Azure Event Hubs Authentication Issue with Status Code 401 for Specific Customer Credentials

Question

I am reaching out regarding an issue encountered with Azure Event Hubs authentication for one of our customers. Despite successfully authenticating for most users, we are facing a peculiar problem with a specific customer's credentials, resulting in a 401 Unauthorized error. Below are the details of the issue and the steps we've taken so far:

Problem Description

Our service integrates with Azure Event Hubs, allowing customers to configure their Event Hubs by providing their own credentials. We utilize the ClientSecretCredentialBuilder and EventHubClientBuilder classes to authenticate and establish a connection to the Event Hub. The majority of our customers can connect without issues; however, one particular customer consistently encounters a 401 Unauthorized error when attempting to send events to their Event Hub.

The error message received is as follows:

Status code: 401, Status description: Generic, Error Context [NAMESPACE: DU-MMY-EventHub-NonProd.servicebus.windows.net. ERROR CONTEXT: N/A, PATH: $cbs, REFERENCE_ID: cbs:receiver, LINK_CREDIT: 0] 

Snippet of code

// Build the credential object
ClientSecretCredential credential = new ClientSecretCredentialBuilder()
        .clientId(clientId)
        .clientSecret(clientSecret)
        .tenantId(tenantId)
        .build();

// Build the Event Hub producer client
EventHubProducerClient producer = new EventHubClientBuilder()
        .transportType(AmqpTransportType.AMQP_WEB_SOCKETS)
        .fullyQualifiedNamespace(eventHubNamespace)
        .eventHubName(eventHubName)
        .credential(credential)

EventDataBatch eventDataBatch = producer.createBatch(new CreateBatchOptions().setPartitionKey(somekey));
EventData eventData = new EventData(somedata.getBytes());

// Add the EventData to the batch
eventDataBatch.tryAdd(eventData);

// Send the batch of events to the Event Hub
producer.send(eventDataBatch);

What i tried ...

1. We have verified that the customer's credentials (Client ID, Client Secret, Tenant ID) are correct. Interestingly, intentionally providing an incorrect client secret results in a different error (AADSTS7000215: Invalid client secret provided.), indicating that our authentication flow is functioning as expected for invalid credentials.
2. Logging and Diagnostics: We have enabled diagnostic settings for the Event Hub to capture runtime audit logs and application metrics logs in out test setup. However, the logs do not provide additional details beyond the initial 401 Unauthorized error from service side.

So wanted. to check on the following..

1. Given the error message and context, are there specific areas within the Azure Event Hubs or Azure Active Directory configurations that we should investigate further?
2. Is there a way to enable more detailed logging or tracing for Azure Event Hubs that could provide insights into why the authentication is failing for this specific customer?
3. Could there be any limitations or restrictions on the customer's Azure subscription or service principal that might lead to this authentication issue?

Answer 1

@Sanjay M Santhosh

I'm glad that you were able to resolve your issue and thank you for posting your solution so that others experiencing the same thing can easily reference this! Since the Microsoft Q&A community has a policy that "The question author cannot accept their own answer. They can only accept answers by others ", I'll repost your solution in case you'd like to accept the answer .

Ask:

I am reaching out regarding an issue encountered with Azure Event Hubs authentication for one of our customers. Despite successfully authenticating for most users, we are facing a peculiar problem with a specific customer's credentials, resulting in a 401 Unauthorized error. Below are the details of the issue and the steps we've taken so far:

Problem Description

Our service integrates with Azure Event Hubs, allowing customers to configure their Event Hubs by providing their own credentials. We utilize the ClientSecretCredentialBuilder and EventHubClientBuilder classes to authenticate and establish a connection to the Event Hub. The majority of our customers can connect without issues; however, one particular customer consistently encounters a 401 Unauthorized error when attempting to send events to their Event Hub.

The error message received is as follows:

Status code: 401, Status description: Generic, Error Context [NAMESPACE: DU-MMY-EventHub-NonProd.servicebus.windows.net. ERROR CONTEXT: N/A, PATH: $cbs, REFERENCE_ID: cbs:receiver, LINK_CREDIT: 0] 

Snippet of code

// Build the credential object
ClientSecretCredential credential = new ClientSecretCredentialBuilder()
        .clientId(clientId)
        .clientSecret(clientSecret)
        .tenantId(tenantId)
        .build();
// Build the Event Hub producer client
EventHubProducerClient producer = new EventHubClientBuilder()
        .transportType(AmqpTransportType.AMQP_WEB_SOCKETS)
        .fullyQualifiedNamespace(eventHubNamespace)
        .eventHubName(eventHubName)
        .credential(credential)
EventDataBatch eventDataBatch = producer.createBatch(new CreateBatchOptions().setPartitionKey(somekey));
EventData eventData = new EventData(somedata.getBytes());
// Add the EventData to the batch
eventDataBatch.tryAdd(eventData);
// Send the batch of events to the Event Hub
producer.send(eventDataBatch);

What i tried ...

1. We have verified that the customer's credentials (Client ID, Client Secret, Tenant ID) are correct. Interestingly, intentionally providing an incorrect client secret results in a different error (AADSTS7000215: Invalid client secret provided.), indicating that our authentication flow is functioning as expected for invalid credentials.
2. Logging and Diagnostics: We have enabled diagnostic settings for the Event Hub to capture runtime audit logs and application metrics logs in out test setup. However, the logs do not provide additional details beyond the initial 401 Unauthorized error from service side.

So wanted. to check on the following..

1. Given the error message and context, are there specific areas within the Azure Event Hubs or Azure Active Directory configurations that we should investigate further?
2. Is there a way to enable more detailed logging or tracing for Azure Event Hubs that could provide insights into why the authentication is failing for this specific customer?
3. Could there be any limitations or restrictions on the customer's Azure subscription or service principal that might lead to this authentication issue?

Solution: The root cause of the issue was straightforward: it was a typo in the Event Hub name provided by the customer that caused the confusion. The error message was unclear, which made it challenging to pinpoint the problem. Thank you for your assistance

If I missed anything please let me know and I'd be happy to add it to my answer, or feel free to comment below with any additional information.

If you have any other questions, please let me know. Thank you again for your time and patience throughout this issue.

---

Please don’t forget to Accept Answer and Yes for "was this answer helpful" wherever the information provided helps you, this can be beneficial to other community members