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authorStephan Mueller <smueller@chronox.de>2016-03-28 16:47:55 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2016-04-05 20:35:53 +0800
commit4218ebe8cab421c72f134cca1374e0985303f34a (patch)
tree813c3ec09204f4cd35998aaca752c22ae88beecd
parentbdb6cf9f6fe6d9af905ea34b7c4bb78ea601329e (diff)
downloadlinux-4218ebe8cab421c72f134cca1374e0985303f34a.tar.gz
crypto: drbg - set HMAC key only when altered
The HMAC implementation allows setting the HMAC key independently from the hashing operation. Therefore, the key only needs to be set when a new key is generated. This patch increases the speed of the HMAC DRBG by at least 35% depending on the use case. The patch is fully CAVS tested. Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--crypto/drbg.c39
1 files changed, 25 insertions, 14 deletions
diff --git a/crypto/drbg.c b/crypto/drbg.c
index 1b86310db7b1..0a3538f6cf22 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -592,8 +592,10 @@ static const struct drbg_state_ops drbg_ctr_ops = {
******************************************************************/
#if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC)
-static int drbg_kcapi_hash(struct drbg_state *drbg, const unsigned char *key,
- unsigned char *outval, const struct list_head *in);
+static int drbg_kcapi_hash(struct drbg_state *drbg, unsigned char *outval,
+ const struct list_head *in);
+static void drbg_kcapi_hmacsetkey(struct drbg_state *drbg,
+ const unsigned char *key);
static int drbg_init_hash_kernel(struct drbg_state *drbg);
static int drbg_fini_hash_kernel(struct drbg_state *drbg);
#endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */
@@ -619,9 +621,11 @@ static int drbg_hmac_update(struct drbg_state *drbg, struct list_head *seed,
LIST_HEAD(seedlist);
LIST_HEAD(vdatalist);
- if (!reseed)
+ if (!reseed) {
/* 10.1.2.3 step 2 -- memset(0) of C is implicit with kzalloc */
memset(drbg->V, 1, drbg_statelen(drbg));
+ drbg_kcapi_hmacsetkey(drbg, drbg->C);
+ }
drbg_string_fill(&seed1, drbg->V, drbg_statelen(drbg));
list_add_tail(&seed1.list, &seedlist);
@@ -641,12 +645,13 @@ static int drbg_hmac_update(struct drbg_state *drbg, struct list_head *seed,
prefix = DRBG_PREFIX1;
/* 10.1.2.2 step 1 and 4 -- concatenation and HMAC for key */
seed2.buf = &prefix;
- ret = drbg_kcapi_hash(drbg, drbg->C, drbg->C, &seedlist);
+ ret = drbg_kcapi_hash(drbg, drbg->C, &seedlist);
if (ret)
return ret;
+ drbg_kcapi_hmacsetkey(drbg, drbg->C);
/* 10.1.2.2 step 2 and 5 -- HMAC for V */
- ret = drbg_kcapi_hash(drbg, drbg->C, drbg->V, &vdatalist);
+ ret = drbg_kcapi_hash(drbg, drbg->V, &vdatalist);
if (ret)
return ret;
@@ -681,7 +686,7 @@ static int drbg_hmac_generate(struct drbg_state *drbg,
while (len < buflen) {
unsigned int outlen = 0;
/* 10.1.2.5 step 4.1 */
- ret = drbg_kcapi_hash(drbg, drbg->C, drbg->V, &datalist);
+ ret = drbg_kcapi_hash(drbg, drbg->V, &datalist);
if (ret)
return ret;
outlen = (drbg_blocklen(drbg) < (buflen - len)) ?
@@ -796,7 +801,7 @@ static int drbg_hash_df(struct drbg_state *drbg,
while (len < outlen) {
short blocklen = 0;
/* 10.4.1 step 4.1 */
- ret = drbg_kcapi_hash(drbg, NULL, tmp, entropylist);
+ ret = drbg_kcapi_hash(drbg, tmp, entropylist);
if (ret)
goto out;
/* 10.4.1 step 4.2 */
@@ -874,7 +879,7 @@ static int drbg_hash_process_addtl(struct drbg_state *drbg,
list_add_tail(&data1.list, &datalist);
list_add_tail(&data2.list, &datalist);
list_splice_tail(addtl, &datalist);
- ret = drbg_kcapi_hash(drbg, NULL, drbg->scratchpad, &datalist);
+ ret = drbg_kcapi_hash(drbg, drbg->scratchpad, &datalist);
if (ret)
goto out;
@@ -907,7 +912,7 @@ static int drbg_hash_hashgen(struct drbg_state *drbg,
while (len < buflen) {
unsigned int outlen = 0;
/* 10.1.1.4 step hashgen 4.1 */
- ret = drbg_kcapi_hash(drbg, NULL, dst, &datalist);
+ ret = drbg_kcapi_hash(drbg, dst, &datalist);
if (ret) {
len = ret;
goto out;
@@ -956,7 +961,7 @@ static int drbg_hash_generate(struct drbg_state *drbg,
list_add_tail(&data1.list, &datalist);
drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg));
list_add_tail(&data2.list, &datalist);
- ret = drbg_kcapi_hash(drbg, NULL, drbg->scratchpad, &datalist);
+ ret = drbg_kcapi_hash(drbg, drbg->scratchpad, &datalist);
if (ret) {
len = ret;
goto out;
@@ -1600,14 +1605,20 @@ static int drbg_fini_hash_kernel(struct drbg_state *drbg)
return 0;
}
-static int drbg_kcapi_hash(struct drbg_state *drbg, const unsigned char *key,
- unsigned char *outval, const struct list_head *in)
+static void drbg_kcapi_hmacsetkey(struct drbg_state *drbg,
+ const unsigned char *key)
+{
+ struct sdesc *sdesc = (struct sdesc *)drbg->priv_data;
+
+ crypto_shash_setkey(sdesc->shash.tfm, key, drbg_statelen(drbg));
+}
+
+static int drbg_kcapi_hash(struct drbg_state *drbg, unsigned char *outval,
+ const struct list_head *in)
{
struct sdesc *sdesc = (struct sdesc *)drbg->priv_data;
struct drbg_string *input = NULL;
- if (key)
- crypto_shash_setkey(sdesc->shash.tfm, key, drbg_statelen(drbg));
crypto_shash_init(&sdesc->shash);
list_for_each_entry(input, in, list)
crypto_shash_update(&sdesc->shash, input->buf, input->len);