CVE-2026-61798

## Summary `io.netty.incubator:netty-incubator-codec-ohttp-hpke-classes-boringssl` exposes raw HPKE private key bytes in string representations and error messages. `BoringSSLAsymmetricCipherKeyPair.toString()` includes the private-key parameter object, and `BoringSSLAsymmetricKeyParameter.toString()` renders the full byte array with `Arrays.toString(bytes)`. Separately, failed native key initialization includes `Arrays.toString(privateKeyBytes)` in the thrown `IllegalArgumentException` message. Applications that log key-pair objects or exceptions can persist private key material in logs. ## Details `codec-ohttp-hpke-classes-boringssl/src/main/java/io/netty/incubator/codec/hpke/boringssl/BoringSSLAsymmetricCipherKeyPair.java` renders private key material through `toString()`: - `BoringSSLAsymmetricCipherKeyPair.toString()` at lines 72-78 concatenates `"privateKey=" + privateKey`. - `privateKey` is a `BoringSSLAsymmetricKeyParameter` created with `isPrivate=true` at lines 26-36. `codec-ohttp-hpke-classes-boringssl/src/main/java/io/netty/incubator/codec/hpke/boringssl/BoringSSLAsymmetricKeyParameter.java` then renders all bytes: - `BoringSSLAsymmetricKeyParameter.toString()` at lines 70-76 returns `"bytes=" + Arrays.toString(bytes)` regardless of whether `isPrivate` is true. A separate error path in `codec-ohttp-hpke-classes-boringssl/src/main/java/io/netty/incubator/codec/hpke/boringssl/BoringSSL.java` also exposes caller-provided private key bytes: - `EVP_HPKE_KEY_init_or_throw(...)` at lines 228-232 throws `IllegalArgumentException("privateKeyBytes does not contain a valid private key: " + Arrays.toString(privateKeyBytes))` when BoringSSL rejects the key. Because Java logging frameworks commonly call `toString()` for structured objects and commonly persist exception messages, these paths can place complete HPKE private key material in logs or telemetry. ## Proof of concept Safe local verification was performed without native BoringSSL by compiling the rel