crypto/rsa/rsa_ossl.c:819: error: BUFFER_OVERRUN_L3
  Offset: [1, +oo] Size: [0, 8388607] by call to `BN_div`.
Showing all 17 steps of the trace


crypto/rsa/rsa_ossl.c:701:14: Call
699.           BN_with_flags(c, I, BN_FLG_CONSTTIME);
700.   
701.           if (!BN_mod(r1, c, rsa->q, ctx)) {
                    ^
702.               BN_free(c);
703.               goto err;

crypto/bn/bn_div.c:188:1: Parameter `*dv->d`
  186.    * If 'dv' or 'rm' is NULL, the respective value is not returned.
  187.    */
  188. > int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
  189.              BN_CTX *ctx)
  190.   {

crypto/bn/bn_div.c:303:10: Call
  301.   
  302.       /* Setup to 'res' */
  303.       if (!bn_wexpand(res, (loop + 1)))
                  ^
  304.           goto err;
  305.       res->neg = (num->neg ^ divisor->neg);

crypto/bn/bn_lib.c:939:1: Parameter `*a->d`
    937.   }
    938.   
    939. > BIGNUM *bn_wexpand(BIGNUM *a, int words)
    940.   {
    941.       return (words <= a->dmax) ? a : bn_expand2(a, words);

crypto/rsa/rsa_ossl.c:817:9: Call
815.           if (pr1 == NULL)
816.               goto err;
817.           BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
               ^
818.   
819.           if (!BN_mod(r0, pr1, rsa->p, ctx)) {

crypto/bn/bn_lib.c:874:1: Parameter `*b->d`
  872.   }
  873.   
  874. > void BN_with_flags(BIGNUM *dest, const BIGNUM *b, int flags)
  875.   {
  876.       dest->d = b->d;

crypto/bn/bn_lib.c:876:5: Assignment
  874.   void BN_with_flags(BIGNUM *dest, const BIGNUM *b, int flags)
  875.   {
  876.       dest->d = b->d;
             ^
  877.       dest->top = b->top;
  878.       dest->dmax = b->dmax;

crypto/rsa/rsa_ossl.c:819:14: Call
817.           BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
818.   
819.           if (!BN_mod(r0, pr1, rsa->p, ctx)) {
                    ^
820.               BN_free(pr1);
821.               goto err;

crypto/bn/bn_div.c:188:1: Parameter `*dv->d`
  186.    * If 'dv' or 'rm' is NULL, the respective value is not returned.
  187.    */
  188. > int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
  189.              BN_CTX *ctx)
  190.   {

crypto/bn/bn_div.c:303:10: Call
  301.   
  302.       /* Setup to 'res' */
  303.       if (!bn_wexpand(res, (loop + 1)))
                  ^
  304.           goto err;
  305.       res->neg = (num->neg ^ divisor->neg);

crypto/bn/bn_lib.c:939:1: Parameter `*a->d`
    937.   }
    938.   
    939. > BIGNUM *bn_wexpand(BIGNUM *a, int words)
    940.   {
    941.       return (words <= a->dmax) ? a : bn_expand2(a, words);

crypto/bn/bn_div.c:456:9: Call
  454.            */
  455.           int neg = num->neg;
  456.           BN_rshift(rm, snum, norm_shift);
                 ^
  457.           if (!BN_is_zero(rm))
  458.               rm->neg = neg;

crypto/bn/bn_shift.c:122:1: <Length trace>
120.   }
121.   
122. > int BN_rshift(BIGNUM *r, const BIGNUM *a, int n)
123.   {
124.       int i, j, nw, lb, rb;

crypto/bn/bn_shift.c:122:1: Parameter `*a->d`
    120.   }
    121.   
    122. > int BN_rshift(BIGNUM *r, const BIGNUM *a, int n)
    123.   {
    124.       int i, j, nw, lb, rb;

crypto/bn/bn_shift.c:153:5: Assignment
    151.       }
    152.   
    153.       f = &(a->d[nw]);
               ^
    154.       t = r->d;
    155.       j = a->top - nw;

crypto/bn/bn_shift.c:162:15: Assignment
    160.               *(t++) = *(f++);
    161.       } else {
    162.           l = *(f++);
                         ^
    163.           for (i = j - 1; i != 0; i--) {
    164.               tmp = (l >> rb) & BN_MASK2;

crypto/bn/bn_shift.c:165:17: Array access: Offset: [1, +oo] Size: [0, 8388607] by call to `BN_div` 
    163.           for (i = j - 1; i != 0; i--) {
    164.               tmp = (l >> rb) & BN_MASK2;
    165.               l = *(f++);
                           ^
    166.               *(t++) = (tmp | (l << lb)) & BN_MASK2;
    167.           }

int BN_rshift(BIGNUM *r, const BIGNUM *a, int n)
{
    int i, j, nw, lb, rb;
    BN_ULONG *t, *f;
    BN_ULONG l, tmp;
    bn_check_top(r);
    bn_check_top(a);
    if (n < 0) {
        BNerr(BN_F_BN_RSHIFT, BN_R_INVALID_SHIFT);
        return 0;
    }
    nw = n / BN_BITS2;
    rb = n % BN_BITS2;
    lb = BN_BITS2 - rb;
    if (nw >= a->top || a->top == 0) {
        BN_zero(r);
        return 1;
    }
    i = (BN_num_bits(a) - n + (BN_BITS2 - 1)) / BN_BITS2;
    if (r != a) {
        if (bn_wexpand(r, i) == NULL)
            return 0;
        r->neg = a->neg;
    } else {
        if (n == 0)
            return 1;
    }
    f = &(a->d[nw]);
    t = r->d;
    j = a->top - nw;
    r->top = i;
    if (rb == 0) {
        for (i = j; i != 0; i--)
            *(t++) = *(f++);
    } else {
        l = *(f++);
        for (i = j - 1; i != 0; i--) {
            tmp = (l >> rb) & BN_MASK2;
            l = *(f++);
            *(t++) = (tmp | (l << lb)) & BN_MASK2;
        }
        if ((l = (l >> rb) & BN_MASK2))
            *(t) = l;
    }
    if (!r->top)
        r->neg = 0;
    bn_check_top(r);
    return 1;
}
['static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)\n{\n    BIGNUM *r1, *m1, *vrfy, *r2, *m[RSA_MAX_PRIME_NUM - 2];\n    int ret = 0, i, ex_primes = 0, smooth = 0;\n    RSA_PRIME_INFO *pinfo;\n    BN_CTX_start(ctx);\n    r1 = BN_CTX_get(ctx);\n    r2 = BN_CTX_get(ctx);\n    m1 = BN_CTX_get(ctx);\n    vrfy = BN_CTX_get(ctx);\n    if (vrfy == NULL)\n        goto err;\n    if (rsa->version == RSA_ASN1_VERSION_MULTI\n        && ((ex_primes = sk_RSA_PRIME_INFO_num(rsa->prime_infos)) <= 0\n             || ex_primes > RSA_MAX_PRIME_NUM - 2))\n        goto err;\n    if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) {\n        BIGNUM *factor = BN_new();\n        if (factor == NULL)\n            goto err;\n        if (!(BN_with_flags(factor, rsa->p, BN_FLG_CONSTTIME),\n              BN_MONT_CTX_set_locked(&rsa->_method_mod_p, rsa->lock,\n                                     factor, ctx))\n            || !(BN_with_flags(factor, rsa->q, BN_FLG_CONSTTIME),\n                 BN_MONT_CTX_set_locked(&rsa->_method_mod_q, rsa->lock,\n                                        factor, ctx))) {\n            BN_free(factor);\n            goto err;\n        }\n        for (i = 0; i < ex_primes; i++) {\n            pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i);\n            BN_with_flags(factor, pinfo->r, BN_FLG_CONSTTIME);\n            if (!BN_MONT_CTX_set_locked(&pinfo->m, rsa->lock, factor, ctx)) {\n                BN_free(factor);\n                goto err;\n            }\n        }\n        BN_free(factor);\n        smooth = (ex_primes == 0)\n                 && (rsa->meth->bn_mod_exp == BN_mod_exp_mont)\n                 && (BN_num_bits(rsa->q) == BN_num_bits(rsa->p));\n    }\n    if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)\n        if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, rsa->lock,\n                                    rsa->n, ctx))\n            goto err;\n    if (smooth) {\n        if (\n            !bn_from_mont_fixed_top(m1, I, rsa->_method_mod_q, ctx)\n            || !bn_to_mont_fixed_top(m1, m1, rsa->_method_mod_q, ctx)\n            || !BN_mod_exp_mont_consttime(m1, m1, rsa->dmq1, rsa->q, ctx,\n                                          rsa->_method_mod_q)\n            || !bn_from_mont_fixed_top(r1, I, rsa->_method_mod_p, ctx)\n            || !bn_to_mont_fixed_top(r1, r1, rsa->_method_mod_p, ctx)\n            || !BN_mod_exp_mont_consttime(r1, r1, rsa->dmp1, rsa->p, ctx,\n                                          rsa->_method_mod_p)\n            || !bn_mod_sub_fixed_top(r1, r1, m1, rsa->p)\n            || !bn_to_mont_fixed_top(r1, r1, rsa->_method_mod_p, ctx)\n            || !bn_mul_mont_fixed_top(r1, r1, rsa->iqmp, rsa->_method_mod_p,\n                                      ctx)\n            || !bn_mul_fixed_top(r0, r1, rsa->q, ctx)\n            || !bn_mod_add_fixed_top(r0, r0, m1, rsa->n))\n            goto err;\n        goto tail;\n    }\n    {\n        BIGNUM *c = BN_new();\n        if (c == NULL)\n            goto err;\n        BN_with_flags(c, I, BN_FLG_CONSTTIME);\n        if (!BN_mod(r1, c, rsa->q, ctx)) {\n            BN_free(c);\n            goto err;\n        }\n        {\n            BIGNUM *dmq1 = BN_new();\n            if (dmq1 == NULL) {\n                BN_free(c);\n                goto err;\n            }\n            BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);\n            if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx,\n                                       rsa->_method_mod_q)) {\n                BN_free(c);\n                BN_free(dmq1);\n                goto err;\n            }\n            BN_free(dmq1);\n        }\n        if (!BN_mod(r1, c, rsa->p, ctx)) {\n            BN_free(c);\n            goto err;\n        }\n        BN_free(c);\n    }\n    {\n        BIGNUM *dmp1 = BN_new();\n        if (dmp1 == NULL)\n            goto err;\n        BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);\n        if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx,\n                                   rsa->_method_mod_p)) {\n            BN_free(dmp1);\n            goto err;\n        }\n        BN_free(dmp1);\n    }\n    if (ex_primes > 0) {\n        BIGNUM *di = BN_new(), *cc = BN_new();\n        if (cc == NULL || di == NULL) {\n            BN_free(cc);\n            BN_free(di);\n            goto err;\n        }\n        for (i = 0; i < ex_primes; i++) {\n            if ((m[i] = BN_CTX_get(ctx)) == NULL) {\n                BN_free(cc);\n                BN_free(di);\n                goto err;\n            }\n            pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i);\n            BN_with_flags(cc, I, BN_FLG_CONSTTIME);\n            BN_with_flags(di, pinfo->d, BN_FLG_CONSTTIME);\n            if (!BN_mod(r1, cc, pinfo->r, ctx)) {\n                BN_free(cc);\n                BN_free(di);\n                goto err;\n            }\n            if (!rsa->meth->bn_mod_exp(m[i], r1, di, pinfo->r, ctx, pinfo->m)) {\n                BN_free(cc);\n                BN_free(di);\n                goto err;\n            }\n        }\n        BN_free(cc);\n        BN_free(di);\n    }\n    if (!BN_sub(r0, r0, m1))\n        goto err;\n    if (BN_is_negative(r0))\n        if (!BN_add(r0, r0, rsa->p))\n            goto err;\n    if (!BN_mul(r1, r0, rsa->iqmp, ctx))\n        goto err;\n    {\n        BIGNUM *pr1 = BN_new();\n        if (pr1 == NULL)\n            goto err;\n        BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);\n        if (!BN_mod(r0, pr1, rsa->p, ctx)) {\n            BN_free(pr1);\n            goto err;\n        }\n        BN_free(pr1);\n    }\n    if (BN_is_negative(r0))\n        if (!BN_add(r0, r0, rsa->p))\n            goto err;\n    if (!BN_mul(r1, r0, rsa->q, ctx))\n        goto err;\n    if (!BN_add(r0, r1, m1))\n        goto err;\n    if (ex_primes > 0) {\n        BIGNUM *pr2 = BN_new();\n        if (pr2 == NULL)\n            goto err;\n        for (i = 0; i < ex_primes; i++) {\n            pinfo = sk_RSA_PRIME_INFO_value(rsa->prime_infos, i);\n            if (!BN_sub(r1, m[i], r0)) {\n                BN_free(pr2);\n                goto err;\n            }\n            if (!BN_mul(r2, r1, pinfo->t, ctx)) {\n                BN_free(pr2);\n                goto err;\n            }\n            BN_with_flags(pr2, r2, BN_FLG_CONSTTIME);\n            if (!BN_mod(r1, pr2, pinfo->r, ctx)) {\n                BN_free(pr2);\n                goto err;\n            }\n            if (BN_is_negative(r1))\n                if (!BN_add(r1, r1, pinfo->r)) {\n                    BN_free(pr2);\n                    goto err;\n                }\n            if (!BN_mul(r1, r1, pinfo->pp, ctx)) {\n                BN_free(pr2);\n                goto err;\n            }\n            if (!BN_add(r0, r0, r1)) {\n                BN_free(pr2);\n                goto err;\n            }\n        }\n        BN_free(pr2);\n    }\n tail:\n    if (rsa->e && rsa->n) {\n        if (rsa->meth->bn_mod_exp == BN_mod_exp_mont) {\n            if (!BN_mod_exp_mont(vrfy, r0, rsa->e, rsa->n, ctx,\n                                 rsa->_method_mod_n))\n                goto err;\n        } else {\n            bn_correct_top(r0);\n            if (!rsa->meth->bn_mod_exp(vrfy, r0, rsa->e, rsa->n, ctx,\n                                       rsa->_method_mod_n))\n                goto err;\n        }\n        if (!BN_sub(vrfy, vrfy, I))\n            goto err;\n        if (BN_is_zero(vrfy)) {\n            bn_correct_top(r0);\n            ret = 1;\n            goto err;\n        }\n        if (!BN_mod(vrfy, vrfy, rsa->n, ctx))\n            goto err;\n        if (BN_is_negative(vrfy))\n            if (!BN_add(vrfy, vrfy, rsa->n))\n                goto err;\n        if (!BN_is_zero(vrfy)) {\n            BIGNUM *d = BN_new();\n            if (d == NULL)\n                goto err;\n            BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);\n            if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx,\n                                       rsa->_method_mod_n)) {\n                BN_free(d);\n                goto err;\n            }\n            BN_free(d);\n        }\n    }\n    bn_correct_top(r0);\n    ret = 1;\n err:\n    BN_CTX_end(ctx);\n    return ret;\n}', 'int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,\n           BN_CTX *ctx)\n{\n    int norm_shift, i, j, loop;\n    BIGNUM *tmp, wnum, *snum, *sdiv, *res;\n    BN_ULONG *resp, *wnump;\n    BN_ULONG d0, d1;\n    int num_n, div_n;\n    int no_branch = 0;\n    if ((num->top > 0 && num->d[num->top - 1] == 0) ||\n        (divisor->top > 0 && divisor->d[divisor->top - 1] == 0)) {\n        BNerr(BN_F_BN_DIV, BN_R_NOT_INITIALIZED);\n        return 0;\n    }\n    bn_check_top(num);\n    bn_check_top(divisor);\n    if ((BN_get_flags(num, BN_FLG_CONSTTIME) != 0)\n        || (BN_get_flags(divisor, BN_FLG_CONSTTIME) != 0)) {\n        no_branch = 1;\n    }\n    bn_check_top(dv);\n    bn_check_top(rm);\n    if (BN_is_zero(divisor)) {\n        BNerr(BN_F_BN_DIV, BN_R_DIV_BY_ZERO);\n        return 0;\n    }\n    if (!no_branch && BN_ucmp(num, divisor) < 0) {\n        if (rm != NULL) {\n            if (BN_copy(rm, num) == NULL)\n                return 0;\n        }\n        if (dv != NULL)\n            BN_zero(dv);\n        return 1;\n    }\n    BN_CTX_start(ctx);\n    res = (dv == NULL) ? BN_CTX_get(ctx) : dv;\n    tmp = BN_CTX_get(ctx);\n    snum = BN_CTX_get(ctx);\n    sdiv = BN_CTX_get(ctx);\n    if (sdiv == NULL)\n        goto err;\n    norm_shift = BN_BITS2 - ((BN_num_bits(divisor)) % BN_BITS2);\n    if (!(BN_lshift(sdiv, divisor, norm_shift)))\n        goto err;\n    sdiv->neg = 0;\n    norm_shift += BN_BITS2;\n    if (!(BN_lshift(snum, num, norm_shift)))\n        goto err;\n    snum->neg = 0;\n    if (no_branch) {\n        if (snum->top <= sdiv->top + 1) {\n            if (bn_wexpand(snum, sdiv->top + 2) == NULL)\n                goto err;\n            for (i = snum->top; i < sdiv->top + 2; i++)\n                snum->d[i] = 0;\n            snum->top = sdiv->top + 2;\n        } else {\n            if (bn_wexpand(snum, snum->top + 1) == NULL)\n                goto err;\n            snum->d[snum->top] = 0;\n            snum->top++;\n        }\n    }\n    div_n = sdiv->top;\n    num_n = snum->top;\n    loop = num_n - div_n;\n    wnum.neg = 0;\n    wnum.d = &(snum->d[loop]);\n    wnum.top = div_n;\n    wnum.flags = BN_FLG_STATIC_DATA;\n    wnum.dmax = snum->dmax - loop;\n    d0 = sdiv->d[div_n - 1];\n    d1 = (div_n == 1) ? 0 : sdiv->d[div_n - 2];\n    wnump = &(snum->d[num_n - 1]);\n    if (!bn_wexpand(res, (loop + 1)))\n        goto err;\n    res->neg = (num->neg ^ divisor->neg);\n    res->top = loop - no_branch;\n    resp = &(res->d[loop - 1]);\n    if (!bn_wexpand(tmp, (div_n + 1)))\n        goto err;\n    if (!no_branch) {\n        if (BN_ucmp(&wnum, sdiv) >= 0) {\n            bn_clear_top2max(&wnum);\n            bn_sub_words(wnum.d, wnum.d, sdiv->d, div_n);\n            *resp = 1;\n        } else\n            res->top--;\n    }\n    resp++;\n    if (res->top == 0)\n        res->neg = 0;\n    else\n        resp--;\n    for (i = 0; i < loop - 1; i++, wnump--) {\n        BN_ULONG q, l0;\n# if defined(BN_DIV3W)\n        q = bn_div_3_words(wnump, d1, d0);\n# else\n        BN_ULONG n0, n1, rem = 0;\n        n0 = wnump[0];\n        n1 = wnump[-1];\n        if (n0 == d0)\n            q = BN_MASK2;\n        else {\n#  ifdef BN_LLONG\n            BN_ULLONG t2;\n#   if defined(BN_LLONG) && defined(BN_DIV2W) && !defined(bn_div_words)\n            q = (BN_ULONG)(((((BN_ULLONG) n0) << BN_BITS2) | n1) / d0);\n#   else\n            q = bn_div_words(n0, n1, d0);\n#   endif\n#   ifndef REMAINDER_IS_ALREADY_CALCULATED\n            rem = (n1 - q * d0) & BN_MASK2;\n#   endif\n            t2 = (BN_ULLONG) d1 *q;\n            for (;;) {\n                if (t2 <= ((((BN_ULLONG) rem) << BN_BITS2) | wnump[-2]))\n                    break;\n                q--;\n                rem += d0;\n                if (rem < d0)\n                    break;\n                t2 -= d1;\n            }\n#  else\n            BN_ULONG t2l, t2h;\n            q = bn_div_words(n0, n1, d0);\n#   ifndef REMAINDER_IS_ALREADY_CALCULATED\n            rem = (n1 - q * d0) & BN_MASK2;\n#   endif\n#   if defined(BN_UMULT_LOHI)\n            BN_UMULT_LOHI(t2l, t2h, d1, q);\n#   elif defined(BN_UMULT_HIGH)\n            t2l = d1 * q;\n            t2h = BN_UMULT_HIGH(d1, q);\n#   else\n            {\n                BN_ULONG ql, qh;\n                t2l = LBITS(d1);\n                t2h = HBITS(d1);\n                ql = LBITS(q);\n                qh = HBITS(q);\n                mul64(t2l, t2h, ql, qh);\n            }\n#   endif\n            for (;;) {\n                if ((t2h < rem) || ((t2h == rem) && (t2l <= wnump[-2])))\n                    break;\n                q--;\n                rem += d0;\n                if (rem < d0)\n                    break;\n                if (t2l < d1)\n                    t2h--;\n                t2l -= d1;\n            }\n#  endif\n        }\n# endif\n        l0 = bn_mul_words(tmp->d, sdiv->d, div_n, q);\n        tmp->d[div_n] = l0;\n        wnum.d--;\n        l0 = bn_sub_words(wnum.d, wnum.d, tmp->d, div_n + 1);\n        q -= l0;\n        for (l0 = 0 - l0, j = 0; j < div_n; j++)\n            tmp->d[j] = sdiv->d[j] & l0;\n        l0 = bn_add_words(wnum.d, wnum.d, tmp->d, div_n);\n        (*wnump) += l0;\n        resp--;\n        *resp = q;\n    }\n    bn_correct_top(snum);\n    if (rm != NULL) {\n        int neg = num->neg;\n        BN_rshift(rm, snum, norm_shift);\n        if (!BN_is_zero(rm))\n            rm->neg = neg;\n        bn_check_top(rm);\n    }\n    if (no_branch)\n        bn_correct_top(res);\n    BN_CTX_end(ctx);\n    return 1;\n err:\n    bn_check_top(rm);\n    BN_CTX_end(ctx);\n    return 0;\n}', 'BIGNUM *bn_wexpand(BIGNUM *a, int words)\n{\n    return (words <= a->dmax) ? a : bn_expand2(a, words);\n}', 'void BN_with_flags(BIGNUM *dest, const BIGNUM *b, int flags)\n{\n    dest->d = b->d;\n    dest->top = b->top;\n    dest->dmax = b->dmax;\n    dest->neg = b->neg;\n    dest->flags = ((dest->flags & BN_FLG_MALLOCED)\n                   | (b->flags & ~BN_FLG_MALLOCED)\n                   | BN_FLG_STATIC_DATA | flags);\n}', 'int BN_rshift(BIGNUM *r, const BIGNUM *a, int n)\n{\n    int i, j, nw, lb, rb;\n    BN_ULONG *t, *f;\n    BN_ULONG l, tmp;\n    bn_check_top(r);\n    bn_check_top(a);\n    if (n < 0) {\n        BNerr(BN_F_BN_RSHIFT, BN_R_INVALID_SHIFT);\n        return 0;\n    }\n    nw = n / BN_BITS2;\n    rb = n % BN_BITS2;\n    lb = BN_BITS2 - rb;\n    if (nw >= a->top || a->top == 0) {\n        BN_zero(r);\n        return 1;\n    }\n    i = (BN_num_bits(a) - n + (BN_BITS2 - 1)) / BN_BITS2;\n    if (r != a) {\n        if (bn_wexpand(r, i) == NULL)\n            return 0;\n        r->neg = a->neg;\n    } else {\n        if (n == 0)\n            return 1;\n    }\n    f = &(a->d[nw]);\n    t = r->d;\n    j = a->top - nw;\n    r->top = i;\n    if (rb == 0) {\n        for (i = j; i != 0; i--)\n            *(t++) = *(f++);\n    } else {\n        l = *(f++);\n        for (i = j - 1; i != 0; i--) {\n            tmp = (l >> rb) & BN_MASK2;\n            l = *(f++);\n            *(t++) = (tmp | (l << lb)) & BN_MASK2;\n        }\n        if ((l = (l >> rb) & BN_MASK2))\n            *(t) = l;\n    }\n    if (!r->top)\n        r->neg = 0;\n    bn_check_top(r);\n    return 1;\n}']