aboutsummaryrefslogtreecommitdiff
path: root/rsa.c
diff options
context:
space:
mode:
Diffstat (limited to 'rsa.c')
-rw-r--r--rsa.c90
1 files changed, 52 insertions, 38 deletions
diff --git a/rsa.c b/rsa.c
index 3adbd49..9fd4b90 100644
--- a/rsa.c
+++ b/rsa.c
@@ -473,20 +473,13 @@ static hal_error_t modexpng(hal_core_t *core,
.dP = dP_buf, .dP_len = sizeof(dP_buf),
.dQ = dQ_buf, .dQ_len = sizeof(dQ_buf),
.qInv = u_buf, .qInv_len = sizeof(u_buf),
- .bf = bf_buf, .bf_len = sizeof(bf_buf),
- .ubf = ubf_buf, .ubf_len = sizeof(ubf_buf),
};
if (bf) {
- if ((err = unpack_fp(bf, bf_buf, sizeof(bf_buf))) != HAL_OK ||
- (err = unpack_fp(ubf, ubf_buf, sizeof(ubf_buf))) != HAL_OK)
+ if ((err = unpack_fp(bf, (args.bf = bf_buf), (args.bf_len = sizeof(bf_buf)))) != HAL_OK ||
+ (err = unpack_fp(ubf, (args.ubf = ubf_buf), (args.ubf_len = sizeof(ubf_buf)))) != HAL_OK)
goto fail;
}
- else {
- /* set blinding factors to (1,1) */
- memset(bf_buf, 0, sizeof(bf_buf)); bf_buf[sizeof(bf_buf) - 1] = 1;
- memset(ubf_buf, 0, sizeof(ubf_buf)); ubf_buf[sizeof(ubf_buf) - 1] = 1;
- }
if ((err = unpack_fp(msg, msgbuf, sizeof(msgbuf))) != HAL_OK ||
(err = unpack_fp(key->d, expbuf, sizeof(expbuf))) != HAL_OK ||
@@ -499,10 +492,11 @@ static hal_error_t modexpng(hal_core_t *core,
(err = hal_modexpng(&args)) != HAL_OK)
goto fail;
- fp_read_unsigned_bin(res, resbuf, sizeof(resbuf));
- /* we do the blinding factor mutation in create_blinding_factors,
- * so we don't need to read them back from the core
- */
+ fp_read_unsigned_bin(res, resbuf, sizeof(resbuf));
+ if (bf) {
+ fp_read_unsigned_bin(bf, bf_buf, sizeof(bf_buf));
+ fp_read_unsigned_bin(ubf, ubf_buf, sizeof(ubf_buf));
+ }
fail:
memset(msgbuf, 0, sizeof(msgbuf));
@@ -620,14 +614,16 @@ int fp_exptmod(fp_int *a, fp_int *b, fp_int *c, fp_int *d)
/*
* Create blinding factors.
+ *
+ * If there is no blinding cache, bf and ubf point to user-supplied fp_ints.
+ * If there is a blinding cache, this returns pointers to a cache entry.
*/
-static hal_error_t create_blinding_factors(hal_rsa_key_t *key, fp_int *bf, fp_int *ubf)
+static hal_error_t create_blinding_factors(hal_rsa_key_t *key, fp_int **bf, fp_int **ubf)
{
if (key == NULL || bf == NULL || ubf == NULL)
return HAL_ERROR_IMPOSSIBLE;
- const int precalc = !(key->flags & RSA_FLAG_PRECALC_N_DONE);
uint8_t rnd[fp_unsigned_bin_size(unconst_fp_int(key->n))];
hal_error_t err = HAL_OK;
@@ -645,43 +641,53 @@ static hal_error_t create_blinding_factors(hal_rsa_key_t *key, fp_int *bf, fp_in
best_index = i;
}
if (fp_cmp_mag(b->n, key->n) == FP_EQ) {
- if (fp_sqrmod(b->bf, key->n, b->bf) != FP_OKAY ||
- fp_sqrmod(b->ubf, key->n, b->ubf) != FP_OKAY)
+ /*
+ * ModExpNG does blinding factor mutation in hardware.
+ * ModExpA7 needs it done in software here.
+ */
+ if (!hal_modexp_using_modexpng() &&
+ (fp_sqrmod(b->bf, key->n, b->bf) != FP_OKAY ||
+ fp_sqrmod(b->ubf, key->n, b->ubf) != FP_OKAY))
continue; /* should never happen, but be safe */
- fp_copy(b->bf, bf);
- fp_copy(b->ubf, ubf);
+ *bf = b->bf;
+ *ubf = b->ubf;
err = HAL_OK;
goto fail;
}
}
+
+ /* Didn't find the modulus in the cache, so create a new cache entry. */
+ {
+ bfc_slot_t *b = &bfc.slot[best_index];
+ fp_copy(key->n, b->n);
+ b->lru = ++bfc.lru;
+ *bf = b->bf;
+ *ubf = b->ubf;
+ }
+#else
+ if (*bf == NULL || *ubf == NULL)
+ lose(HAL_ERROR_BAD_ARGUMENTS);
#endif
if ((err = hal_get_random(NULL, rnd, sizeof(rnd))) != HAL_OK)
goto fail;
- fp_init(bf);
- fp_read_unsigned_bin(bf, rnd, sizeof(rnd));
- fp_copy(bf, ubf);
+ fp_init(*bf);
+ fp_read_unsigned_bin(*bf, rnd, sizeof(rnd));
+ fp_copy(*bf, *ubf);
+
+ const int precalc = !(key->flags & RSA_FLAG_PRECALC_N_DONE);
/* bf = ubf ** e mod n */
- if ((err = modexp(NULL, precalc, bf, key->e, key->n, bf,
+ if ((err = modexp(NULL, precalc, *bf, key->e, key->n, *bf,
key->nC, sizeof(key->nC), key->nF, sizeof(key->nF))) != HAL_OK)
goto fail;
if (precalc)
key->flags |= RSA_FLAG_PRECALC_N_DONE | RSA_FLAG_NEEDS_SAVING;
- FP_CHECK(fp_invmod(ubf, unconst_fp_int(key->n), ubf));
-
-#if HAL_RSA_BLINDING_CACHE_SIZE > 0
- {
- bfc_slot_t *b = &bfc.slot[best_index];
- fp_copy(key->n, b->n);
- fp_copy(bf, b->bf);
- fp_copy(ubf, b->ubf);
- b->lru = ++bfc.lru;
- }
-#endif
+ /* ubf = ubf ** -1 mod n */
+ FP_CHECK(fp_invmod(*ubf, unconst_fp_int(key->n), *ubf));
fail:
hal_rsa_bf_unlock();
@@ -699,12 +705,16 @@ static hal_error_t rsa_crt(hal_core_t *core1, hal_core_t *core2, hal_rsa_key_t *
return HAL_ERROR_IMPOSSIBLE;
hal_error_t err = HAL_OK;
- fp_int bf[1] = INIT_FP_INT;
- fp_int ubf[1] = INIT_FP_INT;
+#if HAL_RSA_BLINDING_CACHE_SIZE > 0
+ fp_int *bf, *ubf;
+#else
+ fp_int _bf[1] = INIT_FP_INT, *bf = _bf;
+ fp_int _ubf[1] = INIT_FP_INT, *ubf = _ubf;
+#endif
if (hal_modexp_using_modexpng()) {
if (blinding) {
- if ((err = create_blinding_factors(key, bf, ubf)) != HAL_OK)
+ if ((err = create_blinding_factors(key, &bf, &ubf)) != HAL_OK)
return err;
return modexpng(core1, msg, key, bf, ubf, sig);
}
@@ -713,6 +723,10 @@ static hal_error_t rsa_crt(hal_core_t *core1, hal_core_t *core2, hal_rsa_key_t *
}
}
+ /*
+ * ModExpA7 from here down
+ */
+
const int precalc = !(key->flags & RSA_FLAG_PRECALC_PQ_DONE);
fp_int t[1] = INIT_FP_INT;
fp_int m1[1] = INIT_FP_INT;
@@ -722,7 +736,7 @@ static hal_error_t rsa_crt(hal_core_t *core1, hal_core_t *core2, hal_rsa_key_t *
* Handle blinding if requested.
*/
if (blinding) {
- if ((err = create_blinding_factors(key, bf, ubf)) != HAL_OK)
+ if ((err = create_blinding_factors(key, &bf, &ubf)) != HAL_OK)
goto fail;
/* msg = (msg * bf) % modulus */
FP_CHECK(fp_mulmod(msg, bf, unconst_fp_int(key->n), msg));
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-24 04:51:10 +0000