Fix | Reenable SqlBulkCopy in least-privilege environments

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/SqlBulkCopy.cs

@@ -477,11 +477,12 @@ private string CreateInitialQuery()
             }
             else if (!string.IsNullOrEmpty(CatalogName))
             {
-                CatalogName = SqlServerEscapeHelper.EscapeStringAsLiteral(SqlServerEscapeHelper.EscapeIdentifier(CatalogName));
+                CatalogName = SqlServerEscapeHelper.EscapeIdentifier(CatalogName);
             }
 
             string objectName = ADP.BuildMultiPartName(parts);
             string escapedObjectName = SqlServerEscapeHelper.EscapeStringAsLiteral(objectName);
+            string catalogNameStringLiteral = CatalogName is null ? null : SqlServerEscapeHelper.EscapeStringAsLiteral(CatalogName);
             // Specify the column names explicitly. This is to ensure that we can map to hidden
             // columns (e.g. columns in temporal tables.) If the target table doesn't exist,
             // OBJECT_ID will return NULL and @Column_Names will remain non-null. The subsequent
@@ -526,6 +527,11 @@ private string CreateInitialQuery()
             // we use STRING_AGG in that case and the COALESCE method otherwise.
             //
             // See: https://learn.microsoft.com/en-us/sql/t-sql/functions/serverproperty-transact-sql
+            //
+            // All of this is wrapped in an test against HAS_PERMS_BY_NAME. This test verifies that
+            // the user possesses the necessary permissions to access sys.all_columns. If they do not
+            // @Column_Names will remain NULL (and be coalesced to *) and SqlBulkCopy will degrade
+            // gracefully, silently dropping support for hidden columns and column aliases.
             return $"""
 SELECT @@TRANCOUNT;
 
@@ -535,6 +541,7 @@ private string CreateInitialQuery()
 DECLARE @Column_Name_Query_SORT NVARCHAR(MAX);
 DECLARE @Column_Name_Query NVARCHAR(MAX);
 DECLARE @Column_Names NVARCHAR(MAX) = NULL;
+DECLARE @Has_Permissions INT = HAS_PERMS_BY_NAME('{catalogNameStringLiteral}.[sys].[all_columns]', 'OBJECT', 'SELECT');
 
 CREATE TABLE #Column_Aliases
 (
@@ -554,28 +561,35 @@ IF CAST(SERVERPROPERTY('EngineEdition') AS INT) = 6
     SET @Column_Name_Query_SORT = N'ORDER BY [column_id] ASC';
 END
 
-IF EXISTS (SELECT TOP 1 * FROM sys.all_columns WHERE [object_id] = OBJECT_ID('sys.all_columns') AND [name] = 'graph_type')
-BEGIN
-    SET @Column_Name_Query_FILTER = N'WHERE [object_id] = @Object_ID AND COALESCE([graph_type], 0) NOT IN (1, 3, 4, 6, 7)';
-
-    EXEC sp_executesql N'
-    INSERT INTO #Column_Aliases ([Canonical_Column_Name], [Canonical_Column_Id], [Aliased_Column_Name])
-        SELECT [name], [column_id], ''$to_id'' FROM {CatalogName}.[sys].[all_columns] WHERE [object_id] = @Object_ID AND COALESCE([graph_type], 0) = 8
-    UNION ALL
-        SELECT [name], [column_id], ''$from_id'' FROM {CatalogName}.[sys].[all_columns] WHERE [object_id] = @Object_ID AND COALESCE([graph_type], 0) = 5
-    UNION ALL
-        SELECT [name], [column_id], ''$edge_id'' FROM {CatalogName}.[sys].[all_columns] WHERE [object_id] = @Object_ID AND COALESCE([graph_type], 0) = 2 AND [name] LIKE ''$edge[_]id[_]%''
-    UNION ALL
-        SELECT [name], [column_id], ''$node_id'' FROM {CatalogName}.[sys].[all_columns] WHERE [object_id] = @Object_ID AND COALESCE([graph_type], 0) = 2 AND [name] LIKE ''$node[_]id[_]%''',
-    N'@Object_ID INT', @Object_ID = @Object_ID
-END
-ELSE
+IF @Has_Permissions = 1
 BEGIN
-    SET @Column_Name_Query_FILTER = N'WHERE [object_id] = @Object_ID';
+    IF EXISTS (SELECT TOP 1 * FROM {CatalogName}.[sys].[all_columns] WHERE [object_id] = OBJECT_ID('{catalogNameStringLiteral}.[sys].[all_columns]') AND [name] = 'graph_type')
+    BEGIN
+        SET @Column_Name_Query_FILTER = N'WHERE [object_id] = @Object_ID AND COALESCE([graph_type], 0) NOT IN (1, 3, 4, 6, 7)';
+
+        EXEC sp_executesql N'
+        INSERT INTO #Column_Aliases ([Canonical_Column_Name], [Canonical_Column_Id], [Aliased_Column_Name])
+            SELECT [name], [column_id], ''$to_id'' FROM {catalogNameStringLiteral}.[sys].[all_columns] WHERE [object_id] = @Object_ID AND COALESCE([graph_type], 0) = 8
+        UNION ALL
+            SELECT [name], [column_id], ''$from_id'' FROM {catalogNameStringLiteral}.[sys].[all_columns] WHERE [object_id] = @Object_ID AND COALESCE([graph_type], 0) = 5
+        UNION ALL
+            SELECT [name], [column_id], ''$edge_id'' FROM {catalogNameStringLiteral}.[sys].[all_columns] WHERE [object_id] = @Object_ID AND COALESCE([graph_type], 0) = 2 AND [name] LIKE ''$edge[_]id[_]%''
+        UNION ALL
+            SELECT [name], [column_id], ''$node_id'' FROM {catalogNameStringLiteral}.[sys].[all_columns] WHERE [object_id] = @Object_ID AND COALESCE([graph_type], 0) = 2 AND [name] LIKE ''$node[_]id[_]%''',
+        N'@Object_ID INT', @Object_ID = @Object_ID
+    END
+    ELSE
+    BEGIN
+        SET @Column_Name_Query_FILTER = N'WHERE [object_id] = @Object_ID';
+    END
+    SET @Column_Name_Query = @Column_Name_Query_SELECT + ' FROM {catalogNameStringLiteral}.[sys].[all_columns] ' + @Column_Name_Query_FILTER + ' ' + @Column_Name_Query_SORT + ';'
+
+    EXEC sp_executesql @Column_Name_Query, N'@Object_ID INT, @Column_Names NVARCHAR(MAX) OUTPUT', @Object_ID = @Object_ID, @Column_Names = @Column_Names OUTPUT;
+
+    DELETE FROM #Column_Aliases
+    WHERE [Aliased_Column_Name] IN (SELECT [name] FROM {CatalogName}.[sys].[all_columns] WHERE [object_id] = @Object_ID)
 END
-SET @Column_Name_Query = @Column_Name_Query_SELECT + ' FROM {CatalogName}.[sys].[all_columns] ' + @Column_Name_Query_FILTER + ' ' + @Column_Name_Query_SORT + ';'
 
-EXEC sp_executesql @Column_Name_Query, N'@Object_ID INT, @Column_Names NVARCHAR(MAX) OUTPUT', @Object_ID = @Object_ID, @Column_Names = @Column_Names OUTPUT;
 SELECT @Column_Names = COALESCE(@Column_Names, '*');
 
 SET FMTONLY ON;
@@ -586,7 +600,6 @@ UNION ALL
 
 SELECT [Canonical_Column_Name], [Aliased_Column_Name]
 FROM #Column_Aliases
-WHERE [Aliased_Column_Name] NOT IN (SELECT [name] FROM {CatalogName}.[sys].[all_columns] WHERE [object_id] = @Object_ID)
 ORDER BY [Canonical_Column_Id] ASC
 
 DROP TABLE #Column_Aliases

src/Microsoft.Data.SqlClient/tests/Common/Fixtures/DatabaseObjects/DatabaseObject.cs

@@ -12,19 +12,28 @@ namespace Microsoft.Data.SqlClient.Tests.Common.Fixtures.DatabaseObjects;
 /// Base class for a transient database object (such as a table, type or
 /// stored procedure.)
 /// </summary>
-public abstract class DatabaseObject : IDisposable
+/// <typeparam name="TState">
+/// The type of the internal state accessible to derived types at the point of object creation
+/// via the <see cref="State"/> property.
+/// </typeparam>
+public abstract class DatabaseObject<TState> : IDisposable
 {
     private readonly bool _shouldDrop;
 
     protected SqlConnection Connection { get; }
 
+    protected TState State { get; }
+
     public string Name { get; }
 
-    protected DatabaseObject(SqlConnection connection, string name, string definition, bool shouldCreate, bool shouldDrop)
+    public string UnescapedName => Name.Substring(1, Name.Length - 2).Replace("]]", "]");
+
+    protected DatabaseObject(SqlConnection connection, string name, string definition, TState state, bool shouldCreate, bool shouldDrop)
     {
         _shouldDrop = shouldDrop;
 
         Connection = connection;
+        State = state;
         Name = name;
 
         if (shouldCreate)
@@ -261,3 +270,15 @@ public void Dispose()
         GC.SuppressFinalize(this);
     }
 }
+
+/// <summary>
+/// Base class for a transient database object (such as a table, type or
+/// stored procedure.)
+/// </summary>
+public abstract class DatabaseObject : DatabaseObject<object?>
+{
+    protected DatabaseObject(SqlConnection connection, string name, string definition, bool shouldCreate, bool shouldDrop)
+        : base(connection, name, definition, state: null, shouldCreate, shouldDrop)
+    {
+    }
+}

src/Microsoft.Data.SqlClient/tests/Common/Fixtures/DatabaseObjects/DatabaseUser.cs

@@ -0,0 +1,64 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.Data.SqlClient.Tests.Common.Fixtures.DatabaseObjects;
+
+/// <summary>
+/// A transient database user, created at the start of its scope and dropped when disposed.
+/// </summary>
+/// <remarks>
+/// This class assumes that the associated server login already exists.
+/// </remarks>
+public sealed class DatabaseUser : DatabaseObject<string>
+{
+    public string DatabaseName => State;
+
+    /// <summary>
+    /// Initializes a new instance of the DatabaseUser class using the specified SQL connection
+    /// and associated server login.
+    /// </summary>
+    /// <param name="connection">The SQL connection used to interact with the database.</param>
+    /// <param name="database">The name of the database where the user will be created.</param>
+    /// <param name="login">The server login which the database user will be associated with.</param>
+    public DatabaseUser(SqlConnection connection, string database, ServerLogin login)
+        : base(connection, login.Name, $"FOR LOGIN {login.Name}", database, shouldCreate: true, shouldDrop: true)
+    {
+    }
+
+    protected override void CreateObject(string definition)
+    {
+        using SqlCommand createCommand = new($"CREATE USER {Name} {definition}", Connection);
+
+        ExecuteCommandInDatabase(createCommand);
+    }
+
+    protected override void DropObject()
+    {
+        using SqlCommand dropCommand = new($"IF USER_ID('{UnescapedName}') IS NOT NULL DROP USER {Name}", Connection);
+
+        ExecuteCommandInDatabase(dropCommand);
+    }
+
+    private void ExecuteCommandInDatabase(SqlCommand command)
+    {
+        string? originalDatabase = DatabaseName == command.Connection.Database ? null : command.Connection.Database;
+
+        try
+        {
+            if (originalDatabase is not null)
+            {
+                command.Connection.ChangeDatabase(DatabaseName);
+            }
+
+            command.ExecuteNonQuery();
+        }
+        finally
+        {
+            if (originalDatabase is not null)
+            {
+                command.Connection.ChangeDatabase(originalDatabase);
+            }
+        }
+    }
+}

src/Microsoft.Data.SqlClient/tests/Common/Fixtures/DatabaseObjects/ServerLogin.cs

@@ -0,0 +1,89 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.Data.SqlClient.Tests.Common.Fixtures.DatabaseObjects;
+
+/// <summary>
+/// A transient server login, created at the start of its scope and dropped when disposed.
+/// </summary>
+public sealed class ServerLogin : DatabaseObject<string>
+{
+    public string Password => State;
+
+    /// <summary>
+    /// Initializes a new instance of the ServerLogin class using the specified SQL connection, login name prefix, and default database.
+    /// The login will be created with a randomly generated password that meets SQL Server's password complexity requirements.
+    /// </summary>
+    /// <param name="connection">The SQL connection used to interact with the database.</param>
+    /// <param name="namePrefix">The prefix for the login name.</param>
+    /// <param name="defaultDatabase">The default database for the login. If null, not set.</param>
+    public ServerLogin(SqlConnection connection, string namePrefix, string? defaultDatabase = null)
+        : this(connection, GenerateLongName(namePrefix), GeneratePassword(), defaultDatabase)
+    {
+    }
+
+    private ServerLogin(SqlConnection connection, string namePrefix, string password, string? defaultDatabase)
+        : base(connection, namePrefix, GenerateDefinition(password, defaultDatabase), password, shouldCreate: true, shouldDrop: true)
+    {
+    }
+
+    private static string GenerateDefinition(string password, string? defaultDatabase) =>
+        $"WITH PASSWORD='{password}'" +
+            (string.IsNullOrEmpty(defaultDatabase) ? string.Empty : $", DEFAULT_DATABASE=[{defaultDatabase}]");
+
+    /// <summary>
+    /// Generates a password which meets the SQL Server password complexity requirements, which are:
+    /// <list type="number">
+    /// <item>Minimum length of 8 characters</item>
+    /// <item>Must contain characters from three of the following four categories:</item>
+    /// <list type="number">
+    /// <item>Uppercase letters (A-Z)</item>
+    /// <item>Lowercase letters (a-z)</item>
+    /// <item>Digits (0-9)</item>
+    /// <item>Non-alphanumeric characters (e.g. !, $, #, %)</item>
+    /// </list>
+    /// </list>
+    /// </summary>
+    /// <returns>A compliant password.</returns>
+    private static string GeneratePassword()
+    {
+        const int PasswordLength = 16;
+        const char UpperCaseStart = 'A';
+        const char LowerCaseStart = 'a';
+        const char DigitsStart = '0';
+
+        // First 5 characters are uppercase letters, next 5 are lowercase letters, and the last 6 are digits
+        Span<char> passwordDigits = stackalloc char[PasswordLength];
+        Random rnd = new();
+
+        for(int i = 0; i < 5; i++)
+        {
+            passwordDigits[i] = (char)(UpperCaseStart + rnd.Next(26));
+        }
+        for (int i = 5; i < 10; i++)
+        {
+            passwordDigits[i] = (char)(LowerCaseStart + rnd.Next(26));
+        }
+        for (int i = 10; i < PasswordLength; i++)
+        {
+            passwordDigits[i] = (char)(DigitsStart + rnd.Next(10));
+        }
+
+        return passwordDigits.ToString();
+    }
+
+    protected override void CreateObject(string definition)
+    {
+        using SqlCommand createCommand = new($"CREATE LOGIN {Name} {definition}", Connection);
+
+        createCommand.ExecuteNonQuery();
+    }
+
+    protected override void DropObject()
+    {
+        using SqlCommand dropCommand = new($"IF SUSER_ID('{UnescapedName}') IS NOT NULL DROP LOGIN {Name}", Connection);
+
+        dropCommand.ExecuteNonQuery();
+    }
+}

src/Microsoft.Data.SqlClient/tests/ManualTests/DataCommon/DataTestUtility.cs

@@ -98,6 +98,10 @@ public static class DataTestUtility
         private static bool? s_isVectorSupported;
         private static bool? s_isVectorFloat16Supported;
 
+        // Login permissions
+        private static bool? s_isSysAdmin;
+        private static bool? s_isSecurityAdmin;
+
         // Azure Synapse EngineEditionId == 6
         // More could be read at https://learn.microsoft.com/en-us/sql/t-sql/functions/serverproperty-transact-sql?view=sql-server-ver16#propertyname
         public static bool IsAzureSynapse
@@ -231,6 +235,20 @@ private static bool CheckVectorFloat16Supported()
             }
         }
 
+        public static bool IsSysAdmin =>
+            s_isSysAdmin ??= IsTCPConnStringSetup() &&
+                IsServerRoleMember("sysadmin");
+
+        public static bool IsSecurityAdmin =>
+            s_isSecurityAdmin ??= IsTCPConnStringSetup() &&
+                IsServerRoleMember("securityadmin");
+
+        public static bool CanCreateLogins =>
+            IsSysAdmin || IsSecurityAdmin;
+
+        public static bool CanUseSqlAuthentication =>
+            IsSysAdmin && GetAuthenticationMode() == 2;
+
         static DataTestUtility()
         {
             Config c = Config.Load();
@@ -531,6 +549,30 @@ public static bool IsTypePresent(string typeName)
             return (int)command.ExecuteScalar() > 0;
         }
 
+        public static bool IsServerRoleMember(string roleName)
+        {
+            using SqlConnection connection = new(TCPConnectionString);
+            using SqlCommand command = new("SELECT IS_SRVROLEMEMBER(@role)", connection);
+
+            connection.Open();
+            command.Parameters.AddWithValue("@role", roleName);
+
+            // IS_SRVROLEMEMBER returns 1 if the caller is a member of the specified server role, 0 if not, and DBNull.Value if the role is not valid.
+            return command.ExecuteScalar() is int result && result == 1;
+        }
+
+        public static int GetAuthenticationMode()
+        {
+            using SqlConnection connection = new(TCPConnectionString);
+
+            connection.Open();
+            using SqlCommand command = new("EXEC xp_instance_regread N'HKEY_LOCAL_MACHINE', N'Software\\Microsoft\\MSSQLServer\\MSSQLServer', N'LoginMode'", connection);
+            using SqlDataReader reader = command.ExecuteReader();
+
+            reader.Read();
+            return reader.GetInt32(1);
+        }
+
         public static bool IsAdmin
         {
             get

src/Microsoft.Data.SqlClient/tests/ManualTests/Extensions/CodeAnalysis.netfx.cs

@@ -0,0 +1,20 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+#if NETFRAMEWORK
+
+namespace System.Diagnostics.CodeAnalysis;
+
+#nullable enable
+
+[AttributeUsage(AttributeTargets.Method | AttributeTargets.Property, Inherited = false, AllowMultiple = true)]
+internal sealed class MemberNotNullAttribute : Attribute
+{
+    public MemberNotNullAttribute(string member) => Members = [member];
+
+    public MemberNotNullAttribute(params string[] members) => Members = members;
+
+    public string[] Members { get; }
+}
+#endif

src/Microsoft.Data.SqlClient/tests/ManualTests/Microsoft.Data.SqlClient.ManualTests.csproj

@@ -45,6 +45,7 @@
     <Compile Include="DataCommon\SystemDataResourceManager.cs" />
     <Compile Include="DataCommon\UsernamePasswordProvider.cs" />
     <Compile Include="DataCommon\XEventScope.cs" />
+    <Compile Include="Extensions\CodeAnalysis.netfx.cs" />
     <Compile Include="Extensions\StreamExtensions.netfx.cs" />
     <Compile Include="SQL\Common\AsyncDebugScope.cs" />
     <Compile Include="SQL\Common\ConnectionPoolWrapper.cs" />
@@ -57,6 +58,7 @@
     <Compile Include="SQL\Common\SystemDataInternals\FedAuthTokenHelper.cs" />
     <Compile Include="SQL\Common\SystemDataInternals\TdsParserHelper.cs" />
     <Compile Include="SQL\Common\SystemDataInternals\TdsParserStateObjectHelper.cs" />
+    <Compile Include="SQL\SqlBulkCopyTest\UnprivilegedLogin.cs" />
     <Compile Include="XUnitAssemblyAttributes.cs" />
 
     <!-- Content files -->