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author | Herbert Xu <herbert@gondor.apana.org.au> | 2008-11-02 14:38:11 +0100 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2008-12-25 01:01:30 +0100 |
commit | dec8b78606ebd5f309c38f2fb10196ce996dd18d (patch) | |
tree | 005ef526f1b0e953a3a57e6c991e0921fcd5234b /crypto/ahash.c | |
parent | crypto: hash - Export shash through ahash (diff) | |
download | linux-dec8b78606ebd5f309c38f2fb10196ce996dd18d.tar.xz linux-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 'crypto/ahash.c')
-rw-r--r-- | crypto/ahash.c | 14 |
1 files changed, 14 insertions, 0 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) { |