diff options
Diffstat (limited to 'crypto/drbg.c')
| -rw-r--r-- | crypto/drbg.c | 59 |
1 files changed, 35 insertions, 24 deletions
diff --git a/crypto/drbg.c b/crypto/drbg.c index 2a7860f..a76b3cb 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -646,7 +646,7 @@ out: /* Generate function of CTR DRBG as defined in 10.2.1.5.2 */ static int drbg_ctr_generate(struct drbg_state *drbg, unsigned char *buf, unsigned int buflen, - struct drbg_string *addtl) + struct list_head *addtl) { int len = 0; int ret = 0; @@ -656,11 +656,8 @@ static int drbg_ctr_generate(struct drbg_state *drbg, memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); /* 10.2.1.5.2 step 2 */ - if (addtl && 0 < addtl->len) { - LIST_HEAD(addtllist); - - list_add_tail(&addtl->list, &addtllist); - ret = drbg_ctr_update(drbg, &addtllist, 2); + if (addtl && !list_empty(addtl)) { + ret = drbg_ctr_update(drbg, addtl, 2); if (ret) return 0; } @@ -777,7 +774,7 @@ static int drbg_hmac_update(struct drbg_state *drbg, struct list_head *seed, static int drbg_hmac_generate(struct drbg_state *drbg, unsigned char *buf, unsigned int buflen, - struct drbg_string *addtl) + struct list_head *addtl) { int len = 0; int ret = 0; @@ -785,11 +782,8 @@ static int drbg_hmac_generate(struct drbg_state *drbg, LIST_HEAD(datalist); /* 10.1.2.5 step 2 */ - if (addtl && 0 < addtl->len) { - LIST_HEAD(addtllist); - - list_add_tail(&addtl->list, &addtllist); - ret = drbg_hmac_update(drbg, &addtllist, 1); + if (addtl && !list_empty(addtl)) { + ret = drbg_hmac_update(drbg, addtl, 1); if (ret) return ret; } @@ -813,14 +807,10 @@ static int drbg_hmac_generate(struct drbg_state *drbg, } /* 10.1.2.5 step 6 */ - if (addtl && 0 < addtl->len) { - LIST_HEAD(addtllist); - - list_add_tail(&addtl->list, &addtllist); - ret = drbg_hmac_update(drbg, &addtllist, 1); - } else { + if (addtl && !list_empty(addtl)) + ret = drbg_hmac_update(drbg, addtl, 1); + else ret = drbg_hmac_update(drbg, NULL, 1); - } if (ret) return ret; @@ -944,7 +934,7 @@ out: /* processing of additional information string for Hash DRBG */ static int drbg_hash_process_addtl(struct drbg_state *drbg, - struct drbg_string *addtl) + struct list_head *addtl) { int ret = 0; struct drbg_string data1, data2; @@ -955,7 +945,7 @@ static int drbg_hash_process_addtl(struct drbg_state *drbg, memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); /* 10.1.1.4 step 2 */ - if (!addtl || 0 == addtl->len) + if (!addtl || list_empty(addtl)) return 0; /* 10.1.1.4 step 2a */ @@ -963,7 +953,7 @@ static int drbg_hash_process_addtl(struct drbg_state *drbg, drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); list_add_tail(&data1.list, &datalist); list_add_tail(&data2.list, &datalist); - list_add_tail(&addtl->list, &datalist); + list_splice_tail(addtl, &datalist); ret = drbg_kcapi_hash(drbg, NULL, drbg->scratchpad, &datalist); if (ret) goto out; @@ -1029,7 +1019,7 @@ out: /* generate function for Hash DRBG as defined in 10.1.1.4 */ static int drbg_hash_generate(struct drbg_state *drbg, unsigned char *buf, unsigned int buflen, - struct drbg_string *addtl) + struct list_head *addtl) { int len = 0; int ret = 0; @@ -1347,6 +1337,12 @@ static int drbg_generate(struct drbg_state *drbg, { int len = 0; struct drbg_state *shadow = NULL; + LIST_HEAD(addtllist); + struct drbg_string timestamp; + union { + cycles_t cycles; + unsigned char char_cycles[sizeof(cycles_t)]; + } now; if (0 == buflen || !buf) { pr_devel("DRBG: no output buffer provided\n"); @@ -1407,8 +1403,23 @@ static int drbg_generate(struct drbg_state *drbg, /* 9.3.1 step 7.4 */ addtl = NULL; } + + /* + * Mix the time stamp into the DRBG state if the DRBG is not in + * test mode. If there are two callers invoking the DRBG at the same + * time, i.e. before the first caller merges its shadow state back, + * both callers would obtain the same random number stream without + * changing the state here. + */ + if (!drbg->test_data) { + now.cycles = random_get_entropy(); + drbg_string_fill(×tamp, now.char_cycles, sizeof(cycles_t)); + list_add_tail(×tamp.list, &addtllist); + } + if (addtl && 0 < addtl->len) + list_add_tail(&addtl->list, &addtllist); /* 9.3.1 step 8 and 10 */ - len = shadow->d_ops->generate(shadow, buf, buflen, addtl); + len = shadow->d_ops->generate(shadow, buf, buflen, &addtllist); /* 10.1.1.4 step 6, 10.1.2.5 step 7, 10.2.1.5.2 step 7 */ shadow->reseed_ctr++; |
