Finance and operations storage account security updates

This article describes the latest security enhancements in the finance and operations storage account.

Frequently asked questions

I receive the following error on my developer machine/customer-hosted environment: "Fetching a valid storage connection string is disabled." How can I fix this error?

The Microsoft.Dynamics.Clx.ServicesWrapper.CloudInfrastructure::GetCsuStorageConnectionString() public method is being deprecated. Learn more in End of support for sharing storage account connection strings via public API GetCsuStorageConnectionString.

If the flight is set to false by default, an issue occurs when changes are deployed in developer environments or customer-hosted environments (CHEs). In this case, you receive the following error on your developer machine:

EnableSharingOfValidStorageConnectionString is false. Fetching a valid storage connection string has been disabled.

If you receive the error, follow these steps.

  1. In Microsoft SQL Server Management Studio (SSMS), run the following query.

    declare @flightName NVARCHAR(100) = 'EnableSharingOfValidStorageConnectionString';
    IF NOT EXISTS (SELECT TOP 1 1 FROM SysFlighting WHERE flightName = @flightName)
    INSERT INTO SYSFLIGHTING(FLIGHTNAME,ENABLED, FLIGHTSERVICEID,PARTITION)
    SELECT @flightName, 1, 12719367,RECID FROM DBO.[PARTITIONS];
    ELSE
    UPDATE SysFlighting SET enabled = 1, flightServiceId = 12719367 WHERE flightName = @flightName;
    select * from SysFlighting where flightName = 'EnableSharingOfValidStorageConnectionString';
    
  2. In the CHE, restart Application Object Server (AOS) and the Batch service.

Which managed identity is used to connect to the storage account?

The finance and operations environment doesn't share details about the managed identity that is used to connect to the storage account. Additionally, the platform runtime doesn't have access to the managed identity information.

How does the platform code use managed identity to connect to the storage account when the identity isn't available?

An implementation of the TokenCredential object and token is regularly refreshed by using a service that runs behind the scenes.

Previously, a connection string allowed unrestricted access to perform almost any operation on a storage account. After the introduction of role-based access control (RBAC) and managed identities, which permissions are now restricted or disabled?

We grant almost all the permissions that are required to perform operations in the data plane. Additionally, permissions that are related to containers, queues, and tables in the control plane are usually provided. However, storage account–level permissions and some network-related permissions are restricted.

Does CloudInfrastructure.GetCsuStorageConnectionString() throw an error if the EnableSharingOfValidStorageConnectionString flight isn't enabled?

Yes. We're deprecating the GetCsuStorageConnectionString() API. We recommend that you use the CloudStorageAccount, BlobServiceClient, or TableServiceClient object that SharedServiceUnitStorage returns for interaction with the storage account.

The following APIs are available in SharedServiceUnitStorage:

  • public CloudStorageAccount GetSharedServiceUnitStorageAccount()
  • public TableServiceClient GetSharedServiceTableServiceClient()
  • public BlobServiceClient GetSharedServiceBlobServiceClient()

How can I get access to the connection string of the finance and operations managed storage account?

We plan to retire all APIs that provide access to the connection string, such as CloudInfrastructure.GetCsuStorageConnectionString(). Although there might be alternative ways to obtain a handle to the connection string, other restrictions will be put in place to render those methods ineffective.

In the future, when the managed identity–based integration is enabled, it won't be possible to connect to the storage account by using connection strings that are shared through APIs outside the finance and operations process, such as interactive AOS, Batch AOS, or the Data Import/Export Framework (DIXF) service.

Because we're disabling the account access key at the storage account level, any access that uses the account access key will no longer work.

What happens when I invoke CloudInfrastructure.GetCsuStorageConnectionString() in environments when the managed identity–based integration is also enabled?

When the managed identity–based integration is enabled, an invalid connection string is returned in this situation.

If you use the invalid connection string, all the existing constructs continue to work, provided that they're accessed within the AOS process space. The exceptions are those constructs that are tightly coupled with the access key, such as GetSharedAccessSignature.

For example, the following code continues to work as it is.

String connectionString = CloudInfrastructure.GetCsuStorageConnectionString();
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(connectionString);
CloudBlobClient blobClient = cloudStorageAccount.CreateCloudBlobClient();
CloudBlobContainer blobContainer = blobClient.GetContainerReference(containerName);

How will the code continue to work with invalid connection strings that are used within the AOS process space?

We intercept the outbound HTTPS requests that the storage software development kit (SDK) makes, to ensure that Azure Blob Storage treats the requests as if a client used a valid connection string to make them. This interception enables the operations to be processed as expected, even if you use the invalid connection string that is returned because of the managed identity-based integration.

Can you provide more details about why GetSharedAccessSignature() fails, whereas other constructs continue to work?

When you invoke GetSharedAccessSignature() on a blob, container, queue, or other storage resources, the shared access signature (SAS) URL or token is generated within the SDK by using the account key that is stored in the SharedAccessCredential to sign the URL.

If CloudStorageAccount and other related objects are constructed by using an invalid account key, that invalid key is used to sign the SAS URL. Although the token/URL can be successfully generated, any attempt to use it to connect to the storage account fails and throws a "403 (Forbidden)" error, because the signature is invalid.

The SAS URL patterns might differ because the managed identity–based integration is enabled in one environment but not the other. When you connect to the storage account by using managed identity, a user-delegated SAS URL is generated instead of the SAS token or URL that is generated by using a connection string.

Can I generate a user-delegated SAS URL by using WindowsAzure.Storage v9.3.3?

No, you can't generate a user-delegated SAS URL by using WindowsAzure.Storage v9.3.3, because it doesn't support this functionality.

Can a user-delegated SAS URL that is generated by using Azure.Storage v12 or later work with a codebase that is written by using WindowsAzure.Storage v9.3.3?

Yes, a user-delegated SAS URL that is generated by using Azure.Storage v12 works with WindowsAzure.Storage v9.3.3 constructs. It's validated in the same way by using internal workflows and various test code.

Note

Provided that you don't manually parse the SAS URL or token (by searching for various tokens, such as se and st, which might cause you to bump into a new token), you're OK, because the URL patterns are different.

What known issues exist if the managed identity that is used is incompatible with previous libraries?

  • You can't generate an SAS URL by using GetSharedAccessSignature(), regardless of the library that you use with managed identity.
  • To generate a user-delegated SAS URL, you must use the Azure.Storage.Blobs SDK (v12 or later).
  • Currently, user-delegated SAS URLs can't be generated for tables and queues. The Azure Storage team will roll out support for those resources. The tentative general availability (GA) date is March 2025. To use this feature, the SDK must be upgraded.
  • User-delegated SAS URLs can't be generated for a period that is longer than seven days. This limit is a hard limit, and there are no plans to extend it.
  • You can't generate a user-delegated SAS at the container level to modify a container-level attribute or check for container existence.

Does this change affect connections to a customer-managed storage account from finance and operations apps (AOS/Interactive AOS, and so on)?

No, there's no impact. Additionally, no request that is made from those libraries will be intercepted.

Do you have any guidance about the use of code or libraries that are available in the platform code?

Refrain from using any classes or methods that are exposed in the Microsoft.Dynamics.Clx.ServicesWrapper.Infrastructure.Interceptor namespace, because they're intended for internal use only and are subject to change.