Azure Storage: BlobClient: Download using DefaultCredential locally with Visual Studio: Issuer validation failed. Issuer did not match

Question

I want to download a Blob from a private container in an Azure Storage Account from my local machine using Visual Studio (2022).

To achieve that I am using

DefaultAzureCredential credential = new DefaultAzureCredential();
Uri uri = new Uri("https://xxx.blob.core.windows.net/xxx/xxx.json");
BlobClient blobClient = new BlobClient(uri, credential);
Response<BlobDownloadResult> downloadResponse = blobClient.DownloadContent();

When I execute the code I get the following error

Issuer validation failed. Issuer did not match.

I authenticated in VS 2022 as described here: Managed Identity - how to debug locally

What do I need to do to successfully download the Blob?

Answer 1

As described in https://learn.microsoft.com/en-us/dotnet/api/azure.identity.defaultazurecredential?view=azure-dotnet DefaultAzureCredential tries different options to get a credential, and one of them is VisualStudioCredential.

For me to get it working locally I had to provide the VisualStudioTenantId:

DefaultAzureCredentialOptions defaultAzureCredentialOptions = new DefaultAzureCredentialOptions()
{
    VisualStudioTenantId = "xxx"
};
DefaultAzureCredential credential = new DefaultAzureCredential(defaultAzureCredentialOptions);
Uri uri = new Uri("https://xxx.blob.core.windows.net/xxx/xxx.json");
BlobClient blobClient = new BlobClient(uri, credential);
Response<BlobDownloadResult> downloadResponse = blobClient.DownloadContent();