Server failed to authenticate error when metadata values contain trailing whitespace

[joeax]

Which service(blob, file, queue) does this issue concern?

blob

Which version of the SDK was used? Please provide the output of pip freeze.

azure-common==1.1.23 azure-storage-blob==2.1.0 azure-storage-common==2.1.0

What problem was encountered?

Call to create_blob_from_bytes() throws an error [azure.common.AzureHttpError] when any of the metadata values have leading or trailing whitespace.

azure.common.AzureHttpError: Server failed to authenticate the request. Make sure the value of Authorization header is formed correctly including the signature. ErrorCode: AuthenticationFailed
<?xml version="1.0" encoding="utf-8"?><Error><Code>AuthenticationFailed</Code><Message>Server failed to authenticate the request. Make sure the value of Authorization header is formed correctly including the signature.
RequestId:78143b83-701e-0007-57a6-53ca4f000000
Time:2019-08-15T20:14:22.7942254Z</Message><AuthenticationErrorDetail>The MAC signature found in the HTTP request '(redacted base64 string)' is not the same as any computed signature. Server used following string to sign: 'PUT 61932 ...'

Have you found a mitigation/solution?

Yes, trim all values in the metadata dict.

Old metadata (throws error):

metadata = {'LDate': '6/19/2018 12:15:16 PM', 'DocName': 'Utah Contracts 1    ', 'FileExtension': 'docx'}
service.create_blob_from_bytes(container, name, content, content_settings=content_settings, metadata=metadata)

New metadata (no error):

metadata = {'LDate': '6/19/2018 12:15:16 PM', 'DocName': 'Utah Contracts 1', 'FileExtension': 'docx'}
service.create_blob_from_bytes(container, name, content, content_settings=content_settings, metadata=metadata)