static unsigned int BN_STACK_pop(BN_STACK *st)
{
    return st->indexes[--(st->depth)];
}
['int rsa_sp800_56b_generate_key(RSA *rsa, int nbits, const BIGNUM *efixed,\n                               BN_GENCB *cb)\n{\n    int ret = 0;\n    int ok;\n    BN_CTX *ctx = NULL;\n    BIGNUM *e = NULL;\n    if (!rsa_sp800_56b_validate_strength(nbits, -1))\n        return 0;\n    ctx = BN_CTX_new();\n    if (ctx == NULL)\n        return 0;\n    if (efixed == NULL) {\n        e = BN_new();\n        if (e == NULL || !BN_set_word(e, 65537))\n            goto err;\n    } else {\n        e = (BIGNUM *)efixed;\n    }\n    for (;;) {\n        if (!rsa_fips186_4_gen_prob_primes(rsa, NULL, NULL, NULL, NULL, NULL,\n                                           NULL, NULL, NULL, NULL, NULL, NULL,\n                                           NULL, nbits, e, ctx, cb))\n            goto err;\n        ok = rsa_sp800_56b_derive_params_from_pq(rsa, nbits, e, ctx);\n        if (ok < 0)\n            goto err;\n        if (ok > 0)\n            break;\n    }\n    ret = rsa_sp800_56b_pairwise_test(rsa, ctx);\nerr:\n    if (efixed == NULL)\n        BN_free(e);\n    BN_CTX_free(ctx);\n    return ret;\n}', 'int rsa_fips186_4_gen_prob_primes(RSA *rsa, BIGNUM *p1, BIGNUM *p2,\n                                  BIGNUM *Xpout, const BIGNUM *Xp,\n                                  const BIGNUM *Xp1, const BIGNUM *Xp2,\n                                  BIGNUM *q1, BIGNUM *q2, BIGNUM *Xqout,\n                                  const BIGNUM *Xq, const BIGNUM *Xq1,\n                                  const BIGNUM *Xq2, int nbits,\n                                  const BIGNUM *e, BN_CTX *ctx, BN_GENCB *cb)\n{\n    int ret = 0, ok;\n    BIGNUM *Xpo = NULL, *Xqo = NULL, *tmp = NULL;\n    if (nbits < RSA_FIPS1864_MIN_KEYGEN_KEYSIZE) {\n        RSAerr(RSA_F_RSA_FIPS186_4_GEN_PROB_PRIMES, RSA_R_INVALID_KEY_LENGTH);\n        return 0;\n    }\n    if (!rsa_check_public_exponent(e)) {\n        RSAerr(RSA_F_RSA_FIPS186_4_GEN_PROB_PRIMES,\n               RSA_R_PUB_EXPONENT_OUT_OF_RANGE);\n        goto err;\n    }\n    BN_CTX_start(ctx);\n    tmp = BN_CTX_get(ctx);\n    Xpo = (Xpout != NULL) ? Xpout : BN_CTX_get(ctx);\n    Xqo = (Xqout != NULL) ? Xqout : BN_CTX_get(ctx);\n    if (tmp == NULL || Xpo == NULL || Xqo == NULL)\n        goto err;\n    if (rsa->p == NULL)\n        rsa->p = BN_secure_new();\n    if (rsa->q == NULL)\n        rsa->q = BN_secure_new();\n    if (rsa->p == NULL || rsa->q == NULL)\n        goto err;\n    if (!bn_rsa_fips186_4_gen_prob_primes(rsa->p, Xpo, p1, p2, Xp, Xp1, Xp2,\n                                          nbits, e, ctx, cb))\n        goto err;\n    for(;;) {\n        if (!bn_rsa_fips186_4_gen_prob_primes(rsa->q, Xqo, q1, q2, Xq, Xq1,\n                                              Xq2, nbits, e, ctx, cb))\n            goto err;\n        ok = rsa_check_pminusq_diff(tmp, Xpo, Xqo, nbits);\n        if (ok < 0)\n            goto err;\n        if (ok == 0)\n            continue;\n        ok = rsa_check_pminusq_diff(tmp, rsa->p, rsa->q, nbits);\n        if (ok < 0)\n            goto err;\n        if (ok == 0)\n            continue;\n        break;\n    }\n    ret = 1;\nerr:\n    if (Xpo != Xpout)\n        BN_clear(Xpo);\n    if (Xqo != Xqout)\n        BN_clear(Xqo);\n    BN_clear(tmp);\n    BN_CTX_end(ctx);\n    return ret;\n}', 'int rsa_sp800_56b_derive_params_from_pq(RSA *rsa, int nbits,\n                                        const BIGNUM *e, BN_CTX *ctx)\n{\n    int ret = -1;\n    BIGNUM *p1, *q1, *lcm, *p1q1, *gcd;\n    BN_CTX_start(ctx);\n    p1 = BN_CTX_get(ctx);\n    q1 = BN_CTX_get(ctx);\n    lcm = BN_CTX_get(ctx);\n    p1q1 = BN_CTX_get(ctx);\n    gcd = BN_CTX_get(ctx);\n    if (gcd == NULL)\n        goto err;\n    if (rsa_get_lcm(ctx, rsa->p, rsa->q, lcm, gcd, p1, q1, p1q1) != 1)\n        goto err;\n    BN_free(rsa->e);\n    rsa->e = BN_dup(e);\n    if (rsa->e == NULL)\n        goto err;\n    BN_clear_free(rsa->d);\n    rsa->d = BN_secure_new();\n    if (rsa->d == NULL || BN_mod_inverse(rsa->d, e, lcm, ctx) == NULL)\n        goto err;\n    if (BN_num_bits(rsa->d) <= (nbits >> 1)) {\n        ret = 0;\n        goto err;\n    }\n    if (rsa->n == NULL)\n        rsa->n = BN_new();\n    if (rsa->n == NULL || !BN_mul(rsa->n, rsa->p, rsa->q, ctx))\n        goto err;\n    if (rsa->dmp1 == NULL)\n        rsa->dmp1 = BN_new();\n    if (rsa->dmp1 == NULL || !BN_mod(rsa->dmp1, rsa->d, p1, ctx))\n        goto err;\n    if (rsa->dmq1 == NULL)\n        rsa->dmq1 = BN_secure_new();\n    if (rsa->dmq1 == NULL || !BN_mod(rsa->dmq1, rsa->d, q1, ctx))\n        goto err;\n    BN_free(rsa->iqmp);\n    rsa->iqmp = BN_secure_new();\n    if (rsa->iqmp == NULL\n            || BN_mod_inverse(rsa->iqmp, rsa->q, rsa->p, ctx) == NULL)\n        goto err;\n    ret = 1;\nerr:\n    if (ret != 1) {\n        BN_free(rsa->e);\n        rsa->e = NULL;\n        BN_free(rsa->d);\n        rsa->d = NULL;\n        BN_free(rsa->n);\n        rsa->n = NULL;\n        BN_free(rsa->iqmp);\n        rsa->iqmp = NULL;\n        BN_free(rsa->dmq1);\n        rsa->dmq1 = NULL;\n        BN_free(rsa->dmp1);\n        rsa->dmp1 = NULL;\n    }\n    BN_clear(p1);\n    BN_clear(q1);\n    BN_clear(lcm);\n    BN_clear(p1q1);\n    BN_clear(gcd);\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 rsa_get_lcm(BN_CTX *ctx, const BIGNUM *p, const BIGNUM *q,\n                BIGNUM *lcm, BIGNUM *gcd, BIGNUM *p1, BIGNUM *q1,\n                BIGNUM *p1q1)\n{\n    return BN_sub(p1, p, BN_value_one())\n           && BN_sub(q1, q, BN_value_one())\n           && BN_mul(p1q1, p1, q1, ctx)\n           && BN_gcd(gcd, p1, q1, ctx)\n           && BN_div(lcm, NULL, p1q1, gcd, ctx);\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}', '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}']