Add MySql support to the Certificate DB

MimeKit/Cryptography/MySqlCertificateDatabase.cs

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+//
+// MySqlCertificateDatabase.cs
+//
+// Author: Rob Blackin <[email protected]>
+//
+// Copyright (c) 2013-2024 .NET Foundation and Contributors
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+//
+
+using System;
+using System.Text;
+using System.Data;
+using System.Data.Common;
+using System.Collections.Generic;
+
+using Org.BouncyCastle.X509;
+using Org.BouncyCastle.Security;
+
+using MimeKit.Utils;
+using System.Runtime.CompilerServices;
+
+namespace MimeKit.Cryptography {
+	/// <summary>
+	/// An X.509 certificate database built on SQL Server.
+	/// </summary>
+	/// <remarks>
+	/// <para>An X.509 certificate database is used for storing certificates, metdata related to the certificates
+	/// (such as encryption algorithms supported by the associated client), certificate revocation lists (CRLs),
+	/// and private keys.</para>
+	/// <para>This particular database uses MySql to store the data.</para>
+	/// </remarks>
+	public class MySqlCertificateDatabase : SqlCertificateDatabase
+	{
+		/// <summary>
+		/// Initialize a new instance of the <see cref="MySqlCertificateDatabase"/> class.
+		/// </summary>
+		/// <remarks>
+		/// Creates a new <see cref="MySqlCertificateDatabase"/> using the provided SQL Server database connection.
+		/// </remarks>
+		/// <param name="connection">The SQL Server connection.</param>
+		/// <param name="password">The password used for encrypting and decrypting the private keys.</param>
+		/// <exception cref="System.ArgumentNullException">
+		/// <para><paramref name="connection"/> is <c>null</c>.</para>
+		/// <para>-or-</para>
+		/// <para><paramref name="password"/> is <c>null</c>.</para>
+		/// </exception>
+		public MySqlCertificateDatabase (DbConnection connection, string password) : base (connection, password)
+		{
+		}
+
+		/// <summary>
+		/// Initialize a new instance of the <see cref="MySqlCertificateDatabase"/> class.
+		/// </summary>
+		/// <remarks>
+		/// Creates a new <see cref="MySqlCertificateDatabase"/> using the provided SQL Server database connection.
+		/// </remarks>
+		/// <param name="connection">The SQL Server connection.</param>
+		/// <param name="password">The password used for encrypting and decrypting the private keys.</param>
+		/// <param name="random">The secure pseudo-random number generator.</param>
+		/// <exception cref="System.ArgumentNullException">
+		/// <para><paramref name="connection"/> is <c>null</c>.</para>
+		/// <para>-or-</para>
+		/// <para><paramref name="password"/> is <c>null</c>.</para>
+		/// <para>-or-</para>
+		/// <para><paramref name="random"/> is <c>null</c>.</para>
+		/// </exception>
+		public MySqlCertificateDatabase (DbConnection connection, string password, SecureRandom random) : base (connection, password, random)
+		{
+		}
+
+		/// <summary>
+		/// Adds a column to a table.
+		/// </summary>
+		/// <remarks>
+		/// Adds a column to a table.
+		/// </remarks>
+		/// <param name="connection">The database connection.</param>
+		/// <param name="table">The table.</param>
+		/// <param name="column">The column to add.</param>
+		protected override void AddTableColumn (DbConnection connection, DataTable table, DataColumn column)
+		{
+			var statement = new StringBuilder ("ALTER TABLE ");
+			int primaryKeys = table.PrimaryKey?.Length ?? 0;
+
+			statement.Append (table.TableName);
+			statement.Append (" ADD COLUMN ");
+			Build (statement, table, column, ref primaryKeys);
+
+			using (var command = connection.CreateCommand ()) {
+				command.CommandText = statement.ToString ();
+				command.CommandType = CommandType.Text;
+				command.ExecuteNonQuery ();
+			}
+		}
+
+		/// <summary>
+		/// Create a table.
+		/// </summary>
+		/// <remarks>
+		/// Creates the specified table.
+		/// </remarks>
+		/// <param name="connection">The database connection.</param>
+		/// <param name="table">The table.</param>
+		protected override void CreateTable (DbConnection connection, DataTable table)
+		{
+			int primaryKeys = 0;
+
+			var statement = new StringBuilder ($"Create table IF NOT EXISTS {table.TableName} (");
+
+			foreach (DataColumn column in table.Columns) {
+				Build (statement, table, column, ref primaryKeys);
+				statement.Append (", ");
+			}
+
+			if (table.Columns.Count > 0)
+				statement.Length -= 2;
+
+			statement.Append (')');
+
+			using (var command = connection.CreateCommand ()) {
+				command.CommandText = statement.ToString ();
+				command.CommandType = CommandType.Text;
+				command.ExecuteNonQuery ();
+			}
+		}
+
+		static void Build (StringBuilder statement, DataTable table, DataColumn column, ref int primaryKeys)
+		{
+			statement.Append (column.ColumnName);
+			statement.Append (' ');
+
+			if (column.DataType == typeof (long) || column.DataType == typeof (int)) {
+				if (column.AutoIncrement)
+					statement.Append ("int NOT NULL AUTO_INCREMENT");
+				else if (column.DataType == typeof (long))
+					statement.Append ("DateTime(3)");
+				else
+					statement.Append ("int");
+			} else if (column.DataType == typeof (bool)) {
+				statement.Append ("tinyint UNSIGNED");
+			} else if (column.DataType == typeof (byte[])) {
+				statement.Append ($"varbinary(4096)");
+			} else if (column.DataType == typeof (string)) {
+				statement.Append ("varchar(256)");
+			} else {
+				throw new NotImplementedException ();
+			}
+
+			if (table != null && table.PrimaryKey != null && primaryKeys < table.PrimaryKey.Length) {
+				for (int i = 0; i < table.PrimaryKey.Length; i++) {
+					if (column == table.PrimaryKey[i]) {
+						statement.Append (" PRIMARY KEY ");
+						primaryKeys++;
+						break;
+					}
+				}
+			}
+
+			if (!column.AllowDBNull)
+				statement.Append (" NOT NULL");
+		}
+
+		/// <summary>
+		/// Gets the columns for the specified table.
+		/// </summary>
+		/// <remarks>
+		/// Gets the list of columns for the specified table.
+		/// </remarks>
+		/// <param name="connection">The database connection.</param>
+		/// <param name="tableName">The name of the table.</param>
+		/// <returns>The list of columns.</returns>
+		protected override IList<DataColumn> GetTableColumns (DbConnection connection, string tableName)
+		{
+			using (var command = connection.CreateCommand ()) {
+				command.CommandText = $"select * from {tableName} LIMIT 1";
+				using (var reader = command.ExecuteReader ()) {
+					var columns = new List<DataColumn> ();
+					var table = reader.GetSchemaTable ();
+
+					foreach (DataRow row in table.Rows)
+						columns.Add (new DataColumn { ColumnName = row.Field<string> ("ColumnName") });
+
+					return columns;
+				}
+			}
+		}
+
+		/// <summary>
+		/// Creates an index for faster table lookups.
+		/// </summary>
+		/// <remarks>
+		/// Creates an index for faster table lookups.
+		/// </remarks>
+		/// <param name="connection">The database connection.</param>
+		/// <param name="tableName">The name of the table.</param>
+		/// <param name="columnNames">The names of the columns to index.</param>
+		protected override void CreateIndex (DbConnection connection, string tableName, string[] columnNames)
+		{
+			var indexName = GenerateIndexName (tableName, columnNames);
+			var query = string.Format ("SELECT COUNT(distinct index_name) indexExists FROM INFORMATION_SCHEMA.STATISTICS WHERE table_schema=DATABASE() AND table_name='{0}' AND index_name='{1}';", tableName, indexName);
+			var indexExists = 0;
+			using (var command = connection.CreateCommand ()) {
+				command.CommandText = query;
+				using (var reader = command.ExecuteReader ()) {
+					reader.Read();
+					indexExists=reader.GetInt32 (0);
+				}
+			}
+
+			if (indexExists == 0) {
+				using (var command = connection.CreateCommand ()) {
+					command.CommandText = string.Format("CREATE INDEX {0} ON {1}({2})", indexName, tableName, string.Join (", ", columnNames));
+					command.ExecuteNonQuery ();
+				}
+			}
+		}
+
+		/// <summary>
+		/// Removes an index that is no longer needed.
+		/// </summary>
+		/// <remarks>
+		/// Removes an index that is no longer needed.
+		/// </remarks>
+		/// <param name="connection">The database connection.</param>
+		/// <param name="tableName">The name of the table.</param>
+		/// <param name="columnNames">The names of the columns that were indexed.</param>
+		protected override void RemoveIndex (DbConnection connection, string tableName, string[] columnNames)
+		{
+			var indexName = GenerateIndexName (tableName, columnNames);
+			var query = string.Format ("SELECT COUNT(distinct index_name) indexExists FROM INFORMATION_SCHEMA.STATISTICS WHERE table_schema=DATABASE() AND table_name='{0}' AND index_name='{1}';", tableName, indexName);
+			var indexExists = 0;
+			using (var command = connection.CreateCommand ()) {
+				command.CommandText = query;
+				using (var reader = command.ExecuteReader ()) {
+					reader.Read ();
+					indexExists = reader.GetInt32 (0);
+				}
+			}
+
+			if (indexExists == 1) {
+				using (var command = connection.CreateCommand ()) {
+					command.CommandText = string.Format ("DROP INDEX {0} ON {1}", indexName, tableName);
+					command.ExecuteNonQuery ();
+				}
+			}
+		}
+
+		/// <summary>
+		/// Gets the database command to select the record matching the specified certificate.
+		/// </summary>
+		/// <remarks>
+		/// Gets the database command to select the record matching the specified certificate.
+		/// </remarks>
+		/// <returns>The database command.</returns>
+		/// <param name="connection">The database connection.</param>
+		/// <param name="certificate">The certificate.</param>
+		/// <param name="fields">The fields to return.</param>
+		protected override DbCommand GetSelectCommand (DbConnection connection, X509Certificate certificate, X509CertificateRecordFields fields)
+		{
+			var fingerprint = certificate.GetFingerprint ().ToLowerInvariant ();
+			var serialNumber = certificate.SerialNumber.ToString ();
+			var issuerName = certificate.IssuerDN.ToString ();
+			var command = connection.CreateCommand ();
+			var query = CreateSelectQuery (fields);
+
+			// FIXME: Is this really the best way to query for an exact match of a certificate?
+			query = query.Append (" WHERE ISSUERNAME = @ISSUERNAME AND SERIALNUMBER = @SERIALNUMBER AND FINGERPRINT = @FINGERPRINT LIMIT 1;");
+			command.AddParameterWithValue ("@ISSUERNAME", issuerName);
+			command.AddParameterWithValue ("@SERIALNUMBER", serialNumber);
+			command.AddParameterWithValue ("@FINGERPRINT", fingerprint);
+
+			command.CommandText = query.ToString ();
+			command.CommandType = CommandType.Text;
+
+			return command;
+		}
+
+		/// <summary>
+		/// Gets the database command to insert the specified certificate record.
+		/// </summary>
+		/// <remarks>
+		/// Gets the database command to insert the specified certificate record.
+		/// </remarks>
+		/// <returns>The database command.</returns>
+		/// <param name="connection">The database connection.</param>
+		/// <param name="record">The certificate record.</param>
+		protected override DbCommand GetInsertCommand (DbConnection connection, X509CertificateRecord record)
+		{
+			var statement = new StringBuilder ("INSERT INTO CERTIFICATES(");
+			var variables = new StringBuilder ("VALUES(");
+			var command = connection.CreateCommand ();
+			var columns = CertificatesTable.Columns;
+
+			for (int i = 1; i < columns.Count; i++) {
+				if (i > 1) {
+					statement.Append (", ");
+					variables.Append (", ");
+				}
+
+				var value = GetValue (record, columns[i].ColumnName);
+				if (value is DateTime dateTime && dateTime < DateUtils.UnixEpoch)
+					value = DateUtils.UnixEpoch;
+
+				if (columns[i].ColumnName == "PRIVATEKEY" && value is DBNull)
+					value = Array.Empty<byte> ();
+
+				var variable = "@" + columns[i];
+
+				command.AddParameterWithValue (variable, value);
+				statement.Append (columns[i]);
+				variables.Append (variable);
+			}
+
+			statement.Append (')');
+			variables.Append (')');
+
+			command.CommandText = statement + " " + variables;
+			command.CommandType = CommandType.Text;
+
+			return command;
+		}
+
+		private static string GenerateIndexName(string tableName, string[] columnNames)
+		{
+			var name = string.Format ("{0}_{1}_INDEX", tableName, string.Join ("_", columnNames));
+			return name.Length <= 64 ? name : name.Substring (0, 56) + name.GetHashCode().ToString("X8");
+		}
+	}
+}