Enable HTTPS endpoint identification in JsseSslEngineFactory - #2243
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hyperxpro merged 1 commit intoJul 18, 2026
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A JDK SSLEngine does not verify the peer hostname unless the endpoint identification algorithm is set, so JsseSslEngineFactory accepted a certificate valid for any host. DefaultSslEngineFactory already enables it. Set it here too, honoring disableHttpsEndpointIdentificationAlgorithm, so a custom JDK SSLContext no longer silently loses hostname verification.
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Motivation
JsseSslEngineFactory creates the SSLEngine using sslContext.createSSLEngine(host, port) but only enables client mode via setUseClientMode(true). It never configures endpoint identification, so a JDK SSLEngine does not verify the server hostname during the TLS handshake. As a result, any certificate signed by a trusted CA is accepted regardless of the requested hostname, leaving the connection vulnerable to man-in-the-middle attacks. DefaultSslEngineFactory correctly enables hostname verification.
This regression was introduced in #2104, which removed the shared setEndpointIdentificationAlgorithm("HTTPS") call from configureSslEngine() and restored it only in DefaultSslEngineFactory, unintentionally leaving the pure JSSE path (used with a user-supplied JDK SSLContext) without hostname verification.
Modification
Update JsseSslEngineFactory.newSslEngine() to configure the engine's SSLParameters with setEndpointIdentificationAlgorithm("HTTPS"), unless config.isDisableHttpsEndpointIdentificationAlgorithm() is enabled. This matches the behavior of DefaultSslEngineFactory while preserving the documented opt-out.
Result
Connections created through JsseSslEngineFactory with a custom JDK SSLContext now perform hostname verification during the TLS handshake, matching the default implementation. Existing opt-out behavior remains unchanged, and the DefaultSslEngineFactory path is unaffected.