Azure Key Vault - Empty Secrets

Sometimes you would like to create an empty secret in Azure Key Vault, just so you would be able to optimize your ARM/Bicep files to support multiple authentication types, for example.
However, since the Azure Portal does not allow you to create a Key Vault secret without specifying any value, this seems to be quite impossible. Or is it?

Getting Started

Before you can use any of the PowerShell commands mentioned below, you will have to make sure you are connected to the correct Azure Tenant/Subscription.
This can be done by using the following:

Connect-AzAccount

Set-AzContext -Subscription $subscriptionId -Tenant $tenantId

Creating the secret

To create a new secret within an existing Azure Key Vault instance, you need to provide a SecureString-object containing the actual secret value.
Using PowerShell, you would be able to generate this SecureString by using the ConvertTo-SecureString-command. Unfortunately, this does not accept providing an empty string either.

A workaround to this approach is to simply initialize a new SecureString-object which will - since the constructor does not require you to provide any actual value - generate a blank secret for you.

$emptySecret = (new-object System.Security.SecureString)

Once this new object has been instantiated, it is just a matter of passing it along to the proper Az-command to create the empty secret within any given Azure Key Vault.

Set-AzKeyVaultSecret -VaultName $keyVaultName -Name $secretName -SecretValue $emptySecret

Conclusion

As long as the constructor of this SecureString-object does not get updated to require you to provide the secret value, you will always be able to use this little workaround to create a blank secret in Azure Key Vault.