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, 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}', 'BIGNUM *BN_CTX_get(BN_CTX *ctx)\n{\n    BIGNUM *ret;\n    CTXDBG("ENTER 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    ret->flags &= (~BN_FLG_CONSTTIME);\n    ctx->used++;\n    CTXDBG("LEAVE BN_CTX_get()", ctx);\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    a->flags &= ~BN_FLG_FIXED_TOP;\n    bn_check_top(a);\n    return 1;\n}', 'static ossl_inline BIGNUM *bn_expand(BIGNUM *a, int bits)\n{\n    if (bits > (INT_MAX - BN_BITS2 + 1))\n        return NULL;\n    if (((bits+BN_BITS2-1)/BN_BITS2) <= (a)->dmax)\n        return a;\n    return bn_expand2((a),(bits+BN_BITS2-1)/BN_BITS2);\n}', 'int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)\n{\n    int ret = bn_mul_fixed_top(r, a, b, ctx);\n    bn_correct_top(r);\n    bn_check_top(r);\n    return ret;\n}', 'int bn_mul_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)\n{\n    int ret = 0;\n    int top, al, bl;\n    BIGNUM *rr;\n#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)\n    int i;\n#endif\n#ifdef BN_RECURSION\n    BIGNUM *t = NULL;\n    int j = 0, k;\n#endif\n    bn_check_top(a);\n    bn_check_top(b);\n    bn_check_top(r);\n    al = a->top;\n    bl = b->top;\n    if ((al == 0) || (bl == 0)) {\n        BN_zero(r);\n        return 1;\n    }\n    top = al + bl;\n    BN_CTX_start(ctx);\n    if ((r == a) || (r == b)) {\n        if ((rr = BN_CTX_get(ctx)) == NULL)\n            goto err;\n    } else\n        rr = r;\n#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)\n    i = al - bl;\n#endif\n#ifdef BN_MUL_COMBA\n    if (i == 0) {\n# if 0\n        if (al == 4) {\n            if (bn_wexpand(rr, 8) == NULL)\n                goto err;\n            rr->top = 8;\n            bn_mul_comba4(rr->d, a->d, b->d);\n            goto end;\n        }\n# endif\n        if (al == 8) {\n            if (bn_wexpand(rr, 16) == NULL)\n                goto err;\n            rr->top = 16;\n            bn_mul_comba8(rr->d, a->d, b->d);\n            goto end;\n        }\n    }\n#endif\n#ifdef BN_RECURSION\n    if ((al >= BN_MULL_SIZE_NORMAL) && (bl >= BN_MULL_SIZE_NORMAL)) {\n        if (i >= -1 && i <= 1) {\n            if (i >= 0) {\n                j = BN_num_bits_word((BN_ULONG)al);\n            }\n            if (i == -1) {\n                j = BN_num_bits_word((BN_ULONG)bl);\n            }\n            j = 1 << (j - 1);\n            assert(j <= al || j <= bl);\n            k = j + j;\n            t = BN_CTX_get(ctx);\n            if (t == NULL)\n                goto err;\n            if (al > j || bl > j) {\n                if (bn_wexpand(t, k * 4) == NULL)\n                    goto err;\n                if (bn_wexpand(rr, k * 4) == NULL)\n                    goto err;\n                bn_mul_part_recursive(rr->d, a->d, b->d,\n                                      j, al - j, bl - j, t->d);\n            } else {\n                if (bn_wexpand(t, k * 2) == NULL)\n                    goto err;\n                if (bn_wexpand(rr, k * 2) == NULL)\n                    goto err;\n                bn_mul_recursive(rr->d, a->d, b->d, j, al - j, bl - j, t->d);\n            }\n            rr->top = top;\n            goto end;\n        }\n    }\n#endif\n    if (bn_wexpand(rr, top) == NULL)\n        goto err;\n    rr->top = top;\n    bn_mul_normal(rr->d, a->d, al, b->d, bl);\n#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)\n end:\n#endif\n    rr->neg = a->neg ^ b->neg;\n    rr->flags |= BN_FLG_FIXED_TOP;\n    if (r != rr && BN_copy(r, rr) == NULL)\n        goto err;\n    ret = 1;\n err:\n    bn_check_top(r);\n    BN_CTX_end(ctx);\n    return ret;\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}']