Commit ecfc4329 authored by Herbert Xu's avatar Herbert Xu
Browse files

[CRYPTO] skcipher: Add skcipher_geniv_alloc/skcipher_geniv_free 



This patch creates the infrastructure to help the construction of givcipher
templates that wrap around existing blkcipher/ablkcipher algorithms by adding
an IV generator to them.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 927eead5

crypto/ablkcipher.c

+9 −1
Original line number Diff line number Diff line
@@ -80,6 +80,7 @@ static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type, 
	crt->setkey = setkey;

	crt->encrypt = alg->encrypt;

	crt->decrypt = alg->decrypt;

	crt->base = __crypto_ablkcipher_cast(tfm);

	crt->ivsize = alg->ivsize;



	return 0;
@@ -122,11 +123,13 @@ static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type, 
	if (alg->ivsize > PAGE_SIZE / 8)

		return -EINVAL;



	crt->setkey = setkey;

	crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?

		      alg->setkey : setkey;

	crt->encrypt = alg->encrypt;

	crt->decrypt = alg->decrypt;

	crt->givencrypt = alg->givencrypt;

	crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;

	crt->base = __crypto_ablkcipher_cast(tfm);

	crt->ivsize = alg->ivsize;



	return 0;
@@ -155,6 +158,11 @@ const struct crypto_type crypto_givcipher_type = { 
};

EXPORT_SYMBOL_GPL(crypto_givcipher_type);



const char *crypto_default_geniv(const struct crypto_alg *alg)

{

	return alg->cra_flags & CRYPTO_ALG_ASYNC ? "eseqiv" : "chainiv";

}



int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,

			 u32 type, u32 mask)

{

crypto/blkcipher.c

+184 −1
Original line number Diff line number Diff line
@@ -14,8 +14,8 @@ 
 *

 */



#include <crypto/internal/skcipher.h>

#include <crypto/scatterwalk.h>

#include <linux/crypto.h>

#include <linux/errno.h>

#include <linux/hardirq.h>

#include <linux/kernel.h>
@@ -450,6 +450,7 @@ static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm) 
	crt->setkey = async_setkey;

	crt->encrypt = async_encrypt;

	crt->decrypt = async_decrypt;

	crt->base = __crypto_ablkcipher_cast(tfm);

	crt->ivsize = alg->ivsize;



	return 0;
@@ -509,5 +510,187 @@ const struct crypto_type crypto_blkcipher_type = { 
};

EXPORT_SYMBOL_GPL(crypto_blkcipher_type);



static int crypto_grab_nivcipher(struct crypto_skcipher_spawn *spawn,

				const char *name, u32 type, u32 mask)

{

	struct crypto_alg *alg;

	int err;



	type = crypto_skcipher_type(type);

	mask = crypto_skcipher_mask(mask) | CRYPTO_ALG_GENIV;



	alg = crypto_alg_mod_lookup(name, type, mask);

	if (IS_ERR(alg))

		return PTR_ERR(alg);



	err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);

	crypto_mod_put(alg);

	return err;

}



struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl,

					     struct rtattr **tb, u32 type,

					     u32 mask)

{

	struct {

		int (*setkey)(struct crypto_ablkcipher *tfm, const u8 *key,

			      unsigned int keylen);

		int (*encrypt)(struct ablkcipher_request *req);

		int (*decrypt)(struct ablkcipher_request *req);



		unsigned int min_keysize;

		unsigned int max_keysize;

		unsigned int ivsize;



		const char *geniv;

	} balg;

	const char *name;

	struct crypto_skcipher_spawn *spawn;

	struct crypto_attr_type *algt;

	struct crypto_instance *inst;

	struct crypto_alg *alg;

	int err;



	algt = crypto_get_attr_type(tb);

	err = PTR_ERR(algt);

	if (IS_ERR(algt))

		return ERR_PTR(err);



	if ((algt->type ^ (CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV)) &

	    algt->mask)

		return ERR_PTR(-EINVAL);



	name = crypto_attr_alg_name(tb[1]);

	err = PTR_ERR(name);

	if (IS_ERR(name))

		return ERR_PTR(err);



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

	if (!inst)

		return ERR_PTR(-ENOMEM);



	spawn = crypto_instance_ctx(inst);



	/* Ignore async algorithms if necessary. */

	mask |= crypto_requires_sync(algt->type, algt->mask);



	crypto_set_skcipher_spawn(spawn, inst);

	err = crypto_grab_nivcipher(spawn, name, type, mask);

	if (err)

		goto err_free_inst;



	alg = crypto_skcipher_spawn_alg(spawn);



	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==

	    CRYPTO_ALG_TYPE_BLKCIPHER) {

		balg.ivsize = alg->cra_blkcipher.ivsize;

		balg.min_keysize = alg->cra_blkcipher.min_keysize;

		balg.max_keysize = alg->cra_blkcipher.max_keysize;



		balg.setkey = async_setkey;

		balg.encrypt = async_encrypt;

		balg.decrypt = async_decrypt;



		balg.geniv = alg->cra_blkcipher.geniv;

	} else {

		balg.ivsize = alg->cra_ablkcipher.ivsize;

		balg.min_keysize = alg->cra_ablkcipher.min_keysize;

		balg.max_keysize = alg->cra_ablkcipher.max_keysize;



		balg.setkey = alg->cra_ablkcipher.setkey;

		balg.encrypt = alg->cra_ablkcipher.encrypt;

		balg.decrypt = alg->cra_ablkcipher.decrypt;



		balg.geniv = alg->cra_ablkcipher.geniv;

	}



	err = -EINVAL;

	if (!balg.ivsize)

		goto err_drop_alg;



	/*

	 * This is only true if we're constructing an algorithm with its

	 * default IV generator.  For the default generator we elide the

	 * template name and double-check the IV generator.

	 */

	if (algt->mask & CRYPTO_ALG_GENIV) {

		if (!balg.geniv)

			balg.geniv = crypto_default_geniv(alg);

		err = -EAGAIN;

		if (strcmp(tmpl->name, balg.geniv))

			goto err_drop_alg;



		memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);

		memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,

		       CRYPTO_MAX_ALG_NAME);

	} else {

		err = -ENAMETOOLONG;

		if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,

			     "%s(%s)", tmpl->name, alg->cra_name) >=

		    CRYPTO_MAX_ALG_NAME)

			goto err_drop_alg;

		if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,

			     "%s(%s)", tmpl->name, alg->cra_driver_name) >=

		    CRYPTO_MAX_ALG_NAME)

			goto err_drop_alg;

	}



	inst->alg.cra_flags = CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV;

	inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;

	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_givcipher_type;



	inst->alg.cra_ablkcipher.ivsize = balg.ivsize;

	inst->alg.cra_ablkcipher.min_keysize = balg.min_keysize;

	inst->alg.cra_ablkcipher.max_keysize = balg.max_keysize;

	inst->alg.cra_ablkcipher.geniv = balg.geniv;



	inst->alg.cra_ablkcipher.setkey = balg.setkey;

	inst->alg.cra_ablkcipher.encrypt = balg.encrypt;

	inst->alg.cra_ablkcipher.decrypt = balg.decrypt;



out:

	return inst;



err_drop_alg:

	crypto_drop_skcipher(spawn);

err_free_inst:

	kfree(inst);

	inst = ERR_PTR(err);

	goto out;

}

EXPORT_SYMBOL_GPL(skcipher_geniv_alloc);



void skcipher_geniv_free(struct crypto_instance *inst)

{

	crypto_drop_skcipher(crypto_instance_ctx(inst));

	kfree(inst);

}

EXPORT_SYMBOL_GPL(skcipher_geniv_free);



int skcipher_geniv_init(struct crypto_tfm *tfm)

{

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

	struct crypto_ablkcipher *cipher;



	cipher = crypto_spawn_skcipher(crypto_instance_ctx(inst));

	if (IS_ERR(cipher))

		return PTR_ERR(cipher);



	tfm->crt_ablkcipher.base = cipher;

	tfm->crt_ablkcipher.reqsize += crypto_ablkcipher_reqsize(cipher);



	return 0;

}

EXPORT_SYMBOL_GPL(skcipher_geniv_init);



void skcipher_geniv_exit(struct crypto_tfm *tfm)

{

	crypto_free_ablkcipher(tfm->crt_ablkcipher.base);

}

EXPORT_SYMBOL_GPL(skcipher_geniv_exit);



MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("Generic block chaining cipher type");

include/crypto/internal/skcipher.h

+18 −0
Original line number Diff line number Diff line
@@ -15,6 +15,9 @@ 


#include <crypto/algapi.h>

#include <crypto/skcipher.h>

#include <linux/types.h>



struct rtattr;



struct crypto_skcipher_spawn {

	struct crypto_spawn base;
@@ -50,6 +53,21 @@ static inline struct crypto_ablkcipher *crypto_spawn_skcipher( 
				 crypto_skcipher_mask(0)));

}



const char *crypto_default_geniv(const struct crypto_alg *alg);



struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl,

					     struct rtattr **tb, u32 type,

					     u32 mask);

void skcipher_geniv_free(struct crypto_instance *inst);

int skcipher_geniv_init(struct crypto_tfm *tfm);

void skcipher_geniv_exit(struct crypto_tfm *tfm);



static inline struct crypto_ablkcipher *skcipher_geniv_cipher(

	struct crypto_ablkcipher *geniv)

{

	return crypto_ablkcipher_crt(geniv)->base;

}



static inline void *skcipher_givcrypt_reqctx(

	struct skcipher_givcrypt_request *req)

{

include/linux/crypto.h

+14 −4
Original line number Diff line number Diff line
@@ -52,6 +52,12 @@ 
 */

#define CRYPTO_ALG_NEED_FALLBACK	0x00000100



/*

 * This bit is set for symmetric key ciphers that have already been wrapped

 * with a generic IV generator to prevent them from being wrapped again.

 */

#define CRYPTO_ALG_GENIV		0x00000200



/*

 * Transform masks and values (for crt_flags).

 */
@@ -331,6 +337,8 @@ struct ablkcipher_tfm { 
	int (*givencrypt)(struct skcipher_givcrypt_request *req);

	int (*givdecrypt)(struct skcipher_givcrypt_request *req);



	struct crypto_ablkcipher *base;



	unsigned int ivsize;

	unsigned int reqsize;

};
@@ -541,14 +549,14 @@ static inline struct crypto_ablkcipher *__crypto_ablkcipher_cast( 


static inline u32 crypto_skcipher_type(u32 type)

{

	type &= ~CRYPTO_ALG_TYPE_MASK;

	type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);

	type |= CRYPTO_ALG_TYPE_BLKCIPHER;

	return type;

}



static inline u32 crypto_skcipher_mask(u32 mask)

{

	mask &= ~CRYPTO_ALG_TYPE_MASK;

	mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);

	mask |= CRYPTO_ALG_TYPE_BLKCIPHER_MASK;

	return mask;

}
@@ -623,7 +631,9 @@ static inline void crypto_ablkcipher_clear_flags(struct crypto_ablkcipher *tfm, 
static inline int crypto_ablkcipher_setkey(struct crypto_ablkcipher *tfm,

					   const u8 *key, unsigned int keylen)

{

	return crypto_ablkcipher_crt(tfm)->setkey(tfm, key, keylen);

	struct ablkcipher_tfm *crt = crypto_ablkcipher_crt(tfm);



	return crt->setkey(crt->base, key, keylen);

}



static inline struct crypto_ablkcipher *crypto_ablkcipher_reqtfm(
@@ -655,7 +665,7 @@ static inline unsigned int crypto_ablkcipher_reqsize( 
static inline void ablkcipher_request_set_tfm(

	struct ablkcipher_request *req, struct crypto_ablkcipher *tfm)

{

	req->base.tfm = crypto_ablkcipher_tfm(tfm);

	req->base.tfm = crypto_ablkcipher_tfm(crypto_ablkcipher_crt(tfm)->base);

}



static inline struct ablkcipher_request *ablkcipher_request_cast(