async download_blob authenticationerror when equal sign '=' in the url

[gverkes]

• Package Name: azure-storage-blob
• Package Version: 12.1.0
• Operating System: Windows 10
• Python Version: 3.7.3

Describe the bug
Whenever there is a blob that has a equal sign ('=') in the url the async BlobServiceClient will give me an AuthenticationError. The same file without the equal sign or using non-async BlobServiceClient works fine.

To Reproduce
The following code will give me a an authentication error AuthenticationErrorDetail:The MAC signature found in the HTTP request '...' is not the same as any computed signature.

from azure.storage.blob.aio import BlobServiceClient
blob_service_client = BlobServiceClient.from_connection_string(conn_str)

async with blob_service_client:
    container_client = blob_service_client.get_container_client("data")

    with open("./dl_test2/height=10.png", "wb") as f:
        stream = await container_client.download_blob("height=10.png")
        data = await stream.readall()
        f.write(data)

Whereas the following two work:

1. without the equal sign in the url:

from azure.storage.blob.aio import BlobServiceClient
blob_service_client = BlobServiceClient.from_connection_string(conn_str)

async with blob_service_client:
    container_client = blob_service_client.get_container_client("data")

    with open("./dl_test2/height=10.png", "wb") as f:
        # exactly same file without the equal sign
        stream = await container_client.download_blob("height10.png")
        data = await stream.readall()
        f.write(data)

2. using the non-async BlobServiceClient, with the equal sign in the url

from azure.storage.blob import BlobServiceClient
blob_service_client = BlobServiceClient.from_connection_string(conn_str)

async with blob_service_client:
    container_client = blob_service_client.get_container_client("data")

    with open("./dl_test2/height=10.png", "wb") as f:
        # with the equal sign
        stream = container_client.download_blob("height=10.png")
        data = stream.readall()
        f.write(data)

[kaerm]

Thanks for the feedback @gverkes, I am looping in the right team to take a look at this.

[xiafu-msft]

Hi @gverkes

Thanks so much for reporting the problem and providing the detailed steps to reproduce that!
I was able to reproduce the problem. It should be a storage bug. we are still investigating that.
Sorry about the inconvenience...

[xiafu-msft]

Created an issue in our dependency and see if they have any insight about this aio-libs/yarl#420

[ghost]

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @xgithubtriage.

[aviramha]

Probably a duplicate of this #11028