74 lines
2.5 KiB
C#
74 lines
2.5 KiB
C#
//------------------------------------------------------------------------------
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// <copyright file="SqlException.cs" company="Microsoft">
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// Copyright (c) Microsoft Corporation. All rights reserved.
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// </copyright>
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// <owner current="true" primary="true">balnee</owner>
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// <owner current="true" primary="false">krishnib</owner>
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//------------------------------------------------------------------------------
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namespace System.Data.SqlClient
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{
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using System;
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using System.Data.SqlClient;
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using System.Security.Cryptography;
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/// <summary>
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/// Base class containing raw key bytes for symmetric key algorithms. Some encryption algorithms can use the key directly while others derive sub keys from this.
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/// If an algorithm needs to derive more keys, have a derived class from this and use it in the corresponding encryption algorithm.
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/// </summary>
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internal class SqlClientSymmetricKey
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{
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/// <summary>
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/// DPAPI protected key
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/// </summary>
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protected readonly byte[] _rootKey;
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/// <summary>
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/// Constructor that initializes the root key.
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/// </summary>
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/// <param name="rootKey">root key</param>
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internal SqlClientSymmetricKey(byte[] rootKey)
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{
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// Key validation
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if (rootKey == null || rootKey.Length == 0) {
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throw SQL.NullColumnEncryptionKeySysErr();
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}
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_rootKey = rootKey;
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}
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/// <summary>
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/// Returns a copy of the plain text key
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/// This is needed for actual encryption/decryption.
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/// </summary>
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internal virtual byte[] RootKey
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{
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get
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{
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return _rootKey;
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}
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}
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/// <summary>
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/// Computes SHA256 value of the plain text key bytes
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/// </summary>
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/// <returns>A string containing SHA256 hash of the root key</returns>
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internal virtual string GetKeyHash()
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{
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return SqlSecurityUtility.GetSHA256Hash(RootKey);
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}
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/// <summary>
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/// Gets the length of the root key
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/// </summary>
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/// <returns>
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/// Returns the length of the root key
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/// </returns>
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internal virtual int Length()
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{
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// Note: DPAPI preserves the original byte length
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// so for now, this is as same as returning the length of the raw key.
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return _rootKey.Length;
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}
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}
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}
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