File storage REST API Dir creation

Hello Dmitry,

Thank for your question!

I understand that you are experiencing a 403 error when attempting to create a directory, although other operations are functioning correctly. Considering that the date in your x-ms-date header (Sun, 04 May 2025 22:11:02 GMT) is prior to the current time in you location (Day, Month-Date, year, time, AM-PM), this should not be the main reason for the 403 "AuthenticationFailed" error in Azure Storage.

The string-to-sign seems to have an issue with the CanonicalizedResource part. Specifically, the query parameter restype=directory is appended as a separate line, which is incorrect. According to the Azure Shared Key authorization documentation, query parameters should not be included in the CanonicalizedResource unless they are part of a specific set of signed query parameters (e.g., comp, snapshot), and restype is not one of them.

The string-to-sign for Shared Key authorization should follow this format for Azure File Storage:

StringToSign = VERB + "\n" +
               Content-Encoding + "\n" +
               Content-Language + "\n" +
               Content-Length + "\n" +
               Content-MD5 + "\n" +
               Content-Type + "\n" +
               Date + "\n" +
               If-Modified-Since + "\n" +
               If-Match + "\n" +
               If-None-Match + "\n" +
               If-Unmodified-Since + "\n" +
               Range + "\n" +
               CanonicalizedHeaders +
               CanonicalizedResource

Issues in Your String-to-Sign:

The line /skillrx/skillrx-staging-env/test_created\nrestype:directory is incorrect. The restype=directory query parameter should not be included in the CanonicalizedResource. The CanonicalizedResource should only include the account name and the resource path, like:

/skillrx/skillrx-staging-env/test_created

You have included x-ms-date and x-ms-version, which is correct, but ensure they are sorted alphabetically and formatted properly. Your format looks correct here:

x-ms-date:Sun, 04 May 2025 22:11:02 GMT\nx-ms-version:2025-01-05

The empty fields (e.g., Content-Length, Content-Type) are correctly represented as empty strings (\n), which is fine for a directory creation request since no body is sent.

the corrected string-to-sign should be:

PUT\n\n\n\n\n\n\n\n\n\n\n\nx-ms-date:Sun, 04 May 2025 22:11:02 GMT\nx-ms-version:2025-01-05\n/skillrx/skillrx-staging-env/test_created

• Verify the storage account key is correct and corresponds to the skillrx account.
• Ensure the account has permissions to create directories in the skillrx-staging-env file share.
• The HMAC-SHA256 signature must be computed correctly using the storage account key.
• Ensure the storage account key is correct and has permissions to create directories.
• The x-ms-date header must be within 15 minutes of the server's time.

Hope the above answer helps! Please let us know do you have any further queries.

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