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Donenfeld" , Ard Biesheuvel , linux-crypto@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] lib/crypto: Add a sentence about zeroizing raw key structures Date: Wed, 4 Nov 2026 11:53:52 +0100 Message-ID: <20261104105352.135540-1-thuth@redhat.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Let's make it clear that raw key material has to be zeroized, too. Suggested-by: Eric Biggers Signed-off-by: Thomas Huth --- Suggested here: https://lore.kernel.org/linux-crypto/20260930201434.GA61218@google.com/ Documentation/crypto/libcrypto-zeroization.rst | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Documentation/crypto/libcrypto-zeroization.rst b/Documentation/crypto/libcrypto-zeroization.rst index 76b6506711634..fe9f94413d1f2 100644 --- a/Documentation/crypto/libcrypto-zeroization.rst +++ b/Documentation/crypto/libcrypto-zeroization.rst @@ -47,7 +47,9 @@ The following types of structures hold sensitive material and should be zeroized after use: - **Key structures** (e.g. ``struct aes_key``, ``struct hmac_sha256_key``): - contain expanded round keys or prepared key material. + contain expanded round keys or prepared key material. Note: Arrays and + structures that contain raw key material (e.g. raw AES keys) of course + need to be zeroized as well as soon as the data is not required anymore. - **HMAC/MAC context structures** (e.g. ``struct hmac_sha256_ctx``, ``struct aes_cmac_ctx``): contain inner and outer hash states derived from -- 2.56.0