scripts

AWS Support recommended using the python script as the primary deployment mechanism.

There are no currently no ansible modules for AWS GuardDuty

Python Script Notes

The disable script breaks a little but a fix is provided in the issues list

The enable script messages the root account email for each account and for EVERY region that is listed to be ‘enabled’ so for a large scale deployment many multiple emails may be delivered!

Apple Mac OSX Security and Privacy Allow Button is not working

Problem

From time to time there seems to be some ongoing issues where Apple Mac OSX Security and Privacy Allow Button is not working.

No matter how many times you click ‘allow’ it simple doesn’t function (yet the button highlights blue as if its been pressed) and this happens regardless of whether you unlock the ‘padlock’ to make changes.

Seems its something to do with actually clicking the allow button when you are attempting to unblock system extensions via the Security and Privacy system preferences.

This also doesn’t seems to be resolved with removing mouse / track pad preferences as some sites have suggest.

Image result for allow button not working mac

Workaround

Effectively we are going to program a click on the button using Apple Script instead of a manual mouse click using the Screenshot program to get the coordinates of the allow button when the system preferences window is open.

  1. Open the Apple Script editor (Applications > Utilities > Script Editor)

2. Enter the following

tell application "System Events"
	click at {x, y}
end tell

3. Use Command > Shift and 4 (Mac OSX Built in selective screenshot tool) and hover the cursor over your ‘allow’ button which will give you the x and y coordinates for the ‘click’

Cursor when the selective screenshot is active (use the displayed numbers for your X and Y coordinates)

 

4. Enter the correct coordinates in the script then press the Play button

The allow button should then ‘be pressed’ as expected giving you access to see the extensions that are blocked so you can selective enable them then click OK.

Hope this helps

JSCS

Cloud Hosting With Multiple Proxy Servers

Scenario

A customer had a requirement for Cloud Hosting With Multiple Proxy Servers and wanted to send some traffic direct to the internet (host or url whitelist), some hosts or urls to one proxy in their cloud hosting and some traffic via another proxy in another peered network in their cloud hosting.

Solution

Our solution in the end was simple but it does required endpoint configuration (the browsers needs to point to the pac file in order for this to work – this was configured via AD GPO for the AppStream instances in Amazon Web Services as the AppStream instances were domain joined.)

This is also supported on Windows and Mac Endpoints via the proxy autoconfiguration file.

This means we can whitelist traffic to the internet, we can send other url or hosts specific matches to various internal proxy servers and for all else we can return a proxy server that doesnt exist and if it points to 127.0.0.1 its a very quick ‘failure’ response.

The response message to the clients is not perfect (users receive ‘The Proxy Server is not responding’) but as a simple working solution this was considered tolerable.

Windows > Configure it in Internet Explorer

Internet Explorer pac file configuration
Internet Explorer pac file configuration

Mac > Configure it in Network Settings

Mac automatic proxy configuration
Mac automatic proxy configuration

PAC File Configuration

function FindProxyForURL(url, host) {

// If the hostname matches, send direct.
if (shExpMatch(host, "*.microsoft.com") ||
shExpMatch(host, "*.google.com"))
return "DIRECT";

// If the hostname matches, send direct.
if (shExpMatch(host, "*.myotherwebsite.com") ||
shExpMatch(host, "*.myotherwebsite2.com"))
return "PROXY internal.squid.proxy:3128";

// If the hostname matches, send direct.
if (shExpMatch(host, "*.myotherwebsite3.com") ||
shExpMatch(host, "*.myotherwebsite4.com"))
return "PROXY internal.squid.proxy2:3128";


// DEFAULT RULE: All other traffic, use below proxies, in fail-over order.
return "PROXY 127.0.0.1:8081";

}

AWS Workspaces Error – This OS/platform is not authorized to access your Workspace

Situation

Recently a customer received the following message ‘this OS/platform is not authorized to access your Workspace’ when connecting to newly built AWS Workspace instance whilst attempting to connect via ‘Web Access’ https://clients.amazonworkspaces.com/

In more recent WorkSpace Updates (Jan 2019) if you dont explicitly have Web Access enabled you will receive a ERR_CM_REQUEST_FAILED message

This OS/platform is not authorized to access your Workspace
If the problem persists please contact your Workspaces Administrator.
ERR_DEVICE_ACCESS_DENIED

Solution

Web Access needs to be explicitly enabled. As these were relatively new workspaces (May 2018) the workspaces also didn’t have to be rebuilt to allow web connectivity contrary to the AWS documentation.

 

Open the AWS Console

Select Workspaces

Expand Directories

Select your Directory and click Actions then Update Details

Expand the 4th Section Access Control Options

Tick Web Access

Scroll to the bottom of the update details page and click Update and Exit

 

 

 

AWS AppStream 2.0 Image Builder X Drive not being created

Problem

This month on creation of a new image builder in AWS AppStream we noticed that the AWS AppStream 2.0 Image Builder X Drive was not being created.

The X drive is the temporary drive for uploading and downloading files to and from the AppStream instance, and usually where we house deployment scripts, build scripts, GPOS and installation files.

Solution

As of AppStream Image builder version Base-Image-Builder-05-02-2018 this is by design.

You should update any scripts or pointers

from “X:\Temporary Files” drive

to “C:\Users\ImageBuilderAdmin\My Files\Temporary Files”

#aws #appstream2.0

 

How to find an AWS AppStream 2.0 users homedrive path

Scenario

AWS AppStream 2.0 generates a SHA-256 hash of the users NameID for their Home Drive – when using SAML (aka Federated) authentication. This can potentially make it difficult to find the users home share if browsing from AWS S3 or for support teams when supporting users or uploading documents to the users ‘home drive’.

Example

In this document is an example of a federated users home drive autocreated in S3 after the user has accessed AppStream 2.0 for the first time.

This script will simply create a function in Windows powershell and allow you to generate the SHA256 hash based on the NameID and so you can discover the users homepath.

Function Get-StringHash([String] $String,$HashName = "MD5")
{
$StringBuilder = New-Object System.Text.StringBuilder
[System.Security.Cryptography.HashAlgorithm]::Create($HashName).ComputeHash([System.Text.Encoding]::UTF8.GetBytes($String))|%{
[Void]$StringBuilder.Append($_.ToString("x2"))
}
$StringBuilder.ToString()
}

$myvar = Read-Host –Prompt 'Enter string to hash'
Get-StringHash $myvar "SHA256"

Result

As we know the users NameID being passed into the AppStream session (in this instance its actually my email address)

AWS IAM CERTIFICATE_VERIFY_FAILED

Situation

When attempting to call AWS CLI commands we were receiving a CERTIFICATE_VERIFY_FAILED error message. We were using a proxy service. In this specific instance we were connecting to AWS IAM via zScaler Internet Access (ZIA)

Example

we were running a simple

aws iam get-role --role-name vmimport

 

Workaround

include–no-verifyssl to by pass the ssl verification

aws iam get-role --role-name vmimport --no-verify-ssl

Solution

Drop or whitelist the iam.amazonaws.com from SSL inspection on the proxy server