How to authenticate Azure REST APIs to Storage Queue with SAS?

Question

I'm trying to add a message to my Storage Queue using the REST API provided in this document: https://learn.microsoft.com/en-us/rest/api/storageservices/put-message

Please note that I cannot use the Azure Libraries for this task, there are no Libraries that I know of for Service Now and I'm setting up the test trigger in Python to simulate the REST API calls that would be made from Service Now. In all instances, I receive a 403 error code with no details in the response or the header of the response.

import os, requests, datetime
date = datetime.datetime.utcnow().strftime('%a, %d %b %Y %H:%M:%S GMT')

storage_account = "testacc"
queue = "test-queue"

msg = """<QueueMessage>  
<MessageText>Testing 123</MessageText>  
</QueueMessage>
"""

api = f"https://{storage_account}.queue.core.windows.net/{queue}/messages/?visibilitytimeout=30&timeout=30"
header = {
    "Authorization": f"SharedAccessSignature https://{storage_account}.queue.core.windows.net/?sv=2020-08-04&ss=q&srt=sco&sp=rwau&se=2022-03-03T17:52:52Z&st=2022-02-17T09:52:52Z&spr=https&sig=<REDACTED SIG>", 
    "Content-Type": "application/xml",
    "Content-Length": "str(len(msg))"
}

resp = requests.post(url=api, data=msg, headers=header)

print(resp.headers, resp.status_code)

I am not sure how to design the Authentication key for this API, any tips and suggestions would be appreciated. Thank you.

Answer 1

You don't have to include the Authorization header in the request. Simply use your SAS URL to send the request (with other headers) and the request should work fine.

The reason you do not need Authorization header is because the authorization information is already included in your SAS Token ( sig portion of your SAS Token).

Your code would be something like:

api = f"https://{storage_account}.queue.core.windows.net/{queue}/messages/?visibilitytimeout=30&timeout=30&sv=2020-08-04&ss=q&srt=sco&sp=rwau&se=2022-03-03T17:52:52Z&st=2022-02-17T09:52:52Z&spr=https&sig=<REDACTED SIG>"
header = {
    "Content-Type": "application/xml",
    "Content-Length": "str(len(msg))"
}

resp = requests.post(url=api, data=msg, headers=header)

print(resp.headers, resp.status_code)