Access customized HTML pages in the B2C custom policies from azure blob storage private endpoint

Question

Hi,

We have followed this tutorial and created customized html pages for our login flows. https://learn.microsoft.com/en-us/azure/active-directory-b2c/customize-ui-with-html?pivots=b2c-custom-policy#2-create-an-azure-blob-storage-account

Due to security reasons, we will not be able to use the azure public storage account to access the html pages. Can we use the private endpoint within the <LoadUri> element of custom policies to access the html pages.

I'm not able to get any reference or documents with this regard. @AmanpreetSingh-MSFT , can you please clarify.

Answer 1

Hello @Sakthi • Thank you for reaching out.

The recommendation is to allow Public access to the B2C HTML pages. If you want to allow only Private access, you can grant access to Azure Storage resources using shared access signatures (SAS), which generates a URL with additional parameters to allow access to blobs. This URL can be configured as the LoadURI in the policy to specify the custom HTML page.

Keep in mind that the maximum length of the URL in the LoadURI parameter in the B2C custom policy can be 120 characters. If the SAS URL exceeds this limit, you will not be able to use the URL.

Read more:
https://learn.microsoft.com/en-us/azure/storage/common/storage-sas-overview

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Answer 2

Hello,

Trying what you indicate in your answer and typing the URL in LoadURI, the browser changes the URL because the token contains special characters. Is there any way to overcome this limitation?

Thank you.