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authorHerbert Xu <herbert@gondor.apana.org.au>2008-11-02 21:38:11 +0800
committerHerbert Xu <herbert@gondor.apana.org.au>2008-12-25 11:01:30 +1100
commitdec8b78606ebd5f309c38f2fb10196ce996dd18d (patch)
tree005ef526f1b0e953a3a57e6c991e0921fcd5234b
parent3b2f6df08258e2875f42bd630eece7e7241a053b (diff)
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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: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--crypto/ahash.c14
-rw-r--r--crypto/shash.c14
-rw-r--r--include/crypto/hash.h21
-rw-r--r--include/crypto/internal/hash.h5
-rw-r--r--include/linux/crypto.h1
5 files changed, 50 insertions, 5 deletions
diff --git a/crypto/ahash.c b/crypto/ahash.c
index 27128f2c687..7d4e33dfe21 100644
--- a/crypto/ahash.c
+++ b/crypto/ahash.c
@@ -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)
{
diff --git a/crypto/shash.c b/crypto/shash.c
index 3f4c713a21e..26aff3feefc 100644
--- a/crypto/shash.c
+++ b/crypto/shash.c
@@ -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)
{
diff --git a/include/crypto/hash.h b/include/crypto/hash.h
index f9b51d40895..cd16d6e668c 100644
--- a/include/crypto/hash.h
+++ b/include/crypto/hash.h
@@ -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);
diff --git a/include/crypto/internal/hash.h b/include/crypto/internal/hash.h
index 32d3a8ed06d..92fbe738585 100644
--- a/include/crypto/internal/hash.h
+++ b/include/crypto/internal/hash.h
@@ -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)
{
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 44c72f0f9b0..77a1f3d9416 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -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);