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Diffstat (limited to '')
| -rw-r--r-- | CryptoPP/mars.cpp | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/CryptoPP/mars.cpp b/CryptoPP/mars.cpp new file mode 100644 index 000000000..fe9b1186a --- /dev/null +++ b/CryptoPP/mars.cpp @@ -0,0 +1,154 @@ +// mars.cpp - written and placed in the public domain by Wei Dai + +// includes IBM's key setup "tweak" proposed in August 1999 (http://www.research.ibm.com/security/key-setup.txt) + +#include "pch.h" +#include "mars.h" +#include "misc.h" + +NAMESPACE_BEGIN(CryptoPP) + +void MARS::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &) +{ + AssertValidKeyLength(length); + + // Initialize T[] with the key data + FixedSizeSecBlock<word32, 15> T; + GetUserKey(LITTLE_ENDIAN_ORDER, T.begin(), 15, userKey, length); + T[length/4] = length/4; + + for (unsigned int j=0; j<4; j++) // compute 10 words of K[] in each iteration + { + unsigned int i; + // Do linear transformation + for (i=0; i<15; i++) + T[i] = T[i] ^ rotlFixed(T[(i+8)%15] ^ T[(i+13)%15], 3) ^ (4*i+j); + + // Do four rounds of stirring + for (unsigned int k=0; k<4; k++) + for (i=0; i<15; i++) + T[i] = rotlFixed(T[i] + Sbox[T[(i+14)%15]%512], 9); + + // Store next 10 key words into K[] + for (i=0; i<10; i++) + m_k[10*j+i] = T[4*i%15]; + } + + // Modify multiplication key-words + for(unsigned int i = 5; i < 37; i += 2) + { + word32 m, w = m_k[i] | 3; + m = (~w ^ (w<<1)) & (~w ^ (w>>1)) & 0x7ffffffe; + m &= m>>1; m &= m>>2; m &= m>>4; + m |= m<<1; m |= m<<2; m |= m<<4; + m &= 0x7ffffffc; + w ^= rotlMod(Sbox[265 + (m_k[i] & 3)], m_k[i-1]) & m; + m_k[i] = w; + } +} + +#define S(a) Sbox[(a)&0x1ff] +#define S0(a) Sbox[(a)&0xff] +#define S1(a) Sbox[((a)&0xff) + 256] + +typedef BlockGetAndPut<word32, LittleEndian> Block; + +void MARS::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const +{ + unsigned int i; + word32 a, b, c, d, l, m, r, t; + const word32 *k = m_k; + + Block::Get(inBlock)(a)(b)(c)(d); + + a += k[0]; b += k[1]; c += k[2]; d += k[3]; + + for (i=0; i<8; i++) + { + b = (b ^ S0(a)) + S1(a>>8); + c += S0(a>>16); + a = rotrFixed(a, 24); + d ^= S1(a); + a += (i%4==0) ? d : 0; + a += (i%4==1) ? b : 0; + t = a; a = b; b = c; c = d; d = t; + } + + for (i=0; i<16; i++) + { + t = rotlFixed(a, 13); + r = rotlFixed(t * k[2*i+5], 10); + m = a + k[2*i+4]; + l = rotlMod((S(m) ^ rotrFixed(r, 5) ^ r), r); + c += rotlMod(m, rotrFixed(r, 5)); + (i<8 ? b : d) += l; + (i<8 ? d : b) ^= r; + a = b; b = c; c = d; d = t; + } + + for (i=0; i<8; i++) + { + a -= (i%4==2) ? d : 0; + a -= (i%4==3) ? b : 0; + b ^= S1(a); + c -= S0(a>>24); + t = rotlFixed(a, 24); + d = (d - S1(a>>16)) ^ S0(t); + a = b; b = c; c = d; d = t; + } + + a -= k[36]; b -= k[37]; c -= k[38]; d -= k[39]; + + Block::Put(xorBlock, outBlock)(a)(b)(c)(d); +} + +void MARS::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const +{ + unsigned int i; + word32 a, b, c, d, l, m, r, t; + const word32 *k = m_k; + + Block::Get(inBlock)(d)(c)(b)(a); + + d += k[36]; c += k[37]; b += k[38]; a += k[39]; + + for (i=0; i<8; i++) + { + b = (b ^ S0(a)) + S1(a>>8); + c += S0(a>>16); + a = rotrFixed(a, 24); + d ^= S1(a); + a += (i%4==0) ? d : 0; + a += (i%4==1) ? b : 0; + t = a; a = b; b = c; c = d; d = t; + } + + for (i=0; i<16; i++) + { + t = rotrFixed(a, 13); + r = rotlFixed(a * k[35-2*i], 10); + m = t + k[34-2*i]; + l = rotlMod((S(m) ^ rotrFixed(r, 5) ^ r), r); + c -= rotlMod(m, rotrFixed(r, 5)); + (i<8 ? b : d) -= l; + (i<8 ? d : b) ^= r; + a = b; b = c; c = d; d = t; + } + + for (i=0; i<8; i++) + { + a -= (i%4==2) ? d : 0; + a -= (i%4==3) ? b : 0; + b ^= S1(a); + c -= S0(a>>24); + t = rotlFixed(a, 24); + d = (d - S1(a>>16)) ^ S0(t); + a = b; b = c; c = d; d = t; + } + + d -= k[0]; c -= k[1]; b -= k[2]; a -= k[3]; + + Block::Put(xorBlock, outBlock)(d)(c)(b)(a); +} + +NAMESPACE_END |