diff options
| -rw-r--r-- | crypto/drbg.c | 52 | ||||
| -rw-r--r-- | include/crypto/drbg.h | 1 |
2 files changed, 46 insertions, 7 deletions
diff --git a/crypto/drbg.c b/crypto/drbg.c index aca86847ea49..92843488af09 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -1062,13 +1062,18 @@ static void drbg_async_seed(struct work_struct *work) LIST_HEAD(seedlist); struct drbg_state *drbg = container_of(work, struct drbg_state, seed_work); + int ret; get_blocking_random_bytes(drbg->seed_buf, drbg->seed_buf_len); drbg_string_fill(&data, drbg->seed_buf, drbg->seed_buf_len); list_add_tail(&data.list, &seedlist); mutex_lock(&drbg->drbg_mutex); - __drbg_seed(drbg, &seedlist, true); + ret = __drbg_seed(drbg, &seedlist, true); + if (!ret && drbg->jent) { + crypto_free_rng(drbg->jent); + drbg->jent = NULL; + } memzero_explicit(drbg->seed_buf, drbg->seed_buf_len); mutex_unlock(&drbg->drbg_mutex); } @@ -1103,10 +1108,24 @@ static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers, drbg->test_data.len); pr_devel("DRBG: using test entropy\n"); } else { - pr_devel("DRBG: (re)seeding with %zu bytes of entropy\n", - drbg->seed_buf_len); + /* Get seed from in-kernel /dev/urandom */ get_random_bytes(drbg->seed_buf, drbg->seed_buf_len); - drbg_string_fill(&data1, drbg->seed_buf, drbg->seed_buf_len); + + /* Get seed from Jitter RNG */ + if (!drbg->jent || + crypto_rng_get_bytes(drbg->jent, + drbg->seed_buf + drbg->seed_buf_len, + drbg->seed_buf_len)) { + drbg_string_fill(&data1, drbg->seed_buf, + drbg->seed_buf_len); + pr_devel("DRBG: (re)seeding with %zu bytes of entropy\n", + drbg->seed_buf_len); + } else { + drbg_string_fill(&data1, drbg->seed_buf, + drbg->seed_buf_len * 2); + pr_devel("DRBG: (re)seeding with %zu bytes of entropy\n", + drbg->seed_buf_len * 2); + } } list_add_tail(&data1.list, &seedlist); @@ -1131,7 +1150,7 @@ static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers, * Clear the initial entropy buffer as the async call may not overwrite * that buffer for quite some time. */ - memzero_explicit(drbg->seed_buf, drbg->seed_buf_len); + memzero_explicit(drbg->seed_buf, drbg->seed_buf_len * 2); if (ret) goto out; /* @@ -1171,6 +1190,10 @@ static inline void drbg_dealloc_state(struct drbg_state *drbg) #endif kzfree(drbg->seed_buf); drbg->seed_buf = NULL; + if (drbg->jent) { + crypto_free_rng(drbg->jent); + drbg->jent = NULL; + } } /* @@ -1246,14 +1269,29 @@ static inline int drbg_alloc_state(struct drbg_state *drbg) ret = -EFAULT; goto err; } - /* ensure we have sufficient buffer space for initial seed */ + /* + * Ensure we have sufficient buffer space for initial seed which + * consists of the seed from get_random_bytes and the Jitter RNG. + */ drbg->seed_buf_len = ((drbg->seed_buf_len + 1) / 2) * 3; - drbg->seed_buf = kzalloc(drbg->seed_buf_len, GFP_KERNEL); + drbg->seed_buf = kzalloc(drbg->seed_buf_len * 2, GFP_KERNEL); if (!drbg->seed_buf) goto err; INIT_WORK(&drbg->seed_work, drbg_async_seed); + drbg->jent = crypto_alloc_rng("jitterentropy_rng", 0, 0); + if(IS_ERR(drbg->jent)) + { + pr_info("DRBG: could not allocate Jitter RNG handle for seeding\n"); + /* + * As the Jitter RNG is a module that may not be present, we + * continue with the operation and do not fully tie the DRBG + * to the Jitter RNG. + */ + drbg->jent = NULL; + } + return 0; err: diff --git a/include/crypto/drbg.h b/include/crypto/drbg.h index 46994b25dc85..c3f208dc83ee 100644 --- a/include/crypto/drbg.h +++ b/include/crypto/drbg.h @@ -123,6 +123,7 @@ struct drbg_state { struct work_struct seed_work; /* asynchronous seeding support */ u8 *seed_buf; /* buffer holding the seed */ size_t seed_buf_len; + struct crypto_rng *jent; const struct drbg_state_ops *d_ops; const struct drbg_core *core; struct drbg_string test_data; |