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Commit 0ddd9f1a authored by Eric Biggers's avatar Eric Biggers Committed by James Morris
Browse files

KEYS: DH: ensure the KDF counter is properly aligned 



Accessing a 'u8[4]' through a '__be32 *' violates alignment rules.  Just
make the counter a __be32 instead.

Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarStephan Mueller <smueller@chronox.de>
Signed-off-by: default avatarJames Morris <james.l.morris@oracle.com>
parent 281590b4

security/keys/dh.c

+3 −13
Original line number Diff line number Diff line
@@ -130,14 +130,6 @@ static void kdf_dealloc(struct kdf_sdesc *sdesc) 
	kzfree(sdesc);

}



/* convert 32 bit integer into its string representation */

static inline void crypto_kw_cpu_to_be32(u32 val, u8 *buf)

{

	__be32 *a = (__be32 *)buf;



	*a = cpu_to_be32(val);

}



/*

 * Implementation of the KDF in counter mode according to SP800-108 section 5.1

 * as well as SP800-56A section 5.8.1 (Single-step KDF).
@@ -154,16 +146,14 @@ static int kdf_ctr(struct kdf_sdesc *sdesc, const u8 *src, unsigned int slen, 
	unsigned int h = crypto_shash_digestsize(desc->tfm);

	int err = 0;

	u8 *dst_orig = dst;

	u32 i = 1;

	u8 iteration[sizeof(u32)];

	__be32 counter = cpu_to_be32(1);



	while (dlen) {

		err = crypto_shash_init(desc);

		if (err)

			goto err;



		crypto_kw_cpu_to_be32(i, iteration);

		err = crypto_shash_update(desc, iteration, sizeof(u32));

		err = crypto_shash_update(desc, (u8 *)&counter, sizeof(__be32));

		if (err)

			goto err;
@@ -189,7 +179,7 @@ static int kdf_ctr(struct kdf_sdesc *sdesc, const u8 *src, unsigned int slen, 


			dlen -= h;

			dst += h;

			i++;

			counter = cpu_to_be32(be32_to_cpu(counter) + 1);

		}

	}