Handle unexpected end of stream errors from KMS.

[vbabanin]

JAVA-6015

[Copilot]

Pull request overview

This PR adds handling for unexpected end-of-stream errors from KMS providers during encryption operations. The key change is detecting when a KMS provider closes a connection prematurely (returning -1 from read operations) and throwing a descriptive MongoException instead of allowing undefined behavior.

Key changes:

• Added EOF detection in KMS stream reading logic for both sync and reactive drivers
• Extracted SSL context building utilities to a shared test fixture to support new test infrastructure
• Added test case that simulates KMS server abruptly closing connections

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
driver-sync/src/main/com/mongodb/client/internal/Crypt.java	Added EOF check when reading from KMS provider streams and updated exception wrapping logic
driver-reactive-streams/src/main/com/mongodb/reactivestreams/client/internal/crypt/KeyManagementService.java	Added EOF detection in async stream reading callback
driver-sync/src/test/functional/com/mongodb/fixture/EncryptionFixture.java	Extracted SSL context and KeyManagerFactory creation utilities for test reuse
driver-sync/src/test/functional/com/mongodb/client/auth/AbstractX509AuthenticationTest.java	Refactored to use shared SSL context utilities from EncryptionFixture
driver-sync/src/test/functional/com/mongodb/client/AbstractClientSideEncryptionKmsTlsTest.java	Added test simulating KMS server EOF scenario with fake SSL server
.evergreen/run-kms-tls-tests.sh	Added server keystore generation and configuration for KMS TLS testing

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