static unsigned int BN_STACK_pop(BN_STACK *st)
{
    return st->indexes[--(st->depth)];
}
['int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)\n{\n    int ret = 1;\n    bn_check_top(n);\n    if ((b->A == NULL) || (b->Ai == NULL)) {\n        BNerr(BN_F_BN_BLINDING_CONVERT_EX, BN_R_NOT_INITIALIZED);\n        return 0;\n    }\n    if (b->counter == -1)\n        b->counter = 0;\n    else if (!BN_BLINDING_update(b, ctx))\n        return 0;\n    if (r != NULL && (BN_copy(r, b->Ai) == NULL))\n        return 0;\n    if (b->m_ctx != NULL)\n        ret = BN_mod_mul_montgomery(n, n, b->A, b->m_ctx, ctx);\n    else\n        ret = BN_mod_mul(n, n, b->A, b->mod, ctx);\n    return ret;\n}', 'int BN_mod_mul_montgomery(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,\n                          BN_MONT_CTX *mont, BN_CTX *ctx)\n{\n    int ret = bn_mul_mont_fixed_top(r, a, b, mont, ctx);\n    bn_correct_top(r);\n    bn_check_top(r);\n    return ret;\n}', 'int bn_mul_mont_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,\n                          BN_MONT_CTX *mont, BN_CTX *ctx)\n{\n    BIGNUM *tmp;\n    int ret = 0;\n    int num = mont->N.top;\n#if defined(OPENSSL_BN_ASM_MONT) && defined(MONT_WORD)\n    if (num > 1 && a->top == num && b->top == num) {\n        if (bn_wexpand(r, num) == NULL)\n            return 0;\n        if (bn_mul_mont(r->d, a->d, b->d, mont->N.d, mont->n0, num)) {\n            r->neg = a->neg ^ b->neg;\n            r->top = num;\n            r->flags |= BN_FLG_FIXED_TOP;\n            return 1;\n        }\n    }\n#endif\n    if ((a->top + b->top) > 2 * num)\n        return 0;\n    BN_CTX_start(ctx);\n    tmp = BN_CTX_get(ctx);\n    if (tmp == NULL)\n        goto err;\n    bn_check_top(tmp);\n    if (a == b) {\n        if (!bn_sqr_fixed_top(tmp, a, ctx))\n            goto err;\n    } else {\n        if (!bn_mul_fixed_top(tmp, a, b, ctx))\n            goto err;\n    }\n#ifdef MONT_WORD\n    if (!bn_from_montgomery_word(r, tmp, mont))\n        goto err;\n#else\n    if (!BN_from_montgomery(r, tmp, mont, ctx))\n        goto err;\n#endif\n    ret = 1;\n err:\n    BN_CTX_end(ctx);\n    return ret;\n}', 'void BN_CTX_start(BN_CTX *ctx)\n{\n    CTXDBG("ENTER BN_CTX_start()", ctx);\n    if (ctx->err_stack || ctx->too_many)\n        ctx->err_stack++;\n    else if (!BN_STACK_push(&ctx->stack, ctx->used)) {\n        BNerr(BN_F_BN_CTX_START, BN_R_TOO_MANY_TEMPORARY_VARIABLES);\n        ctx->err_stack++;\n    }\n    CTXDBG("LEAVE BN_CTX_start()", ctx);\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_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}', 'void BN_CTX_end(BN_CTX *ctx)\n{\n    CTXDBG("ENTER BN_CTX_end()", ctx);\n    if (ctx->err_stack)\n        ctx->err_stack--;\n    else {\n        unsigned int fp = BN_STACK_pop(&ctx->stack);\n        if (fp < ctx->used)\n            BN_POOL_release(&ctx->pool, ctx->used - fp);\n        ctx->used = fp;\n        ctx->too_many = 0;\n    }\n    CTXDBG("LEAVE BN_CTX_end()", ctx);\n}', 'static unsigned int BN_STACK_pop(BN_STACK *st)\n{\n    return st->indexes[--(st->depth)];\n}']