From 6212f2c7f70c591efb0d9f3d50ad29112392fee2 Mon Sep 17 00:00:00 2001 From: Sebastian Siewior Date: Thu, 6 Mar 2008 18:56:19 +0800 Subject: [PATCH] [CRYPTO] xts: Use proper alignment The XTS blockmode uses a copy of the IV which is saved on the stack and may or may not be properly aligned. If it is not, it will break hardware cipher like the geode or padlock. This patch encrypts the IV in place so we don't have to worry about alignment. Signed-off-by: Sebastian Siewior Tested-by: Stefan Hellermann Signed-off-by: Herbert Xu --- crypto/xts.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/crypto/xts.c b/crypto/xts.c index 8eb08bfaf7c..d87b0f3102c 100644 --- a/crypto/xts.c +++ b/crypto/xts.c @@ -77,16 +77,16 @@ static int setkey(struct crypto_tfm *parent, const u8 *key, } struct sinfo { - be128 t; + be128 *t; struct crypto_tfm *tfm; void (*fn)(struct crypto_tfm *, u8 *, const u8 *); }; static inline void xts_round(struct sinfo *s, void *dst, const void *src) { - be128_xor(dst, &s->t, src); /* PP <- T xor P */ + be128_xor(dst, s->t, src); /* PP <- T xor P */ s->fn(s->tfm, dst, dst); /* CC <- E(Key1,PP) */ - be128_xor(dst, dst, &s->t); /* C <- T xor CC */ + be128_xor(dst, dst, s->t); /* C <- T xor CC */ } static int crypt(struct blkcipher_desc *d, @@ -101,7 +101,6 @@ static int crypt(struct blkcipher_desc *d, .tfm = crypto_cipher_tfm(ctx->child), .fn = fn }; - be128 *iv; u8 *wsrc; u8 *wdst; @@ -109,20 +108,20 @@ static int crypt(struct blkcipher_desc *d, if (!w->nbytes) return err; + s.t = (be128 *)w->iv; avail = w->nbytes; wsrc = w->src.virt.addr; wdst = w->dst.virt.addr; /* calculate first value of T */ - iv = (be128 *)w->iv; - tw(crypto_cipher_tfm(ctx->tweak), (void *)&s.t, w->iv); + tw(crypto_cipher_tfm(ctx->tweak), w->iv, w->iv); goto first; for (;;) { do { - gf128mul_x_ble(&s.t, &s.t); + gf128mul_x_ble(s.t, s.t); first: xts_round(&s, wdst, wsrc);