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| author |   Herbert Xu <herbert@gondor.apana.org.au> | 2008-11-02 21:38:11 +0800 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2008-12-25 11:01:30 +1100 |
| commit | dec8b78606ebd5f309c38f2fb10196ce996dd18d (patch) | |
| tree | 005ef526f1b0e953a3a57e6c991e0921fcd5234b /include/crypto/hash.h | |
| parent | crypto: hash - Export shash through ahash (diff) | |
| download | linux-dev-dec8b78606ebd5f309c38f2fb10196ce996dd18d.tar.xz linux-dev-dec8b78606ebd5f309c38f2fb10196ce996dd18d.zip | |
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>
Diffstat (limited to '')
| -rw-r--r-- | include/crypto/hash.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/include/crypto/hash.h b/include/crypto/hash.h index f9b51d408953..cd16d6e668ce 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); |