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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 #include "desimpl.h" |
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20 |
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21 #include "destables.h" |
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22 #include "../../../source/common/inlines.h" |
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23 #include "des.inl" |
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24 #include "pluginconfig.h" |
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25 #include "symmetriccipherimpl.h" |
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26 #include <cryptostrength.h> |
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27 |
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28 |
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29 // bit 0 is left-most in byte |
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30 static const TInt bytebit[] = {0200,0100,040,020,010,04,02,01}; |
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31 |
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32 using namespace SoftwareCrypto; |
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33 |
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34 /* CDesImpl */ |
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35 CDesImpl::CDesImpl( |
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36 TUid aImplementationUid, |
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37 TUint8 aBlockBytes, |
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38 TUid aCryptoMode, |
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39 TUid aOperationMode, |
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40 TUid aPadding) : |
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41 CSymmetricBlockCipherImpl(aBlockBytes, aCryptoMode, aOperationMode, aPadding), |
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42 iImplementationUid(aImplementationUid) |
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43 { |
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44 } |
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45 |
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46 CDesImpl* CDesImpl::NewL(TUid aImplementationUid, const CKey& aKey, TUid aCryptoMode, TUid aOperationMode, TUid aPadding) |
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47 { |
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48 CDesImpl* self = CDesImpl::NewLC(aImplementationUid, aKey, aCryptoMode, aOperationMode, aPadding); |
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49 CleanupStack::Pop(self); |
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50 return self; |
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51 } |
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52 |
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53 CDesImpl* CDesImpl::NewLC(TUid aImplementationUid, const CKey& aKey, TUid aCryptoMode, TUid aOperationMode, TUid aPadding) |
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54 { |
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55 CDesImpl* self = new(ELeave) CDesImpl(aImplementationUid, KDesBlockBytes, aCryptoMode, aOperationMode, aPadding); |
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56 CleanupStack::PushL(self); |
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57 self->ConstructL(aKey); |
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58 |
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59 const TDesC8& keyContent = aKey.GetTDesC8L(KSymmetricKeyParameterUid); |
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60 TCrypto::IsSymmetricWeakEnoughL(BytesToBits(keyContent.Size()) - keyContent.Size()); |
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61 return self; |
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62 } |
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63 |
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64 CDesImpl::~CDesImpl() |
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65 { |
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66 // make sure key information isn't visible to other processes if the |
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67 // page is reused. |
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68 Mem::FillZ(&iK, sizeof(iK)); |
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69 } |
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70 |
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71 void CDesImpl::ConstructL(const CKey& aKey) |
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72 { |
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73 CSymmetricBlockCipherImpl::ConstructL(aKey); |
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74 SetKeySchedule(); |
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75 } |
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76 |
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77 CExtendedCharacteristics* CDesImpl::CreateExtendedCharacteristicsL() |
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78 { |
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79 // All Symbian software plug-ins have unlimited concurrency, cannot be reserved |
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80 // for exclusive use and are not CERTIFIED to be standards compliant. |
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81 |
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82 return CExtendedCharacteristics::NewL(KMaxTInt, EFalse); |
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83 } |
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84 |
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85 const CExtendedCharacteristics* CDesImpl::GetExtendedCharacteristicsL() |
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86 { |
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87 return CDesImpl::CreateExtendedCharacteristicsL(); |
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88 } |
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89 |
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90 TUid CDesImpl::ImplementationUid() const |
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91 { |
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92 return iImplementationUid; |
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93 } |
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94 |
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95 TBool CDesImpl::IsValidKeyLength(TInt aKeyBytes) const |
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96 { |
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97 return (aKeyBytes == KDesKeyBytes); |
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98 } |
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99 |
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100 TInt CDesImpl::GetKeyStrength() const |
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101 { |
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102 // parity bits are excluded |
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103 return BytesToBits(KDesKeyBytes - 8); |
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104 } |
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105 |
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106 void CDesImpl::TransformEncrypt( |
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107 TUint8* aBuffer, |
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108 TUint aNumBlocks) |
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109 { |
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110 for (TInt i = 0; i < aNumBlocks; ++i) |
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111 { |
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112 ModeEncryptStart(aBuffer); |
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113 TUint32 l, r; |
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114 // Split the block into 2 word-sized big endian portions |
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115 GetBlockBigEndian(aBuffer, l, r); |
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116 IPerm(l,r); |
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117 DoTransform(l, r, iK); |
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118 FPerm(l,r); |
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119 |
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120 // Put the portions back into the block as little endian |
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121 PutBlockBigEndian(aBuffer, r, l); |
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122 |
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123 ModeEncryptEnd(aBuffer); |
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124 aBuffer += KDesBlockBytes; |
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125 } |
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126 } |
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127 |
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128 void CDesImpl::TransformDecrypt( |
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129 TUint8* aBuffer, |
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130 TUint aNumBlocks) |
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131 { |
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132 for (TInt i = 0; i < aNumBlocks; ++i) |
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133 { |
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134 ModeDecryptStart(aBuffer); |
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135 |
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136 TUint32 l, r; |
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137 // Split the block into 2 word-sized big endian portions |
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138 GetBlockBigEndian(aBuffer, l, r); |
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139 |
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140 IPerm(l,r); |
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141 DoTransform(l, r, iK); |
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142 FPerm(l,r); |
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143 |
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144 // Put the portions back into the block as little endian |
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145 PutBlockBigEndian(aBuffer, r, l); |
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146 |
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147 ModeDecryptEnd(aBuffer); |
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148 aBuffer += KDesBlockBytes; |
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149 } |
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150 } |
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151 |
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152 void CDesImpl::SetKeySchedule() |
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153 { |
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154 if (iCryptoMode.iUid == KCryptoModeEncrypt) |
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155 { |
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156 SetEncryptKeySchedule(*iKey, iK); |
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157 } |
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158 else |
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159 { |
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160 ASSERT(iCryptoMode.iUid == KCryptoModeDecrypt); |
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161 SetDecryptKeySchedule(*iKey, iK); |
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162 } |
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163 } |
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164 |
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165 void CDesImpl::DoTransform(TUint32& l, TUint32& r, const TUint32* aKeySchedule) |
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166 { |
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167 TInt i = 0; |
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168 for (; i<8; i++) |
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169 { |
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170 TUint32 work = rotrFixed(r, 4U) ^ aKeySchedule[4*i+0]; |
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171 l ^= DES_TABLE::sbox[6][(work) & 0x3f] |
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172 ^ DES_TABLE::sbox[4][(work >> 8) & 0x3f] |
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173 ^ DES_TABLE::sbox[2][(work >> 16) & 0x3f] |
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174 ^ DES_TABLE::sbox[0][(work >> 24) & 0x3f]; |
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175 work = r ^ aKeySchedule[4*i+1]; |
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176 l ^= DES_TABLE::sbox[7][(work) & 0x3f] |
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177 ^ DES_TABLE::sbox[5][(work >> 8) & 0x3f] |
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178 ^ DES_TABLE::sbox[3][(work >> 16) & 0x3f] |
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179 ^ DES_TABLE::sbox[1][(work >> 24) & 0x3f]; |
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180 |
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181 work = rotrFixed(l, 4U) ^ aKeySchedule[4*i+2]; |
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182 r ^= DES_TABLE::sbox[6][(work) & 0x3f] |
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183 ^ DES_TABLE::sbox[4][(work >> 8) & 0x3f] |
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184 ^ DES_TABLE::sbox[2][(work >> 16) & 0x3f] |
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185 ^ DES_TABLE::sbox[0][(work >> 24) & 0x3f]; |
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186 work = l ^ aKeySchedule[4*i+3]; |
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187 r ^= DES_TABLE::sbox[7][(work) & 0x3f] |
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188 ^ DES_TABLE::sbox[5][(work >> 8) & 0x3f] |
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189 ^ DES_TABLE::sbox[3][(work >> 16) & 0x3f] |
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190 ^ DES_TABLE::sbox[1][(work >> 24) & 0x3f]; |
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191 } |
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192 } |
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193 |
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194 void CDesImpl::SetEncryptKeySchedule(const TDesC8& aKey, TUint32* aKeySchedule) |
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195 { |
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196 TInt i=0, j=0, l=0, m=0; |
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197 |
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198 // Form a byte array from aKey, taking endianess into account (little->big) |
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199 TUint8 key[8]; // For big endian byte array |
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200 Mem::Copy(&key, &aKey[0], 8); |
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201 |
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202 TUint8 buffer[56+56+8]; |
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203 TUint8* const pc1m = &buffer[0]; /* place to modify pc1 into */ |
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204 TUint8* const pcr = pc1m + 56; /* place to rotate pc1 into */ |
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205 TUint8* const ks = pcr + 56; |
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206 |
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207 for (j=0; j<56; j++) |
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208 {/* convert pc1 to bits of key */ |
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209 l = DES_TABLE::pc1[j]-1; /* integer bit location */ |
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210 m = l & 07; /* find bit */ |
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211 pc1m[j]=(key[l>>3] & /* find which key byte l is in */ |
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212 bytebit[m]) /* and which bit of that byte */ |
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213 ? (TUint8)1 : (TUint8)0; /* and store 1-bit result */ |
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214 } |
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215 |
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216 for (i=0; i<16; i++) |
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217 {/* key chunk for each iteration */ |
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218 Mem::FillZ(ks,8); /* Clear key schedule */ |
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219 for (j=0; j<56; j++) |
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220 /* rotate pc1 the right amount */ |
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221 pcr[j] = pc1m[(l=j+DES_TABLE::totrot[i])<(j<28? 28 : 56) ? l: l-28]; |
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222 |
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223 /* rotate left and right halves independently */ |
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224 |
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225 for (j=0; j<48; j++) |
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226 {/* select bits individually */ |
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227 /* check bit that goes to ks[j] */ |
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228 if (pcr[DES_TABLE::pc2[j]-1]) |
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229 {/* mask it in if it's there */ |
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230 l= j % 6; |
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231 ks[j/6] |= bytebit[l] >> 2; |
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232 } |
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233 } |
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234 |
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235 /* Now convert to odd/even interleaved form for use in F */ |
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236 (*(aKeySchedule+(2*i))) = ((TUint32)ks[0] << 24) |
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237 | ((TUint32)ks[2] << 16) |
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238 | ((TUint32)ks[4] << 8) |
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239 | ((TUint32)ks[6]); |
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240 |
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241 (*(aKeySchedule+(2*i+1))) = ((TUint32)ks[1] << 24) |
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242 | ((TUint32)ks[3] << 16) |
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243 | ((TUint32)ks[5] << 8) |
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244 | ((TUint32)ks[7]); |
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245 } |
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246 } |
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247 |
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248 void CDesImpl::SetDecryptKeySchedule(const TDesC8& aKey, TUint32* aKeySchedule) |
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249 { |
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250 SetEncryptKeySchedule(aKey, aKeySchedule); |
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251 ReverseKeySchedule(aKeySchedule); |
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252 } |