TechShizz | Tech Guides

Customise Office 365 Encrypted Email Notification

Problem
You need to customize the Encrypted email notification that is sent to the recipient of an encrypted email so suit the company's branding/image.
Solution

Connect to the Office 365 Tenant via the Azure PowerShell Module. Use these commands

#Header:
Set-OMEConfiguration -Identity "OME Configuration" -EmailText "Encrypted message from CompanyName secure messaging system."

#Disclaimer:
Set-OMEConfiguration -Identity "OME Configuration" -DisclaimerText "This message is confidential for the use of the addressee only."

#Text that appears at the top of the encrypted mail viewing portal:
Set-OMEConfiguration -Identity "OME Configuration" -PortalText "CompanyName secure email portal."

#Logo:
Set-OMEConfiguration -Identity "OME configuration" -Image (Get-Content "C:\Users\%username%\Desktop\logo.png" –Encoding byte)
#Supported file formats: .png, .jpg, .bmp, or .tiff
#Optimal size of logo file: less than 40 KB
#Optimal size of logo image: 170x70 pixels

#Background color:
Set-OMEConfiguration -Identity "OME Configuration" -BackgroundColor "#ffffff"

One Drive character limit | PowerShell to find file path character length | File Path Character Limit

Problem

One Drive will not sync files with more than 400 charactes in the file path

Cause

Limitation

Solution

Use this script and execute to create a list of all files and their number of characters. Address by shortening folder and file names. 

 $pathToScan = "C:\APP1-Data\SharePointData\MW\MW - Documents" # The path to scan and the the lengths for (sub-directories will be scanned as well).
$outputFilePath = "C:\temp\PathLengths.txt" # This must be a file in a directory that exists and does not require admin rights to write to.
$writeToConsoleAsWell = $true # Writing to the console will be much slower.

# Open a new file stream (nice and fast) and write all the paths and their lengths to it.
$outputFileDirectory = Split-Path $outputFilePath -Parent
if (!(Test-Path $outputFileDirectory)) { New-Item $outputFileDirectory -ItemType Directory }
$stream = New-Object System.IO.StreamWriter($outputFilePath, $false)
Get-ChildItem -Path $pathToScan -Recurse -Force | Select-Object -Property FullName, @{Name="FullNameLength";Expression={($_.FullName.Length)}} | Sort-Object -Property FullNameLength -Descending | ForEach-Object {
$filePath = $_.FullName
$length = $_.FullNameLength
$string = "$length : $filePath"

# Write to the Console.
if ($writeToConsoleAsWell) { Write-Host $string }

#Write to the file.
$stream.WriteLine($string)
}
$stream.Close()


Disable Autodiscover for Office 365 Migration

When migrating to Office 365 the internal outlook users are not able to use autodiscover.

This is because the internal exchange server also uses autodiscover in IIS.

Use this description to remove the internal AutodiscoverVirtualDirectory

Be sure that this is the proper migration plan for you’re organization!

1. Open an elevated command prompt and back-up the IIS configuration (Just in case !):

cd %windir%system32inetsrvappcmd.exe add backup “Before Removing Autodiscover”

2. Open an elevated Exchange Management Shell and retrieve the current autodiscover virtual directory:

Get-AutodiscoverVirtualDirectory | fl Name, Server, InternalUrl, Identity

Copy the Identity value to the clipboard.

3. In the Exchange Management Shell, remove the autodiscover virtual directory:

Remove-AutodiscoverVirtualDirectory -Identity “ALPHAAutodiscover (Default Web Site)”

When you’re identity contains a space, use the quotation marks ”

You will have to confirm by typing a “Y”.

4. Check that the autodiscover virtual directory is gone:

Get-AutodiscoverVirtualDirectory | fl Name, Server, InternalUrl, Identity

This should now return nothing.

5. Now, with Outlook running on a desktop, hold the Ctrl button, right-click on the Outlook icon in the system tray, and select Test E-mail AutoConfiguration. Enter your email address and password and click the Test button. The results should come from the Office 365 server.

DNS | TLSA Records to ensure the validity of SSL certificates

TLSA Records are a new feature which adds an additional layer of security for checking the validity of server certificates. The TLSA record is placed in DNS, which can be queried by a client to verify the SHA hash the domain holds against the certificate a server has presented the client. If the Key matches DNS has "agreed" that the certificate does indeed match. This security protects against the wrongful issuing of certificates by CA's and also the theft of certificates. 

#Add a TLSA DNS Record
Add-DNSServerResourceRecord -CertificateAssociationData 2a8f2d8af0eb123898f74c866ac3fa669054e23c17bc7a95bd0234192dc635d0 -CertificateUsage DomainIssuedCertificate -MatchType Sha256Hash -Selector SubjectPublicKeyInfo -TLSA -ZoneName www.techshizz.com -Name _443._tcp.www

This record combines with DNSSEC provides a robust security system to protect agains man in the middle attacks. Due to the need to DNSSEC, and a provider who offers TLSA, it's going to be a premium service if used on the internet. It does come with server 2016 for internal usage on the corporate infrastructure. 

DNS Time Based Policy

We can configure DNS in server 2016 to DENY, IGNORE or ALLOW the response of DNS requests. Here are the commands required to configure this. 

#Get current server time
Get-Date -DisplayHint Time

#Get current DNS Policies
Get-DnsServerQueryResolutionPolicy -ZoneName demo.com

#Add a new Policy called "Time-Policy" to deny dns requests between 4AM and 11PM.
Add-DnsServerQueryResolutionPolicy -zoneName demo.com -Name "Time-Policy" -Action DENY -TimeOfDay "eq,04:00-23:00" -ProcessingOrder 2

#Check result
Get-DnsServerQueryResolutionPolicy -ZoneName demo.com

#Change Processing order (1 takes precedence)
Set-DnsServerQueryResolutionPolicy -ZoneName demo.com -Name "Time-Policy" -ProcessingOrder 1

#Check result
Get-DnsServerQueryResolutionPolicy -ZoneName demo.com

#Remove the time policy
Remove-DnsServerQueryResolutionPolicy -zoneName demo.com -Name "Time-Policy" -Force

#Re-add the time policy but with IGNORE request instead
Add-DnsServerQueryResolutionPolicy -zoneName demo.com -Name "Time-Policy" -Action IGNORE -TimeOfDay "eq,04:00-23:00" -ProcessingOrder 1

#Remove Time policy again
Remove-DnsServerQueryResolutionPolicy -zoneName hmm.com -Name "Time-Policy" -Force

#Add time policy to DENY between 11PM and Midnight, Order 1
Add-DnsServerQueryResolutionPolicy -zoneName demo.com -Name "Time-Policy" -Action DENY -TimeOfDay "eq,23:00-23:59" -ProcessingOrder 1 

#Check Result
Get-DnsServerQueryResolutionPolicy -ZoneName demo.com

#Change Policy order to 3
Set-DnsServerQueryResolutionPolicy -ZoneName demo.com -Name "Time-Policy" -ProcessingOrder 3

#Check result
Get-DnsServerQueryResolutionPolicy -ZoneName demo.com