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| 1 | +// 3way.cpp - modifed by Wei Dai from Joan Daemen's 3way.c |
| 2 | +// The original code and all modifications are in the public domain. |
| 3 | + |
| 4 | +#include "pch.h" |
| 5 | +#include "3way.h" |
| 6 | +#include "misc.h" |
| 7 | + |
| 8 | +NAMESPACE_BEGIN(CryptoPP) |
| 9 | + |
| 10 | +void ThreeWay_TestInstantiations() |
| 11 | +{ |
| 12 | + ThreeWay::Encryption x1; |
| 13 | + ThreeWay::Decryption x2; |
| 14 | +} |
| 15 | + |
| 16 | +static const word32 START_E = 0x0b0b; // round constant of first encryption round |
| 17 | +static const word32 START_D = 0xb1b1; // round constant of first decryption round |
| 18 | +static const word32 RC_MODULUS = 0x11011; |
| 19 | + |
| 20 | +static inline word32 reverseBits(word32 a) |
| 21 | +{ |
| 22 | + a = ((a & 0xAAAAAAAA) >> 1) | ((a & 0x55555555) << 1); |
| 23 | + a = ((a & 0xCCCCCCCC) >> 2) | ((a & 0x33333333) << 2); |
| 24 | + return ((a & 0xF0F0F0F0) >> 4) | ((a & 0x0F0F0F0F) << 4); |
| 25 | +} |
| 26 | + |
| 27 | +#define mu(a0, a1, a2) \ |
| 28 | +{ \ |
| 29 | + a1 = reverseBits(a1); \ |
| 30 | + word32 t = reverseBits(a0); \ |
| 31 | + a0 = reverseBits(a2); \ |
| 32 | + a2 = t; \ |
| 33 | +} |
| 34 | + |
| 35 | +#define pi_gamma_pi(a0, a1, a2) \ |
| 36 | +{ \ |
| 37 | + word32 b0, b2; \ |
| 38 | + b2 = rotlFixed(a2, 1U); \ |
| 39 | + b0 = rotlFixed(a0, 22U); \ |
| 40 | + a0 = rotlFixed(b0 ^ (a1|(~b2)), 1U); \ |
| 41 | + a2 = rotlFixed(b2 ^ (b0|(~a1)), 22U);\ |
| 42 | + a1 ^= (b2|(~b0)); \ |
| 43 | +} |
| 44 | + |
| 45 | +// thanks to Paulo Barreto for this optimized theta() |
| 46 | +#define theta(a0, a1, a2) \ |
| 47 | +{ \ |
| 48 | + word32 b0, b1, c; \ |
| 49 | + c = a0 ^ a1 ^ a2; \ |
| 50 | + c = rotlFixed(c, 16U) ^ rotlFixed(c, 8U); \ |
| 51 | + b0 = (a0 << 24) ^ (a2 >> 8) ^ (a1 << 8) ^ (a0 >> 24); \ |
| 52 | + b1 = (a1 << 24) ^ (a0 >> 8) ^ (a2 << 8) ^ (a1 >> 24); \ |
| 53 | + a0 ^= c ^ b0; \ |
| 54 | + a1 ^= c ^ b1; \ |
| 55 | + a2 ^= c ^ (b0 >> 16) ^ (b1 << 16); \ |
| 56 | +} |
| 57 | + |
| 58 | +#define rho(a0, a1, a2) \ |
| 59 | +{ \ |
| 60 | + theta(a0, a1, a2); \ |
| 61 | + pi_gamma_pi(a0, a1, a2); \ |
| 62 | +} |
| 63 | + |
| 64 | +void ThreeWay::Base::UncheckedSetKey(const byte *uk, unsigned int length, const NameValuePairs ¶ms) |
| 65 | +{ |
| 66 | + AssertValidKeyLength(length); |
| 67 | + |
| 68 | + m_rounds = GetRoundsAndThrowIfInvalid(params, this); |
| 69 | + |
| 70 | + for (unsigned int i=0; i<3; i++) |
| 71 | + m_k[i] = (word32)uk[4*i+3] | ((word32)uk[4*i+2]<<8) | ((word32)uk[4*i+1]<<16) | ((word32)uk[4*i]<<24); |
| 72 | + |
| 73 | + if (!IsForwardTransformation()) |
| 74 | + { |
| 75 | + theta(m_k[0], m_k[1], m_k[2]); |
| 76 | + mu(m_k[0], m_k[1], m_k[2]); |
| 77 | + m_k[0] = ByteReverse(m_k[0]); |
| 78 | + m_k[1] = ByteReverse(m_k[1]); |
| 79 | + m_k[2] = ByteReverse(m_k[2]); |
| 80 | + } |
| 81 | +} |
| 82 | + |
| 83 | +void ThreeWay::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const |
| 84 | +{ |
| 85 | + typedef BlockGetAndPut<word32, BigEndian> Block; |
| 86 | + |
| 87 | + word32 a0, a1, a2; |
| 88 | + Block::Get(inBlock)(a0)(a1)(a2); |
| 89 | + |
| 90 | + word32 rc = START_E; |
| 91 | + |
| 92 | + for(unsigned i=0; i<m_rounds; i++) |
| 93 | + { |
| 94 | + a0 ^= m_k[0] ^ (rc<<16); |
| 95 | + a1 ^= m_k[1]; |
| 96 | + a2 ^= m_k[2] ^ rc; |
| 97 | + rho(a0, a1, a2); |
| 98 | + |
| 99 | + rc <<= 1; |
| 100 | + if (rc&0x10000) rc ^= 0x11011; |
| 101 | + } |
| 102 | + a0 ^= m_k[0] ^ (rc<<16); |
| 103 | + a1 ^= m_k[1]; |
| 104 | + a2 ^= m_k[2] ^ rc; |
| 105 | + theta(a0, a1, a2); |
| 106 | + |
| 107 | + Block::Put(xorBlock, outBlock)(a0)(a1)(a2); |
| 108 | +} |
| 109 | + |
| 110 | +void ThreeWay::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const |
| 111 | +{ |
| 112 | + typedef BlockGetAndPut<word32, LittleEndian> Block; |
| 113 | + |
| 114 | + word32 a0, a1, a2; |
| 115 | + Block::Get(inBlock)(a0)(a1)(a2); |
| 116 | + |
| 117 | + word32 rc = START_D; |
| 118 | + |
| 119 | + mu(a0, a1, a2); |
| 120 | + for(unsigned i=0; i<m_rounds; i++) |
| 121 | + { |
| 122 | + a0 ^= m_k[0] ^ (rc<<16); |
| 123 | + a1 ^= m_k[1]; |
| 124 | + a2 ^= m_k[2] ^ rc; |
| 125 | + rho(a0, a1, a2); |
| 126 | + |
| 127 | + rc <<= 1; |
| 128 | + if (rc&0x10000) rc ^= 0x11011; |
| 129 | + } |
| 130 | + a0 ^= m_k[0] ^ (rc<<16); |
| 131 | + a1 ^= m_k[1]; |
| 132 | + a2 ^= m_k[2] ^ rc; |
| 133 | + theta(a0, a1, a2); |
| 134 | + mu(a0, a1, a2); |
| 135 | + |
| 136 | + Block::Put(xorBlock, outBlock)(a0)(a1)(a2); |
| 137 | +} |
| 138 | + |
| 139 | +NAMESPACE_END |
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