static unsigned int BN_STACK_pop(BN_STACK *st)
{
    return st->indexes[--(st->depth)];
}
['ECDSA_SIG *ossl_ecdsa_sign_sig(const unsigned char *dgst, int dgst_len,\n                               const BIGNUM *in_kinv, const BIGNUM *in_r,\n                               EC_KEY *eckey)\n{\n    int ok = 0, i;\n    BIGNUM *kinv = NULL, *s, *m = NULL, *tmp = NULL, *blind = NULL;\n    BIGNUM *blindm = NULL;\n    const BIGNUM *order, *ckinv;\n    BN_CTX *ctx = NULL;\n    const EC_GROUP *group;\n    ECDSA_SIG *ret;\n    const BIGNUM *priv_key;\n    group = EC_KEY_get0_group(eckey);\n    priv_key = EC_KEY_get0_private_key(eckey);\n    if (group == NULL || priv_key == NULL) {\n        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_PASSED_NULL_PARAMETER);\n        return NULL;\n    }\n    if (!EC_KEY_can_sign(eckey)) {\n        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);\n        return NULL;\n    }\n    ret = ECDSA_SIG_new();\n    if (ret == NULL) {\n        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);\n        return NULL;\n    }\n    ret->r = BN_new();\n    ret->s = BN_new();\n    if (ret->r == NULL || ret->s == NULL) {\n        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);\n        goto err;\n    }\n    s = ret->s;\n    ctx = BN_CTX_secure_new();\n    if (ctx == NULL) {\n        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);\n        goto err;\n    }\n    BN_CTX_start(ctx);\n    tmp = BN_CTX_get(ctx);\n    m = BN_CTX_get(ctx);\n    blind = BN_CTX_get(ctx);\n    blindm = BN_CTX_get(ctx);\n    if (blindm == NULL) {\n        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);\n        goto err;\n    }\n    order = EC_GROUP_get0_order(group);\n    if (order == NULL) {\n        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_EC_LIB);\n        goto err;\n    }\n    i = BN_num_bits(order);\n    if (8 * dgst_len > i)\n        dgst_len = (i + 7) / 8;\n    if (!BN_bin2bn(dgst, dgst_len, m)) {\n        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);\n        goto err;\n    }\n    if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7))) {\n        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);\n        goto err;\n    }\n    do {\n        if (in_kinv == NULL || in_r == NULL) {\n            if (!ecdsa_sign_setup(eckey, ctx, &kinv, &ret->r, dgst, dgst_len)) {\n                ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_ECDSA_LIB);\n                goto err;\n            }\n            ckinv = kinv;\n        } else {\n            ckinv = in_kinv;\n            if (BN_copy(ret->r, in_r) == NULL) {\n                ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);\n                goto err;\n            }\n        }\n        do {\n            if (!BN_priv_rand(blind, BN_num_bits(order) - 1,\n                              BN_RAND_TOP_ANY, BN_RAND_BOTTOM_ANY))\n                goto err;\n        } while (BN_is_zero(blind));\n        BN_set_flags(blind, BN_FLG_CONSTTIME);\n        BN_set_flags(blindm, BN_FLG_CONSTTIME);\n        BN_set_flags(tmp, BN_FLG_CONSTTIME);\n        if (!BN_mod_mul(tmp, blind, priv_key, order, ctx)) {\n            ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);\n            goto err;\n        }\n        if (!BN_mod_mul(tmp, tmp, ret->r, order, ctx)) {\n            ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);\n            goto err;\n        }\n        if (!BN_mod_mul(blindm, blind, m, order, ctx)) {\n            ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);\n            goto err;\n        }\n        if (!BN_mod_add_quick(s, tmp, blindm, order)) {\n            ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);\n            goto err;\n        }\n        if (BN_mod_inverse(blind, blind, order, ctx) == NULL) {\n            ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);\n            goto err;\n        }\n        if (!BN_mod_mul(s, s, blind, order, ctx)) {\n            ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);\n            goto err;\n        }\n        if (!BN_mod_mul(s, s, ckinv, order, ctx)) {\n            ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);\n            goto err;\n        }\n        if (BN_is_zero(s)) {\n            if (in_kinv != NULL && in_r != NULL) {\n                ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, EC_R_NEED_NEW_SETUP_VALUES);\n                goto err;\n            }\n        } else\n            break;\n    }\n    while (1);\n    ok = 1;\n err:\n    if (!ok) {\n        ECDSA_SIG_free(ret);\n        ret = NULL;\n    }\n    BN_CTX_end(ctx);\n    BN_CTX_free(ctx);\n    BN_clear_free(kinv);\n    return ret;\n}', 'void BN_CTX_start(BN_CTX *ctx)\n{\n    CTXDBG_ENTRY("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_EXIT(ctx);\n}', 'int BN_mod_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m,\n               BN_CTX *ctx)\n{\n    BIGNUM *t;\n    int ret = 0;\n    bn_check_top(a);\n    bn_check_top(b);\n    bn_check_top(m);\n    BN_CTX_start(ctx);\n    if ((t = BN_CTX_get(ctx)) == NULL)\n        goto err;\n    if (a == b) {\n        if (!BN_sqr(t, a, ctx))\n            goto err;\n    } else {\n        if (!BN_mul(t, a, b, ctx))\n            goto err;\n    }\n    if (!BN_nnmod(r, t, m, ctx))\n        goto err;\n    bn_check_top(r);\n    ret = 1;\n err:\n    BN_CTX_end(ctx);\n    return ret;\n}', 'int BN_mul(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    bn_correct_top(rr);\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_ENTRY("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_EXIT(ctx);\n}', 'static unsigned int BN_STACK_pop(BN_STACK *st)\n{\n    return st->indexes[--(st->depth)];\n}']