DestinationHttpClient does not apply client certificates #254

Describe the Bug

Hi team!

We are using the SAP Cloud SDK for Python and noticed that DestinationHttpClient doesn't configure client certificates, even though the destination contains them.

We can manually update the session after the client has been created, but this should be handled automatically by the SDK.

Could you please have a look? Let me know if you need any additional information.

Thanks & Best regards
Marc

Steps to Reproduce

Setup a destination with authentication type ClientCertificateAuthentication. The exported destination looks like:

{
    "destination": {
        "Authentication": "ClientCertificateAuthentication",
        "Description": "Test Destination",
        "KeyStore.Source": "DestinationService",
        "KeyStoreLocation": "combined.pem",
        "KeyStorePassword": "<removed>",
        "Name": "GRL_AI_DEV_INTERNAL_API",
        "ProxyType": "Internet",
        "Type": "HTTP",
        "URL": "https://<removed>"
    },
    "exportTime": "2026-08-04 08:44:14.414277468"
}

and setup a client like this:

destination = client.get_destination(
    "GRL_AI_DEV_INTERNAL_API",
    level=ConsumptionLevel.PROVIDER_SUBACCOUNT
)

dest_http_client = DestinationHttpClient(destination)

response = dest_http_client.request(
    "GET", 
    "/somePath/"
)

The dest_http_client is not setup with the client certificate and subsequent calls fail with a http 401, as the server expects a certificate.

Expected Behavior

The DestinationHttpClient should configure the certification settings for dest_http_client.

In the SAP Cloud SDK for Java, this works correctly:

Destination destination = DestinationAccessor.getDestination(destinationName).asHttp();
HttpClient httpClient = HttpClientAccessor.getHttpClient(destination);

Screenshots

Certificate from destination is available:

But not transferred to the client:

Used Versions

• SDK version: 0.39.0
• Python: 3.11

Code Examples

See above

Stack Trace

No error stack, but a HTTP 401 from the server expecting a client certificate.

Log File

No response

Affected Development Phase

Development

Impact

Impaired

Timeline

No response