Adding network share validation in sql migration. (#1203)

* adding network file validator contract

* Adding UNC path validation

* Using helper methods for sanity checks

* Fixed the validation variable type

* Fixing if condition

src/Microsoft.SqlTools.ServiceLayer/Migration/Contracts/ValidateNetworkFileShare.cs

@@ -0,0 +1,21 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlTools.Hosting.Protocol.Contracts;
+
+namespace Microsoft.SqlTools.ServiceLayer.Migration.Contracts
+{
+    public class ValidateNetworkFileShareRequestParams
+    {
+        public string Path { get; set; }
+        public string Username { get; set; }
+        public string Password { get; set; }
+    }
+
+    public class ValidateNetworkFileShareRequest
+    {
+        public static readonly RequestType<ValidateNetworkFileShareRequestParams, bool> Type = RequestType<ValidateNetworkFileShareRequestParams, bool>.Create("migration/validateNetworkFileShare");
+    }
+}

src/Microsoft.SqlTools.ServiceLayer/Migration/Contracts/ValidateWindowsAccount.cs

@@ -13,14 +13,8 @@ namespace Microsoft.SqlTools.ServiceLayer.Migration.Contracts
         public string Password { get; set; }
     }
 
-    public class ValidateWindowsAccountResult
-    {
-        public bool Success { get; set; }
-        public string ErrorMessage { get; set; }
-    }
-
     public class ValidateWindowsAccountRequest
     {
-        public static readonly RequestType<ValidateWindowsAccountRequestParams, ValidateWindowsAccountResult> Type = RequestType<ValidateWindowsAccountRequestParams, ValidateWindowsAccountResult>.Create("migration/validateWindowsAccount");
+        public static readonly RequestType<ValidateWindowsAccountRequestParams, bool> Type = RequestType<ValidateWindowsAccountRequestParams, bool>.Create("migration/validateWindowsAccount");
     }
 }

src/Microsoft.SqlTools.ServiceLayer/Migration/MigrationService.cs

@@ -22,7 +22,8 @@ using Microsoft.Win32.SafeHandles;
 using System.ComponentModel;
 using System.Runtime.InteropServices;
 using System.Text.RegularExpressions;
-
+using System.Security.Principal;
+using System.IO;
 namespace Microsoft.SqlTools.ServiceLayer.Migration
 {
     /// <summary>
@@ -93,6 +94,7 @@ namespace Microsoft.SqlTools.ServiceLayer.Migration
             this.ServiceHost = serviceHost;
             this.ServiceHost.SetRequestHandler(MigrationAssessmentsRequest.Type, HandleMigrationAssessmentsRequest);
             this.ServiceHost.SetRequestHandler(ValidateWindowsAccountRequest.Type, HandleValidateWindowsAccountRequest);
+            this.ServiceHost.SetRequestHandler(ValidateNetworkFileShareRequest.Type, HandleValidateNetworkFileShareRequest);
         }
 
         /// <summary>
@@ -259,24 +261,18 @@ namespace Microsoft.SqlTools.ServiceLayer.Migration
 
         internal async Task HandleValidateWindowsAccountRequest(
             ValidateWindowsAccountRequestParams parameters,
-            RequestContext<ValidateWindowsAccountResult> requestContext)
+            RequestContext<bool> requestContext)
         {
-            var domainUserRegex = new Regex(@"^[A-Za-z0-9\\\._-]{7,}$");
+            if (!ValidateWindowsDomainUsername(parameters.Username))
-            // Checking if the username string is in 'domain\name' format
-            if (!domainUserRegex.Match(parameters.Username).Success)
             {
-                await requestContext.SendResult(new ValidateWindowsAccountResult()
+                await requestContext.SendError("Invalid user name format. Example: Domain\\username");
-                {
-                    Success = false,
-                    ErrorMessage = "Invalid user name format. Example: Domain\\username"
-                });
                 return;
             }
             if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
             {
                 int separator = parameters.Username.IndexOf("\\");
-                string domainName = (separator > -1) ? parameters.Username.Substring(0, separator) : string.Empty;
+                string domainName = parameters.Username.Substring(0, separator);
-                string userName = (separator > -1) ? parameters.Username.Substring(separator + 1, parameters.Username.Length - separator - 1) : string.Empty;
+                string userName = parameters.Username.Substring(separator + 1, parameters.Username.Length - separator - 1);
 
                 const int LOGON32_PROVIDER_DEFAULT = 0;
                 const int LOGON32_LOGON_INTERACTIVE = 2;
@@ -286,23 +282,102 @@ namespace Microsoft.SqlTools.ServiceLayer.Migration
                     LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT,
                     out safeAccessTokenHandle);
 
-                if (false == returnValue)
+                if (!returnValue)
                 {
                     int ret = Marshal.GetLastWin32Error();
                     string errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
-                    await requestContext.SendResult(new ValidateWindowsAccountResult()
+                    await requestContext.SendError(errorMessage);
-                    {
+                }
-                        Success = returnValue,
+                else
-                        ErrorMessage = errorMessage
+                {
-                    });
+                    await requestContext.SendResult(true);
+                }
+            } 
+            else 
+            {
+                await requestContext.SendResult(true);
+            }
+        }
+
+        internal async Task HandleValidateNetworkFileShareRequest(
+            ValidateNetworkFileShareRequestParams parameters,
+            RequestContext<bool> requestContext)
+        {
+            if (!ValidateWindowsDomainUsername(parameters.Username))
+            {
+                await requestContext.SendError("Invalid user name format. Example: Domain\\username");
+                return;
+            }
+
+            if (!ValidateUNCPath(parameters.Path))
+            {
+                await requestContext.SendError("Invalid network share path. Example: \\\\Servername.domainname.com\\Backupfolder");
+                return;
+            }
+
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            {
+                int separator = parameters.Username.IndexOf("\\");
+                string domainName = parameters.Username.Substring(0, separator);
+                string userName = parameters.Username.Substring(separator + 1, parameters.Username.Length - separator - 1);
+
+                const int LOGON32_PROVIDER_WINNT50 = 3;
+                const int LOGON32_LOGON_NEW_CREDENTIALS = 9;
+
+                SafeAccessTokenHandle safeAccessTokenHandle;
+                bool returnValue = LogonUser(
+                    userName, 
+                    domainName, 
+                    parameters.Password,
+                    LOGON32_LOGON_NEW_CREDENTIALS,
+                    LOGON32_PROVIDER_WINNT50,
+                    out safeAccessTokenHandle);
+
+                if (!returnValue)
+                {
+                    int ret = Marshal.GetLastWin32Error();
+                    string errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
+                    await requestContext.SendError(errorMessage);
                     return;
                 }
-            }
+                await WindowsIdentity.RunImpersonated(
-            await requestContext.SendResult(new ValidateWindowsAccountResult()
+                safeAccessTokenHandle,
+                // User action  
+                async () =>
+                {
+                    if(!Directory.Exists(parameters.Path)){
+                        await requestContext.SendError("Cannot connect to file share");
+                    } else {
+                        await requestContext.SendResult(true);
+                    }
+                }
+                );
+            } 
+            else 
             {
-                Success = true,
+                await requestContext.SendResult(true);
-                ErrorMessage = ""
+            }
-            });
+        }
+
+        /// <summary>
+        /// Check if the username is in 'domain\username' format.
+        /// </summary>
+        /// <returns></returns>
+        internal bool ValidateWindowsDomainUsername(string username)
+        {
+            var domainUserRegex = new Regex(@"^(?<domain>[A-Za-z0-9\._-]*)\\(?<username>[A-Za-z0-9\._-]*)$");
+            return domainUserRegex.IsMatch(username);
+        }
+
+
+        /// <summary>
+        /// Checks if the file path is in UNC format '\\Servername.domainname.com\Backupfolder'
+        /// </summary>
+        /// <param name="path"></param>
+        /// <returns></returns>
+        internal bool ValidateUNCPath(string path)
+        {
+            return new Uri(path).IsUnc;
         }
     }
 }