From: Matt Caswell <matt@openssl.org>
Date: Wed, 4 Nov 2015 17:30:22 +0000 (+0000)
Subject: Fix bug in nistp224/256/521 where have_precompute_mult always returns 0
X-Git-Tag: OpenSSL_1_0_2g~48
X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff_plain;h=e94f52e0c70dc42f5de5b7982525f76cfe42fa90

Fix bug in nistp224/256/521 where have_precompute_mult always returns 0

During precomputation if the group given is well known then we memcpy a
well known precomputation. However we go the wrong label in the code and
don't store the data properly. Consequently if we call have_precompute_mult
the data isn't there and we return 0.

RT#3600

Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit 615614c8862fb89dcf1551a4e113be0789dddf5f)
---

diff --git a/crypto/ec/ecp_nistp224.c b/crypto/ec/ecp_nistp224.c
index ed09f97ade..d81cc9ce6b 100644
--- a/crypto/ec/ecp_nistp224.c
+++ b/crypto/ec/ecp_nistp224.c
@@ -1657,8 +1657,7 @@ int ec_GFp_nistp224_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
      */
     if (0 == EC_POINT_cmp(group, generator, group->generator, ctx)) {
         memcpy(pre->g_pre_comp, gmul, sizeof(pre->g_pre_comp));
-        ret = 1;
-        goto err;
+        goto done;
     }
     if ((!BN_to_felem(pre->g_pre_comp[0][1][0], &group->generator->X)) ||
         (!BN_to_felem(pre->g_pre_comp[0][1][1], &group->generator->Y)) ||
@@ -1736,6 +1735,7 @@ int ec_GFp_nistp224_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
     }
     make_points_affine(31, &(pre->g_pre_comp[0][1]), tmp_felems);
 
+ done:
     if (!EC_EX_DATA_set_data(&group->extra_data, pre, nistp224_pre_comp_dup,
                              nistp224_pre_comp_free,
                              nistp224_pre_comp_clear_free))
diff --git a/crypto/ec/ecp_nistp256.c b/crypto/ec/ecp_nistp256.c
index a5887086c6..78d191aac7 100644
--- a/crypto/ec/ecp_nistp256.c
+++ b/crypto/ec/ecp_nistp256.c
@@ -2249,8 +2249,7 @@ int ec_GFp_nistp256_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
      */
     if (0 == EC_POINT_cmp(group, generator, group->generator, ctx)) {
         memcpy(pre->g_pre_comp, gmul, sizeof(pre->g_pre_comp));
-        ret = 1;
-        goto err;
+        goto done;
     }
     if ((!BN_to_felem(x_tmp, &group->generator->X)) ||
         (!BN_to_felem(y_tmp, &group->generator->Y)) ||
@@ -2337,6 +2336,7 @@ int ec_GFp_nistp256_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
     }
     make_points_affine(31, &(pre->g_pre_comp[0][1]), tmp_smallfelems);
 
+ done:
     if (!EC_EX_DATA_set_data(&group->extra_data, pre, nistp256_pre_comp_dup,
                              nistp256_pre_comp_free,
                              nistp256_pre_comp_clear_free))
diff --git a/crypto/ec/ecp_nistp521.c b/crypto/ec/ecp_nistp521.c
index 360b9a3516..c53a61bbfb 100644
--- a/crypto/ec/ecp_nistp521.c
+++ b/crypto/ec/ecp_nistp521.c
@@ -2056,8 +2056,7 @@ int ec_GFp_nistp521_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
      */
     if (0 == EC_POINT_cmp(group, generator, group->generator, ctx)) {
         memcpy(pre->g_pre_comp, gmul, sizeof(pre->g_pre_comp));
-        ret = 1;
-        goto err;
+        goto done;
     }
     if ((!BN_to_felem(pre->g_pre_comp[1][0], &group->generator->X)) ||
         (!BN_to_felem(pre->g_pre_comp[1][1], &group->generator->Y)) ||
@@ -2115,6 +2114,7 @@ int ec_GFp_nistp521_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
     }
     make_points_affine(15, &(pre->g_pre_comp[1]), tmp_felems);
 
+ done:
     if (!EC_EX_DATA_set_data(&group->extra_data, pre, nistp521_pre_comp_dup,
                              nistp521_pre_comp_free,
                              nistp521_pre_comp_clear_free))