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Commit 3f8214ea authored by Herbert Xu's avatar Herbert Xu
Browse files

[CRYPTO] ctr: Use crypto_inc and crypto_xor 



This patch replaces the custom inc/xor in CTR with the generic functions.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent d0b9007a

crypto/ctr.c

+16 −55
Original line number Diff line number Diff line
@@ -31,51 +31,6 @@ struct crypto_ctr_ctx { 
	u8 *nonce;

};



static inline void __ctr_inc_byte(u8 *a, unsigned int size)

{

	u8 *b = (a + size);

	u8 c;



	for (; size; size--) {

		c = *--b + 1;

		*b = c;

		if (c)

			break;

	}

}



static void ctr_inc_quad(u8 *a, unsigned int size)

{

	__be32 *b = (__be32 *)(a + size);

	u32 c;



	for (; size >= 4; size -=4) {

		c = be32_to_cpu(*--b) + 1;

		*b = cpu_to_be32(c);

		if (c)

			return;

	}



	__ctr_inc_byte(a, size);

}



static void xor_byte(u8 *a, const u8 *b, unsigned int bs)

{

	for (; bs; bs--)

		*a++ ^= *b++;

}



static void xor_quad(u8 *dst, const u8 *src, unsigned int bs)

{

	u32 *a = (u32 *)dst;

	u32 *b = (u32 *)src;



	for (; bs >= 4; bs -= 4)

		*a++ ^= *b++;



	xor_byte((u8 *)a, (u8 *)b, bs);

}



static int crypto_ctr_setkey(struct crypto_tfm *parent, const u8 *key,

			     unsigned int keylen)

{
@@ -111,7 +66,8 @@ static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk, 
	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =

		   crypto_cipher_alg(tfm)->cia_encrypt;

	unsigned int bsize = crypto_cipher_blocksize(tfm);

	unsigned long alignmask = crypto_cipher_alignmask(tfm);

	unsigned long alignmask = crypto_cipher_alignmask(tfm) |

				  (__alignof__(u32) - 1);

	u8 ks[bsize + alignmask];

	u8 *keystream = (u8 *)ALIGN((unsigned long)ks, alignmask + 1);

	u8 *src = walk->src.virt.addr;
@@ -121,13 +77,13 @@ static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk, 
	do {

		/* create keystream */

		fn(crypto_cipher_tfm(tfm), keystream, ctrblk);

		xor_quad(keystream, src, min(nbytes, bsize));

		crypto_xor(keystream, src, min(nbytes, bsize));



		/* copy result into dst */

		memcpy(dst, keystream, min(nbytes, bsize));



		/* increment counter in counterblock */

		ctr_inc_quad(ctrblk + (bsize - countersize), countersize);

		crypto_inc(ctrblk + bsize - countersize, countersize);



		if (nbytes < bsize)

			break;
@@ -148,7 +104,8 @@ static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk, 
	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =

		   crypto_cipher_alg(tfm)->cia_encrypt;

	unsigned int bsize = crypto_cipher_blocksize(tfm);

	unsigned long alignmask = crypto_cipher_alignmask(tfm);

	unsigned long alignmask = crypto_cipher_alignmask(tfm) |

				  (__alignof__(u32) - 1);

	unsigned int nbytes = walk->nbytes;

	u8 *src = walk->src.virt.addr;

	u8 ks[bsize + alignmask];
@@ -157,10 +114,10 @@ static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk, 
	do {

		/* create keystream */

		fn(crypto_cipher_tfm(tfm), keystream, ctrblk);

		xor_quad(src, keystream, min(nbytes, bsize));

		crypto_xor(src, keystream, min(nbytes, bsize));



		/* increment counter in counterblock */

		ctr_inc_quad(ctrblk + (bsize - countersize), countersize);

		crypto_inc(ctrblk + bsize - countersize, countersize);



		if (nbytes < bsize)

			break;
@@ -184,7 +141,8 @@ static int crypto_ctr_crypt(struct blkcipher_desc *desc, 
	unsigned int bsize = crypto_cipher_blocksize(child);

	struct ctr_instance_ctx *ictx =

		crypto_instance_ctx(crypto_tfm_alg_instance(&tfm->base));

	unsigned long alignmask = crypto_cipher_alignmask(child);

	unsigned long alignmask = crypto_cipher_alignmask(child) |

				  (__alignof__(u32) - 1);

	u8 cblk[bsize + alignmask];

	u8 *counterblk = (u8 *)ALIGN((unsigned long)cblk, alignmask + 1);

	int err;
@@ -198,8 +156,7 @@ static int crypto_ctr_crypt(struct blkcipher_desc *desc, 
	memcpy(counterblk + ictx->noncesize, walk.iv, ictx->ivsize);



	/* initialize counter portion of counter block */

	ctr_inc_quad(counterblk + (bsize - ictx->countersize),

		     ictx->countersize);

	crypto_inc(counterblk + bsize - ictx->countersize, ictx->countersize);



	while (walk.nbytes) {

		if (walk.src.virt.addr == walk.dst.virt.addr)
@@ -284,6 +241,10 @@ static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb) 
	    (countersize > alg->cra_blocksize) || (countersize < 4))

		goto out_put_alg;



	/* If this is false we'd fail the alignment of crypto_inc. */

	if ((alg->cra_blocksize - countersize) % 4)

		goto out_put_alg;



	inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);

	err = -ENOMEM;

	if (!inst)
@@ -316,7 +277,7 @@ static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb) 
	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;

	inst->alg.cra_priority = alg->cra_priority;

	inst->alg.cra_blocksize = 1;

	inst->alg.cra_alignmask = 3;

	inst->alg.cra_alignmask = __alignof__(u32) - 1;

	inst->alg.cra_type = &crypto_blkcipher_type;



	inst->alg.cra_blkcipher.ivsize = ivsize;