삽질하다 도저히 문제 파악이 안돼서 opcUaManager로 분리 테스트 중

opcUaManager/Services/CertService.cs

@@ -0,0 +1,158 @@
+using System.Security.Cryptography;
+using System.Security.Cryptography.X509Certificates;
+using OpcUaManager.Models;
+
+namespace OpcUaManager.Services;
+
+/// <summary>
+/// OPC UA 클라이언트용 X.509 인증서를 생성하고 PFX로 저장합니다.
+/// 원본 Program.cs 의 인증서 체계(pki/ 폴더 구조, X509KeyStorageFlags)를 유지합니다.
+/// </summary>
+public class CertService
+{
+    private readonly ILogger<CertService> _logger;
+    private readonly string _pkiRoot;
+
+    public CertService(ILogger<CertService> logger, IWebHostEnvironment env)
+    {
+        _logger  = logger;
+        _pkiRoot = Path.Combine(env.ContentRootPath, "pki");
+    }
+
+    private void EnsurePkiDirectories()
+    {
+        Directory.CreateDirectory(Path.Combine(_pkiRoot, "own",      "certs"));
+        Directory.CreateDirectory(Path.Combine(_pkiRoot, "trusted",  "certs"));
+        Directory.CreateDirectory(Path.Combine(_pkiRoot, "issuers",  "certs"));
+        Directory.CreateDirectory(Path.Combine(_pkiRoot, "rejected", "certs"));
+    }
+
+    public Task<CertCreateResult> GenerateAsync(CertCreateRequest req)
+    {
+        try
+        {
+            EnsurePkiDirectories();
+
+            string appUri = $"urn:{req.ClientHostName}:{req.ApplicationName}";
+
+            // ── 1. RSA 키 생성 ────────────────────────────────────────
+            using var rsa = RSA.Create(2048);
+
+            // ── 2. Distinguished Name ──────────────────────────────────
+            var dn = new X500DistinguishedName(
+                $"CN={req.ApplicationName}, O={req.ClientHostName}, C=KR");
+
+            // ── 3. Certificate Request ─────────────────────────────────
+            var certReq = new CertificateRequest(
+                dn, rsa, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
+
+            // ── 4. Extensions ──────────────────────────────────────────
+            certReq.CertificateExtensions.Add(
+                new X509BasicConstraintsExtension(false, false, 0, true));
+
+            certReq.CertificateExtensions.Add(
+                new X509KeyUsageExtension(
+                    X509KeyUsageFlags.DigitalSignature |
+                    X509KeyUsageFlags.NonRepudiation   |
+                    X509KeyUsageFlags.KeyEncipherment  |
+                    X509KeyUsageFlags.DataEncipherment,
+                    critical: true));
+
+            certReq.CertificateExtensions.Add(
+                new X509EnhancedKeyUsageExtension(
+                    new OidCollection
+                    {
+                        new Oid("1.3.6.1.5.5.7.3.2"),  // clientAuth
+                        new Oid("1.3.6.1.5.5.7.3.1")   // serverAuth
+                    }, false));
+
+            certReq.CertificateExtensions.Add(
+                new X509SubjectKeyIdentifierExtension(certReq.PublicKey, false));
+
+            // ── 5. Subject Alternative Names ──────────────────────────
+            var sanBuilder = new SubjectAlternativeNameBuilder();
+            sanBuilder.AddUri(new Uri(appUri));
+
+            if (!string.IsNullOrWhiteSpace(req.ServerIp) &&
+                System.Net.IPAddress.TryParse(req.ServerIp, out var ip))
+                sanBuilder.AddIpAddress(ip);
+
+            if (!string.IsNullOrWhiteSpace(req.ServerHostName))
+                sanBuilder.AddDnsName(req.ServerHostName);
+
+            sanBuilder.AddDnsName(req.ClientHostName);
+            sanBuilder.AddDnsName("localhost");
+
+            certReq.CertificateExtensions.Add(sanBuilder.Build());
+
+            // ── 6. 자체 서명 인증서 생성 ──────────────────────────────
+            var notBefore = DateTimeOffset.UtcNow.AddMinutes(-5);
+            var notAfter  = notBefore.AddDays(req.ValidDays);
+
+            // FIX: CreateSelfSigned 는 이미 RSA 키가 연결된 X509Certificate2 를 반환함
+            // → CopyWithPrivateKey() 를 추가로 호출하면
+            //   "The certificate already has an associated private key" 에러 발생
+            // → CreateSelfSigned 결과를 직접 Export(Pfx) 하면 개인키 포함됨
+            using var certWithKey = certReq.CreateSelfSigned(notBefore, notAfter);
+
+            // ── 7. PFX 내보내기 ───────────────────────────────────────
+            string pfxPassword = string.IsNullOrEmpty(req.PfxPassword) ? "" : req.PfxPassword;
+
+            // .NET 9 이상: X509CertificateLoader 권장이지만 net8 에서는 Export 사용
+            byte[] pfxBytes = certWithKey.Export(X509ContentType.Pfx, pfxPassword);
+
+            string pfxFileName = $"{req.ApplicationName}.pfx";
+            string pfxPath     = Path.Combine(_pkiRoot, "own", "certs", pfxFileName);
+            File.WriteAllBytes(pfxPath, pfxBytes);
+
+            // ── 8. Trusted 폴더에 DER(공개키) 복사 ───────────────────
+            byte[] derBytes = certWithKey.Export(X509ContentType.Cert);
+            string derPath  = Path.Combine(_pkiRoot, "trusted", "certs",
+                $"{req.ApplicationName}[{certWithKey.Thumbprint}].der");
+            File.WriteAllBytes(derPath, derBytes);
+
+            _logger.LogInformation(
+                "인증서 생성 완료 → {PfxPath} | Thumbprint: {Thumbprint}",
+                pfxPath, certWithKey.Thumbprint);
+
+            return Task.FromResult(new CertCreateResult
+            {
+                Success        = true,
+                Message        = $"인증서 생성 완료: {pfxFileName}",
+                PfxPath        = pfxPath,
+                ApplicationUri = appUri,
+                Thumbprint     = certWithKey.Thumbprint ?? string.Empty,
+                SerialNumber   = certWithKey.SerialNumber ?? string.Empty,
+                NotBefore      = notBefore.ToString("yyyy-MM-dd HH:mm:ss UTC"),
+                NotAfter       = notAfter.ToString("yyyy-MM-dd HH:mm:ss UTC"),
+            });
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "인증서 생성 실패");
+            return Task.FromResult(new CertCreateResult
+            {
+                Success = false,
+                Message = $"인증서 생성 실패: {ex.Message}"
+            });
+        }
+    }
+
+    /// <summary>
+    /// 기존 PFX를 로드합니다 (원본 코드와 동일한 플래그).
+    /// </summary>
+    public X509Certificate2 LoadPfx(string pfxPath, string pfxPassword)
+    {
+        return new X509Certificate2(
+            pfxPath,
+            pfxPassword,
+            X509KeyStorageFlags.Exportable | X509KeyStorageFlags.MachineKeySet);
+    }
+
+    public IEnumerable<string> ListCertificates()
+    {
+        string dir = Path.Combine(_pkiRoot, "own", "certs");
+        if (!Directory.Exists(dir)) return [];
+        return Directory.GetFiles(dir, "*.pfx").Select(Path.GetFileName)!;
+    }
+}

opcUaManager/Services/DatabaseService.cs

@@ -0,0 +1,223 @@
+using Npgsql;
+using OpcUaManager.Models;
+
+namespace OpcUaManager.Services;
+
+/// <summary>
+/// PostgreSQL opc_history 테이블에 대한 읽기/쓰기를 담당합니다.
+/// 원본 SaveToDatabase 함수의 INSERT 패턴을 그대로 유지하며,
+/// OPC 태그 읽기(OpcSessionService)와 DB 저장을 조율합니다.
+/// </summary>
+public class DatabaseService
+{
+    private readonly ILogger<DatabaseService> _logger;
+    private readonly OpcSessionService        _sessionSvc;
+
+    public DatabaseService(ILogger<DatabaseService> logger, OpcSessionService sessionSvc)
+    {
+        _logger     = logger;
+        _sessionSvc = sessionSvc;
+    }
+
+    // ── 연결 문자열 빌더 ──────────────────────────────────────────────
+
+    private static string BuildConnString(DbWriteRequest req)
+        => $"Host={req.DbHost};Username={req.DbUser};Password={req.DbPassword};Database={req.DbName}";
+
+    // ── DB/테이블 초기화 (최초 한 번) ────────────────────────────────
+
+    /// <summary>
+    /// opc_history 테이블이 없으면 자동 생성합니다.
+    /// 원본 코드에는 없었지만, 프로젝트화 시 처음 실행 환경을 위해 추가합니다.
+    /// </summary>
+    public async Task<(bool Ok, string Msg)> EnsureTableAsync(DbWriteRequest req)
+    {
+        const string ddl = """
+            CREATE TABLE IF NOT EXISTS opc_history (
+                id          BIGSERIAL PRIMARY KEY,
+                tag_name    TEXT        NOT NULL,
+                tag_value   DOUBLE PRECISION NOT NULL,
+                status_code TEXT        NOT NULL,
+                created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
+            );
+            """;
+        try
+        {
+            await using var conn = new NpgsqlConnection(BuildConnString(req));
+            await conn.OpenAsync();
+            await using var cmd = new NpgsqlCommand(ddl, conn);
+            await cmd.ExecuteNonQueryAsync();
+            return (true, "테이블 확인/생성 완료");
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "테이블 초기화 실패");
+            return (false, ex.Message);
+        }
+    }
+
+    // ── OPC 읽기 + DB 저장 루프 ──────────────────────────────────────
+
+    /// <summary>
+    /// OPC 노드를 req.Count 회 읽고 각 결과를 DB에 저장합니다.
+    /// 원본 for 루프 + SaveToDatabase 패턴을 그대로 유지합니다.
+    /// </summary>
+    public async Task<DbWriteResult> WriteLoopAsync(DbWriteRequest req)
+    {
+        if (!_sessionSvc.IsConnected)
+            return new DbWriteResult { Success = false, Message = "OPC 세션이 연결되어 있지 않습니다." };
+
+        var (tableOk, tableMsg) = await EnsureTableAsync(req);
+        if (!tableOk)
+            return new DbWriteResult { Success = false, Message = $"테이블 오류: {tableMsg}" };
+
+        var records = new List<DbWriteRecord>();
+        int saved   = 0;
+
+        for (int i = 1; i <= req.Count; i++)
+        {
+            // ── 1. OPC 태그 읽기 ────────────────────────────────────
+            double val     = 0;
+            string status  = "Unknown";
+            bool   dbSaved = false;
+
+            try
+            {
+                var (rawVal, sc) = await _sessionSvc.ReadValueAsync(req.TagNodeId);
+                val    = Convert.ToDouble(rawVal);
+                status = sc;
+                _logger.LogInformation("[{I}/{N}] {Tag} = {Val} ({Status})",
+                    i, req.Count, req.TagName, val, status);
+            }
+            catch (Exception ex)
+            {
+                status = $"ReadError: {ex.Message}";
+                _logger.LogWarning("[{I}/{N}] OPC 읽기 실패: {Msg}", i, req.Count, ex.Message);
+            }
+
+            // ── 2. DB 저장 (원본 SaveToDatabase 로직) ───────────────
+            try
+            {
+                await SaveToDatabaseAsync(req, val, status);
+                dbSaved = true;
+                saved++;
+                _logger.LogInformation("[{I}/{N}] DB 저장 완료.", i, req.Count);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "[{I}/{N}] DB 저장 실패", i, req.Count);
+            }
+
+            records.Add(new DbWriteRecord
+            {
+                Seq       = i,
+                Timestamp = DateTime.UtcNow,
+                TagName   = req.TagName,
+                Value     = val,
+                StatusCode = status,
+                DbSaved   = dbSaved
+            });
+
+            // ── 3. 인터벌 대기 (마지막 회차는 생략) ─────────────────
+            if (i < req.Count && req.IntervalMs > 0)
+                await Task.Delay(req.IntervalMs);
+        }
+
+        return new DbWriteResult
+        {
+            Success    = saved > 0,
+            Message    = $"{saved}/{req.Count}회 저장 완료",
+            SavedCount = saved,
+            Records    = records
+        };
+    }
+
+    // ── 원본 SaveToDatabase (INSERT 패턴 동일) ────────────────────────
+
+    private async Task SaveToDatabaseAsync(DbWriteRequest req, double val, string status)
+    {
+        await using var conn = new NpgsqlConnection(BuildConnString(req));
+        await conn.OpenAsync();
+
+        // 원본 동일 INSERT
+        const string sql =
+            "INSERT INTO opc_history (tag_name, tag_value, status_code) " +
+            "VALUES (@tag, @val, @status)";
+
+        await using var cmd = new NpgsqlCommand(sql, conn);
+        cmd.Parameters.AddWithValue("tag",    req.TagName);
+        cmd.Parameters.AddWithValue("val",    val);
+        cmd.Parameters.AddWithValue("status", status);
+
+        await cmd.ExecuteNonQueryAsync();
+    }
+
+    // ── DB 조회 ───────────────────────────────────────────────────────
+
+    public async Task<DbQueryResult> QueryRecentAsync(DbWriteRequest req, int limit = 100)
+    {
+        try
+        {
+            await using var conn = new NpgsqlConnection(BuildConnString(req));
+            await conn.OpenAsync();
+
+            string sql = $"""
+                SELECT id, tag_name, tag_value, status_code, created_at
+                FROM opc_history
+                ORDER BY id DESC
+                LIMIT {limit}
+                """;
+
+            await using var cmd  = new NpgsqlCommand(sql, conn);
+            await using var reader = await cmd.ExecuteReaderAsync();
+
+            var rows = new List<OpcHistoryRow>();
+            while (await reader.ReadAsync())
+            {
+                rows.Add(new OpcHistoryRow
+                {
+                    Id         = reader.GetInt64(0),
+                    TagName    = reader.GetString(1),
+                    TagValue   = reader.GetDouble(2),
+                    StatusCode = reader.GetString(3),
+                    CreatedAt  = reader.GetDateTime(4)
+                });
+            }
+
+            // 전체 카운트
+            await reader.CloseAsync();
+            await using var cntCmd = new NpgsqlCommand("SELECT COUNT(*) FROM opc_history", conn);
+            long total = (long)(await cntCmd.ExecuteScalarAsync() ?? 0L);
+
+            return new DbQueryResult
+            {
+                Success    = true,
+                TotalCount = (int)total,
+                Rows       = rows
+            };
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "DB 조회 실패");
+            return new DbQueryResult { Success = false, Message = ex.Message };
+        }
+    }
+
+    // ── 연결 테스트 ───────────────────────────────────────────────────
+
+    public async Task<(bool Ok, string Msg)> TestConnectionAsync(DbWriteRequest req)
+    {
+        try
+        {
+            await using var conn = new NpgsqlConnection(BuildConnString(req));
+            await conn.OpenAsync();
+            await using var cmd = new NpgsqlCommand("SELECT version()", conn);
+            var ver = await cmd.ExecuteScalarAsync();
+            return (true, $"연결 성공: {ver}");
+        }
+        catch (Exception ex)
+        {
+            return (false, ex.Message);
+        }
+    }
+}

opcUaManager/Services/OpcCrawlerService.cs

@@ -0,0 +1,161 @@
+using Opc.Ua;
+using Opc.Ua.Client;
+using OpcUaManager.Models;
+
+namespace OpcUaManager.Services;
+
+/// <summary>
+/// 원본 HoneywellCrawler 를 Service 로 분리.
+/// v1.5.374.70: BrowseNextAsync 가 튜플 반환이 아닌 BrowseNextResponse 객체 반환으로 변경됨.
+/// </summary>
+public class OpcCrawlerService
+{
+    private readonly ILogger<OpcCrawlerService> _logger;
+    private readonly OpcSessionService          _sessionSvc;
+
+    public OpcCrawlerService(ILogger<OpcCrawlerService> logger, OpcSessionService sessionSvc)
+    {
+        _logger     = logger;
+        _sessionSvc = sessionSvc;
+    }
+
+    public async Task<CrawlResult> CrawlAsync(CrawlRequest req)
+    {
+        if (!_sessionSvc.IsConnected)
+            return new CrawlResult { Success = false, Message = "세션이 연결되어 있지 않습니다." };
+
+        var session = _sessionSvc.GetRawSession();
+        if (session == null)
+            return new CrawlResult { Success = false, Message = "Raw 세션을 가져올 수 없습니다." };
+
+        var tags = new List<TagMaster>();
+
+        try
+        {
+            _logger.LogInformation("저인망 탐사 시작: {NodeId}", req.StartNodeId);
+            NodeId rootNode = NodeId.Parse(req.StartNodeId);
+            await BrowseRecursiveAsync(session, rootNode, 0, req.MaxDepth, tags);
+
+            string csvPath = await SaveToCsvAsync(tags);
+
+            _logger.LogInformation("탐사 완료: {Count}개 노드", tags.Count);
+            return new CrawlResult
+            {
+                Success    = true,
+                Message    = $"탐사 완료: {tags.Count}개 노드 발견",
+                TotalNodes = tags.Count,
+                Tags       = tags,
+                CsvPath    = csvPath
+            };
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Crawler 실행 오류");
+            return new CrawlResult { Success = false, Message = ex.Message, Tags = tags };
+        }
+    }
+
+    private async Task BrowseRecursiveAsync(
+        Session session, NodeId nodeId, int level, int maxDepth, List<TagMaster> tags)
+    {
+        try
+        {
+            // 원본 동일: BrowseAsync 객체 방식
+            BrowseDescription description = new()
+            {
+                NodeId          = nodeId,
+                BrowseDirection = BrowseDirection.Forward,
+                ReferenceTypeId = ReferenceTypeIds.HierarchicalReferences,
+                IncludeSubtypes = true,
+                NodeClassMask   = (uint)(NodeClass.Variable | NodeClass.Object),
+                ResultMask      = (uint)BrowseResultMask.All
+            };
+
+            BrowseResponse response = await session.BrowseAsync(
+                null, null, 0, [description], default);
+
+            if (response?.Results == null || response.Results.Count == 0) return;
+
+            foreach (var result in response.Results)
+            {
+                await ProcessReferencesAsync(session, result.References, level, maxDepth, tags);
+
+                byte[] cp = result.ContinuationPoint;
+                while (cp != null && cp.Length > 0)
+                {
+                    // FIX CS8130/CS1503: BrowseNextAsync 튜플 방식 → BrowseNextResponse 객체 방식
+                    // v1.5.374.70 에서 반환 타입이 Task<BrowseNextResponse> 로 변경됨
+                    BrowseNextResponse nextResponse = await session.BrowseNextAsync(
+                        null,
+                        false,
+                        new ByteStringCollection { cp },
+                        default);
+
+                    if (nextResponse?.Results != null && nextResponse.Results.Count > 0)
+                    {
+                        var nextResult = nextResponse.Results[0];
+                        await ProcessReferencesAsync(session, nextResult.References, level, maxDepth, tags);
+                        cp = nextResult.ContinuationPoint;
+                    }
+                    else
+                    {
+                        break;
+                    }
+                }
+            }
+        }
+        catch (Exception ex)
+        {
+            // 원본과 동일: 특정 노드 권한 에러 무시
+            _logger.LogDebug("노드 탐색 건너뜀 [{Level}] {NodeId}: {Msg}", level, nodeId, ex.Message);
+        }
+    }
+
+    private async Task ProcessReferencesAsync(
+        Session session,
+        ReferenceDescriptionCollection? references,
+        int level,
+        int maxDepth,
+        List<TagMaster> tags)
+    {
+        if (references == null || references.Count == 0) return;
+
+        foreach (var rd in references)
+        {
+            NodeId childId = ExpandedNodeId.ToNodeId(rd.NodeId, session.NamespaceUris);
+
+            tags.Add(new TagMaster
+            {
+                TagName    = rd.BrowseName.Name ?? "Unknown",
+                FullNodeId = childId.ToString(),
+                NodeClass  = rd.NodeClass.ToString(),
+                Level      = level
+            });
+
+            _logger.LogDebug("{Indent}[{Class}] {Name} ({Id})",
+                new string(' ', level * 2), rd.NodeClass, rd.BrowseName.Name, childId);
+
+            if (rd.NodeClass == NodeClass.Object && level < maxDepth)
+                await BrowseRecursiveAsync(session, childId, level + 1, maxDepth, tags);
+        }
+    }
+
+    private async Task<string> SaveToCsvAsync(List<TagMaster> tags)
+    {
+        string path = Path.GetFullPath("Honeywell_FullMap.csv");
+        try
+        {
+            await using var sw = new StreamWriter(path);
+            await sw.WriteLineAsync("Level,Class,Name,NodeId");
+            foreach (var tag in tags)
+                await sw.WriteLineAsync($"{tag.Level},{tag.NodeClass},{tag.TagName},{tag.FullNodeId}");
+
+            _logger.LogInformation("CSV 저장 완료: {Path}", path);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "CSV 저장 실패");
+        }
+        return path;
+    }
+}

opcUaManager/Services/OpcSessionService.cs

@@ -0,0 +1,180 @@
+using System.Text;
+using Opc.Ua;
+using Opc.Ua.Client;
+using OpcUaManager.Models;
+
+// Microsoft.AspNetCore.Http.ISession 과 Opc.Ua.Client.ISession 충돌 해소
+using OpcUaISession = Opc.Ua.Client.ISession;
+
+// Microsoft.AspNetCore.Http.StatusCodes 와 Opc.Ua.StatusCodes 충돌 해소
+using OpcStatusCodes = Opc.Ua.StatusCodes;
+
+namespace OpcUaManager.Services;
+
+/// <summary>
+/// OPC UA 세션을 싱글톤으로 관리합니다.
+/// v1.5.374.70 API 기준으로 수정되었습니다.
+/// </summary>
+public class OpcSessionService : IAsyncDisposable
+{
+    private readonly ILogger<OpcSessionService> _logger;
+    private readonly CertService _certService;
+
+    private OpcUaISession?             _session;
+    private ApplicationConfiguration?  _appConfig;
+    private readonly SemaphoreSlim      _lock = new(1, 1);
+
+    public bool   IsConnected => _session?.Connected == true;
+    public string SessionId   => _session?.SessionId?.ToString() ?? string.Empty;
+
+    public OpcSessionService(ILogger<OpcSessionService> logger, CertService certService)
+    {
+        _logger      = logger;
+        _certService = certService;
+    }
+
+    public async Task<ConnectResult> ConnectAsync(ConnectRequest req)
+    {
+        await _lock.WaitAsync();
+        try
+        {
+            if (IsConnected)
+                await InternalCloseAsync();
+
+            string endpointUrl = $"opc.tcp://{req.ServerIp}:{req.Port}";
+
+            // ── 1. 클라이언트 인증서 로드 ────────────────────────────
+            System.Security.Cryptography.X509Certificates.X509Certificate2? clientCert = null;
+            if (!string.IsNullOrWhiteSpace(req.PfxPath) && File.Exists(req.PfxPath))
+                clientCert = _certService.LoadPfx(req.PfxPath, req.PfxPassword);
+
+            string appUri = string.IsNullOrWhiteSpace(req.ApplicationUri)
+                ? $"urn:{System.Net.Dns.GetHostName()}:{req.ApplicationName}"
+                : req.ApplicationUri;
+
+            // ── 2. ApplicationConfiguration ───────────────────────────
+            _appConfig = new ApplicationConfiguration
+            {
+                ApplicationName = req.ApplicationName,
+                ApplicationType = ApplicationType.Client,
+                ApplicationUri  = appUri,
+                SecurityConfiguration = new SecurityConfiguration
+                {
+                    ApplicationCertificate = clientCert != null
+                        ? new CertificateIdentifier { Certificate = clientCert }
+                        : new CertificateIdentifier(),
+                    TrustedPeerCertificates = new CertificateTrustList
+                        { StoreType = "Directory", StorePath = Path.GetFullPath("pki/trusted") },
+                    TrustedIssuerCertificates = new CertificateTrustList
+                        { StoreType = "Directory", StorePath = Path.GetFullPath("pki/issuers") },
+                    RejectedCertificateStore = new CertificateTrustList
+                        { StoreType = "Directory", StorePath = Path.GetFullPath("pki/rejected") },
+                    AutoAcceptUntrustedCertificates = true,
+                    AddAppCertToTrustedStore        = true
+                },
+                TransportQuotas     = new TransportQuotas     { OperationTimeout     = 15000 },
+                ClientConfiguration = new ClientConfiguration { DefaultSessionTimeout = req.SessionTimeoutMs }
+            };
+
+            // FIX CS1061: ValidateAsync → Validate (v1.5.374.70에서 동기 메서드)
+            _appConfig.Validate(ApplicationType.Client);
+
+            // FIX CS0104: StatusCodes → OpcStatusCodes 별칭 사용
+            _appConfig.CertificateValidator.CertificateValidation += (_, e) =>
+            {
+                if (e.Error.StatusCode != OpcStatusCodes.Good) e.Accept = true;
+            };
+
+            // ── 3. Endpoint Discovery ─────────────────────────────────
+            _logger.LogInformation("Endpoint Discovery: {Url}", endpointUrl);
+            var endpointConfig = EndpointConfiguration.Create(_appConfig);
+
+            // FIX CS0117: DiscoveryClient.CreateAsync 없음 → 동기 Create 사용
+            EndpointDescriptionCollection endpoints;
+            using (var discovery = DiscoveryClient.Create(new Uri(endpointUrl), endpointConfig))
+            {
+                endpoints = discovery.GetEndpoints(null);
+            }
+
+            var selected = endpoints
+                .OrderByDescending(e => e.SecurityLevel)
+                .FirstOrDefault(e => e.SecurityPolicyUri.Contains(req.SecurityPolicy))
+                ?? endpoints.OrderByDescending(e => e.SecurityLevel).First();
+
+            var endpoint = new ConfiguredEndpoint(null, selected, endpointConfig);
+
+            // FIX CS1503: UserIdentity(user, byte[]) → UserIdentity(user, string)
+            // v1.5.374.70 에서 password 파라미터가 string 으로 변경됨
+            var identity = new UserIdentity(req.UserName, req.Password);
+
+            // ── 5. Session.Create ─────────────────────────────────────
+#pragma warning disable CS0618
+            _session = await Session.Create(
+                _appConfig,
+                endpoint,
+                false,
+                "OpcUaManagerSession",
+                (uint)req.SessionTimeoutMs,
+                identity,
+                null);
+#pragma warning restore CS0618
+
+            string secMode = selected.SecurityMode.ToString();
+            _logger.LogInformation("OPC UA 연결 완료 | SessionId={Id} | Security={Sec}",
+                _session.SessionId, secMode);
+
+            return new ConnectResult
+            {
+                Success      = true,
+                Message      = "연결 성공",
+                SessionId    = _session.SessionId.ToString(),
+                EndpointUrl  = endpointUrl,
+                SecurityMode = secMode
+            };
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "OPC UA 연결 실패");
+            return new ConnectResult { Success = false, Message = ex.Message };
+        }
+        finally
+        {
+            _lock.Release();
+        }
+    }
+
+    public async Task<bool> DisconnectAsync()
+    {
+        await _lock.WaitAsync();
+        try   { await InternalCloseAsync(); return true; }
+        finally { _lock.Release(); }
+    }
+
+    private async Task InternalCloseAsync()
+    {
+        if (_session != null)
+        {
+            try   { await _session.CloseAsync(); } catch { /* ignore */ }
+            _session.Dispose();
+            _session = null;
+        }
+    }
+
+    public async Task<(object? Value, string StatusCode)> ReadValueAsync(string nodeId)
+    {
+        if (!IsConnected || _session == null)
+            throw new InvalidOperationException("세션이 연결되어 있지 않습니다.");
+
+        var result = await _session.ReadValueAsync(nodeId);
+        return (result.Value, result.StatusCode.ToString());
+    }
+
+    public Session? GetRawSession() => _session as Session;
+
+    public async ValueTask DisposeAsync()
+    {
+        await InternalCloseAsync();
+        _lock.Dispose();
+        GC.SuppressFinalize(this);
+    }
+}