crypto: hmac - Prehash ipad/opad
This patch uses crypto_shash_export/crypto_shash_import to prehash
ipad/opad to speed up hmac. This is partly based on a similar patch
by Steffen Klassert.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/hmac.c b/crypto/hmac.c
index 02aa53e..15c2eb5 100644
--- a/crypto/hmac.c
+++ b/crypto/hmac.c
@@ -27,7 +27,7 @@
#include <linux/string.h>
struct hmac_ctx {
- struct shash_desc *desc;
+ struct crypto_shash *hash;
};
static inline void *align_ptr(void *p, unsigned int align)
@@ -38,8 +38,7 @@
static inline struct hmac_ctx *hmac_ctx(struct crypto_shash *tfm)
{
return align_ptr(crypto_shash_ctx_aligned(tfm) +
- crypto_shash_blocksize(tfm) * 2 +
- crypto_shash_digestsize(tfm),
+ crypto_shash_statesize(tfm) * 2,
crypto_tfm_ctx_alignment());
}
@@ -48,28 +47,33 @@
{
int bs = crypto_shash_blocksize(parent);
int ds = crypto_shash_digestsize(parent);
+ int ss = crypto_shash_statesize(parent);
char *ipad = crypto_shash_ctx_aligned(parent);
- char *opad = ipad + bs;
- char *digest = opad + bs;
- struct hmac_ctx *ctx = align_ptr(digest + ds,
+ char *opad = ipad + ss;
+ struct hmac_ctx *ctx = align_ptr(opad + ss,
crypto_tfm_ctx_alignment());
+ struct crypto_shash *hash = ctx->hash;
+ struct {
+ struct shash_desc shash;
+ char ctx[crypto_shash_descsize(hash)];
+ } desc;
unsigned int i;
+ desc.shash.tfm = hash;
+ desc.shash.flags = crypto_shash_get_flags(parent) &
+ CRYPTO_TFM_REQ_MAY_SLEEP;
+
if (keylen > bs) {
int err;
- ctx->desc->flags = crypto_shash_get_flags(parent) &
- CRYPTO_TFM_REQ_MAY_SLEEP;
-
- err = crypto_shash_digest(ctx->desc, inkey, keylen, digest);
+ err = crypto_shash_digest(&desc.shash, inkey, keylen, ipad);
if (err)
return err;
- inkey = digest;
keylen = ds;
- }
+ } else
+ memcpy(ipad, inkey, keylen);
- memcpy(ipad, inkey, keylen);
memset(ipad + keylen, 0, bs - keylen);
memcpy(opad, ipad, bs);
@@ -78,24 +82,37 @@
opad[i] ^= 0x5c;
}
- return 0;
+ return crypto_shash_init(&desc.shash) ?:
+ crypto_shash_update(&desc.shash, ipad, bs) ?:
+ crypto_shash_export(&desc.shash, ipad) ?:
+ crypto_shash_init(&desc.shash) ?:
+ crypto_shash_update(&desc.shash, opad, bs) ?:
+ crypto_shash_export(&desc.shash, opad);
+}
+
+static int hmac_export(struct shash_desc *pdesc, void *out)
+{
+ struct shash_desc *desc = shash_desc_ctx(pdesc);
+
+ desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ return crypto_shash_export(desc, out);
+}
+
+static int hmac_import(struct shash_desc *pdesc, const void *in)
+{
+ struct shash_desc *desc = shash_desc_ctx(pdesc);
+ struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
+
+ desc->tfm = ctx->hash;
+ desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ return crypto_shash_import(desc, in);
}
static int hmac_init(struct shash_desc *pdesc)
{
- struct crypto_shash *parent = pdesc->tfm;
- int bs = crypto_shash_blocksize(parent);
- int ds = crypto_shash_digestsize(parent);
- char *ipad = crypto_shash_ctx_aligned(parent);
- struct hmac_ctx *ctx = align_ptr(ipad + bs * 2 + ds,
- crypto_tfm_ctx_alignment());
- struct shash_desc *desc = shash_desc_ctx(pdesc);
-
- desc->tfm = ctx->desc->tfm;
- desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
-
- return crypto_shash_init(desc) ?:
- crypto_shash_update(desc, ipad, bs);
+ return hmac_import(pdesc, crypto_shash_ctx_aligned(pdesc->tfm));
}
static int hmac_update(struct shash_desc *pdesc,
@@ -111,16 +128,16 @@
static int hmac_final(struct shash_desc *pdesc, u8 *out)
{
struct crypto_shash *parent = pdesc->tfm;
- int bs = crypto_shash_blocksize(parent);
int ds = crypto_shash_digestsize(parent);
- char *opad = crypto_shash_ctx_aligned(parent) + bs;
- char *digest = opad + bs;
+ int ss = crypto_shash_statesize(parent);
+ char *opad = crypto_shash_ctx_aligned(parent) + ss;
struct shash_desc *desc = shash_desc_ctx(pdesc);
desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
- return crypto_shash_final(desc, digest) ?:
- crypto_shash_digest(desc, opad, bs + ds, out);
+ return crypto_shash_final(desc, out) ?:
+ crypto_shash_import(desc, opad) ?:
+ crypto_shash_finup(desc, out, ds, out);
}
static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
@@ -128,16 +145,16 @@
{
struct crypto_shash *parent = pdesc->tfm;
- int bs = crypto_shash_blocksize(parent);
int ds = crypto_shash_digestsize(parent);
- char *opad = crypto_shash_ctx_aligned(parent) + bs;
- char *digest = opad + bs;
+ int ss = crypto_shash_statesize(parent);
+ char *opad = crypto_shash_ctx_aligned(parent) + ss;
struct shash_desc *desc = shash_desc_ctx(pdesc);
desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
- return crypto_shash_finup(desc, data, nbytes, digest) ?:
- crypto_shash_digest(desc, opad, bs + ds, out);
+ return crypto_shash_finup(desc, data, nbytes, out) ?:
+ crypto_shash_import(desc, opad) ?:
+ crypto_shash_finup(desc, out, ds, out);
}
static int hmac_init_tfm(struct crypto_tfm *tfm)
@@ -155,21 +172,14 @@
parent->descsize = sizeof(struct shash_desc) +
crypto_shash_descsize(hash);
- ctx->desc = kmalloc(parent->descsize, GFP_KERNEL);
- if (!ctx->desc) {
- crypto_free_shash(hash);
- return -ENOMEM;
- }
-
- ctx->desc->tfm = hash;
+ ctx->hash = hash;
return 0;
}
static void hmac_exit_tfm(struct crypto_tfm *tfm)
{
struct hmac_ctx *ctx = hmac_ctx(__crypto_shash_cast(tfm));
- crypto_free_shash(ctx->desc->tfm);
- kzfree(ctx->desc);
+ crypto_free_shash(ctx->hash);
}
static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
@@ -179,6 +189,7 @@
struct shash_alg *salg;
int err;
int ds;
+ int ss;
err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
if (err)
@@ -190,8 +201,10 @@
err = -EINVAL;
ds = salg->digestsize;
+ ss = salg->statesize;
alg = &salg->base;
- if (ds > alg->cra_blocksize)
+ if (ds > alg->cra_blocksize ||
+ ss < alg->cra_blocksize)
goto out_put_alg;
inst = shash_alloc_instance("hmac", alg);
@@ -208,11 +221,12 @@
inst->alg.base.cra_blocksize = alg->cra_blocksize;
inst->alg.base.cra_alignmask = alg->cra_alignmask;
+ ss = ALIGN(ss, alg->cra_alignmask + 1);
inst->alg.digestsize = ds;
+ inst->alg.statesize = ss;
inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) +
- ALIGN(alg->cra_blocksize * 2 + ds,
- crypto_tfm_ctx_alignment());
+ ALIGN(ss * 2, crypto_tfm_ctx_alignment());
inst->alg.base.cra_init = hmac_init_tfm;
inst->alg.base.cra_exit = hmac_exit_tfm;
@@ -221,6 +235,8 @@
inst->alg.update = hmac_update;
inst->alg.final = hmac_final;
inst->alg.finup = hmac_finup;
+ inst->alg.export = hmac_export;
+ inst->alg.import = hmac_import;
inst->alg.setkey = hmac_setkey;
err = shash_register_instance(tmpl, inst);