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Diffstat (limited to 'crypto/drbg.c')
-rw-r--r--crypto/drbg.c111
1 files changed, 44 insertions, 67 deletions
diff --git a/crypto/drbg.c b/crypto/drbg.c
index ea85d4a0fe9e..761104e93d44 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1036,17 +1036,38 @@ static const struct drbg_state_ops drbg_hash_ops = {
******************************************************************/
static inline int __drbg_seed(struct drbg_state *drbg, struct list_head *seed,
- int reseed)
+ int reseed, enum drbg_seed_state new_seed_state)
{
int ret = drbg->d_ops->update(drbg, seed, reseed);
if (ret)
return ret;
- drbg->seeded = true;
+ drbg->seeded = new_seed_state;
/* 10.1.1.2 / 10.1.1.3 step 5 */
drbg->reseed_ctr = 1;
+ switch (drbg->seeded) {
+ case DRBG_SEED_STATE_UNSEEDED:
+ /* Impossible, but handle it to silence compiler warnings. */
+ fallthrough;
+ case DRBG_SEED_STATE_PARTIAL:
+ /*
+ * Require frequent reseeds until the seed source is
+ * fully initialized.
+ */
+ drbg->reseed_threshold = 50;
+ break;
+
+ case DRBG_SEED_STATE_FULL:
+ /*
+ * Seed source has become fully initialized, frequent
+ * reseeds no longer required.
+ */
+ drbg->reseed_threshold = drbg_max_requests(drbg);
+ break;
+ }
+
return ret;
}
@@ -1066,12 +1087,10 @@ static inline int drbg_get_random_bytes(struct drbg_state *drbg,
return 0;
}
-static void drbg_async_seed(struct work_struct *work)
+static int drbg_seed_from_random(struct drbg_state *drbg)
{
struct drbg_string data;
LIST_HEAD(seedlist);
- struct drbg_state *drbg = container_of(work, struct drbg_state,
- seed_work);
unsigned int entropylen = drbg_sec_strength(drbg->core->flags);
unsigned char entropy[32];
int ret;
@@ -1082,26 +1101,15 @@ static void drbg_async_seed(struct work_struct *work)
drbg_string_fill(&data, entropy, entropylen);
list_add_tail(&data.list, &seedlist);
- mutex_lock(&drbg->drbg_mutex);
-
ret = drbg_get_random_bytes(drbg, entropy, entropylen);
if (ret)
- goto unlock;
-
- /* Set seeded to false so that if __drbg_seed fails the
- * next generate call will trigger a reseed.
- */
- drbg->seeded = false;
-
- __drbg_seed(drbg, &seedlist, true);
-
- if (drbg->seeded)
- drbg->reseed_threshold = drbg_max_requests(drbg);
+ goto out;
-unlock:
- mutex_unlock(&drbg->drbg_mutex);
+ ret = __drbg_seed(drbg, &seedlist, true, DRBG_SEED_STATE_FULL);
+out:
memzero_explicit(entropy, entropylen);
+ return ret;
}
/*
@@ -1123,6 +1131,7 @@ static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers,
unsigned int entropylen = drbg_sec_strength(drbg->core->flags);
struct drbg_string data1;
LIST_HEAD(seedlist);
+ enum drbg_seed_state new_seed_state = DRBG_SEED_STATE_FULL;
/* 9.1 / 9.2 / 9.3.1 step 3 */
if (pers && pers->len > (drbg_max_addtl(drbg))) {
@@ -1150,6 +1159,9 @@ static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers,
BUG_ON((entropylen * 2) > sizeof(entropy));
/* Get seed from in-kernel /dev/urandom */
+ if (!rng_is_initialized())
+ new_seed_state = DRBG_SEED_STATE_PARTIAL;
+
ret = drbg_get_random_bytes(drbg, entropy, entropylen);
if (ret)
goto out;
@@ -1206,7 +1218,7 @@ static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers,
memset(drbg->C, 0, drbg_statelen(drbg));
}
- ret = __drbg_seed(drbg, &seedlist, reseed);
+ ret = __drbg_seed(drbg, &seedlist, reseed, new_seed_state);
out:
memzero_explicit(entropy, entropylen * 2);
@@ -1386,19 +1398,25 @@ static int drbg_generate(struct drbg_state *drbg,
* here. The spec is a bit convoluted here, we make it simpler.
*/
if (drbg->reseed_threshold < drbg->reseed_ctr)
- drbg->seeded = false;
+ drbg->seeded = DRBG_SEED_STATE_UNSEEDED;
- if (drbg->pr || !drbg->seeded) {
+ if (drbg->pr || drbg->seeded == DRBG_SEED_STATE_UNSEEDED) {
pr_devel("DRBG: reseeding before generation (prediction "
"resistance: %s, state %s)\n",
drbg->pr ? "true" : "false",
- drbg->seeded ? "seeded" : "unseeded");
+ (drbg->seeded == DRBG_SEED_STATE_FULL ?
+ "seeded" : "unseeded"));
/* 9.3.1 steps 7.1 through 7.3 */
len = drbg_seed(drbg, addtl, true);
if (len)
goto err;
/* 9.3.1 step 7.4 */
addtl = NULL;
+ } else if (rng_is_initialized() &&
+ drbg->seeded == DRBG_SEED_STATE_PARTIAL) {
+ len = drbg_seed_from_random(drbg);
+ if (len)
+ goto err;
}
if (addtl && 0 < addtl->len)
@@ -1491,51 +1509,15 @@ static int drbg_generate_long(struct drbg_state *drbg,
return 0;
}
-static void drbg_schedule_async_seed(struct random_ready_callback *rdy)
-{
- struct drbg_state *drbg = container_of(rdy, struct drbg_state,
- random_ready);
-
- schedule_work(&drbg->seed_work);
-}
-
static int drbg_prepare_hrng(struct drbg_state *drbg)
{
- int err;
-
/* We do not need an HRNG in test mode. */
if (list_empty(&drbg->test_data.list))
return 0;
drbg->jent = crypto_alloc_rng("jitterentropy_rng", 0, 0);
- INIT_WORK(&drbg->seed_work, drbg_async_seed);
-
- drbg->random_ready.owner = THIS_MODULE;
- drbg->random_ready.func = drbg_schedule_async_seed;
-
- err = add_random_ready_callback(&drbg->random_ready);
-
- switch (err) {
- case 0:
- break;
-
- case -EALREADY:
- err = 0;
- fallthrough;
-
- default:
- drbg->random_ready.func = NULL;
- return err;
- }
-
- /*
- * Require frequent reseeds until the seed source is fully
- * initialized.
- */
- drbg->reseed_threshold = 50;
-
- return err;
+ return 0;
}
/*
@@ -1578,7 +1560,7 @@ static int drbg_instantiate(struct drbg_state *drbg, struct drbg_string *pers,
if (!drbg->core) {
drbg->core = &drbg_cores[coreref];
drbg->pr = pr;
- drbg->seeded = false;
+ drbg->seeded = DRBG_SEED_STATE_UNSEEDED;
drbg->reseed_threshold = drbg_max_requests(drbg);
ret = drbg_alloc_state(drbg);
@@ -1629,11 +1611,6 @@ free_everything:
*/
static int drbg_uninstantiate(struct drbg_state *drbg)
{
- if (drbg->random_ready.func) {
- del_random_ready_callback(&drbg->random_ready);
- cancel_work_sync(&drbg->seed_work);
- }
-
if (!IS_ERR_OR_NULL(drbg->jent))
crypto_free_rng(drbg->jent);
drbg->jent = NULL;
generated by cgit v1.2.3 (git 2.0.4) at 2024-09-14 13:29:32 +0000