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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 "rsaimpl.h" |
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20 #include "rsafunction.h" |
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21 #include "pluginconfig.h" |
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22 #include <cryptopanic.h> |
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23 #include <cryptostrength.h> |
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24 #include <securityerr.h> |
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25 |
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26 using namespace SoftwareCrypto; |
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27 |
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28 /* CRSAImpl */ |
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29 CRSAImpl::CRSAImpl( |
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30 TUid aImplementationUid, |
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31 TUid aCryptoMode, |
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32 TUid aPadding) : |
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33 CAsymmetricCipherImpl(aCryptoMode, aPadding), |
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34 iImplementationUid(aImplementationUid) |
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35 { |
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36 } |
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37 |
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38 CRSAImpl* CRSAImpl::NewL(TUid aImplementationUid, const CKey& aKey, TUid aCryptoMode, TUid aPadding) |
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39 { |
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40 CRSAImpl* self = CRSAImpl::NewLC(aImplementationUid, aKey, aCryptoMode, aPadding); |
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41 CleanupStack::Pop(self); |
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42 return self; |
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43 } |
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44 |
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45 CRSAImpl* CRSAImpl::NewLC(TUid aImplementationUid, const CKey& aKey, TUid aCryptoMode, TUid aPadding) |
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46 { |
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47 CRSAImpl* self = new(ELeave) CRSAImpl(aImplementationUid, aCryptoMode, aPadding); |
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48 CleanupStack::PushL(self); |
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49 self->ConstructL(aKey); |
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50 return self; |
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51 } |
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52 |
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53 CRSAImpl::~CRSAImpl() |
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54 { |
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55 } |
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56 |
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57 TInt CRSAImpl::GetMaximumOutputLengthL() const |
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58 { |
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59 const TInteger& N = iKey->GetBigIntL(KRsaKeyParameterNUid); |
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60 |
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61 if (iCryptoMode.iUid == KCryptoModeDecrypt) |
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62 return N.ByteCount() - iPadding->MinPaddingLength(); |
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63 else |
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64 return N.ByteCount(); |
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65 } |
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66 |
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67 TInt CRSAImpl::GetMaximumInputLengthL() const |
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68 { |
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69 const TInteger& N = iKey->GetBigIntL(KRsaKeyParameterNUid); |
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70 |
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71 if (iCryptoMode.iUid == KCryptoModeEncrypt) |
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72 return N.ByteCount() - iPadding->MinPaddingLength(); |
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73 else |
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74 return N.ByteCount(); |
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75 } |
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76 |
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77 void CRSAImpl::ConstructL(const CKey& aKey) |
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78 { |
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79 const TInteger& N = aKey.GetBigIntL(KRsaKeyParameterNUid); |
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80 TCrypto::IsAsymmetricWeakEnoughL(N.BitCount()); |
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81 CAsymmetricCipherImpl::ConstructL(aKey); |
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82 |
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83 if (! IsValidKeyLengthL(N.ByteCount())) |
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84 { |
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85 User::Leave(KErrKeySize); |
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86 } |
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87 } |
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88 |
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89 CExtendedCharacteristics* CRSAImpl::CreateExtendedCharacteristicsL() |
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90 { |
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91 // All Symbian software plug-ins have unlimited concurrency, cannot be reserved |
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92 // for exclusive use and are not CERTIFIED to be standards compliant. |
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93 return CExtendedCharacteristics::NewL(KMaxTInt, EFalse); |
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94 } |
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95 |
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96 const CExtendedCharacteristics* CRSAImpl::GetExtendedCharacteristicsL() |
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97 { |
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98 return CRSAImpl::CreateExtendedCharacteristicsL(); |
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99 } |
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100 |
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101 TUid CRSAImpl::ImplementationUid() const |
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102 { |
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103 return iImplementationUid; |
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104 } |
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105 |
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106 void CRSAImpl::EncryptL(const TDesC8& aInput, TDes8& aOutput) const |
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107 { |
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108 __ASSERT_DEBUG(aOutput.MaxLength() >= GetMaximumOutputLengthL(), User::Panic(KCryptoPanic, ECryptoPanicOutputDescriptorOverflow)); |
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109 __ASSERT_DEBUG(aInput.Length() <= GetMaximumInputLengthL(), User::Panic(KCryptoPanic, ECryptoPanicInputTooLarge)); |
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110 |
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111 HBufC8* buf = HBufC8::NewLC(GetMaximumOutputLengthL()); |
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112 TPtr8 ptr = buf->Des(); |
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113 |
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114 iPadding->PadL(aInput, ptr); |
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115 RInteger input = RInteger::NewL(ptr); |
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116 CleanupStack::PushL(input); |
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117 |
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118 RInteger output; |
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119 RSAFunction::EncryptL(*iKey, input, output); |
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120 CleanupStack::PushL(output); |
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121 |
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122 aOutput.Append(*(output.BufferLC())); |
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123 CleanupStack::PopAndDestroy(4, buf); //BufferLC, output, input, buf |
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124 } |
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125 |
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126 void CRSAImpl::DecryptL(const TDesC8& aInput, TDes8& aOutput) const |
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127 { |
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128 __ASSERT_DEBUG(aOutput.MaxLength() >= GetMaximumOutputLengthL(), User::Panic(KCryptoPanic, ECryptoPanicOutputDescriptorOverflow)); |
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129 __ASSERT_DEBUG(aInput.Length() <= GetMaximumInputLengthL(), User::Panic(KCryptoPanic, ECryptoPanicInputTooLarge)); |
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130 |
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131 RInteger input = RInteger::NewL(aInput); |
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132 CleanupStack::PushL(input); |
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133 |
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134 RInteger output; |
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135 |
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136 RSAFunction::DecryptL(*iKey, input, output); |
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137 CleanupStack::PushL(output); |
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138 |
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139 TPtrC8 ptr = *(output.BufferLC()); |
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140 iPadding->UnPadL(ptr, aOutput); |
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141 |
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142 CleanupStack::PopAndDestroy(3, &input); //BufferLC(), output, input |
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143 } |
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144 |
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145 void CRSAImpl::ProcessL(const TDesC8& aInput, TDes8& aOutput) |
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146 { |
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147 if (iCryptoMode.iUid == KCryptoModeEncrypt) |
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148 { |
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149 EncryptL(aInput, aOutput); |
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150 } |
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151 else |
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152 { |
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153 DecryptL(aInput, aOutput); |
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154 } |
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155 } |
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156 |
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157 TBool CRSAImpl::IsValidKeyLengthL(TInt aKeyBytes) const |
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158 { |
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159 if (aKeyBytes < 1) |
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160 return EFalse; |
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161 |
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162 switch (iCryptoMode.iUid) |
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163 { |
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164 case KCryptoModeEncrypt: |
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165 // Check if GetMaximumInputLengthL() makes sense, |
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166 // if not the key length must be too small |
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167 if (GetMaximumInputLengthL() <= 0) |
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168 return EFalse; |
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169 break; |
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170 |
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171 case KCryptoModeDecrypt: |
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172 // Check if GetMaximumOutputLengthL() makes sense, |
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173 // if not the key length must be too small |
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174 if (GetMaximumOutputLengthL() <= 0) |
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175 return EFalse; |
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176 break; |
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177 } |
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178 return ETrue; |
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179 } |
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180 |