crypto/sm2/sm2_crypt.c:331: error: BUFFER_OVERRUN_L3
  Offset added: [8, +oo] Size: [0, 536870848] by call to `EC_POINT_mul`.
Showing all 16 steps of the trace


crypto/sm2/sm2_crypt.c:331:17: Call
329.       if (!EC_POINT_set_affine_coordinates(group, C1, sm2_ctext->C1x,
330.                                            sm2_ctext->C1y, ctx)
331.               || !EC_POINT_mul(group, C1, NULL, C1, EC_KEY_get0_private_key(key),
                       ^
332.                                ctx)
333.               || !EC_POINT_get_affine_coordinates(group, C1, x2, y2, ctx)) {

crypto/ec/ec_lib.c:947:1: Parameter `p_scalar->top`
  945.   }
  946.   
  947. > int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar,
  948.                    const EC_POINT *point, const BIGNUM *p_scalar, BN_CTX *ctx)
  949.   {

crypto/ec/ec_lib.c:958:12: Call
  956.       scalars[0] = p_scalar;
  957.   
  958.       return EC_POINTs_mul(group, r, g_scalar,
                    ^
  959.                            (point != NULL
  960.                             && p_scalar != NULL), points, scalars, ctx);

crypto/ec/ec_lib.c:909:1: Parameter `(*scalars)->top`
    907.    */
    908.   
    909. > int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
    910.                     size_t num, const EC_POINT *points[],
    911.                     const BIGNUM *scalars[], BN_CTX *ctx)

crypto/ec/ec_lib.c:941:15: Call
    939.       else
    940.           /* use default */
    941.           ret = ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
                         ^
    942.   
    943.       BN_CTX_free(new_ctx);

crypto/ec/ec_mult.c:410:1: Parameter `(*scalars)->top`
      408.    * in the addition if scalar != NULL
      409.    */
      410. > int ec_wNAF_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
      411.                   size_t num, const EC_POINT *points[], const BIGNUM *scalars[],
      412.                   BN_CTX *ctx)

crypto/ec/ec_mult.c:463:20: Call
      461.                * actually set and we always call the ladder version.
      462.                */
      463.               return ec_scalar_mul_ladder(group, r, scalars[0], points[0], ctx);
                                ^
      464.           }
      465.       }

crypto/ec/ec_mult.c:139:1: Parameter `scalar->top`
        137.    * Returns 1 on success, 0 otherwise.
        138.    */
        139. > int ec_scalar_mul_ladder(const EC_GROUP *group, EC_POINT *r,
        140.                            const BIGNUM *scalar, const EC_POINT *point,
        141.                            BN_CTX *ctx)

crypto/ec/ec_mult.c:215:10: Call
        213.       }
        214.   
        215.       if (!BN_copy(k, scalar)) {
                        ^
        216.           ECerr(EC_F_EC_SCALAR_MUL_LADDER, ERR_R_BN_LIB);
        217.           goto err;

crypto/bn/bn_lib.c:281:1: <Offset trace>
279.   }
280.   
281. > BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
282.   {
283.       bn_check_top(b);

crypto/bn/bn_lib.c:281:1: Parameter `b->top`
          279.   }
          280.   
          281. > BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
          282.   {
          283.       bn_check_top(b);

crypto/bn/bn_lib.c:281:1: <Length trace>
279.   }
280.   
281. > BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
282.   {
283.       bn_check_top(b);

crypto/bn/bn_lib.c:281:1: Parameter `*a->d`
          279.   }
          280.   
          281. > BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
          282.   {
          283.       bn_check_top(b);

crypto/bn/bn_lib.c:287:9: Call
          285.       if (a == b)
          286.           return a;
          287.       if (bn_wexpand(a, b->top) == NULL)
                         ^
          288.           return NULL;
          289.   

crypto/bn/bn_lib.c:948:1: Parameter `*a->d`
            946.   }
            947.   
            948. > BIGNUM *bn_wexpand(BIGNUM *a, int words)
            949.   {
            950.       return (words <= a->dmax) ? a : bn_expand2(a, words);

crypto/bn/bn_lib.c:291:9: Array access: Offset added: [8, +oo] Size: [0, 536870848] by call to `EC_POINT_mul` 
          289.   
          290.       if (b->top > 0)
          291.           memcpy(a->d, b->d, sizeof(b->d[0]) * b->top);
                         ^
          292.   
          293.       a->neg = b->neg;

BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
{
    bn_check_top(b);
    if (a == b)
        return a;
    if (bn_wexpand(a, b->top) == NULL)
        return NULL;
    if (b->top > 0)
        memcpy(a->d, b->d, sizeof(b->d[0]) * b->top);
    a->neg = b->neg;
    a->top = b->top;
    a->flags |= b->flags & BN_FLG_FIXED_TOP;
    bn_check_top(a);
    return a;
}
['int sm2_decrypt(const EC_KEY *key,\n                const EVP_MD *digest,\n                const uint8_t *ciphertext,\n                size_t ciphertext_len, uint8_t *ptext_buf, size_t *ptext_len)\n{\n    int rc = 0;\n    int i;\n    BN_CTX *ctx = NULL;\n    const EC_GROUP *group = EC_KEY_get0_group(key);\n    EC_POINT *C1 = NULL;\n    struct SM2_Ciphertext_st *sm2_ctext = NULL;\n    BIGNUM *x2 = NULL;\n    BIGNUM *y2 = NULL;\n    uint8_t *x2y2 = NULL;\n    uint8_t *computed_C3 = NULL;\n    const size_t field_size = ec_field_size(group);\n    const int hash_size = EVP_MD_size(digest);\n    uint8_t *msg_mask = NULL;\n    const uint8_t *C2 = NULL;\n    const uint8_t *C3 = NULL;\n    int msg_len = 0;\n    EVP_MD_CTX *hash = NULL;\n    if (field_size == 0 || hash_size <= 0)\n       goto done;\n    memset(ptext_buf, 0xFF, *ptext_len);\n    sm2_ctext = d2i_SM2_Ciphertext(NULL, &ciphertext, ciphertext_len);\n    if (sm2_ctext == NULL) {\n        SM2err(SM2_F_SM2_DECRYPT, SM2_R_ASN1_ERROR);\n        goto done;\n    }\n    if (sm2_ctext->C3->length != hash_size) {\n        SM2err(SM2_F_SM2_DECRYPT, SM2_R_INVALID_ENCODING);\n        goto done;\n    }\n    C2 = sm2_ctext->C2->data;\n    C3 = sm2_ctext->C3->data;\n    msg_len = sm2_ctext->C2->length;\n    ctx = BN_CTX_new();\n    if (ctx == NULL) {\n        SM2err(SM2_F_SM2_DECRYPT, ERR_R_MALLOC_FAILURE);\n        goto done;\n    }\n    BN_CTX_start(ctx);\n    x2 = BN_CTX_get(ctx);\n    y2 = BN_CTX_get(ctx);\n    if (y2 == NULL) {\n        SM2err(SM2_F_SM2_DECRYPT, ERR_R_BN_LIB);\n        goto done;\n    }\n    msg_mask = OPENSSL_zalloc(msg_len);\n    x2y2 = OPENSSL_zalloc(2 * field_size);\n    computed_C3 = OPENSSL_zalloc(hash_size);\n    if (msg_mask == NULL || x2y2 == NULL || computed_C3 == NULL) {\n        SM2err(SM2_F_SM2_DECRYPT, ERR_R_MALLOC_FAILURE);\n        goto done;\n    }\n    C1 = EC_POINT_new(group);\n    if (C1 == NULL) {\n        SM2err(SM2_F_SM2_DECRYPT, ERR_R_MALLOC_FAILURE);\n        goto done;\n    }\n    if (!EC_POINT_set_affine_coordinates(group, C1, sm2_ctext->C1x,\n                                         sm2_ctext->C1y, ctx)\n            || !EC_POINT_mul(group, C1, NULL, C1, EC_KEY_get0_private_key(key),\n                             ctx)\n            || !EC_POINT_get_affine_coordinates(group, C1, x2, y2, ctx)) {\n        SM2err(SM2_F_SM2_DECRYPT, ERR_R_EC_LIB);\n        goto done;\n    }\n    if (BN_bn2binpad(x2, x2y2, field_size) < 0\n            || BN_bn2binpad(y2, x2y2 + field_size, field_size) < 0\n            || !ECDH_KDF_X9_62(msg_mask, msg_len, x2y2, 2 * field_size, NULL, 0,\n                               digest)) {\n        SM2err(SM2_F_SM2_DECRYPT, ERR_R_INTERNAL_ERROR);\n        goto done;\n    }\n    for (i = 0; i != msg_len; ++i)\n        ptext_buf[i] = C2[i] ^ msg_mask[i];\n    hash = EVP_MD_CTX_new();\n    if (hash == NULL) {\n        SM2err(SM2_F_SM2_DECRYPT, ERR_R_MALLOC_FAILURE);\n        goto done;\n    }\n    if (!EVP_DigestInit(hash, digest)\n            || !EVP_DigestUpdate(hash, x2y2, field_size)\n            || !EVP_DigestUpdate(hash, ptext_buf, msg_len)\n            || !EVP_DigestUpdate(hash, x2y2 + field_size, field_size)\n            || !EVP_DigestFinal(hash, computed_C3, NULL)) {\n        SM2err(SM2_F_SM2_DECRYPT, ERR_R_EVP_LIB);\n        goto done;\n    }\n    if (CRYPTO_memcmp(computed_C3, C3, hash_size) != 0) {\n        SM2err(SM2_F_SM2_DECRYPT, SM2_R_INVALID_DIGEST);\n        goto done;\n    }\n    rc = 1;\n    *ptext_len = msg_len;\n done:\n    if (rc == 0)\n        memset(ptext_buf, 0, *ptext_len);\n    OPENSSL_free(msg_mask);\n    OPENSSL_free(x2y2);\n    OPENSSL_free(computed_C3);\n    EC_POINT_free(C1);\n    BN_CTX_free(ctx);\n    SM2_Ciphertext_free(sm2_ctext);\n    EVP_MD_CTX_free(hash);\n    return rc;\n}', 'int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar,\n                 const EC_POINT *point, const BIGNUM *p_scalar, BN_CTX *ctx)\n{\n    const EC_POINT *points[1];\n    const BIGNUM *scalars[1];\n    points[0] = point;\n    scalars[0] = p_scalar;\n    return EC_POINTs_mul(group, r, g_scalar,\n                         (point != NULL\n                          && p_scalar != NULL), points, scalars, ctx);\n}', 'int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,\n                  size_t num, const EC_POINT *points[],\n                  const BIGNUM *scalars[], BN_CTX *ctx)\n{\n    int ret = 0;\n    size_t i = 0;\n    BN_CTX *new_ctx = NULL;\n    if ((scalar == NULL) && (num == 0)) {\n        return EC_POINT_set_to_infinity(group, r);\n    }\n    if (!ec_point_is_compat(r, group)) {\n        ECerr(EC_F_EC_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);\n        return 0;\n    }\n    for (i = 0; i < num; i++) {\n        if (!ec_point_is_compat(points[i], group)) {\n            ECerr(EC_F_EC_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);\n            return 0;\n        }\n    }\n    if (ctx == NULL && (ctx = new_ctx = BN_CTX_secure_new()) == NULL) {\n        ECerr(EC_F_EC_POINTS_MUL, ERR_R_INTERNAL_ERROR);\n        return 0;\n    }\n    if (group->meth->mul != NULL)\n        ret = group->meth->mul(group, r, scalar, num, points, scalars, ctx);\n    else\n        ret = ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);\n    BN_CTX_free(new_ctx);\n    return ret;\n}', 'int ec_wNAF_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,\n                size_t num, const EC_POINT *points[], const BIGNUM *scalars[],\n                BN_CTX *ctx)\n{\n    const EC_POINT *generator = NULL;\n    EC_POINT *tmp = NULL;\n    size_t totalnum;\n    size_t blocksize = 0, numblocks = 0;\n    size_t pre_points_per_block = 0;\n    size_t i, j;\n    int k;\n    int r_is_inverted = 0;\n    int r_is_at_infinity = 1;\n    size_t *wsize = NULL;\n    signed char **wNAF = NULL;\n    size_t *wNAF_len = NULL;\n    size_t max_len = 0;\n    size_t num_val;\n    EC_POINT **val = NULL;\n    EC_POINT **v;\n    EC_POINT ***val_sub = NULL;\n    const EC_PRE_COMP *pre_comp = NULL;\n    int num_scalar = 0;\n    int ret = 0;\n    if (!BN_is_zero(group->order) && !BN_is_zero(group->cofactor)) {\n        if ((scalar != NULL) && (num == 0)) {\n            return ec_scalar_mul_ladder(group, r, scalar, NULL, ctx);\n        }\n        if ((scalar == NULL) && (num == 1)) {\n            return ec_scalar_mul_ladder(group, r, scalars[0], points[0], ctx);\n        }\n    }\n    if (scalar != NULL) {\n        generator = EC_GROUP_get0_generator(group);\n        if (generator == NULL) {\n            ECerr(EC_F_EC_WNAF_MUL, EC_R_UNDEFINED_GENERATOR);\n            goto err;\n        }\n        pre_comp = group->pre_comp.ec;\n        if (pre_comp && pre_comp->numblocks\n            && (EC_POINT_cmp(group, generator, pre_comp->points[0], ctx) ==\n                0)) {\n            blocksize = pre_comp->blocksize;\n            numblocks = (BN_num_bits(scalar) / blocksize) + 1;\n            if (numblocks > pre_comp->numblocks)\n                numblocks = pre_comp->numblocks;\n            pre_points_per_block = (size_t)1 << (pre_comp->w - 1);\n            if (pre_comp->num != (pre_comp->numblocks * pre_points_per_block)) {\n                ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR);\n                goto err;\n            }\n        } else {\n            pre_comp = NULL;\n            numblocks = 1;\n            num_scalar = 1;\n        }\n    }\n    totalnum = num + numblocks;\n    wsize = OPENSSL_malloc(totalnum * sizeof(wsize[0]));\n    wNAF_len = OPENSSL_malloc(totalnum * sizeof(wNAF_len[0]));\n    wNAF = OPENSSL_malloc((totalnum + 1) * sizeof(wNAF[0]));\n    val_sub = OPENSSL_malloc(totalnum * sizeof(val_sub[0]));\n    if (wNAF != NULL)\n        wNAF[0] = NULL;\n    if (wsize == NULL || wNAF_len == NULL || wNAF == NULL || val_sub == NULL) {\n        ECerr(EC_F_EC_WNAF_MUL, ERR_R_MALLOC_FAILURE);\n        goto err;\n    }\n    num_val = 0;\n    for (i = 0; i < num + num_scalar; i++) {\n        size_t bits;\n        bits = i < num ? BN_num_bits(scalars[i]) : BN_num_bits(scalar);\n        wsize[i] = EC_window_bits_for_scalar_size(bits);\n        num_val += (size_t)1 << (wsize[i] - 1);\n        wNAF[i + 1] = NULL;\n        wNAF[i] =\n            bn_compute_wNAF((i < num ? scalars[i] : scalar), wsize[i],\n                            &wNAF_len[i]);\n        if (wNAF[i] == NULL)\n            goto err;\n        if (wNAF_len[i] > max_len)\n            max_len = wNAF_len[i];\n    }\n    if (numblocks) {\n        if (pre_comp == NULL) {\n            if (num_scalar != 1) {\n                ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR);\n                goto err;\n            }\n        } else {\n            signed char *tmp_wNAF = NULL;\n            size_t tmp_len = 0;\n            if (num_scalar != 0) {\n                ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR);\n                goto err;\n            }\n            wsize[num] = pre_comp->w;\n            tmp_wNAF = bn_compute_wNAF(scalar, wsize[num], &tmp_len);\n            if (!tmp_wNAF)\n                goto err;\n            if (tmp_len <= max_len) {\n                numblocks = 1;\n                totalnum = num + 1;\n                wNAF[num] = tmp_wNAF;\n                wNAF[num + 1] = NULL;\n                wNAF_len[num] = tmp_len;\n                val_sub[num] = pre_comp->points;\n            } else {\n                signed char *pp;\n                EC_POINT **tmp_points;\n                if (tmp_len < numblocks * blocksize) {\n                    numblocks = (tmp_len + blocksize - 1) / blocksize;\n                    if (numblocks > pre_comp->numblocks) {\n                        ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR);\n                        OPENSSL_free(tmp_wNAF);\n                        goto err;\n                    }\n                    totalnum = num + numblocks;\n                }\n                pp = tmp_wNAF;\n                tmp_points = pre_comp->points;\n                for (i = num; i < totalnum; i++) {\n                    if (i < totalnum - 1) {\n                        wNAF_len[i] = blocksize;\n                        if (tmp_len < blocksize) {\n                            ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR);\n                            OPENSSL_free(tmp_wNAF);\n                            goto err;\n                        }\n                        tmp_len -= blocksize;\n                    } else\n                        wNAF_len[i] = tmp_len;\n                    wNAF[i + 1] = NULL;\n                    wNAF[i] = OPENSSL_malloc(wNAF_len[i]);\n                    if (wNAF[i] == NULL) {\n                        ECerr(EC_F_EC_WNAF_MUL, ERR_R_MALLOC_FAILURE);\n                        OPENSSL_free(tmp_wNAF);\n                        goto err;\n                    }\n                    memcpy(wNAF[i], pp, wNAF_len[i]);\n                    if (wNAF_len[i] > max_len)\n                        max_len = wNAF_len[i];\n                    if (*tmp_points == NULL) {\n                        ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR);\n                        OPENSSL_free(tmp_wNAF);\n                        goto err;\n                    }\n                    val_sub[i] = tmp_points;\n                    tmp_points += pre_points_per_block;\n                    pp += blocksize;\n                }\n                OPENSSL_free(tmp_wNAF);\n            }\n        }\n    }\n    val = OPENSSL_malloc((num_val + 1) * sizeof(val[0]));\n    if (val == NULL) {\n        ECerr(EC_F_EC_WNAF_MUL, ERR_R_MALLOC_FAILURE);\n        goto err;\n    }\n    val[num_val] = NULL;\n    v = val;\n    for (i = 0; i < num + num_scalar; i++) {\n        val_sub[i] = v;\n        for (j = 0; j < ((size_t)1 << (wsize[i] - 1)); j++) {\n            *v = EC_POINT_new(group);\n            if (*v == NULL)\n                goto err;\n            v++;\n        }\n    }\n    if (!(v == val + num_val)) {\n        ECerr(EC_F_EC_WNAF_MUL, ERR_R_INTERNAL_ERROR);\n        goto err;\n    }\n    if ((tmp = EC_POINT_new(group)) == NULL)\n        goto err;\n    for (i = 0; i < num + num_scalar; i++) {\n        if (i < num) {\n            if (!EC_POINT_copy(val_sub[i][0], points[i]))\n                goto err;\n        } else {\n            if (!EC_POINT_copy(val_sub[i][0], generator))\n                goto err;\n        }\n        if (wsize[i] > 1) {\n            if (!EC_POINT_dbl(group, tmp, val_sub[i][0], ctx))\n                goto err;\n            for (j = 1; j < ((size_t)1 << (wsize[i] - 1)); j++) {\n                if (!EC_POINT_add\n                    (group, val_sub[i][j], val_sub[i][j - 1], tmp, ctx))\n                    goto err;\n            }\n        }\n    }\n    if (!EC_POINTs_make_affine(group, num_val, val, ctx))\n        goto err;\n    r_is_at_infinity = 1;\n    for (k = max_len - 1; k >= 0; k--) {\n        if (!r_is_at_infinity) {\n            if (!EC_POINT_dbl(group, r, r, ctx))\n                goto err;\n        }\n        for (i = 0; i < totalnum; i++) {\n            if (wNAF_len[i] > (size_t)k) {\n                int digit = wNAF[i][k];\n                int is_neg;\n                if (digit) {\n                    is_neg = digit < 0;\n                    if (is_neg)\n                        digit = -digit;\n                    if (is_neg != r_is_inverted) {\n                        if (!r_is_at_infinity) {\n                            if (!EC_POINT_invert(group, r, ctx))\n                                goto err;\n                        }\n                        r_is_inverted = !r_is_inverted;\n                    }\n                    if (r_is_at_infinity) {\n                        if (!EC_POINT_copy(r, val_sub[i][digit >> 1]))\n                            goto err;\n                        r_is_at_infinity = 0;\n                    } else {\n                        if (!EC_POINT_add\n                            (group, r, r, val_sub[i][digit >> 1], ctx))\n                            goto err;\n                    }\n                }\n            }\n        }\n    }\n    if (r_is_at_infinity) {\n        if (!EC_POINT_set_to_infinity(group, r))\n            goto err;\n    } else {\n        if (r_is_inverted)\n            if (!EC_POINT_invert(group, r, ctx))\n                goto err;\n    }\n    ret = 1;\n err:\n    EC_POINT_free(tmp);\n    OPENSSL_free(wsize);\n    OPENSSL_free(wNAF_len);\n    if (wNAF != NULL) {\n        signed char **w;\n        for (w = wNAF; *w != NULL; w++)\n            OPENSSL_free(*w);\n        OPENSSL_free(wNAF);\n    }\n    if (val != NULL) {\n        for (v = val; *v != NULL; v++)\n            EC_POINT_clear_free(*v);\n        OPENSSL_free(val);\n    }\n    OPENSSL_free(val_sub);\n    return ret;\n}', 'int ec_scalar_mul_ladder(const EC_GROUP *group, EC_POINT *r,\n                         const BIGNUM *scalar, const EC_POINT *point,\n                         BN_CTX *ctx)\n{\n    int i, cardinality_bits, group_top, kbit, pbit, Z_is_one;\n    EC_POINT *p = NULL;\n    EC_POINT *s = NULL;\n    BIGNUM *k = NULL;\n    BIGNUM *lambda = NULL;\n    BIGNUM *cardinality = NULL;\n    int ret = 0;\n    if (point != NULL && EC_POINT_is_at_infinity(group, point))\n        return EC_POINT_set_to_infinity(group, r);\n    if (BN_is_zero(group->order)) {\n        ECerr(EC_F_EC_SCALAR_MUL_LADDER, EC_R_UNKNOWN_ORDER);\n        return 0;\n    }\n    if (BN_is_zero(group->cofactor)) {\n        ECerr(EC_F_EC_SCALAR_MUL_LADDER, EC_R_UNKNOWN_COFACTOR);\n        return 0;\n    }\n    BN_CTX_start(ctx);\n    if (((p = EC_POINT_new(group)) == NULL)\n        || ((s = EC_POINT_new(group)) == NULL)) {\n        ECerr(EC_F_EC_SCALAR_MUL_LADDER, ERR_R_MALLOC_FAILURE);\n        goto err;\n    }\n    if (point == NULL) {\n        if (!EC_POINT_copy(p, group->generator)) {\n            ECerr(EC_F_EC_SCALAR_MUL_LADDER, ERR_R_EC_LIB);\n            goto err;\n        }\n    } else {\n        if (!EC_POINT_copy(p, point)) {\n            ECerr(EC_F_EC_SCALAR_MUL_LADDER, ERR_R_EC_LIB);\n            goto err;\n        }\n    }\n    EC_POINT_BN_set_flags(p, BN_FLG_CONSTTIME);\n    EC_POINT_BN_set_flags(r, BN_FLG_CONSTTIME);\n    EC_POINT_BN_set_flags(s, BN_FLG_CONSTTIME);\n    cardinality = BN_CTX_get(ctx);\n    lambda = BN_CTX_get(ctx);\n    k = BN_CTX_get(ctx);\n    if (k == NULL) {\n        ECerr(EC_F_EC_SCALAR_MUL_LADDER, ERR_R_MALLOC_FAILURE);\n        goto err;\n    }\n    if (!BN_mul(cardinality, group->order, group->cofactor, ctx)) {\n        ECerr(EC_F_EC_SCALAR_MUL_LADDER, ERR_R_BN_LIB);\n        goto err;\n    }\n    cardinality_bits = BN_num_bits(cardinality);\n    group_top = bn_get_top(cardinality);\n    if ((bn_wexpand(k, group_top + 1) == NULL)\n        || (bn_wexpand(lambda, group_top + 1) == NULL)) {\n        ECerr(EC_F_EC_SCALAR_MUL_LADDER, ERR_R_BN_LIB);\n        goto err;\n    }\n    if (!BN_copy(k, scalar)) {\n        ECerr(EC_F_EC_SCALAR_MUL_LADDER, ERR_R_BN_LIB);\n        goto err;\n    }\n    BN_set_flags(k, BN_FLG_CONSTTIME);\n    if ((BN_num_bits(k) > cardinality_bits) || (BN_is_negative(k))) {\n        if (!BN_nnmod(k, k, cardinality, ctx)) {\n            ECerr(EC_F_EC_SCALAR_MUL_LADDER, ERR_R_BN_LIB);\n            goto err;\n        }\n    }\n    if (!BN_add(lambda, k, cardinality)) {\n        ECerr(EC_F_EC_SCALAR_MUL_LADDER, ERR_R_BN_LIB);\n        goto err;\n    }\n    BN_set_flags(lambda, BN_FLG_CONSTTIME);\n    if (!BN_add(k, lambda, cardinality)) {\n        ECerr(EC_F_EC_SCALAR_MUL_LADDER, ERR_R_BN_LIB);\n        goto err;\n    }\n    kbit = BN_is_bit_set(lambda, cardinality_bits);\n    BN_consttime_swap(kbit, k, lambda, group_top + 1);\n    group_top = bn_get_top(group->field);\n    if ((bn_wexpand(s->X, group_top) == NULL)\n        || (bn_wexpand(s->Y, group_top) == NULL)\n        || (bn_wexpand(s->Z, group_top) == NULL)\n        || (bn_wexpand(r->X, group_top) == NULL)\n        || (bn_wexpand(r->Y, group_top) == NULL)\n        || (bn_wexpand(r->Z, group_top) == NULL)\n        || (bn_wexpand(p->X, group_top) == NULL)\n        || (bn_wexpand(p->Y, group_top) == NULL)\n        || (bn_wexpand(p->Z, group_top) == NULL)) {\n        ECerr(EC_F_EC_SCALAR_MUL_LADDER, ERR_R_BN_LIB);\n        goto err;\n    }\n    if (!ec_point_blind_coordinates(group, p, ctx)) {\n        ECerr(EC_F_EC_SCALAR_MUL_LADDER, EC_R_POINT_COORDINATES_BLIND_FAILURE);\n        goto err;\n    }\n    if (!ec_point_ladder_pre(group, r, s, p, ctx)) {\n        ECerr(EC_F_EC_SCALAR_MUL_LADDER, EC_R_LADDER_PRE_FAILURE);\n        goto err;\n    }\n    pbit = 1;\n#define EC_POINT_CSWAP(c, a, b, w, t) do {         \\\n        BN_consttime_swap(c, (a)->X, (b)->X, w);   \\\n        BN_consttime_swap(c, (a)->Y, (b)->Y, w);   \\\n        BN_consttime_swap(c, (a)->Z, (b)->Z, w);   \\\n        t = ((a)->Z_is_one ^ (b)->Z_is_one) & (c); \\\n        (a)->Z_is_one ^= (t);                      \\\n        (b)->Z_is_one ^= (t);                      \\\n} while(0)\n    for (i = cardinality_bits - 1; i >= 0; i--) {\n        kbit = BN_is_bit_set(k, i) ^ pbit;\n        EC_POINT_CSWAP(kbit, r, s, group_top, Z_is_one);\n        if (!ec_point_ladder_step(group, r, s, p, ctx)) {\n            ECerr(EC_F_EC_SCALAR_MUL_LADDER, EC_R_LADDER_STEP_FAILURE);\n            goto err;\n        }\n        pbit ^= kbit;\n    }\n    EC_POINT_CSWAP(pbit, r, s, group_top, Z_is_one);\n#undef EC_POINT_CSWAP\n    if (!ec_point_ladder_post(group, r, s, p, ctx)) {\n        ECerr(EC_F_EC_SCALAR_MUL_LADDER, EC_R_LADDER_POST_FAILURE);\n        goto err;\n    }\n    ret = 1;\n err:\n    EC_POINT_free(p);\n    EC_POINT_free(s);\n    BN_CTX_end(ctx);\n    return ret;\n}', 'BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)\n{\n    bn_check_top(b);\n    if (a == b)\n        return a;\n    if (bn_wexpand(a, b->top) == NULL)\n        return NULL;\n    if (b->top > 0)\n        memcpy(a->d, b->d, sizeof(b->d[0]) * b->top);\n    a->neg = b->neg;\n    a->top = b->top;\n    a->flags |= b->flags & BN_FLG_FIXED_TOP;\n    bn_check_top(a);\n    return a;\n}', 'BIGNUM *bn_wexpand(BIGNUM *a, int words)\n{\n    return (words <= a->dmax) ? a : bn_expand2(a, words);\n}']