1 files changed, 13 insertions, 261 deletions

diff --git a/src/lib/libcrypto/ec/ecp_smpl.c b/src/lib/libcrypto/ec/ecp_smpl.c
index 57e8345364..1fe55307b4 100644
--- a/src/lib/libcrypto/ec/ecp_smpl.c
+++ b/src/lib/libcrypto/ec/ecp_smpl.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ecp_smpl.c,v 1.19 2018/07/10 22:06:14 tb Exp $ */
+/* $OpenBSD: ecp_smpl.c,v 1.20 2018/07/15 05:38:48 jsg Exp $ */
 /* Includes code written by Lenka Fibikova <fibikova@exp-math.uni-essen.de>
  * for the OpenSSL project.
  * Includes code written by Bodo Moeller for the OpenSSL project.
@@ -103,9 +103,6 @@ EC_GFp_simple_method(void)
                 .point_cmp = ec_GFp_simple_cmp,
                 .make_affine = ec_GFp_simple_make_affine,
                 .points_make_affine = ec_GFp_simple_points_make_affine,
-                .mul_generator_ct = ec_GFp_simple_mul_generator_ct,
-                .mul_single_ct = ec_GFp_simple_mul_single_ct,
-                .mul_double_nonct = ec_GFp_simple_mul_double_nonct,
                 .field_mul = ec_GFp_simple_field_mul,
                 .field_sqr = ec_GFp_simple_field_sqr
         };
@@ -223,7 +220,7 @@ ec_GFp_simple_group_set_curve(EC_GROUP * group,
 
         ret = 1;
 
- err:
+err:
         BN_CTX_end(ctx);
         BN_CTX_free(new_ctx);
         return ret;
@@ -268,7 +265,7 @@ ec_GFp_simple_group_get_curve(const EC_GROUP * group, BIGNUM * p, BIGNUM * a, BI
         }
         ret = 1;
 
- err:
+err:
         BN_CTX_free(new_ctx);
         return ret;
 }
@@ -349,7 +346,7 @@ ec_GFp_simple_group_check_discriminant(const EC_GROUP * group, BN_CTX * ctx)
         }
         ret = 1;
 
- err:
+err:
         if (ctx != NULL)
                 BN_CTX_end(ctx);
         BN_CTX_free(new_ctx);
@@ -459,7 +456,7 @@ ec_GFp_simple_set_Jprojective_coordinates_GFp(const EC_GROUP * group, EC_POINT *
         }
         ret = 1;
 
- err:
+err:
         BN_CTX_free(new_ctx);
         return ret;
 }
@@ -507,7 +504,7 @@ ec_GFp_simple_get_Jprojective_coordinates_GFp(const EC_GROUP * group, const EC_P
 
         ret = 1;
 
- err:
+err:
         BN_CTX_free(new_ctx);
         return ret;
 }
@@ -627,7 +624,7 @@ ec_GFp_simple_point_get_affine_coordinates(const EC_GROUP * group, const EC_POIN
 
         ret = 1;
 
- err:
+err:
         BN_CTX_end(ctx);
         BN_CTX_free(new_ctx);
         return ret;
@@ -814,7 +811,7 @@ ec_GFp_simple_add(const EC_GROUP * group, EC_POINT * r, const EC_POINT * a, cons
 
         ret = 1;
 
- end:
+end:
         if (ctx)                /* otherwise we already called BN_CTX_end */
                 BN_CTX_end(ctx);
         BN_CTX_free(new_ctx);
@@ -957,7 +954,7 @@ ec_GFp_simple_dbl(const EC_GROUP * group, EC_POINT * r, const EC_POINT * a, BN_C
 
         ret = 1;
 
- err:
+err:
         BN_CTX_end(ctx);
         BN_CTX_free(new_ctx);
         return ret;
@@ -1078,7 +1075,7 @@ ec_GFp_simple_is_on_curve(const EC_GROUP * group, const EC_POINT * point, BN_CTX
 
         ret = (0 == BN_ucmp(tmp, rh));
 
- err:
+err:
         BN_CTX_end(ctx);
         BN_CTX_free(new_ctx);
         return ret;
@@ -1180,7 +1177,7 @@ ec_GFp_simple_cmp(const EC_GROUP * group, const EC_POINT * a, const EC_POINT * b
         /* points are equal */
         ret = 0;
 
- end:
+end:
         BN_CTX_end(ctx);
         BN_CTX_free(new_ctx);
         return ret;
@@ -1218,7 +1215,7 @@ ec_GFp_simple_make_affine(const EC_GROUP * group, EC_POINT * point, BN_CTX * ctx
         }
         ret = 1;
 
- err:
+err:
         BN_CTX_end(ctx);
         BN_CTX_free(new_ctx);
         return ret;
@@ -1383,7 +1380,7 @@ ec_GFp_simple_points_make_affine(const EC_GROUP * group, size_t num, EC_POINT *
 
         ret = 1;
 
- err:
+err:
         BN_CTX_end(ctx);
         BN_CTX_free(new_ctx);
         if (heap != NULL) {
@@ -1412,248 +1409,3 @@ ec_GFp_simple_field_sqr(const EC_GROUP * group, BIGNUM * r, const BIGNUM * a, BN
 {
         return BN_mod_sqr(r, a, &group->field, ctx);
 }
-
-#define EC_POINT_BN_set_flags(P, flags) do {                            \
-        BN_set_flags(&(P)->X, (flags));                                 \
-        BN_set_flags(&(P)->Y, (flags));                                 \
-        BN_set_flags(&(P)->Z, (flags));                                 \
-} while(0)
-
-#define EC_POINT_CSWAP(c, a, b, w, t) do {                              \
-        if (!BN_swap_ct(c, &(a)->X, &(b)->X, w) ||                      \
-            !BN_swap_ct(c, &(a)->Y, &(b)->Y, w) ||                      \
-            !BN_swap_ct(c, &(a)->Z, &(b)->Z, w))                        \
-                goto err;                                               \
-        t = ((a)->Z_is_one ^ (b)->Z_is_one) & (c);                      \
-        (a)->Z_is_one ^= (t);                                           \
-        (b)->Z_is_one ^= (t);                                           \
-} while(0)
-
-/*
- * This function computes (in constant time) a point multiplication over the
- * EC group.
- *
- * At a high level, it is Montgomery ladder with conditional swaps.
- *
- * It performs either a fixed point multiplication
- *          (scalar * generator)
- * when point is NULL, or a variable point multiplication
- *          (scalar * point)
- * when point is not NULL.
- *
- * scalar should be in the range [0,n) otherwise all constant time bets are off.
- *
- * NB: This says nothing about EC_POINT_add and EC_POINT_dbl,
- * which of course are not constant time themselves.
- *
- * The product is stored in r.
- *
- * Returns 1 on success, 0 otherwise.
- */
-static int
-ec_GFp_simple_mul_ct(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
-    const EC_POINT *point, BN_CTX *ctx)
-{
-        int i, cardinality_bits, group_top, kbit, pbit, Z_is_one;
-        EC_POINT *s = NULL;
-        BIGNUM *k = NULL;
-        BIGNUM *lambda = NULL;
-        BIGNUM *cardinality = NULL;
-        BN_CTX *new_ctx = NULL;
-        int ret = 0;
-
-        if (ctx == NULL && (ctx = new_ctx = BN_CTX_new()) == NULL)
-                return 0;
-
-        BN_CTX_start(ctx);
-
-        if ((s = EC_POINT_new(group)) == NULL)
-                goto err;
-
-        if (point == NULL) {
-                if (!EC_POINT_copy(s, group->generator))
-                        goto err;
-        } else {
-                if (!EC_POINT_copy(s, point))
-                        goto err;
-        }
-
-        EC_POINT_BN_set_flags(s, BN_FLG_CONSTTIME);
-
-        if ((cardinality = BN_CTX_get(ctx)) == NULL)
-                goto err;
-        if ((lambda = BN_CTX_get(ctx)) == NULL)
-                goto err;
-        if ((k = BN_CTX_get(ctx)) == NULL)
-                goto err;
-        if (!BN_mul(cardinality, &group->order, &group->cofactor, ctx))
-                goto err;
-
-        /*
-         * Group cardinalities are often on a word boundary.
-         * So when we pad the scalar, some timing diff might
-         * pop if it needs to be expanded due to carries.
-         * So expand ahead of time.
-         */
-        cardinality_bits = BN_num_bits(cardinality);
-        group_top = cardinality->top;
-        if ((bn_wexpand(k, group_top + 1) == NULL) ||
-            (bn_wexpand(lambda, group_top + 1) == NULL))
-                goto err;
-
-        if (!BN_copy(k, scalar))
-                goto err;
-
-        BN_set_flags(k, BN_FLG_CONSTTIME);
-
-        if (BN_num_bits(k) > cardinality_bits || BN_is_negative(k)) {
-                /*
-                 * This is an unusual input, and we don't guarantee
-                 * constant-timeness
-                 */
-                if (!BN_nnmod(k, k, cardinality, ctx))
-                        goto err;
-        }
-
-        if (!BN_add(lambda, k, cardinality))
-                goto err;
-        BN_set_flags(lambda, BN_FLG_CONSTTIME);
-        if (!BN_add(k, lambda, cardinality))
-                goto err;
-        /*
-         * lambda := scalar + cardinality
-         * k := scalar + 2*cardinality
-         */
-        kbit = BN_is_bit_set(lambda, cardinality_bits);
-        if (!BN_swap_ct(kbit, k, lambda, group_top + 1))
-                goto err;
-
-        group_top = group->field.top;
-        if ((bn_wexpand(&s->X, group_top) == NULL) ||
-            (bn_wexpand(&s->Y, group_top) == NULL) ||
-            (bn_wexpand(&s->Z, group_top) == NULL) ||
-            (bn_wexpand(&r->X, group_top) == NULL) ||
-            (bn_wexpand(&r->Y, group_top) == NULL) ||
-            (bn_wexpand(&r->Z, group_top) == NULL))
-                goto err;
-
-        /* top bit is a 1, in a fixed pos */
-        if (!EC_POINT_copy(r, s))
-                goto err;
-
-        EC_POINT_BN_set_flags(r, BN_FLG_CONSTTIME);
-
-        if (!EC_POINT_dbl(group, s, s, ctx))
-                goto err;
-
-        pbit = 0;
-
-        /*
-         * The ladder step, with branches, is
-         *
-         * k[i] == 0: S = add(R, S), R = dbl(R)
-         * k[i] == 1: R = add(S, R), S = dbl(S)
-         *
-         * Swapping R, S conditionally on k[i] leaves you with state
-         *
-         * k[i] == 0: T, U = R, S
-         * k[i] == 1: T, U = S, R
-         *
-         * Then perform the ECC ops.
-         *
-         * U = add(T, U)
-         * T = dbl(T)
-         *
-         * Which leaves you with state
-         *
-         * k[i] == 0: U = add(R, S), T = dbl(R)
-         * k[i] == 1: U = add(S, R), T = dbl(S)
-         *
-         * Swapping T, U conditionally on k[i] leaves you with state
-         *
-         * k[i] == 0: R, S = T, U
-         * k[i] == 1: R, S = U, T
-         *
-         * Which leaves you with state
-         *
-         * k[i] == 0: S = add(R, S), R = dbl(R)
-         * k[i] == 1: R = add(S, R), S = dbl(S)
-         *
-         * So we get the same logic, but instead of a branch it's a
-         * conditional swap, followed by ECC ops, then another conditional swap.
-         *
-         * Optimization: The end of iteration i and start of i-1 looks like
-         *
-         * ...
-         * CSWAP(k[i], R, S)
-         * ECC
-         * CSWAP(k[i], R, S)
-         * (next iteration)
-         * CSWAP(k[i-1], R, S)
-         * ECC
-         * CSWAP(k[i-1], R, S)
-         * ...
-         *
-         * So instead of two contiguous swaps, you can merge the condition
-         * bits and do a single swap.
-         *
-         * k[i]   k[i-1]    Outcome
-         * 0      0         No Swap
-         * 0      1         Swap
-         * 1      0         Swap
-         * 1      1         No Swap
-         *
-         * This is XOR. pbit tracks the previous bit of k.
-         */
-
-        for (i = cardinality_bits - 1; i >= 0; i--) {
-                kbit = BN_is_bit_set(k, i) ^ pbit;
-                EC_POINT_CSWAP(kbit, r, s, group_top, Z_is_one);
-                if (!EC_POINT_add(group, s, r, s, ctx))
-                        goto err;
-                if (!EC_POINT_dbl(group, r, r, ctx))
-                        goto err;
-                /*
-                 * pbit logic merges this cswap with that of the
-                 * next iteration
-                 */
-                pbit ^= kbit;
-        }
-        /* one final cswap to move the right value into r */
-        EC_POINT_CSWAP(pbit, r, s, group_top, Z_is_one);
-        
-        ret = 1;
-
- err:
-        EC_POINT_free(s);
-        if (ctx != NULL)
-                BN_CTX_end(ctx);
-        BN_CTX_free(new_ctx);
-
-        return ret;
-}
-
-#undef EC_POINT_BN_set_flags
-#undef EC_POINT_CSWAP
-
-int
-ec_GFp_simple_mul_generator_ct(const EC_GROUP *group, EC_POINT *r,
-    const BIGNUM *scalar, BN_CTX *ctx)
-{
-        return ec_GFp_simple_mul_ct(group, r, scalar, NULL, ctx);
-}
-
-int
-ec_GFp_simple_mul_single_ct(const EC_GROUP *group, EC_POINT *r,
-    const BIGNUM *scalar, const EC_POINT *point, BN_CTX *ctx)
-{
-        return ec_GFp_simple_mul_ct(group, r, scalar, point, ctx);
-}
-
-int
-ec_GFp_simple_mul_double_nonct(const EC_GROUP *group, EC_POINT *r,
-    const BIGNUM *g_scalar, const BIGNUM *p_scalar, const EC_POINT *point,
-    BN_CTX *ctx)
-{
-        return ec_wNAF_mul(group, r, g_scalar, 1, &point, &p_scalar, ctx);
-}