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Commit dec8b786 authored by Herbert Xu's avatar Herbert Xu
Browse files

crypto: hash - Add import/export interface 



It is often useful to save the partial state of a hash function
so that it can be used as a base for two or more computations.

The most prominent example is HMAC where all hashes start from
a base determined by the key.  Having an import/export interface
means that we only have to compute that base once rather than
for each message.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 3b2f6df0

crypto/ahash.c

+14 −0
Original line number Diff line number Diff line
@@ -146,6 +146,20 @@ static int ahash_setkey(struct crypto_ahash *tfm, const u8 *key, 
	return ahash->setkey(tfm, key, keylen);

}



int crypto_ahash_import(struct ahash_request *req, const u8 *in)

{

	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);

	struct ahash_alg *alg = crypto_ahash_alg(tfm);



	memcpy(ahash_request_ctx(req), in, crypto_ahash_reqsize(tfm));



	if (alg->reinit)

		alg->reinit(req);



	return 0;

}

EXPORT_SYMBOL_GPL(crypto_ahash_import);



static unsigned int crypto_ahash_ctxsize(struct crypto_alg *alg, u32 type,

					u32 mask)

{

crypto/shash.c

+14 −0
Original line number Diff line number Diff line
@@ -172,6 +172,20 @@ int crypto_shash_digest(struct shash_desc *desc, const u8 *data, 
}

EXPORT_SYMBOL_GPL(crypto_shash_digest);



int crypto_shash_import(struct shash_desc *desc, const u8 *in)

{

	struct crypto_shash *tfm = desc->tfm;

	struct shash_alg *alg = crypto_shash_alg(tfm);



	memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(tfm));



	if (alg->reinit)

		alg->reinit(desc);



	return 0;

}

EXPORT_SYMBOL_GPL(crypto_shash_import);



static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,

			      unsigned int keylen)

{

include/crypto/hash.h

+21 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ struct shash_desc { 


struct shash_alg {

	int (*init)(struct shash_desc *desc);

	int (*reinit)(struct shash_desc *desc);

	int (*update)(struct shash_desc *desc, const u8 *data,

		      unsigned int len);

	int (*final)(struct shash_desc *desc, u8 *out);
@@ -116,6 +117,11 @@ static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm) 
	return crypto_ahash_crt(tfm)->reqsize;

}



static inline void *ahash_request_ctx(struct ahash_request *req)

{

	return req->__ctx;

}



static inline int crypto_ahash_setkey(struct crypto_ahash *tfm,

				      const u8 *key, unsigned int keylen)

{
@@ -130,6 +136,14 @@ static inline int crypto_ahash_digest(struct ahash_request *req) 
	return crt->digest(req);

}



static inline void crypto_ahash_export(struct ahash_request *req, u8 *out)

{

	memcpy(out, ahash_request_ctx(req),

	       crypto_ahash_reqsize(crypto_ahash_reqtfm(req)));

}



int crypto_ahash_import(struct ahash_request *req, const u8 *in);



static inline int crypto_ahash_init(struct ahash_request *req)

{

	struct ahash_tfm *crt = crypto_ahash_crt(crypto_ahash_reqtfm(req));
@@ -262,6 +276,13 @@ int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key, 
int crypto_shash_digest(struct shash_desc *desc, const u8 *data,

			unsigned int len, u8 *out);



static inline void crypto_shash_export(struct shash_desc *desc, u8 *out)

{

	memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));

}



int crypto_shash_import(struct shash_desc *desc, const u8 *in);



static inline int crypto_shash_init(struct shash_desc *desc)

{

	return crypto_shash_alg(desc->tfm)->init(desc);

include/crypto/internal/hash.h

+0 −5
Original line number Diff line number Diff line
@@ -66,11 +66,6 @@ static inline struct ahash_request *ahash_dequeue_request( 
	return ahash_request_cast(crypto_dequeue_request(queue));

}



static inline void *ahash_request_ctx(struct ahash_request *req)

{

	return req->__ctx;

}



static inline int ahash_tfm_in_queue(struct crypto_queue *queue,

					  struct crypto_ahash *tfm)

{

include/linux/crypto.h

+1 −0
Original line number Diff line number Diff line
@@ -221,6 +221,7 @@ struct ablkcipher_alg { 


struct ahash_alg {

	int (*init)(struct ahash_request *req);

	int (*reinit)(struct ahash_request *req);

	int (*update)(struct ahash_request *req);

	int (*final)(struct ahash_request *req);

	int (*digest)(struct ahash_request *req);