From 0ddd9f1a6b7e5746b52959f645fc66859b805e88 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Thu, 8 Jun 2017 14:49:49 +0100 Subject: 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: Eric Biggers Signed-off-by: David Howells Acked-by: Stephan Mueller Signed-off-by: James Morris --- security/keys/dh.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) (limited to 'security/keys/dh.c') diff --git a/security/keys/dh.c b/security/keys/dh.c index 1c1cac677041..63ac87d430db 100644 --- a/security/keys/dh.c +++ b/security/keys/dh.c @@ -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); } } -- cgit v1.2.3-59-g8ed1b