Python generate_container_sas function error with invalid base64-encoded string

Question

I am trying to generator container shared access signature (SAS) using python. I am getting invalid base64 encoded error.

 sas_token = generate_container_sas(
            account_name=account_name,
            container_name=settings.AZURE_CONTAINER_NAME,
            account_key=account_key,
            permission=BlobSasPermissions(read=True),
            expiry=expiry_time,
            start=start_time
        )

Error message

Exception: Invalid base64-encoded string: number of data characters (85) cannot be 1 more than a multiple of 4

I tried to find reason on azure document but failed.

Answer 1

I tried in my environment and got the same error:

Error:

The above error occurs when you pass the wrong access key in the generate_container_sas condition.

You can get the access key from the portal:

When I use the below code with the correct access key. I can able to get the container SAS token with url.

Code:

from datetime import datetime,timedelta
from azure.storage.blob import BlobServiceClient,ContainerSasPermissions,generate_container_sas

account_name = 'Your-storage-account-name'
container_name = 'your-container-name'
account_key = 'your-account-key'

expiry_time = datetime.utcnow() + timedelta(hours=1)


permission = ContainerSasPermissions(read=True, write=True, delete=True, 
                                 list=True,delete_previous_version=True, tag=True)

token = generate_container_sas(account_name=account_name,
                        container_name=container_name,
                        account_key=account_key,
                        permission=permission,
                        expiry=expiry_time)

print(token)
container_url = f"https://{account_name}.blob.core.windows.net/{container_name}?{token}"
print(container_url)

Output:

SAS-token: se=2023-09-14T13%3A34%3A28Z&sp=rwdxlt&sv=2023-01-03&sr=c&sig=xxxxx
https://venkat678.blob.core.windows.net/test?se=2023-09-14T13%3A34%3A28Z&sp=rwdxlt&sv=2023-01-03&sr=c&sig=xxxxxx

Reference:

azure.storage.blob package | Microsoft Learn