crypto/dsa/dsa_gen.c:528: error: BUFFER_OVERRUN_L3
  Offset: [1, +oo] Size: [0, 8388607] by call to `BN_div`.
Showing all 16 steps of the trace


crypto/dsa/dsa_gen.c:457:17: Call
455.   
456.               /* step 4 */
457.               r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx,
                       ^
458.                                           seed_in ? 1 : 0, cb);
459.               if (r > 0)

crypto/bn/bn_prime.c:387:13: Call
  385.           /* now 1 <= check < A */
  386.   
  387.           j = witness(check, A, A1, A1_odd, k, ctx, mont);
                     ^
  388.           if (j == -1)
  389.               goto err;

crypto/bn/bn_prime.c:482:10: Call
    480.                      BN_MONT_CTX *mont)
    481.   {
    482.       if (!BN_mod_exp_mont(w, w, a1_odd, a, ctx, mont)) /* w := w^a1_odd mod a */
                    ^
    483.           return -1;
    484.       if (BN_is_one(w))

crypto/bn/bn_exp.c:457:14: Call
      455.   
      456.       if (a->neg || BN_ucmp(a, m) >= 0) {
      457.           if (!BN_nnmod(val[0], a, m, ctx))
                          ^
      458.               goto err;
      459.           aa = val[0];

crypto/bn/bn_mod.c:126:11: Call
        124.        */
        125.   
        126.       if (!(BN_mod(r, m, d, ctx)))
                         ^
        127.           return 0;
        128.       if (!r->neg)

crypto/bn/bn_div.c:189:1: Parameter `*dv->d`
          187.    * If 'dv' or 'rm' is NULL, the respective value is not returned.
          188.    */
          189. > int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
          190.              BN_CTX *ctx)
          191.   {

crypto/dsa/dsa_gen.c:528:18: Call
526.               if (!BN_lshift1(r0, q))
527.                   goto err;
528.               if (!BN_mod(c, X, r0, ctx))
                        ^
529.                   goto err;
530.               if (!BN_sub(r0, c, BN_value_one()))

crypto/bn/bn_div.c:243:11: Call
  241.   
  242.       BN_CTX_start(ctx);
  243.       tmp = BN_CTX_get(ctx);
                   ^
  244.       snum = BN_CTX_get(ctx);
  245.       sdiv = BN_CTX_get(ctx);

crypto/bn/bn_ctx.c:284:5: Call
    282.       }
    283.       /* OK, make sure the returned bignum is "zero" */
    284.       BN_zero(ret);
               ^
    285.       ctx->used++;
    286.       CTXDBG_RET(ctx, ret);

crypto/bn/bn_lib.c:530:1: Parameter `*a->d`
      528.   }
      529.   
      530. > int BN_set_word(BIGNUM *a, BN_ULONG w)
      531.   {
      532.       bn_check_top(a);

crypto/bn/bn_div.c:462:9: Call
  460.            */
  461.           int neg = num->neg;
  462.           BN_rshift(rm, snum, norm_shift);
                 ^
  463.           if (!BN_is_zero(rm))
  464.               rm->neg = neg;

crypto/bn/bn_shift.c:169:1: <Length trace>
167.   }
168.   
169. > int BN_rshift(BIGNUM *r, const BIGNUM *a, int n)
170.   {
171.       int i, j, nw, lb, rb;

crypto/bn/bn_shift.c:169:1: Parameter `*a->d`
    167.   }
    168.   
    169. > int BN_rshift(BIGNUM *r, const BIGNUM *a, int n)
    170.   {
    171.       int i, j, nw, lb, rb;

crypto/bn/bn_shift.c:200:5: Assignment
    198.       }
    199.   
    200.       f = &(a->d[nw]);
               ^
    201.       t = r->d;
    202.       j = a->top - nw;

crypto/bn/bn_shift.c:209:15: Assignment
    207.               *(t++) = *(f++);
    208.       } else {
    209.           l = *(f++);
                         ^
    210.           for (i = j - 1; i != 0; i--) {
    211.               tmp = (l >> rb) & BN_MASK2;

crypto/bn/bn_shift.c:212:17: Array access: Offset: [1, +oo] Size: [0, 8388607] by call to `BN_div` 
    210.           for (i = j - 1; i != 0; i--) {
    211.               tmp = (l >> rb) & BN_MASK2;
    212.               l = *(f++);
                           ^
    213.               *(t++) = (tmp | (l << lb)) & BN_MASK2;
    214.           }

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) {
        r->neg = a->neg;
        if (bn_wexpand(r, i) == NULL)
            return (0);
    } 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;
    }
    bn_check_top(r);
    return (1);
}
['int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,\n                          const EVP_MD *evpmd, const unsigned char *seed_in,\n                          size_t seed_len, int idx, unsigned char *seed_out,\n                          int *counter_ret, unsigned long *h_ret,\n                          BN_GENCB *cb)\n{\n    int ok = -1;\n    unsigned char *seed = NULL, *seed_tmp = NULL;\n    unsigned char md[EVP_MAX_MD_SIZE];\n    int mdsize;\n    BIGNUM *r0, *W, *X, *c, *test;\n    BIGNUM *g = NULL, *q = NULL, *p = NULL;\n    BN_MONT_CTX *mont = NULL;\n    int i, k, n = 0, m = 0, qsize = N >> 3;\n    int counter = 0;\n    int r = 0;\n    BN_CTX *ctx = NULL;\n    EVP_MD_CTX *mctx = EVP_MD_CTX_new();\n    unsigned int h = 2;\n    if (mctx == NULL)\n        goto err;\n    if (evpmd == NULL) {\n        if (N == 160)\n            evpmd = EVP_sha1();\n        else if (N == 224)\n            evpmd = EVP_sha224();\n        else\n            evpmd = EVP_sha256();\n    }\n    mdsize = EVP_MD_size(evpmd);\n    if (!ret->p || !ret->q || idx >= 0) {\n        if (seed_len == 0)\n            seed_len = mdsize;\n        seed = OPENSSL_malloc(seed_len);\n        if (seed_out)\n            seed_tmp = seed_out;\n        else\n            seed_tmp = OPENSSL_malloc(seed_len);\n        if (seed == NULL || seed_tmp == NULL)\n            goto err;\n        if (seed_in)\n            memcpy(seed, seed_in, seed_len);\n    }\n    if ((ctx = BN_CTX_new()) == NULL)\n        goto err;\n    if ((mont = BN_MONT_CTX_new()) == NULL)\n        goto err;\n    BN_CTX_start(ctx);\n    r0 = BN_CTX_get(ctx);\n    g = BN_CTX_get(ctx);\n    W = BN_CTX_get(ctx);\n    X = BN_CTX_get(ctx);\n    c = BN_CTX_get(ctx);\n    test = BN_CTX_get(ctx);\n    if (ret->p && ret->q) {\n        p = ret->p;\n        q = ret->q;\n        if (idx >= 0)\n            memcpy(seed_tmp, seed, seed_len);\n        goto g_only;\n    } else {\n        p = BN_CTX_get(ctx);\n        q = BN_CTX_get(ctx);\n    }\n    if (!BN_lshift(test, BN_value_one(), L - 1))\n        goto err;\n    for (;;) {\n        for (;;) {\n            unsigned char *pmd;\n            if (!BN_GENCB_call(cb, 0, m++))\n                goto err;\n            if (!seed_in) {\n                if (RAND_bytes(seed, seed_len) <= 0)\n                    goto err;\n            }\n            if (!EVP_Digest(seed, seed_len, md, NULL, evpmd, NULL))\n                goto err;\n            if (mdsize > qsize)\n                pmd = md + mdsize - qsize;\n            else\n                pmd = md;\n            if (mdsize < qsize)\n                memset(md + mdsize, 0, qsize - mdsize);\n            pmd[0] |= 0x80;\n            pmd[qsize - 1] |= 0x01;\n            if (!BN_bin2bn(pmd, qsize, q))\n                goto err;\n            r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx,\n                                        seed_in ? 1 : 0, cb);\n            if (r > 0)\n                break;\n            if (r != 0)\n                goto err;\n            if (seed_in) {\n                ok = 0;\n                DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_Q_NOT_PRIME);\n                goto err;\n            }\n        }\n        if (seed_out)\n            memcpy(seed_out, seed, seed_len);\n        if (!BN_GENCB_call(cb, 2, 0))\n            goto err;\n        if (!BN_GENCB_call(cb, 3, 0))\n            goto err;\n        counter = 0;\n        n = (L - 1) / (mdsize << 3);\n        for (;;) {\n            if ((counter != 0) && !BN_GENCB_call(cb, 0, counter))\n                goto err;\n            BN_zero(W);\n            for (k = 0; k <= n; k++) {\n                for (i = seed_len - 1; i >= 0; i--) {\n                    seed[i]++;\n                    if (seed[i] != 0)\n                        break;\n                }\n                if (!EVP_Digest(seed, seed_len, md, NULL, evpmd, NULL))\n                    goto err;\n                if (!BN_bin2bn(md, mdsize, r0))\n                    goto err;\n                if (!BN_lshift(r0, r0, (mdsize << 3) * k))\n                    goto err;\n                if (!BN_add(W, W, r0))\n                    goto err;\n            }\n            if (!BN_mask_bits(W, L - 1))\n                goto err;\n            if (!BN_copy(X, W))\n                goto err;\n            if (!BN_add(X, X, test))\n                goto err;\n            if (!BN_lshift1(r0, q))\n                goto err;\n            if (!BN_mod(c, X, r0, ctx))\n                goto err;\n            if (!BN_sub(r0, c, BN_value_one()))\n                goto err;\n            if (!BN_sub(p, X, r0))\n                goto err;\n            if (BN_cmp(p, test) >= 0) {\n                r = BN_is_prime_fasttest_ex(p, DSS_prime_checks, ctx, 1, cb);\n                if (r > 0)\n                    goto end;\n                if (r != 0)\n                    goto err;\n            }\n            counter++;\n            if (counter >= (int)(4 * L))\n                break;\n        }\n        if (seed_in) {\n            ok = 0;\n            DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_INVALID_PARAMETERS);\n            goto err;\n        }\n    }\n end:\n    if (!BN_GENCB_call(cb, 2, 1))\n        goto err;\n g_only:\n    if (!BN_sub(test, p, BN_value_one()))\n        goto err;\n    if (!BN_div(r0, NULL, test, q, ctx))\n        goto err;\n    if (idx < 0) {\n        if (!BN_set_word(test, h))\n            goto err;\n    } else\n        h = 1;\n    if (!BN_MONT_CTX_set(mont, p, ctx))\n        goto err;\n    for (;;) {\n        static const unsigned char ggen[4] = { 0x67, 0x67, 0x65, 0x6e };\n        if (idx >= 0) {\n            md[0] = idx & 0xff;\n            md[1] = (h >> 8) & 0xff;\n            md[2] = h & 0xff;\n            if (!EVP_DigestInit_ex(mctx, evpmd, NULL))\n                goto err;\n            if (!EVP_DigestUpdate(mctx, seed_tmp, seed_len))\n                goto err;\n            if (!EVP_DigestUpdate(mctx, ggen, sizeof(ggen)))\n                goto err;\n            if (!EVP_DigestUpdate(mctx, md, 3))\n                goto err;\n            if (!EVP_DigestFinal_ex(mctx, md, NULL))\n                goto err;\n            if (!BN_bin2bn(md, mdsize, test))\n                goto err;\n        }\n        if (!BN_mod_exp_mont(g, test, r0, p, ctx, mont))\n            goto err;\n        if (!BN_is_one(g))\n            break;\n        if (idx < 0 && !BN_add(test, test, BN_value_one()))\n            goto err;\n        h++;\n        if (idx >= 0 && h > 0xffff)\n            goto err;\n    }\n    if (!BN_GENCB_call(cb, 3, 1))\n        goto err;\n    ok = 1;\n err:\n    if (ok == 1) {\n        if (p != ret->p) {\n            BN_free(ret->p);\n            ret->p = BN_dup(p);\n        }\n        if (q != ret->q) {\n            BN_free(ret->q);\n            ret->q = BN_dup(q);\n        }\n        BN_free(ret->g);\n        ret->g = BN_dup(g);\n        if (ret->p == NULL || ret->q == NULL || ret->g == NULL) {\n            ok = -1;\n            goto err;\n        }\n        if (counter_ret != NULL)\n            *counter_ret = counter;\n        if (h_ret != NULL)\n            *h_ret = h;\n    }\n    OPENSSL_free(seed);\n    if (seed_out != seed_tmp)\n        OPENSSL_free(seed_tmp);\n    if (ctx)\n        BN_CTX_end(ctx);\n    BN_CTX_free(ctx);\n    BN_MONT_CTX_free(mont);\n    EVP_MD_CTX_free(mctx);\n    return ok;\n}', 'int BN_is_prime_fasttest_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed,\n                            int do_trial_division, BN_GENCB *cb)\n{\n    int i, j, ret = -1;\n    int k;\n    BN_CTX *ctx = NULL;\n    BIGNUM *A1, *A1_odd, *check;\n    BN_MONT_CTX *mont = NULL;\n    const BIGNUM *A = NULL;\n    if (BN_cmp(a, BN_value_one()) <= 0)\n        return 0;\n    if (checks == BN_prime_checks)\n        checks = BN_prime_checks_for_size(BN_num_bits(a));\n    if (!BN_is_odd(a))\n        return BN_is_word(a, 2);\n    if (do_trial_division) {\n        for (i = 1; i < NUMPRIMES; i++)\n            if (BN_mod_word(a, primes[i]) == 0)\n                return 0;\n        if (!BN_GENCB_call(cb, 1, -1))\n            goto err;\n    }\n    if (ctx_passed != NULL)\n        ctx = ctx_passed;\n    else if ((ctx = BN_CTX_new()) == NULL)\n        goto err;\n    BN_CTX_start(ctx);\n    if (a->neg) {\n        BIGNUM *t;\n        if ((t = BN_CTX_get(ctx)) == NULL)\n            goto err;\n        BN_copy(t, a);\n        t->neg = 0;\n        A = t;\n    } else\n        A = a;\n    A1 = BN_CTX_get(ctx);\n    A1_odd = BN_CTX_get(ctx);\n    check = BN_CTX_get(ctx);\n    if (check == NULL)\n        goto err;\n    if (!BN_copy(A1, A))\n        goto err;\n    if (!BN_sub_word(A1, 1))\n        goto err;\n    if (BN_is_zero(A1)) {\n        ret = 0;\n        goto err;\n    }\n    k = 1;\n    while (!BN_is_bit_set(A1, k))\n        k++;\n    if (!BN_rshift(A1_odd, A1, k))\n        goto err;\n    mont = BN_MONT_CTX_new();\n    if (mont == NULL)\n        goto err;\n    if (!BN_MONT_CTX_set(mont, A, ctx))\n        goto err;\n    for (i = 0; i < checks; i++) {\n        if (!BN_pseudo_rand_range(check, A1))\n            goto err;\n        if (!BN_add_word(check, 1))\n            goto err;\n        j = witness(check, A, A1, A1_odd, k, ctx, mont);\n        if (j == -1)\n            goto err;\n        if (j) {\n            ret = 0;\n            goto err;\n        }\n        if (!BN_GENCB_call(cb, 1, i))\n            goto err;\n    }\n    ret = 1;\n err:\n    if (ctx != NULL) {\n        BN_CTX_end(ctx);\n        if (ctx_passed == NULL)\n            BN_CTX_free(ctx);\n    }\n    BN_MONT_CTX_free(mont);\n    return (ret);\n}', 'static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1,\n                   const BIGNUM *a1_odd, int k, BN_CTX *ctx,\n                   BN_MONT_CTX *mont)\n{\n    if (!BN_mod_exp_mont(w, w, a1_odd, a, ctx, mont))\n        return -1;\n    if (BN_is_one(w))\n        return 0;\n    if (BN_cmp(w, a1) == 0)\n        return 0;\n    while (--k) {\n        if (!BN_mod_mul(w, w, w, a, ctx))\n            return -1;\n        if (BN_is_one(w))\n            return 1;\n        if (BN_cmp(w, a1) == 0)\n            return 0;\n    }\n    bn_check_top(w);\n    return 1;\n}', 'int BN_mod_exp_mont(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,\n                    const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)\n{\n    int i, j, bits, ret = 0, wstart, wend, window, wvalue;\n    int start = 1;\n    BIGNUM *d, *r;\n    const BIGNUM *aa;\n    BIGNUM *val[TABLE_SIZE];\n    BN_MONT_CTX *mont = NULL;\n    if (BN_get_flags(p, BN_FLG_CONSTTIME) != 0) {\n        return BN_mod_exp_mont_consttime(rr, a, p, m, ctx, in_mont);\n    }\n    bn_check_top(a);\n    bn_check_top(p);\n    bn_check_top(m);\n    if (!BN_is_odd(m)) {\n        BNerr(BN_F_BN_MOD_EXP_MONT, BN_R_CALLED_WITH_EVEN_MODULUS);\n        return (0);\n    }\n    bits = BN_num_bits(p);\n    if (bits == 0) {\n        if (BN_is_one(m)) {\n            ret = 1;\n            BN_zero(rr);\n        } else {\n            ret = BN_one(rr);\n        }\n        return ret;\n    }\n    BN_CTX_start(ctx);\n    d = BN_CTX_get(ctx);\n    r = BN_CTX_get(ctx);\n    val[0] = BN_CTX_get(ctx);\n    if (!d || !r || !val[0])\n        goto err;\n    if (in_mont != NULL)\n        mont = in_mont;\n    else {\n        if ((mont = BN_MONT_CTX_new()) == NULL)\n            goto err;\n        if (!BN_MONT_CTX_set(mont, m, ctx))\n            goto err;\n    }\n    if (a->neg || BN_ucmp(a, m) >= 0) {\n        if (!BN_nnmod(val[0], a, m, ctx))\n            goto err;\n        aa = val[0];\n    } else\n        aa = a;\n    if (BN_is_zero(aa)) {\n        BN_zero(rr);\n        ret = 1;\n        goto err;\n    }\n    if (!BN_to_montgomery(val[0], aa, mont, ctx))\n        goto err;\n    window = BN_window_bits_for_exponent_size(bits);\n    if (window > 1) {\n        if (!BN_mod_mul_montgomery(d, val[0], val[0], mont, ctx))\n            goto err;\n        j = 1 << (window - 1);\n        for (i = 1; i < j; i++) {\n            if (((val[i] = BN_CTX_get(ctx)) == NULL) ||\n                !BN_mod_mul_montgomery(val[i], val[i - 1], d, mont, ctx))\n                goto err;\n        }\n    }\n    start = 1;\n    wvalue = 0;\n    wstart = bits - 1;\n    wend = 0;\n#if 1\n    j = m->top;\n    if (m->d[j - 1] & (((BN_ULONG)1) << (BN_BITS2 - 1))) {\n        if (bn_wexpand(r, j) == NULL)\n            goto err;\n        r->d[0] = (0 - m->d[0]) & BN_MASK2;\n        for (i = 1; i < j; i++)\n            r->d[i] = (~m->d[i]) & BN_MASK2;\n        r->top = j;\n        bn_correct_top(r);\n    } else\n#endif\n    if (!BN_to_montgomery(r, BN_value_one(), mont, ctx))\n        goto err;\n    for (;;) {\n        if (BN_is_bit_set(p, wstart) == 0) {\n            if (!start) {\n                if (!BN_mod_mul_montgomery(r, r, r, mont, ctx))\n                    goto err;\n            }\n            if (wstart == 0)\n                break;\n            wstart--;\n            continue;\n        }\n        j = wstart;\n        wvalue = 1;\n        wend = 0;\n        for (i = 1; i < window; i++) {\n            if (wstart - i < 0)\n                break;\n            if (BN_is_bit_set(p, wstart - i)) {\n                wvalue <<= (i - wend);\n                wvalue |= 1;\n                wend = i;\n            }\n        }\n        j = wend + 1;\n        if (!start)\n            for (i = 0; i < j; i++) {\n                if (!BN_mod_mul_montgomery(r, r, r, mont, ctx))\n                    goto err;\n            }\n        if (!BN_mod_mul_montgomery(r, r, val[wvalue >> 1], mont, ctx))\n            goto err;\n        wstart -= wend + 1;\n        wvalue = 0;\n        start = 0;\n        if (wstart < 0)\n            break;\n    }\n#if defined(SPARC_T4_MONT)\n    if (OPENSSL_sparcv9cap_P[0] & (SPARCV9_VIS3 | SPARCV9_PREFER_FPU)) {\n        j = mont->N.top;\n        val[0]->d[0] = 1;\n        for (i = 1; i < j; i++)\n            val[0]->d[i] = 0;\n        val[0]->top = j;\n        if (!BN_mod_mul_montgomery(rr, r, val[0], mont, ctx))\n            goto err;\n    } else\n#endif\n    if (!BN_from_montgomery(rr, r, mont, ctx))\n        goto err;\n    ret = 1;\n err:\n    if (in_mont == NULL)\n        BN_MONT_CTX_free(mont);\n    BN_CTX_end(ctx);\n    bn_check_top(rr);\n    return (ret);\n}', 'int BN_nnmod(BIGNUM *r, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx)\n{\n    if (!(BN_mod(r, m, d, ctx)))\n        return 0;\n    if (!r->neg)\n        return 1;\n    return (d->neg ? BN_sub : BN_add) (r, r, d);\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    tmp = BN_CTX_get(ctx);\n    snum = BN_CTX_get(ctx);\n    sdiv = BN_CTX_get(ctx);\n    if (dv == NULL)\n        res = BN_CTX_get(ctx);\n    else\n        res = dv;\n    if (sdiv == NULL || res == NULL || tmp == NULL || snum == 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.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    res->neg = (num->neg ^ divisor->neg);\n    if (!bn_wexpand(res, (loop + 1)))\n        goto err;\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    if (res->top == 0)\n        res->neg = 0;\n    else\n        resp--;\n    for (i = 0; i < loop - 1; i++, wnump--, resp--) {\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#    ifdef BN_DEBUG_LEVITTE\n            fprintf(stderr, "DEBUG: bn_div_words(0x%08X,0x%08X,0x%08\\\nX) -> 0x%08X\\n", n0, n1, d0, q);\n#    endif\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#   ifdef BN_DEBUG_LEVITTE\n            fprintf(stderr, "DEBUG: bn_div_words(0x%08X,0x%08X,0x%08\\\nX) -> 0x%08X\\n", n0, n1, d0, q);\n#   endif\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 = 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_CTX_get(BN_CTX *ctx)\n{\n    BIGNUM *ret;\n    CTXDBG_ENTRY("BN_CTX_get", ctx);\n    if (ctx->err_stack || ctx->too_many)\n        return NULL;\n    if ((ret = BN_POOL_get(&ctx->pool, ctx->flags)) == NULL) {\n        ctx->too_many = 1;\n        BNerr(BN_F_BN_CTX_GET, BN_R_TOO_MANY_TEMPORARY_VARIABLES);\n        return NULL;\n    }\n    BN_zero(ret);\n    ctx->used++;\n    CTXDBG_RET(ctx, ret);\n    return ret;\n}', 'int BN_set_word(BIGNUM *a, BN_ULONG w)\n{\n    bn_check_top(a);\n    if (bn_expand(a, (int)sizeof(BN_ULONG) * 8) == NULL)\n        return (0);\n    a->neg = 0;\n    a->d[0] = w;\n    a->top = (w ? 1 : 0);\n    bn_check_top(a);\n    return (1);\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        r->neg = a->neg;\n        if (bn_wexpand(r, i) == NULL)\n            return (0);\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    bn_check_top(r);\n    return (1);\n}']