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1 /* |
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2 * Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies). |
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3 * All rights reserved. |
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4 * This component and the accompanying materials are made available |
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5 * under the terms of the License "Eclipse Public License v1.0" |
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6 * which accompanies this distribution, and is available |
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7 * at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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8 * |
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9 * Initial Contributors: |
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10 * Nokia Corporation - initial contribution. |
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11 * |
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12 * Contributors: |
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13 * |
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14 * Description: |
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15 * |
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16 */ |
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17 |
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18 |
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19 #ifndef ARC4IMPL_H |
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20 #define ARC4IMPL_H |
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21 |
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22 /** |
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23 @file |
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24 @internalComponent |
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25 @released |
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26 */ |
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27 |
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28 #include "symmetriccipherimpl.h" |
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29 #include <e32base.h> |
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30 #include <e32cmn.h> |
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31 #include "keys.h" |
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32 |
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33 |
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34 /** |
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35 Plug-in class for ARC4 stream cipher |
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36 */ |
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37 namespace SoftwareCrypto |
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38 { |
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39 using namespace CryptoSpi; |
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40 |
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41 NONSHARABLE_CLASS(CArc4Impl) : public CSymmetricStreamCipherImpl |
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42 { |
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43 public: |
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44 |
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45 /** |
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46 Number of bytes to discard by default from an ARC4 key stream. |
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47 */ |
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48 static const TUint KDefaultDiscardBytes = 768; |
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49 |
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50 /** |
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51 The size of the substitution box (i.e. lookup table) in bytes. |
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52 */ |
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53 static const TInt KSBoxSize = 256; |
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54 |
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55 /** |
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56 Maximum ARC4 key size in bytes.2048 bits |
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57 */ |
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58 static const TInt KMaxARC4KeyBytes = 256; |
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59 |
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60 /** |
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61 Creates an instance of an ARC4 symmetric cipher plug-in. |
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62 @param aKey The key |
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63 @param aDiscardBytes The number of bytes to drop from |
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64 the beginning of the key stream. |
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65 @return A pointer to a CArc4Impl instance |
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66 */ |
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67 static CArc4Impl* NewL(const CKey& aKey, TInt aDiscardBytes); |
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68 |
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69 /** |
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70 Creates an instance of an ARC4 symmetric cipher plug-in, |
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71 and leave it on the cleanup stack |
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72 @param aKey The key |
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73 @param aDiscardBytes The number of bytes to drop from |
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74 the beginning of the key stream. |
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75 @return A pointer to a CArc4Impl instance |
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76 */ |
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77 static CArc4Impl* NewLC(const CKey& aKey, TInt aDiscardBytes); |
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78 |
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79 //Destructor |
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80 ~CArc4Impl(); |
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81 |
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82 //Override MPlugin virtual function |
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83 void Reset(); |
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84 |
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85 //Override CSymmetricCipherImpl virtual functions |
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86 TUid ImplementationUid() const; |
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87 TBool IsValidKeyLength(TInt aKeyBytes) const; |
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88 const CExtendedCharacteristics* GetExtendedCharacteristicsL(); |
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89 |
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90 static CExtendedCharacteristics* CreateExtendedCharacteristicsL(); |
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91 |
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92 private: |
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93 //Constructor |
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94 CArc4Impl(TInt aDiscardBytes); |
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95 |
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96 //second phase of construction |
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97 void ConstructL(const CKey& aKey); |
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98 |
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99 //Override CSymmetricStreamCipherImpl virtual functions |
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100 void DoProcess(TDes8& aData); |
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101 |
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102 void GenerateSBox(); |
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103 TUint8 GenerateByte(); |
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104 void DiscardBytes(TInt aDiscardBytes); |
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105 |
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106 private: |
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107 TUint8 ix; |
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108 TUint8 iy; |
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109 TInt iDiscardBytes; |
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110 TUint8 iState[KSBoxSize]; |
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111 }; |
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112 } |
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113 |
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114 #endif //ARC4IMPL_H |
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115 |
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116 |
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117 |