diff -up openssl-1.0.2k/crypto/bn/bn_lib.c.ecc-ladder openssl-1.0.2k/crypto/bn/bn_lib.c

--- openssl-1.0.2k/crypto/bn/bn_lib.c.ecc-ladder	2019-02-06 12:58:50.575844123 +0100

+++ openssl-1.0.2k/crypto/bn/bn_lib.c	2019-02-08 10:48:53.529291777 +0100

@@ -877,6 +877,38 @@ void BN_consttime_swap(BN_ULONG conditio

     a->top ^= t;

     b->top ^= t;

+    t = (a->neg ^ b->neg) & condition;

+    a->neg ^= t;

+    b->neg ^= t;

+

+    /*-

+     * BN_FLG_STATIC_DATA: indicates that data may not be written to. Intention

+     * is actually to treat it as it's read-only data, and some (if not most)

+     * of it does reside in read-only segment. In other words observation of

+     * BN_FLG_STATIC_DATA in BN_consttime_swap should be treated as fatal

+     * condition. It would either cause SEGV or effectively cause data

+     * corruption.

+     *

+     * BN_FLG_MALLOCED: refers to BN structure itself, and hence must be

+     * preserved.

+     *

+     * BN_FLG_SECURE: must be preserved, because it determines how x->d was

+     * allocated and hence how to free it.

+     *

+     * BN_FLG_CONSTTIME: sufficient to mask and swap

+     *

+     * BN_FLG_FIXED_TOP: indicates that we haven't called bn_correct_top() on

+     * the data, so the d array may be padded with additional 0 values (i.e.

+     * top could be greater than the minimal value that it could be). We should

+     * be swapping it

+     */

+

+#define BN_CONSTTIME_SWAP_FLAGS (BN_FLG_CONSTTIME | BN_FLG_FIXED_TOP)

+

+    t = ((a->flags ^ b->flags) & BN_CONSTTIME_SWAP_FLAGS) & condition;

+    a->flags ^= t;

+    b->flags ^= t;

+

 #define BN_CONSTTIME_SWAP(ind) \

         do { \

                 t = (a->d[ind] ^ b->d[ind]) & condition; \

diff -up openssl-1.0.2k/crypto/ec/ec_mult.c.ecc-ladder openssl-1.0.2k/crypto/ec/ec_mult.c

--- openssl-1.0.2k/crypto/ec/ec_mult.c.ecc-ladder	2017-01-26 14:22:03.000000000 +0100

+++ openssl-1.0.2k/crypto/ec/ec_mult.c	2019-02-08 10:48:53.531291744 +0100

@@ -306,6 +306,224 @@ static signed char *compute_wNAF(const B

     return r;

 }

+#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)

+

+/*-

+ * This functions 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 scalar point multiplication

+ *          (scalar * generator)

+ * when point is NULL, or a generic scalar 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_mul_consttime(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);

+

+    s = EC_POINT_new(group);

+    if (s == 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);

+

+    cardinality = BN_CTX_get(ctx);

+    lambda = BN_CTX_get(ctx);

+    k = BN_CTX_get(ctx);

+    if (k == NULL || !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 + 2) == NULL)

+        || (bn_wexpand(lambda, group_top + 2) == 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);

+    BN_consttime_swap(kbit, k, lambda, group_top + 2);

+

+    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;

+

+#define EC_POINT_CSWAP(c, a, b, w, t) do {         \

+        BN_consttime_swap(c, &(a)->X, &(b)->X, w); \

+        BN_consttime_swap(c, &(a)->Y, &(b)->Y, w); \

+        BN_consttime_swap(c, &(a)->Z, &(b)->Z, w); \

+        t = ((a)->Z_is_one ^ (b)->Z_is_one) & (c); \

+        (a)->Z_is_one ^= (t);                      \

+        (b)->Z_is_one ^= (t);                      \

+} while(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);

+#undef EC_POINT_CSWAP

+

+    ret = 1;

+

+ err:

+    EC_POINT_free(s);

+    BN_CTX_end(ctx);

+    BN_CTX_free(new_ctx);

+

+    return ret;

+}

+

+#undef EC_POINT_BN_set_flags

+

 /*

  * TODO: table should be optimised for the wNAF-based implementation,

  * sometimes smaller windows will give better performance (thus the

@@ -365,6 +583,34 @@ int ec_wNAF_mul(const EC_GROUP *group, E

         return EC_POINT_set_to_infinity(group, r);

     }

+    if (!BN_is_zero(&group->order) && !BN_is_zero(&group->cofactor)) {

+        /*-

+         * Handle the common cases where the scalar is secret, enforcing a constant

+         * time scalar multiplication algorithm.

+         */

+        if ((scalar != NULL) && (num == 0)) {

+            /*-

+             * In this case we want to compute scalar * GeneratorPoint: this

+             * codepath is reached most prominently by (ephemeral) key generation

+             * of EC cryptosystems (i.e. ECDSA keygen and sign setup, ECDH

+             * keygen/first half), where the scalar is always secret. This is why

+             * we ignore if BN_FLG_CONSTTIME is actually set and we always call the

+             * constant time version.

+             */

+            return ec_mul_consttime(group, r, scalar, NULL, ctx);

+        }

+        if ((scalar == NULL) && (num == 1)) {

+            /*-

+             * In this case we want to compute scalar * GenericPoint: this codepath

+             * is reached most prominently by the second half of ECDH, where the

+             * secret scalar is multiplied by the peer's public point. To protect

+             * the secret scalar, we ignore if BN_FLG_CONSTTIME is actually set and

+             * we always call the constant time version.

+             */

+            return ec_mul_consttime(group, r, scalars[0], points[0], ctx);

+        }

+    }

+

     for (i = 0; i < num; i++) {

         if (group->meth != points[i]->meth) {

             ECerr(EC_F_EC_WNAF_MUL, EC_R_INCOMPATIBLE_OBJECTS);