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1 /* |
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2 * Copyright (c) 2003-2009 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 <bigint.h> |
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20 #include <asymmetrickeys.h> |
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21 #include "rsafunction.h" |
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22 #include "../bigint/mont.h" |
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23 |
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24 //Public Encrypt |
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25 void RSAFunction::EncryptL(const CRSAPublicKey& aPublicKey, |
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26 const TInteger& aInput, RInteger& aOutput) |
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27 { |
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28 FunctionL(aPublicKey.N(), aPublicKey.E(), aInput, aOutput); |
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29 } |
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30 |
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31 //Private Decrypt |
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32 void RSAFunction::DecryptL(const CRSAPrivateKey& aPrivateKey, |
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33 const TInteger& aInput, RInteger& aOutput) |
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34 { |
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35 if (aPrivateKey.PrivateKeyType()==EStandard) |
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36 { |
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37 const CRSAPrivateKeyStandard* stdKey = |
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38 static_cast<const CRSAPrivateKeyStandard*>(&aPrivateKey); |
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39 FunctionL(aPrivateKey.N(), stdKey->D(), aInput, aOutput); |
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40 } |
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41 else if (aPrivateKey.PrivateKeyType()==EStandardCRT) |
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42 { |
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43 FunctionCRTL(static_cast<const CRSAPrivateKeyCRT&>(aPrivateKey), aInput, |
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44 aOutput); |
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45 } |
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46 else |
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47 { |
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48 User::Leave(KErrNotSupported); |
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49 } |
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50 } |
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51 |
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52 //Private Encrypt |
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53 void RSAFunction::SignL(const CRSAPrivateKey& aPrivateKey, |
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54 const TInteger& aInput, RInteger& aOutput) |
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55 { |
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56 if (aPrivateKey.PrivateKeyType()==EStandard) |
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57 { |
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58 const CRSAPrivateKeyStandard* stdKey = |
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59 static_cast<const CRSAPrivateKeyStandard*>(&aPrivateKey); |
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60 FunctionL(aPrivateKey.N(), stdKey->D(), aInput, aOutput); |
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61 } |
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62 else if (aPrivateKey.PrivateKeyType()==EStandardCRT) |
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63 { |
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64 FunctionCRTL(static_cast<const CRSAPrivateKeyCRT&>(aPrivateKey), aInput, |
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65 aOutput); |
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66 } |
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67 else |
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68 { |
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69 User::Leave(KErrNotSupported); |
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70 } |
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71 } |
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72 |
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73 //Public Decrypt |
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74 void RSAFunction::VerifyL(const CRSAPublicKey& aPublicKey, |
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75 const TInteger& aInput, RInteger& aOutput) |
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76 { |
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77 FunctionL(aPublicKey.N(), aPublicKey.E(), aInput, aOutput); |
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78 } |
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79 |
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80 //The RSA Trapdoor Function |
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81 void RSAFunction::FunctionL(const TInteger& aModulus, const TInteger& aExponent, |
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82 const TInteger& aBase, RInteger& aOutput) |
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83 { |
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84 IsInputValidL(aBase, aModulus); |
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85 |
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86 aOutput = TInteger::ModularExponentiateL(aBase, aExponent, aModulus); |
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87 } |
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88 |
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89 //The CRT version of the RSA Trapdoor Function |
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90 void RSAFunction::FunctionCRTL(const CRSAPrivateKeyCRT& aPrivateKey, |
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91 const TInteger& aInput, RInteger& aOutput) |
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92 { |
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93 IsInputValidL(aInput, aPrivateKey.N()); |
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94 |
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95 CMontgomeryStructure* montP = CMontgomeryStructure::NewLC(aPrivateKey.P()); |
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96 CMontgomeryStructure* montQ = CMontgomeryStructure::NewLC(aPrivateKey.Q()); |
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97 |
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98 const TInteger& p = aPrivateKey.P(); |
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99 const TInteger& q = aPrivateKey.Q(); |
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100 const TInteger& u = aPrivateKey.QInv(); |
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101 |
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102 //m1 = c^(dP) mod(p) |
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103 RInteger inputReduced = aInput.ModuloL(aPrivateKey.P()); |
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104 CleanupStack::PushL(inputReduced); |
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105 const TInteger& m1 = montP->ExponentiateL(inputReduced, aPrivateKey.DP()); |
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106 CleanupStack::PopAndDestroy(&inputReduced); |
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107 |
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108 //m2 = c^(dQ) mod(Q) |
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109 inputReduced = aInput.ModuloL(aPrivateKey.Q()); |
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110 CleanupStack::PushL(inputReduced); |
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111 const TInteger& m2 = montQ->ExponentiateL(inputReduced, aPrivateKey.DQ()); |
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112 CleanupStack::PopAndDestroy(&inputReduced); |
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113 |
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114 //Calculate CRT |
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115 //h = (m1-m2) qInv mod(p) |
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116 RInteger h = m1.MinusL(m2); |
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117 CleanupStack::PushL(h); |
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118 h *= u; |
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119 h %= p; |
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120 |
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121 //m = m2 + q * h |
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122 h *= q; |
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123 h += m2; |
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124 |
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125 aOutput = h; |
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126 CleanupStack::Pop(&h); |
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127 |
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128 CleanupStack::PopAndDestroy(montQ); |
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129 CleanupStack::PopAndDestroy(montP); |
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130 } |
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131 |