crypto/rsa/rsa_ossl.c:885: error: BUFFER_OVERRUN_L3
  Offset added: [8, +oo] Size: [0, 536870848] by call to `BN_sub`.
Showing all 16 steps of the trace


crypto/rsa/rsa_ossl.c:691:14: Call
689.           BN_with_flags(c, I, BN_FLG_CONSTTIME);
690.   
691.           if (!BN_mod(r1, c, rsa->q, ctx)) {
                    ^
692.               BN_free(c);
693.               goto err;

crypto/bn/bn_div.c:137:1: Parameter `rm->top`
  135.    * If 'dv' or 'rm' is NULL, the respective value is not returned.
  136.    */
  137. > int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
  138.              BN_CTX *ctx)
  139.   {

crypto/rsa/rsa_ossl.c:885:14: Call
883.            * absolute equality, just congruency.
884.            */
885.           if (!BN_sub(vrfy, vrfy, I))
                    ^
886.               goto err;
887.           if (!BN_mod(vrfy, vrfy, rsa->n, ctx))

crypto/bn/bn_add.c:45:1: Parameter `*r->d`
  43.   
  44.   /* signed sub of b from a. */
  45. > int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
  46.   {
  47.       int ret, r_neg, cmp_res;

crypto/bn/bn_add.c:62:19: Call
  60.           } else if (cmp_res < 0) {
  61.               r_neg = !b->neg;
  62.               ret = BN_usub(r, b, a);
                          ^
  63.           } else {
  64.               r_neg = 0;

crypto/bn/bn_add.c:125:1: Parameter `*r->d`
    123.   
    124.   /* unsigned subtraction of b from a, a must be larger than b. */
    125. > int BN_usub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
    126.   {
    127.       int max, min, dif;

crypto/bn/bn_add.c:143:9: Call
    141.       }
    142.   
    143.       if (bn_wexpand(r, max) == NULL)
                   ^
    144.           return 0;
    145.   

crypto/bn/bn_lib.c:942:1: Parameter `*a->d`
      940.   }
      941.   
      942. > BIGNUM *bn_wexpand(BIGNUM *a, int words)
      943.   {
      944.       return (words <= a->dmax) ? a : bn_expand2(a, words);

crypto/bn/bn_lib.c:944:37: Call
      942.   BIGNUM *bn_wexpand(BIGNUM *a, int words)
      943.   {
      944.       return (words <= a->dmax) ? a : bn_expand2(a, words);
                                                 ^
      945.   }
      946.   

crypto/bn/bn_lib.c:244:1: Parameter `*b->d`
        242.    */
        243.   
        244. > BIGNUM *bn_expand2(BIGNUM *b, int words)
        245.   {
        246.       if (words > b->dmax) {

crypto/bn/bn_lib.c:247:23: Call
        245.   {
        246.       if (words > b->dmax) {
        247.           BN_ULONG *a = bn_expand_internal(b, words);
                                     ^
        248.           if (!a)
        249.               return NULL;

crypto/bn/bn_lib.c:208:1: <Offset trace>
206.   /* This is used by bn_expand2() */
207.   /* The caller MUST check that words > b->dmax before calling this */
208. > static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
209.   {
210.       BN_ULONG *a = NULL;

crypto/bn/bn_lib.c:208:1: Parameter `b->top`
          206.   /* This is used by bn_expand2() */
          207.   /* The caller MUST check that words > b->dmax before calling this */
          208. > static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
          209.   {
          210.       BN_ULONG *a = NULL;

crypto/bn/bn_lib.c:208:1: <Length trace>
206.   /* This is used by bn_expand2() */
207.   /* The caller MUST check that words > b->dmax before calling this */
208. > static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
209.   {
210.       BN_ULONG *a = NULL;

crypto/bn/bn_lib.c:208:1: Parameter `*b->d`
          206.   /* This is used by bn_expand2() */
          207.   /* The caller MUST check that words > b->dmax before calling this */
          208. > static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
          209.   {
          210.       BN_ULONG *a = NULL;

crypto/bn/bn_lib.c:231:9: Array access: Offset added: [8, +oo] Size: [0, 536870848] by call to `BN_sub` 
          229.       assert(b->top <= words);
          230.       if (b->top > 0)
          231.           memcpy(a, b->d, sizeof(*a) * b->top);
                         ^
          232.   
          233.       return a;

static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
{
    BN_ULONG *a = NULL;
    if (words > (INT_MAX / (4 * BN_BITS2))) {
        BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_BIGNUM_TOO_LONG);
        return NULL;
    }
    if (BN_get_flags(b, BN_FLG_STATIC_DATA)) {
        BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_EXPAND_ON_STATIC_BIGNUM_DATA);
        return NULL;
    }
    if (BN_get_flags(b, BN_FLG_SECURE))
        a = OPENSSL_secure_zalloc(words * sizeof(*a));
    else
        a = OPENSSL_zalloc(words * sizeof(*a));
    if (a == NULL) {
        BNerr(BN_F_BN_EXPAND_INTERNAL, ERR_R_MALLOC_FAILURE);
        return NULL;
    }
    assert(b->top <= words);
    if (b->top > 0)
        memcpy(a, b->d, sizeof(*a) * b->top);
    return a;
}
['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;\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    {\n        BIGNUM *p = BN_new(), *q = BN_new();\n        if (p == NULL || q == NULL) {\n            BN_free(p);\n            BN_free(q);\n            goto err;\n        }\n        BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);\n        BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);\n        if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) {\n            if (!BN_MONT_CTX_set_locked\n                (&rsa->_method_mod_p, rsa->lock, p, ctx)\n                || !BN_MONT_CTX_set_locked(&rsa->_method_mod_q,\n                                           rsa->lock, q, ctx)) {\n                BN_free(p);\n                BN_free(q);\n                goto err;\n            }\n            if (ex_primes > 0) {\n                BIGNUM *r = BN_new();\n                if (r == NULL) {\n                    BN_free(p);\n                    BN_free(q);\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(r, pinfo->r, BN_FLG_CONSTTIME);\n                    if (!BN_MONT_CTX_set_locked(&pinfo->m, rsa->lock, r, ctx)) {\n                        BN_free(p);\n                        BN_free(q);\n                        BN_free(r);\n                        goto err;\n                    }\n                }\n                BN_free(r);\n            }\n        }\n        BN_free(p);\n        BN_free(q);\n    }\n    if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)\n        if (!BN_MONT_CTX_set_locked\n            (&rsa->_method_mod_n, rsa->lock, rsa->n, ctx))\n            goto err;\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    if (rsa->e && rsa->n) {\n        if (!rsa->meth->bn_mod_exp(vrfy, r0, rsa->e, rsa->n, ctx,\n                                   rsa->_method_mod_n))\n            goto err;\n        if (!BN_sub(vrfy, vrfy, I))\n            goto err;\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    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, 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) && !defined(OPENSSL_NO_ASM)\n        BN_ULONG bn_div_3_words(BN_ULONG *, BN_ULONG, BN_ULONG);\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        if (bn_sub_words(wnum.d, wnum.d, tmp->d, div_n + 1)) {\n            q--;\n            if (bn_add_words(wnum.d, wnum.d, sdiv->d, div_n))\n                (*wnump)++;\n        }\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}', 'int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)\n{\n    int ret, r_neg, cmp_res;\n    bn_check_top(a);\n    bn_check_top(b);\n    if (a->neg != b->neg) {\n        r_neg = a->neg;\n        ret = BN_uadd(r, a, b);\n    } else {\n        cmp_res = BN_ucmp(a, b);\n        if (cmp_res > 0) {\n            r_neg = a->neg;\n            ret = BN_usub(r, a, b);\n        } else if (cmp_res < 0) {\n            r_neg = !b->neg;\n            ret = BN_usub(r, b, a);\n        } else {\n            r_neg = 0;\n            BN_zero(r);\n            ret = 1;\n        }\n    }\n    r->neg = r_neg;\n    bn_check_top(r);\n    return ret;\n}', 'int BN_usub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)\n{\n    int max, min, dif;\n    BN_ULONG t1, t2, borrow, *rp;\n    const BN_ULONG *ap, *bp;\n    bn_check_top(a);\n    bn_check_top(b);\n    max = a->top;\n    min = b->top;\n    dif = max - min;\n    if (dif < 0) {\n        BNerr(BN_F_BN_USUB, BN_R_ARG2_LT_ARG3);\n        return 0;\n    }\n    if (bn_wexpand(r, max) == NULL)\n        return 0;\n    ap = a->d;\n    bp = b->d;\n    rp = r->d;\n    borrow = bn_sub_words(rp, ap, bp, min);\n    ap += min;\n    rp += min;\n    while (dif) {\n        dif--;\n        t1 = *(ap++);\n        t2 = (t1 - borrow) & BN_MASK2;\n        *(rp++) = t2;\n        borrow &= (t1 == 0);\n    }\n    while (max && *--rp == 0)\n        max--;\n    r->top = max;\n    r->neg = 0;\n    bn_pollute(r);\n    return 1;\n}', 'BIGNUM *bn_wexpand(BIGNUM *a, int words)\n{\n    return (words <= a->dmax) ? a : bn_expand2(a, words);\n}', 'BIGNUM *bn_expand2(BIGNUM *b, int words)\n{\n    if (words > b->dmax) {\n        BN_ULONG *a = bn_expand_internal(b, words);\n        if (!a)\n            return NULL;\n        if (b->d) {\n            OPENSSL_cleanse(b->d, b->dmax * sizeof(b->d[0]));\n            bn_free_d(b);\n        }\n        b->d = a;\n        b->dmax = words;\n    }\n    return b;\n}', 'static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)\n{\n    BN_ULONG *a = NULL;\n    if (words > (INT_MAX / (4 * BN_BITS2))) {\n        BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_BIGNUM_TOO_LONG);\n        return NULL;\n    }\n    if (BN_get_flags(b, BN_FLG_STATIC_DATA)) {\n        BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_EXPAND_ON_STATIC_BIGNUM_DATA);\n        return NULL;\n    }\n    if (BN_get_flags(b, BN_FLG_SECURE))\n        a = OPENSSL_secure_zalloc(words * sizeof(*a));\n    else\n        a = OPENSSL_zalloc(words * sizeof(*a));\n    if (a == NULL) {\n        BNerr(BN_F_BN_EXPAND_INTERNAL, ERR_R_MALLOC_FAILURE);\n        return NULL;\n    }\n    assert(b->top <= words);\n    if (b->top > 0)\n        memcpy(a, b->d, sizeof(*a) * b->top);\n    return a;\n}']