From dec8b78606ebd5f309c38f2fb10196ce996dd18d Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sun, 2 Nov 2008 21:38:11 +0800 Subject: 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 --- crypto/ahash.c | 14 ++++++++++++++ crypto/shash.c | 14 ++++++++++++++ include/crypto/hash.h | 21 +++++++++++++++++++++ include/crypto/internal/hash.h | 5 ----- include/linux/crypto.h | 1 + 5 files changed, 50 insertions(+), 5 deletions(-) diff --git a/crypto/ahash.c b/crypto/ahash.c index 27128f2c687a..7d4e33dfe212 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 3f4c713a21ea..26aff3feefc0 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 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); diff --git a/include/crypto/internal/hash.h b/include/crypto/internal/hash.h index 32d3a8ed06de..92fbe7385856 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 44c72f0f9b05..77a1f3d9416d 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); -- cgit v1.2.2