[Bug] AZURE_POD_IDENTITY_AUTHORITY_HOST env not used correctly

[alar0046]

Library version used

1.23.1

Java version

Java 25

Scenario

ManagedIdentityClient - managed identity

Is this a new or an existing app?

None

Issue description and reproduction steps

When setting the environment variable AZURE_POD_IDENTITY_AUTHORITY_HOST to a custom url, e.g. http://127.0.0.1:80 the full imds endpoint is not built correctly.

The bug is in the constructor of class com.microsoft.aad.msal4j.IMDSManagedIdentitySource. The class contains a variable IMDS_TOKEN_PATH that is set to /metadata/identity/oauth2/token. When AZURE_POD_IDENTITY_AUTHORITY_HOST is set, the endpoint is built with the following code:

StringBuilder builder = new StringBuilder(environmentVariables.getEnvironmentVariable(Constants.AZURE_POD_IDENTITY_AUTHORITY_HOST));
builder.append("/" + IMDS_TOKEN_PATH);

This causes the imdsEndpoint to contain an extra /, thus the endpoint becomes http://127.0.0.1:80//metadata/identity/oauth2/token which causes a resource not found exception from Azure.

Relevant code snippets

Expected behavior

For the imds endpoint to be built correctly without a double /

Identity provider

Microsoft Entra ID (Work and School accounts and Personal Microsoft accounts)

Regression

No response

Solution and workarounds

The fix is to remove the extra /.

[gterminator]

Can we decide to not mix String concatenation? I mean we are using + and StringBuilder at the same time.