1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
|
//------------------------------------------------------------------------------
// <copyright file="SqlException.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
// <owner current="true" primary="true">balnee</owner>
// <owner current="true" primary="false">krishnib</owner>
//------------------------------------------------------------------------------
namespace System.Data.SqlClient
{
using System;
using System.Data.SqlClient;
using System.Security.Cryptography;
/// <summary>
/// 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.
/// If an algorithm needs to derive more keys, have a derived class from this and use it in the corresponding encryption algorithm.
/// </summary>
internal class SqlClientSymmetricKey {
/// <summary>
/// The underlying key material
/// </summary>
protected readonly byte[] _rootKey;
/// <summary>
/// Constructor that initializes the root key.
/// </summary>
/// <param name="rootKey">root key</param>
internal SqlClientSymmetricKey(byte[] rootKey) {
// Key validation
if (rootKey == null || rootKey.Length == 0) {
throw SQL.NullColumnEncryptionKeySysErr();
}
_rootKey = rootKey;
}
/// <summary>
/// Empty destructor for binary back compat.
/// </summary>
~SqlClientSymmetricKey() {
}
/// <summary>
/// Returns a copy of the plain text key
/// This is needed for actual encryption/decryption.
/// </summary>
internal virtual byte[] RootKey {
get {
return _rootKey;
}
}
/// <summary>
/// Computes SHA256 value of the plain text key bytes
/// </summary>
/// <returns>A string containing SHA256 hash of the root key</returns>
internal virtual string GetKeyHash() {
return SqlSecurityUtility.GetSHA256Hash(RootKey);
}
/// <summary>
/// Gets the length of the root key
/// </summary>
/// <returns>
/// Returns the length of the root key
/// </returns>
internal virtual int Length() {
return _rootKey.Length;
}
}
}
|
