Linux cryptographic layer development
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From: Hailey Mothershead <hailmo@amazon.com>
To: <herbert@gondor.apana.org.au>
Cc: <davem@davemloft.net>, <linux-crypto@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <hailmo@amazon.com>
Subject: [PATCH 2/2] crypto: aead,cipher - zeroize key buffer after use
Date: Thu, 11 Apr 2024 23:51:57 +0000	[thread overview]
Message-ID: <20240411235157.19801-2-hailmo@amazon.com> (raw)
In-Reply-To: <20240411235157.19801-1-hailmo@amazon.com>

I.G 9.7.B for FIPS 140-3 specifies that variables temporarily holding
cryptographic information should be zeroized once they are no longer
needed. Accomplish this by using kfree_sensitive for buffers that
previously held the private key.

Signed-off-by: Hailey Mothershead <hailmo@amazon.com>
---
 crypto/aead.c   | 2 +-
 crypto/cipher.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/crypto/aead.c b/crypto/aead.c
index 16991095270d..2592d5375de5 100644
--- a/crypto/aead.c
+++ b/crypto/aead.c
@@ -36,7 +36,7 @@ static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
 	memcpy(alignbuffer, key, keylen);
 	ret = crypto_aead_alg(tfm)->setkey(tfm, alignbuffer, keylen);
 	memset(alignbuffer, 0, keylen);
-	kfree(buffer);
+	kfree_sensitive(buffer);
 	return ret;
 }
 
diff --git a/crypto/cipher.c b/crypto/cipher.c
index b47141ed4a9f..efb87fa417e7 100644
--- a/crypto/cipher.c
+++ b/crypto/cipher.c
@@ -35,7 +35,7 @@ static int setkey_unaligned(struct crypto_cipher *tfm, const u8 *key,
 	memcpy(alignbuffer, key, keylen);
 	ret = cia->cia_setkey(crypto_cipher_tfm(tfm), alignbuffer, keylen);
 	memset(alignbuffer, 0, keylen);
-	kfree(buffer);
+	kfree_sensitive(buffer);
 	return ret;
 
 }
-- 
2.40.1


  reply	other threads:[~2024-04-11 23:52 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-11 23:51 [PATCH 1/2] crypto: ecdh - zeroize crpytographic keys after use Hailey Mothershead
2024-04-11 23:51 ` Hailey Mothershead [this message]
2024-04-12  2:54   ` [PATCH 2/2] crypto: aead,cipher - zeroize key buffer " Herbert Xu
2024-04-12  2:55 ` [PATCH 1/2] crypto: ecdh - zeroize crpytographic keys " Herbert Xu

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