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-rwxr-xr-xCryptlib/OpenSSL/crypto/ec/ec2_mult.c26
-rwxr-xr-xCryptlib/OpenSSL/crypto/ec/ec_key.c13
-rwxr-xr-xCryptlib/OpenSSL/crypto/ec/ec_lib.c10
3 files changed, 31 insertions, 18 deletions
diff --git a/Cryptlib/OpenSSL/crypto/ec/ec2_mult.c b/Cryptlib/OpenSSL/crypto/ec/ec2_mult.c
index 7dca5e4b..6b570a3f 100755
--- a/Cryptlib/OpenSSL/crypto/ec/ec2_mult.c
+++ b/Cryptlib/OpenSSL/crypto/ec/ec2_mult.c
@@ -208,9 +208,12 @@ static int gf2m_Mxy(const EC_GROUP *group, const BIGNUM *x, const BIGNUM *y, BIG
/* Computes scalar*point and stores the result in r.
* point can not equal r.
- * Uses algorithm 2P of
+ * Uses a modified algorithm 2P of
* Lopex, J. and Dahab, R. "Fast multiplication on elliptic curves over
* GF(2^m) without precomputation".
+ *
+ * To protect against side-channel attack the function uses constant time
+ * swap avoiding conditional branches.
*/
static int ec_GF2m_montgomery_point_multiply(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
const EC_POINT *point, BN_CTX *ctx)
@@ -244,6 +247,11 @@ static int ec_GF2m_montgomery_point_multiply(const EC_GROUP *group, EC_POINT *r,
x2 = &r->X;
z2 = &r->Y;
+ bn_wexpand(x1, group->field.top);
+ bn_wexpand(z1, group->field.top);
+ bn_wexpand(x2, group->field.top);
+ bn_wexpand(z2, group->field.top);
+
if (!BN_GF2m_mod_arr(x1, &point->X, group->poly)) goto err; /* x1 = x */
if (!BN_one(z1)) goto err; /* z1 = 1 */
if (!group->meth->field_sqr(group, z2, x1, ctx)) goto err; /* z2 = x1^2 = x^2 */
@@ -266,16 +274,12 @@ static int ec_GF2m_montgomery_point_multiply(const EC_GROUP *group, EC_POINT *r,
{
for (; j >= 0; j--)
{
- if (scalar->d[i] & mask)
- {
- if (!gf2m_Madd(group, &point->X, x1, z1, x2, z2, ctx)) goto err;
- if (!gf2m_Mdouble(group, x2, z2, ctx)) goto err;
- }
- else
- {
- if (!gf2m_Madd(group, &point->X, x2, z2, x1, z1, ctx)) goto err;
- if (!gf2m_Mdouble(group, x1, z1, ctx)) goto err;
- }
+ BN_consttime_swap(scalar->d[i] & mask, x1, x2, group->field.top);
+ BN_consttime_swap(scalar->d[i] & mask, z1, z2, group->field.top);
+ if (!gf2m_Madd(group, &point->X, x2, z2, x1, z1, ctx)) goto err;
+ if (!gf2m_Mdouble(group, x1, z1, ctx)) goto err;
+ BN_consttime_swap(scalar->d[i] & mask, x1, x2, group->field.top);
+ BN_consttime_swap(scalar->d[i] & mask, z1, z2, group->field.top);
mask >>= 1;
}
j = BN_BITS2 - 1;
diff --git a/Cryptlib/OpenSSL/crypto/ec/ec_key.c b/Cryptlib/OpenSSL/crypto/ec/ec_key.c
index 522802c0..6c933d22 100755
--- a/Cryptlib/OpenSSL/crypto/ec/ec_key.c
+++ b/Cryptlib/OpenSSL/crypto/ec/ec_key.c
@@ -435,18 +435,27 @@ void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform)
void *EC_KEY_get_key_method_data(EC_KEY *key,
void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
{
- return EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);
+ void *ret;
+
+ CRYPTO_r_lock(CRYPTO_LOCK_EC);
+ ret = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);
+ CRYPTO_r_unlock(CRYPTO_LOCK_EC);
+
+ return ret;
}
-void EC_KEY_insert_key_method_data(EC_KEY *key, void *data,
+void *EC_KEY_insert_key_method_data(EC_KEY *key, void *data,
void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
{
EC_EXTRA_DATA *ex_data;
+
CRYPTO_w_lock(CRYPTO_LOCK_EC);
ex_data = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);
if (ex_data == NULL)
EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func, clear_free_func);
CRYPTO_w_unlock(CRYPTO_LOCK_EC);
+
+ return ex_data;
}
void EC_KEY_set_asn1_flag(EC_KEY *key, int flag)
diff --git a/Cryptlib/OpenSSL/crypto/ec/ec_lib.c b/Cryptlib/OpenSSL/crypto/ec/ec_lib.c
index 5af84376..bbf2799b 100755
--- a/Cryptlib/OpenSSL/crypto/ec/ec_lib.c
+++ b/Cryptlib/OpenSSL/crypto/ec/ec_lib.c
@@ -480,10 +480,10 @@ int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, BN_CTX *ctx)
if (EC_METHOD_get_field_type(EC_GROUP_method_of(a)) !=
EC_METHOD_get_field_type(EC_GROUP_method_of(b)))
return 1;
- /* compare the curve name (if present) */
+ /* compare the curve name (if present in both) */
if (EC_GROUP_get_curve_name(a) && EC_GROUP_get_curve_name(b) &&
- EC_GROUP_get_curve_name(a) == EC_GROUP_get_curve_name(b))
- return 0;
+ EC_GROUP_get_curve_name(a) != EC_GROUP_get_curve_name(b))
+ return 1;
if (!ctx)
ctx_new = ctx = BN_CTX_new();
@@ -1061,12 +1061,12 @@ int EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b, BN
if (group->meth->point_cmp == 0)
{
ECerr(EC_F_EC_POINT_CMP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
- return 0;
+ return -1;
}
if ((group->meth != a->meth) || (a->meth != b->meth))
{
ECerr(EC_F_EC_POINT_CMP, EC_R_INCOMPATIBLE_OBJECTS);
- return 0;
+ return -1;
}
return group->meth->point_cmp(group, a, b, ctx);
}