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166 lines
4.4 KiB
166 lines
4.4 KiB
![]()
4 years ago
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// tea.cpp - modified by Wei Dai from code in the original paper
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#include "pch.h"
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#include "tea.h"
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#include "misc.h"
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// http://github.com/weidai11/cryptopp/issues/503
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#if defined(__xlC__) || defined(__SUNPRO_CC)
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# define MAYBE_VOLATILE(x) (*const_cast<volatile word32*>(&x))
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#else
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# define MAYBE_VOLATILE(x) (x)
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#endif
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NAMESPACE_BEGIN(CryptoPP)
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static const word32 DELTA = 0x9e3779b9;
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typedef BlockGetAndPut<word32, BigEndian> Block;
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#define UINT32_CAST(x) ((word32*)(void*)(x))
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#define CONST_UINT32_CAST(x) ((const word32*)(const void*)(x))
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void TEA::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs ¶ms)
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{
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AssertValidKeyLength(length);
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GetUserKey(BIG_ENDIAN_ORDER, m_k.begin(), 4, userKey, KEYLENGTH);
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m_limit = GetRoundsAndThrowIfInvalid(params, this) * DELTA;
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}
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void TEA::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
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{
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word32 y, z, sum = 0;
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Block::Get(inBlock)(y)(z);
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// http://github.com/weidai11/cryptopp/issues/503
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while (MAYBE_VOLATILE(sum) != m_limit)
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{
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sum += DELTA;
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y += ((z << 4) + m_k[0]) ^ (z + sum) ^ ((z >> 5) + m_k[1]);
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z += ((y << 4) + m_k[2]) ^ (y + sum) ^ ((y >> 5) + m_k[3]);
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}
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Block::Put(xorBlock, outBlock)(y)(z);
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}
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void TEA::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
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{
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word32 y, z, sum = m_limit;
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Block::Get(inBlock)(y)(z);
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// http://github.com/weidai11/cryptopp/issues/503
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while (MAYBE_VOLATILE(sum) != 0)
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{
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z -= ((y << 4) + m_k[2]) ^ (y + sum) ^ ((y >> 5) + m_k[3]);
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y -= ((z << 4) + m_k[0]) ^ (z + sum) ^ ((z >> 5) + m_k[1]);
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sum -= DELTA;
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}
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Block::Put(xorBlock, outBlock)(y)(z);
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}
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void XTEA::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs ¶ms)
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{
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AssertValidKeyLength(length);
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GetUserKey(BIG_ENDIAN_ORDER, m_k.begin(), 4, userKey, KEYLENGTH);
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m_limit = GetRoundsAndThrowIfInvalid(params, this) * DELTA;
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}
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void XTEA::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
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{
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word32 y, z, sum = 0;
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Block::Get(inBlock)(y)(z);
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// http://github.com/weidai11/cryptopp/issues/503
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while (MAYBE_VOLATILE(sum) != m_limit)
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{
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y += ((z<<4 ^ z>>5) + z) ^ (sum + m_k[sum&3]);
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sum += DELTA;
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z += ((y<<4 ^ y>>5) + y) ^ (sum + m_k[sum>>11 & 3]);
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}
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Block::Put(xorBlock, outBlock)(y)(z);
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}
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void XTEA::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
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{
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word32 y, z, sum = m_limit;
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Block::Get(inBlock)(y)(z);
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// http://github.com/weidai11/cryptopp/issues/503
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while (MAYBE_VOLATILE(sum) != 0)
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{
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z -= ((y<<4 ^ y>>5) + y) ^ (sum + m_k[sum>>11 & 3]);
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sum -= DELTA;
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y -= ((z<<4 ^ z>>5) + z) ^ (sum + m_k[sum&3]);
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}
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Block::Put(xorBlock, outBlock)(y)(z);
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}
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#define MX ((z>>5^y<<2)+(y>>3^z<<4))^((sum^y)+(m_k[(p&3)^e]^z))
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void BTEA::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
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{
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CRYPTOPP_UNUSED(xorBlock);
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CRYPTOPP_ASSERT(IsAlignedOn(inBlock,GetAlignmentOf<word32>()));
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CRYPTOPP_ASSERT(IsAlignedOn(outBlock,GetAlignmentOf<word32>()));
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unsigned int n = m_blockSize / 4;
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word32 *v = UINT32_CAST(outBlock);
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ConditionalByteReverse(BIG_ENDIAN_ORDER, v, CONST_UINT32_CAST(inBlock), m_blockSize);
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word32 y, z = v[n-1], e;
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word32 p, q = 6+52/n;
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word32 sum = 0;
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while (q-- > 0)
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{
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sum += DELTA;
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e = sum>>2 & 3;
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for (p = 0; p < n-1; p++)
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{
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y = v[p+1];
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z = v[p] += MX;
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}
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y = v[0];
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z = v[n-1] += MX;
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}
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ConditionalByteReverse(BIG_ENDIAN_ORDER, v, v, m_blockSize);
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}
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void BTEA::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
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{
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CRYPTOPP_UNUSED(xorBlock);
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CRYPTOPP_ASSERT(IsAlignedOn(inBlock,GetAlignmentOf<word32>()));
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CRYPTOPP_ASSERT(IsAlignedOn(outBlock,GetAlignmentOf<word32>()));
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unsigned int n = m_blockSize / 4;
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word32 *v = UINT32_CAST(outBlock);
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ConditionalByteReverse(BIG_ENDIAN_ORDER, v, CONST_UINT32_CAST(inBlock), m_blockSize);
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word32 y = v[0], z, e;
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word32 p, q = 6+52/n;
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word32 sum = q * DELTA;
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while (sum != 0)
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{
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e = sum>>2 & 3;
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for (p = n-1; p > 0; p--)
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{
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z = v[p-1];
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y = v[p] -= MX;
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}
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z = v[n-1];
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y = v[0] -= MX;
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sum -= DELTA;
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}
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ConditionalByteReverse(BIG_ENDIAN_ORDER, v, v, m_blockSize);
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}
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NAMESPACE_END
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