[PATCH v2 2/2] crypto: aead,cipher - zeroize key buffer after use

From: Hailey Mothershead
Date: Mon Apr 15 2024 - 18:19:31 EST


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@xxxxxxxxxx>
---
crypto/aead.c | 3 +--
crypto/cipher.c | 3 +--
2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/crypto/aead.c b/crypto/aead.c
index 16991095270d..c4ece86c45bc 100644
--- a/crypto/aead.c
+++ b/crypto/aead.c
@@ -35,8 +35,7 @@ static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
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..395f0c2fbb9f 100644
--- a/crypto/cipher.c
+++ b/crypto/cipher.c
@@ -34,8 +34,7 @@ static int setkey_unaligned(struct crypto_cipher *tfm, const u8 *key,
alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
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

memsets removed and first patch in series dropped.