yggdrasil/ring
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Avoid hard-coded linkage of WNAF-based multiplication.

Browse Source 
If the application is only using the P-256 implementation in p256-64.c,
then the WNAF code would all be dead code. The change reorganizes the
code so that all modern toolchains should be able to recognize that
fact and eliminate the WNAF-based code when it is unused.

Change-Id: I9f94bd934ca7d2292de4c29bb89e17c940c7cd2a
Reviewed-on: https://boringssl-review.googlesource.com/6173
Reviewed-by: Adam Langley <alangley@gmail.com>
This commit is contained in:
Brian Smith 2015-10-07 18:52:05 -10:00 committed by Adam Langley
parent 80c5fabc63
commit f0523e9f20
7 changed files with 16 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
crypto/ec/ec.c
View File

@ -569,12 +569,7 @@ int EC_GROUP_get_degree(const EC_GROUP *group) {
}
int EC_GROUP_precompute_mult(EC_GROUP *group, BN_CTX *ctx) {
if (group->meth->mul == 0) {
/* use default */
return ec_wNAF_precompute_mult(group, ctx);
}
if (group->meth->precompute_mult != 0) {
if (group->meth->precompute_mult != NULL) {
return group->meth->precompute_mult(group, ctx);
}
@ -582,16 +577,10 @@ int EC_GROUP_precompute_mult(EC_GROUP *group, BN_CTX *ctx) {
}
int EC_GROUP_have_precompute_mult(const EC_GROUP *group) {
if (group->meth->mul == 0) {
/* use default */
return ec_wNAF_have_precompute_mult(group);
if (group->pre_comp != NULL) {
return 1;
}
if (group->meth->have_precompute_mult != 0) {
return group->meth->have_precompute_mult(group);
}
return 0; /* cannot tell whether precomputation has been performed */
return 0;
}
EC_POINT *EC_POINT_new(const EC_GROUP *group) {
@ -797,9 +786,15 @@ int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar,
int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
size_t num, const EC_POINT *points[], const BIGNUM *scalars[],
BN_CTX *ctx) {
if (group->meth->mul == 0) {
/* use default. Warning, not constant-time. */
return ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
size_t i;
for (i = 0; i < num; i++) {
if (points[i]->meth != r->meth) {
break;
}
}
if (i != num) {
OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS);
return 0;
}
return group->meth->mul(group, r, scalar, num, points, scalars, ctx);

5
crypto/ec/ec_montgomery.c
View File

@ -81,9 +81,8 @@ const EC_METHOD *EC_GFp_mont_method(void) {
ec_GFp_mont_group_copy,
ec_GFp_mont_group_set_curve,
ec_GFp_simple_point_get_affine_coordinates,
0 /* mul */,
0 /* precompute_mult */,
0 /* have_precompute_mult */,
ec_wNAF_mul /* XXX: Not constant time. */,
ec_wNAF_precompute_mult,
ec_GFp_mont_field_mul,
ec_GFp_mont_field_sqr,
ec_GFp_mont_field_encode,

3
crypto/ec/internal.h
View File

@ -102,8 +102,6 @@ struct ec_method_st {
size_t num, const EC_POINT *points[], const BIGNUM *scalars[],
BN_CTX *);
int (*precompute_mult)(EC_GROUP *group, BN_CTX *);
int (*have_precompute_mult)(const EC_GROUP *group);
/* internal functions */
@ -170,7 +168,6 @@ int ec_wNAF_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
size_t num, const EC_POINT *points[], const BIGNUM *scalars[],
BN_CTX *);
int ec_wNAF_precompute_mult(EC_GROUP *group, BN_CTX *);
int ec_wNAF_have_precompute_mult(const EC_GROUP *group);
/* method functions in simple.c */
int ec_GFp_simple_group_init(EC_GROUP *);

1
crypto/ec/p224-64.c
View File

@ -1328,7 +1328,6 @@ const EC_METHOD *EC_GFp_nistp224_method(void) {
ec_GFp_nistp224_point_get_affine_coordinates,
ec_GFp_nistp224_points_mul,
0 /* precompute_mult */,
0 /* have_precompute_mult */,
ec_GFp_simple_field_mul,
ec_GFp_simple_field_sqr,
0 /* field_encode */,

2
crypto/ec/p256-64.c
View File

@ -1908,7 +1908,7 @@ const EC_METHOD *EC_GFp_nistp256_method(void) {
ec_GFp_simple_group_copy, ec_GFp_nistp256_group_set_curve,
ec_GFp_nistp256_point_get_affine_coordinates,
ec_GFp_nistp256_points_mul,
0 /* precompute_mult */, 0 /* have_precompute_mult */,
0 /* precompute_mult */,
ec_GFp_simple_field_mul, ec_GFp_simple_field_sqr,
0 /* field_encode */, 0 /* field_decode */, 0 /* field_set_to_one */
};

1
crypto/ec/simple.c
View File

@ -85,7 +85,6 @@ const EC_METHOD *EC_GFp_simple_method(void) {
ec_GFp_simple_point_get_affine_coordinates,
0 /* mul */,
0 /* precompute_mult */,
0 /* have_precompute_mult */,
ec_GFp_simple_field_mul,
ec_GFp_simple_field_sqr,
0 /* field_encode */,

5
crypto/ec/wnaf.c
View File

@ -846,8 +846,3 @@ err:
EC_POINT_free(base);
return ret;
}
int ec_wNAF_have_precompute_mult(const EC_GROUP *group) {
return group->pre_comp != NULL;
}