|
1 /* |
|
2 * Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies). |
|
3 * All rights reserved. |
|
4 * This component and the accompanying materials are made available |
|
5 * under the terms of the License "Eclipse Public License v1.0" |
|
6 * which accompanies this distribution, and is available |
|
7 * at the URL "http://www.eclipse.org/legal/epl-v10.html". |
|
8 * |
|
9 * Initial Contributors: |
|
10 * Nokia Corporation - initial contribution. |
|
11 * |
|
12 * Contributors: |
|
13 * |
|
14 * Description: |
|
15 * |
|
16 */ |
|
17 |
|
18 |
|
19 #include <bigint.h> |
|
20 #include <asymmetrickeys.h> |
|
21 #include "rsafunction.h" |
|
22 #include "../bigint/mont.h" |
|
23 |
|
24 //Public Encrypt |
|
25 void RSAFunction::EncryptL(const CRSAPublicKey& aPublicKey, |
|
26 const TInteger& aInput, RInteger& aOutput) |
|
27 { |
|
28 FunctionL(aPublicKey.N(), aPublicKey.E(), aInput, aOutput); |
|
29 } |
|
30 |
|
31 //Private Decrypt |
|
32 void RSAFunction::DecryptL(const CRSAPrivateKey& aPrivateKey, |
|
33 const TInteger& aInput, RInteger& aOutput) |
|
34 { |
|
35 if (aPrivateKey.PrivateKeyType()==EStandard) |
|
36 { |
|
37 const CRSAPrivateKeyStandard* stdKey = |
|
38 static_cast<const CRSAPrivateKeyStandard*>(&aPrivateKey); |
|
39 FunctionL(aPrivateKey.N(), stdKey->D(), aInput, aOutput); |
|
40 } |
|
41 else if (aPrivateKey.PrivateKeyType()==EStandardCRT) |
|
42 { |
|
43 FunctionCRTL(static_cast<const CRSAPrivateKeyCRT&>(aPrivateKey), aInput, |
|
44 aOutput); |
|
45 } |
|
46 else |
|
47 { |
|
48 User::Leave(KErrNotSupported); |
|
49 } |
|
50 } |
|
51 |
|
52 //Private Encrypt |
|
53 void RSAFunction::SignL(const CRSAPrivateKey& aPrivateKey, |
|
54 const TInteger& aInput, RInteger& aOutput) |
|
55 { |
|
56 if (aPrivateKey.PrivateKeyType()==EStandard) |
|
57 { |
|
58 const CRSAPrivateKeyStandard* stdKey = |
|
59 static_cast<const CRSAPrivateKeyStandard*>(&aPrivateKey); |
|
60 FunctionL(aPrivateKey.N(), stdKey->D(), aInput, aOutput); |
|
61 } |
|
62 else if (aPrivateKey.PrivateKeyType()==EStandardCRT) |
|
63 { |
|
64 FunctionCRTL(static_cast<const CRSAPrivateKeyCRT&>(aPrivateKey), aInput, |
|
65 aOutput); |
|
66 } |
|
67 else |
|
68 { |
|
69 User::Leave(KErrNotSupported); |
|
70 } |
|
71 } |
|
72 |
|
73 //Public Decrypt |
|
74 void RSAFunction::VerifyL(const CRSAPublicKey& aPublicKey, |
|
75 const TInteger& aInput, RInteger& aOutput) |
|
76 { |
|
77 FunctionL(aPublicKey.N(), aPublicKey.E(), aInput, aOutput); |
|
78 } |
|
79 |
|
80 //The RSA Trapdoor Function |
|
81 void RSAFunction::FunctionL(const TInteger& aModulus, const TInteger& aExponent, |
|
82 const TInteger& aBase, RInteger& aOutput) |
|
83 { |
|
84 IsInputValidL(aBase, aModulus); |
|
85 |
|
86 aOutput = TInteger::ModularExponentiateL(aBase, aExponent, aModulus); |
|
87 } |
|
88 |
|
89 //The CRT version of the RSA Trapdoor Function |
|
90 void RSAFunction::FunctionCRTL(const CRSAPrivateKeyCRT& aPrivateKey, |
|
91 const TInteger& aInput, RInteger& aOutput) |
|
92 { |
|
93 IsInputValidL(aInput, aPrivateKey.N()); |
|
94 |
|
95 CMontgomeryStructure* montP = CMontgomeryStructure::NewLC(aPrivateKey.P()); |
|
96 CMontgomeryStructure* montQ = CMontgomeryStructure::NewLC(aPrivateKey.Q()); |
|
97 |
|
98 const TInteger& p = aPrivateKey.P(); |
|
99 const TInteger& q = aPrivateKey.Q(); |
|
100 const TInteger& u = aPrivateKey.QInv(); |
|
101 |
|
102 //m1 = c^(dP) mod(p) |
|
103 RInteger inputReduced = aInput.ModuloL(aPrivateKey.P()); |
|
104 CleanupStack::PushL(inputReduced); |
|
105 const TInteger& m1 = montP->ExponentiateL(inputReduced, aPrivateKey.DP()); |
|
106 CleanupStack::PopAndDestroy(&inputReduced); |
|
107 |
|
108 //m2 = c^(dQ) mod(Q) |
|
109 inputReduced = aInput.ModuloL(aPrivateKey.Q()); |
|
110 CleanupStack::PushL(inputReduced); |
|
111 const TInteger& m2 = montQ->ExponentiateL(inputReduced, aPrivateKey.DQ()); |
|
112 CleanupStack::PopAndDestroy(&inputReduced); |
|
113 |
|
114 //Calculate CRT |
|
115 //h = (m1-m2) qInv mod(p) |
|
116 RInteger h = m1.MinusL(m2); |
|
117 CleanupStack::PushL(h); |
|
118 h *= u; |
|
119 h %= p; |
|
120 |
|
121 //m = m2 + q * h |
|
122 h *= q; |
|
123 h += m2; |
|
124 |
|
125 aOutput = h; |
|
126 CleanupStack::Pop(&h); |
|
127 |
|
128 CleanupStack::PopAndDestroy(montQ); |
|
129 CleanupStack::PopAndDestroy(montP); |
|
130 } |