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Commit 79c65d17 authored by Herbert Xu's avatar Herbert Xu
Browse files

crypto: cbc - Convert to skcipher 



This patch converts cbc over to the skcipher interface.  It also
rearranges the code to allow it to be reused by drivers.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent da40e7a4

crypto/cbc.c

+138 −104
Original line number Diff line number Diff line
@@ -10,42 +10,39 @@ 
 *

 */



#include <crypto/algapi.h>

#include <crypto/internal/skcipher.h>

#include <linux/err.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/log2.h>

#include <linux/module.h>

#include <linux/scatterlist.h>

#include <linux/slab.h>



struct crypto_cbc_ctx {

	struct crypto_cipher *child;

};



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

static int crypto_cbc_setkey(struct crypto_skcipher *parent, const u8 *key,

			     unsigned int keylen)

{

	struct crypto_cbc_ctx *ctx = crypto_tfm_ctx(parent);

	struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(parent);

	struct crypto_cipher *child = ctx->child;

	int err;



	crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);

	crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &

	crypto_cipher_set_flags(child, crypto_skcipher_get_flags(parent) &

				       CRYPTO_TFM_REQ_MASK);

	err = crypto_cipher_setkey(child, key, keylen);

	crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &

	crypto_skcipher_set_flags(parent, crypto_cipher_get_flags(child) &

					  CRYPTO_TFM_RES_MASK);

	return err;

}



static int crypto_cbc_encrypt_segment(struct blkcipher_desc *desc,

				      struct blkcipher_walk *walk,

				      struct crypto_cipher *tfm)

static inline int crypto_cbc_encrypt_segment(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =

		crypto_cipher_alg(tfm)->cia_encrypt;

	int bsize = crypto_cipher_blocksize(tfm);

	unsigned int bsize = crypto_skcipher_blocksize(tfm);

	unsigned int nbytes = walk->nbytes;

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

	u8 *dst = walk->dst.virt.addr;
@@ -53,7 +50,7 @@ static int crypto_cbc_encrypt_segment(struct blkcipher_desc *desc, 


	do {

		crypto_xor(iv, src, bsize);

		fn(crypto_cipher_tfm(tfm), dst, iv);

		fn(tfm, iv, dst);

		memcpy(iv, dst, bsize);



		src += bsize;
@@ -63,20 +60,18 @@ static int crypto_cbc_encrypt_segment(struct blkcipher_desc *desc, 
	return nbytes;

}



static int crypto_cbc_encrypt_inplace(struct blkcipher_desc *desc,

				      struct blkcipher_walk *walk,

				      struct crypto_cipher *tfm)

static inline int crypto_cbc_encrypt_inplace(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =

		crypto_cipher_alg(tfm)->cia_encrypt;

	int bsize = crypto_cipher_blocksize(tfm);

	unsigned int bsize = crypto_skcipher_blocksize(tfm);

	unsigned int nbytes = walk->nbytes;

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

	u8 *iv = walk->iv;



	do {

		crypto_xor(src, iv, bsize);

		fn(crypto_cipher_tfm(tfm), src, src);

		fn(tfm, src, src);

		iv = src;



		src += bsize;
@@ -87,44 +82,52 @@ static int crypto_cbc_encrypt_inplace(struct blkcipher_desc *desc, 
	return nbytes;

}



static int crypto_cbc_encrypt(struct blkcipher_desc *desc,

			      struct scatterlist *dst, struct scatterlist *src,

			      unsigned int nbytes)

static inline int crypto_cbc_encrypt_walk(struct skcipher_request *req,

					  void (*fn)(struct crypto_skcipher *,

						     const u8 *, u8 *))

{

	struct blkcipher_walk walk;

	struct crypto_blkcipher *tfm = desc->tfm;

	struct crypto_cbc_ctx *ctx = crypto_blkcipher_ctx(tfm);

	struct crypto_cipher *child = ctx->child;

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	struct skcipher_walk walk;

	int err;



	blkcipher_walk_init(&walk, dst, src, nbytes);

	err = blkcipher_walk_virt(desc, &walk);

	err = skcipher_walk_virt(&walk, req, false);



	while ((nbytes = walk.nbytes)) {

	while (walk.nbytes) {

		if (walk.src.virt.addr == walk.dst.virt.addr)

			nbytes = crypto_cbc_encrypt_inplace(desc, &walk, child);

			err = crypto_cbc_encrypt_inplace(&walk, tfm, fn);

		else

			nbytes = crypto_cbc_encrypt_segment(desc, &walk, child);

		err = blkcipher_walk_done(desc, &walk, nbytes);

			err = crypto_cbc_encrypt_segment(&walk, tfm, fn);

		err = skcipher_walk_done(&walk, err);

	}



	return err;

}



static int crypto_cbc_decrypt_segment(struct blkcipher_desc *desc,

				      struct blkcipher_walk *walk,

				      struct crypto_cipher *tfm)

static inline void crypto_cbc_encrypt_one(struct crypto_skcipher *tfm,

					  const u8 *src, u8 *dst)

{

	struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);



	crypto_cipher_encrypt_one(ctx->child, dst, src);

}



static int crypto_cbc_encrypt(struct skcipher_request *req)

{

	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =

		crypto_cipher_alg(tfm)->cia_decrypt;

	int bsize = crypto_cipher_blocksize(tfm);

	return crypto_cbc_encrypt_walk(req, crypto_cbc_encrypt_one);

}



static inline int crypto_cbc_decrypt_segment(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	unsigned int bsize = crypto_skcipher_blocksize(tfm);

	unsigned int nbytes = walk->nbytes;

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

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

	u8 *iv = walk->iv;



	do {

		fn(crypto_cipher_tfm(tfm), dst, src);

		fn(tfm, src, dst);

		crypto_xor(dst, iv, bsize);

		iv = src;
@@ -137,13 +140,11 @@ static int crypto_cbc_decrypt_segment(struct blkcipher_desc *desc, 
	return nbytes;

}



static int crypto_cbc_decrypt_inplace(struct blkcipher_desc *desc,

				      struct blkcipher_walk *walk,

				      struct crypto_cipher *tfm)

static inline int crypto_cbc_decrypt_inplace(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =

		crypto_cipher_alg(tfm)->cia_decrypt;

	int bsize = crypto_cipher_blocksize(tfm);

	unsigned int bsize = crypto_skcipher_blocksize(tfm);

	unsigned int nbytes = walk->nbytes;

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

	u8 last_iv[bsize];
@@ -153,7 +154,7 @@ static int crypto_cbc_decrypt_inplace(struct blkcipher_desc *desc, 
	memcpy(last_iv, src, bsize);



	for (;;) {

		fn(crypto_cipher_tfm(tfm), src, src);

		fn(tfm, src, src);

		if ((nbytes -= bsize) < bsize)

			break;

		crypto_xor(src, src - bsize, bsize);
@@ -166,35 +167,46 @@ static int crypto_cbc_decrypt_inplace(struct blkcipher_desc *desc, 
	return nbytes;

}



static int crypto_cbc_decrypt(struct blkcipher_desc *desc,

			      struct scatterlist *dst, struct scatterlist *src,

			      unsigned int nbytes)

static inline int crypto_cbc_decrypt_blocks(

	struct skcipher_walk *walk, struct crypto_skcipher *tfm,

	void (*fn)(struct crypto_skcipher *, const u8 *, u8 *))

{

	struct blkcipher_walk walk;

	struct crypto_blkcipher *tfm = desc->tfm;

	struct crypto_cbc_ctx *ctx = crypto_blkcipher_ctx(tfm);

	struct crypto_cipher *child = ctx->child;

	if (walk->src.virt.addr == walk->dst.virt.addr)

		return crypto_cbc_decrypt_inplace(walk, tfm, fn);

	else

		return crypto_cbc_decrypt_segment(walk, tfm, fn);

}



static inline void crypto_cbc_decrypt_one(struct crypto_skcipher *tfm,

					  const u8 *src, u8 *dst)

{

	struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);



	crypto_cipher_decrypt_one(ctx->child, dst, src);

}



static int crypto_cbc_decrypt(struct skcipher_request *req)

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	struct skcipher_walk walk;

	int err;



	blkcipher_walk_init(&walk, dst, src, nbytes);

	err = blkcipher_walk_virt(desc, &walk);

	err = skcipher_walk_virt(&walk, req, false);



	while ((nbytes = walk.nbytes)) {

		if (walk.src.virt.addr == walk.dst.virt.addr)

			nbytes = crypto_cbc_decrypt_inplace(desc, &walk, child);

		else

			nbytes = crypto_cbc_decrypt_segment(desc, &walk, child);

		err = blkcipher_walk_done(desc, &walk, nbytes);

	while (walk.nbytes) {

		err = crypto_cbc_decrypt_blocks(&walk, tfm,

						crypto_cbc_decrypt_one);

		err = skcipher_walk_done(&walk, err);

	}



	return err;

}



static int crypto_cbc_init_tfm(struct crypto_tfm *tfm)

static int crypto_cbc_init_tfm(struct crypto_skcipher *tfm)

{

	struct crypto_instance *inst = (void *)tfm->__crt_alg;

	struct crypto_spawn *spawn = crypto_instance_ctx(inst);

	struct crypto_cbc_ctx *ctx = crypto_tfm_ctx(tfm);

	struct skcipher_instance *inst = skcipher_alg_instance(tfm);

	struct crypto_spawn *spawn = skcipher_instance_ctx(inst);

	struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);

	struct crypto_cipher *cipher;



	cipher = crypto_spawn_cipher(spawn);
@@ -205,72 +217,94 @@ static int crypto_cbc_init_tfm(struct crypto_tfm *tfm) 
	return 0;

}



static void crypto_cbc_exit_tfm(struct crypto_tfm *tfm)

static void crypto_cbc_exit_tfm(struct crypto_skcipher *tfm)

{

	struct crypto_cbc_ctx *ctx = crypto_tfm_ctx(tfm);

	struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);



	crypto_free_cipher(ctx->child);

}



static struct crypto_instance *crypto_cbc_alloc(struct rtattr **tb)

static void crypto_cbc_free(struct skcipher_instance *inst)

{

	struct crypto_instance *inst;

	crypto_drop_skcipher(skcipher_instance_ctx(inst));

	kfree(inst);

}



static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb)

{

	struct skcipher_instance *inst;

	struct crypto_spawn *spawn;

	struct crypto_alg *alg;

	int err;



	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);

	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER);

	if (err)

		return ERR_PTR(err);

		return err;



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

	if (!inst)

		return -ENOMEM;



	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,

				  CRYPTO_ALG_TYPE_MASK);

	err = PTR_ERR(alg);

	if (IS_ERR(alg))

		return ERR_CAST(alg);

		goto err_free_inst;



	inst = ERR_PTR(-EINVAL);

	if (!is_power_of_2(alg->cra_blocksize))

		goto out_put_alg;

	spawn = skcipher_instance_ctx(inst);

	err = crypto_init_spawn(spawn, alg, skcipher_crypto_instance(inst),

				CRYPTO_ALG_TYPE_MASK);

	crypto_mod_put(alg);

	if (err)

		goto err_free_inst;



	inst = crypto_alloc_instance("cbc", alg);

	if (IS_ERR(inst))

		goto out_put_alg;

	err = crypto_inst_setname(skcipher_crypto_instance(inst), "cbc", alg);

	if (err)

		goto err_drop_spawn;



	err = -EINVAL;

	if (!is_power_of_2(alg->cra_blocksize))

		goto err_drop_spawn;



	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;

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

	inst->alg.cra_blocksize = alg->cra_blocksize;

	inst->alg.cra_alignmask = alg->cra_alignmask;

	inst->alg.cra_type = &crypto_blkcipher_type;

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

	inst->alg.base.cra_blocksize = alg->cra_blocksize;

	inst->alg.base.cra_alignmask = alg->cra_alignmask;



	/* We access the data as u32s when xoring. */

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

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



	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;

	inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;

	inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;

	inst->alg.ivsize = alg->cra_blocksize;

	inst->alg.min_keysize = alg->cra_cipher.cia_min_keysize;

	inst->alg.max_keysize = alg->cra_cipher.cia_max_keysize;



	inst->alg.cra_ctxsize = sizeof(struct crypto_cbc_ctx);

	inst->alg.base.cra_ctxsize = sizeof(struct crypto_cbc_ctx);



	inst->alg.cra_init = crypto_cbc_init_tfm;

	inst->alg.cra_exit = crypto_cbc_exit_tfm;

	inst->alg.init = crypto_cbc_init_tfm;

	inst->alg.exit = crypto_cbc_exit_tfm;



	inst->alg.cra_blkcipher.setkey = crypto_cbc_setkey;

	inst->alg.cra_blkcipher.encrypt = crypto_cbc_encrypt;

	inst->alg.cra_blkcipher.decrypt = crypto_cbc_decrypt;

	inst->alg.setkey = crypto_cbc_setkey;

	inst->alg.encrypt = crypto_cbc_encrypt;

	inst->alg.decrypt = crypto_cbc_decrypt;



out_put_alg:

	crypto_mod_put(alg);

	return inst;

}

	inst->free = crypto_cbc_free;



static void crypto_cbc_free(struct crypto_instance *inst)

{

	crypto_drop_spawn(crypto_instance_ctx(inst));

	err = skcipher_register_instance(tmpl, inst);

	if (err)

		goto err_drop_spawn;



out:

	return err;



err_drop_spawn:

	crypto_drop_spawn(spawn);

err_free_inst:

	kfree(inst);

	goto out;

}



static struct crypto_template crypto_cbc_tmpl = {

	.name = "cbc",

	.alloc = crypto_cbc_alloc,

	.free = crypto_cbc_free,

	.create = crypto_cbc_create,

	.module = THIS_MODULE,

};