Commit dec8b786 authored by Herbert Xu's avatar Herbert Xu

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
...@@ -146,6 +146,20 @@ static int ahash_setkey(struct crypto_ahash *tfm, const u8 *key, ...@@ -146,6 +146,20 @@ static int ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
return ahash->setkey(tfm, key, keylen); 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, static unsigned int crypto_ahash_ctxsize(struct crypto_alg *alg, u32 type,
u32 mask) u32 mask)
{ {
......
...@@ -172,6 +172,20 @@ int crypto_shash_digest(struct shash_desc *desc, const u8 *data, ...@@ -172,6 +172,20 @@ int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
} }
EXPORT_SYMBOL_GPL(crypto_shash_digest); 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, static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
unsigned int keylen) unsigned int keylen)
{ {
......
...@@ -24,6 +24,7 @@ struct shash_desc { ...@@ -24,6 +24,7 @@ struct shash_desc {
struct shash_alg { struct shash_alg {
int (*init)(struct shash_desc *desc); int (*init)(struct shash_desc *desc);
int (*reinit)(struct shash_desc *desc);
int (*update)(struct shash_desc *desc, const u8 *data, int (*update)(struct shash_desc *desc, const u8 *data,
unsigned int len); unsigned int len);
int (*final)(struct shash_desc *desc, u8 *out); int (*final)(struct shash_desc *desc, u8 *out);
...@@ -116,6 +117,11 @@ static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm) ...@@ -116,6 +117,11 @@ static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm)
return crypto_ahash_crt(tfm)->reqsize; 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, static inline int crypto_ahash_setkey(struct crypto_ahash *tfm,
const u8 *key, unsigned int keylen) const u8 *key, unsigned int keylen)
{ {
...@@ -130,6 +136,14 @@ static inline int crypto_ahash_digest(struct ahash_request *req) ...@@ -130,6 +136,14 @@ static inline int crypto_ahash_digest(struct ahash_request *req)
return crt->digest(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) static inline int crypto_ahash_init(struct ahash_request *req)
{ {
struct ahash_tfm *crt = crypto_ahash_crt(crypto_ahash_reqtfm(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, ...@@ -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, int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out); 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) static inline int crypto_shash_init(struct shash_desc *desc)
{ {
return crypto_shash_alg(desc->tfm)->init(desc); return crypto_shash_alg(desc->tfm)->init(desc);
......
...@@ -66,11 +66,6 @@ static inline struct ahash_request *ahash_dequeue_request( ...@@ -66,11 +66,6 @@ static inline struct ahash_request *ahash_dequeue_request(
return ahash_request_cast(crypto_dequeue_request(queue)); 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, static inline int ahash_tfm_in_queue(struct crypto_queue *queue,
struct crypto_ahash *tfm) struct crypto_ahash *tfm)
{ {
......
...@@ -221,6 +221,7 @@ struct ablkcipher_alg { ...@@ -221,6 +221,7 @@ struct ablkcipher_alg {
struct ahash_alg { struct ahash_alg {
int (*init)(struct ahash_request *req); int (*init)(struct ahash_request *req);
int (*reinit)(struct ahash_request *req);
int (*update)(struct ahash_request *req); int (*update)(struct ahash_request *req);
int (*final)(struct ahash_request *req); int (*final)(struct ahash_request *req);
int (*digest)(struct ahash_request *req); int (*digest)(struct ahash_request *req);
......
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