cham.cpp
// cham.cpp - written and placed in the public domain by Kim Sung Hee and Jeffrey Walton
// Based on "CHAM: A Family of Lightweight Block Ciphers for
// Resource-Constrained Devices" by Bonwook Koo, Dongyoung Roh,
// Hyeonjin Kim, Younghoon Jung, Dong-Geon Lee, and Daesung Kwon
#include "pch.h"
#include "config.h"
#include "cham.h"
#include "misc.h"
#include "cpu.h"
// CHAM table of parameters
// +-------------------------------------------------
// +cipher n k r w k/w
// +-------------------------------------------------
// +CHAM-64/128 64 128 80 16 8
// +CHAM-128/128 128 128 80 32 4
// +CHAM-128/256 128 256 96 32 8
// +-------------------------------------------------
ANONYMOUS_NAMESPACE_BEGIN
using CryptoPP::rotlConstant;
using CryptoPP::rotrConstant;
/// \brief CHAM encryption round
/// \tparam RR the round number residue
/// \tparam KW the number of key words
/// \tparam T words type
/// \param x the state array
/// \param k the subkey table
/// \param i the round number
/// \details CHAM_EncRound applies the encryption round to the plain text.
/// RR is the "round residue" and it is used modulo 4. ProcessAndXorBlock
/// may provide a fully unrolled encryption transformation, or provide
/// a transformation that loops using multiples of 4 encryption rounds.
/// \details CHAM_EncRound calculates indexes into the x[] array based
/// on the round number residue. There is no need for the assignments
/// that shift values in preparations for the next round.
/// \details CHAM_EncRound depends on the round number. The actual round
/// being executed is passed through the parameter <tt>i</tt>. If
/// ProcessAndXorBlock fully unrolled the loop then the parameter
/// <tt>i</tt> would be unnecessary.
template <unsigned int RR, unsigned int KW, class T>
inline void CHAM_EncRound(T x[4], const T k[KW], unsigned int i)
{
CRYPTOPP_CONSTANT(IDX0 = (RR+0) % 4);
CRYPTOPP_CONSTANT(IDX1 = (RR+1) % 4);
CRYPTOPP_CONSTANT(IDX3 = (RR+3+1) % 4);
CRYPTOPP_CONSTANT(R1 = (RR % 2 == 0) ? 1 : 8);
CRYPTOPP_CONSTANT(R2 = (RR % 2 == 0) ? 8 : 1);
// Follows conventions in the ref impl
const T kk = k[i % KW];
const T aa = x[IDX0] ^ static_cast<T>(i);
const T bb = rotlConstant<R1>(x[IDX1]) ^ kk;
x[IDX3] = rotlConstant<R2>(static_cast<T>(aa + bb));
}
/// \brief CHAM decryption round
/// \tparam RR the round number residue
/// \tparam KW the number of key words
/// \tparam T words type
/// \param x the state array
/// \param k the subkey table
/// \param i the round number
/// \details CHAM_DecRound applies the decryption round to the cipher text.
/// RR is the "round residue" and it is used modulo 4. ProcessAndXorBlock
/// may provide a fully unrolled decryption transformation, or provide
/// a transformation that loops using multiples of 4 decryption rounds.
/// \details CHAM_DecRound calculates indexes into the x[] array based
/// on the round number residue. There is no need for the assignments
/// that shift values in preparations for the next round.
/// \details CHAM_DecRound depends on the round number. The actual round
/// being executed is passed through the parameter <tt>i</tt>. If
/// ProcessAndXorBlock fully unrolled the loop then the parameter
/// <tt>i</tt> would be unnecessary.
template <unsigned int RR, unsigned int KW, class T>
inline void CHAM_DecRound(T x[4], const T k[KW], unsigned int i)
{
CRYPTOPP_CONSTANT(IDX0 = (RR+0) % 4);
CRYPTOPP_CONSTANT(IDX1 = (RR+1) % 4);
CRYPTOPP_CONSTANT(IDX3 = (RR+3+1) % 4);
CRYPTOPP_CONSTANT(R1 = (RR % 2 == 0) ? 8 : 1);
CRYPTOPP_CONSTANT(R2 = (RR % 2 == 0) ? 1 : 8);
// Follows conventions in the ref impl
const T kk = k[i % KW];
const T aa = rotrConstant<R1>(x[IDX3]);
const T bb = rotlConstant<R2>(x[IDX1]) ^ kk;
x[IDX0] = static_cast<T>(aa - bb) ^ static_cast<T>(i);
}
ANONYMOUS_NAMESPACE_END
NAMESPACE_BEGIN(CryptoPP)
#if CRYPTOPP_CHAM128_ADVANCED_PROCESS_BLOCKS
# if (CRYPTOPP_SSSE3_AVAILABLE)
extern size_t CHAM64_Enc_AdvancedProcessBlocks_SSSE3(const word16* subKeys, size_t rounds,
const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags);
extern size_t CHAM64_Dec_AdvancedProcessBlocks_SSSE3(const word16* subKeys, size_t rounds,
const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags);
extern size_t CHAM128_Enc_AdvancedProcessBlocks_SSSE3(const word32* subKeys, size_t rounds,
const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags);
extern size_t CHAM128_Dec_AdvancedProcessBlocks_SSSE3(const word32* subKeys, size_t rounds,
const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags);
# endif // CRYPTOPP_SSSE3_AVAILABLE
#endif // CRYPTOPP_CHAM128_ADVANCED_PROCESS_BLOCKS
void CHAM64::Base::UncheckedSetKey(const byte *userKey, unsigned int keyLength, const NameValuePairs &params)
{
CRYPTOPP_UNUSED(params);
m_kw = keyLength/sizeof(word16);
m_rk.New(2*m_kw);
for (size_t i = 0; i < m_kw; userKey += sizeof(word32))
{
// Do not cast the buffer. It will SIGBUS on some ARM and SPARC.
const word32 rk = GetWord<word32>(false, BIG_ENDIAN_ORDER, userKey);
const word16 rk1 = static_cast<word16>(rk >> 16);
m_rk[i] = rk1 ^ rotlConstant<1>(rk1) ^ rotlConstant<8>(rk1);
m_rk[(i + m_kw) ^ 1] = rk1 ^ rotlConstant<1>(rk1) ^ rotlConstant<11>(rk1);
i++;
const word16 rk2 = static_cast<word16>(rk & 0xffff);
m_rk[i] = rk2 ^ rotlConstant<1>(rk2) ^ rotlConstant<8>(rk2);
m_rk[(i + m_kw) ^ 1] = rk2 ^ rotlConstant<1>(rk2) ^ rotlConstant<11>(rk2);
i++;
}
}
void CHAM64::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
// Do not cast the buffer. It will SIGBUS on some ARM and SPARC.
GetBlock<word16, BigEndian> iblock(inBlock);
iblock(m_x[0])(m_x[1])(m_x[2])(m_x[3]);
const int R = 80;
for (int i = 0; i < R; i+=16)
{
CHAM_EncRound< 0, 16>(m_x.begin(), m_rk.begin(), i+0);
CHAM_EncRound< 1, 16>(m_x.begin(), m_rk.begin(), i+1);
CHAM_EncRound< 2, 16>(m_x.begin(), m_rk.begin(), i+2);
CHAM_EncRound< 3, 16>(m_x.begin(), m_rk.begin(), i+3);
CHAM_EncRound< 4, 16>(m_x.begin(), m_rk.begin(), i+4);
CHAM_EncRound< 5, 16>(m_x.begin(), m_rk.begin(), i+5);
CHAM_EncRound< 6, 16>(m_x.begin(), m_rk.begin(), i+6);
CHAM_EncRound< 7, 16>(m_x.begin(), m_rk.begin(), i+7);
CHAM_EncRound< 8, 16>(m_x.begin(), m_rk.begin(), i+8);
CHAM_EncRound< 9, 16>(m_x.begin(), m_rk.begin(), i+9);
CHAM_EncRound<10, 16>(m_x.begin(), m_rk.begin(), i+10);
CHAM_EncRound<11, 16>(m_x.begin(), m_rk.begin(), i+11);
CHAM_EncRound<12, 16>(m_x.begin(), m_rk.begin(), i+12);
CHAM_EncRound<13, 16>(m_x.begin(), m_rk.begin(), i+13);
CHAM_EncRound<14, 16>(m_x.begin(), m_rk.begin(), i+14);
CHAM_EncRound<15, 16>(m_x.begin(), m_rk.begin(), i+15);
}
PutBlock<word16, BigEndian> oblock(xorBlock, outBlock);
oblock(m_x[0])(m_x[1])(m_x[2])(m_x[3]);
}
void CHAM64::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
// Do not cast the buffer. It will SIGBUS on some ARM and SPARC.
GetBlock<word16, BigEndian> iblock(inBlock);
iblock(m_x[0])(m_x[1])(m_x[2])(m_x[3]);
const int R = 80;
for (int i = R-1; i >=0 ; i-=16)
{
CHAM_DecRound<15, 16>(m_x.begin(), m_rk.begin(), i-0);
CHAM_DecRound<14, 16>(m_x.begin(), m_rk.begin(), i-1);
CHAM_DecRound<13, 16>(m_x.begin(), m_rk.begin(), i-2);
CHAM_DecRound<12, 16>(m_x.begin(), m_rk.begin(), i-3);
CHAM_DecRound<11, 16>(m_x.begin(), m_rk.begin(), i-4);
CHAM_DecRound<10, 16>(m_x.begin(), m_rk.begin(), i-5);
CHAM_DecRound< 9, 16>(m_x.begin(), m_rk.begin(), i-6);
CHAM_DecRound< 8, 16>(m_x.begin(), m_rk.begin(), i-7);
CHAM_DecRound< 7, 16>(m_x.begin(), m_rk.begin(), i-8);
CHAM_DecRound< 6, 16>(m_x.begin(), m_rk.begin(), i-9);
CHAM_DecRound< 5, 16>(m_x.begin(), m_rk.begin(), i-10);
CHAM_DecRound< 4, 16>(m_x.begin(), m_rk.begin(), i-11);
CHAM_DecRound< 3, 16>(m_x.begin(), m_rk.begin(), i-12);
CHAM_DecRound< 2, 16>(m_x.begin(), m_rk.begin(), i-13);
CHAM_DecRound< 1, 16>(m_x.begin(), m_rk.begin(), i-14);
CHAM_DecRound< 0, 16>(m_x.begin(), m_rk.begin(), i-15);
}
PutBlock<word16, BigEndian> oblock(xorBlock, outBlock);
oblock(m_x[0])(m_x[1])(m_x[2])(m_x[3]);
}
std::string CHAM128::Base::AlgorithmProvider() const
{
#if defined(CRYPTOPP_SSSE3_AVAILABLE)
if (HasSSSE3())
return "SSSE3";
#endif
return "C++";
}
void CHAM128::Base::UncheckedSetKey(const byte *userKey, unsigned int keyLength, const NameValuePairs &params)
{
CRYPTOPP_UNUSED(params);
m_kw = keyLength/sizeof(word32);
m_rk.New(2*m_kw);
for (size_t i = 0; i < m_kw; userKey += sizeof(word32))
{
// Do not cast the buffer. It will SIGBUS on some ARM and SPARC.
const word32 rk = GetWord<word32>(false, BIG_ENDIAN_ORDER, userKey);
m_rk[i] = rk ^ rotlConstant<1>(rk) ^ rotlConstant<8>(rk);
m_rk[(i + m_kw) ^ 1] = rk ^ rotlConstant<1>(rk) ^ rotlConstant<11>(rk);
i++;
}
}
void CHAM128::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
// Do not cast the buffer. It will SIGBUS on some ARM and SPARC.
GetBlock<word32, BigEndian> iblock(inBlock);
iblock(m_x[0])(m_x[1])(m_x[2])(m_x[3]);
switch (m_kw)
{
case 4: // 128-bit key
{
const int R = 80;
for (int i = 0; i < R; i+=8)
{
CHAM_EncRound<0, 8>(m_x.begin(), m_rk.begin(), i+0);
CHAM_EncRound<1, 8>(m_x.begin(), m_rk.begin(), i+1);
CHAM_EncRound<2, 8>(m_x.begin(), m_rk.begin(), i+2);
CHAM_EncRound<3, 8>(m_x.begin(), m_rk.begin(), i+3);
CHAM_EncRound<4, 8>(m_x.begin(), m_rk.begin(), i+4);
CHAM_EncRound<5, 8>(m_x.begin(), m_rk.begin(), i+5);
CHAM_EncRound<6, 8>(m_x.begin(), m_rk.begin(), i+6);
CHAM_EncRound<7, 8>(m_x.begin(), m_rk.begin(), i+7);
}
break;
}
case 8: // 256-bit key
{
const int R = 96;
for (int i = 0; i < R; i+=16)
{
CHAM_EncRound< 0, 16>(m_x.begin(), m_rk.begin(), i+0);
CHAM_EncRound< 1, 16>(m_x.begin(), m_rk.begin(), i+1);
CHAM_EncRound< 2, 16>(m_x.begin(), m_rk.begin(), i+2);
CHAM_EncRound< 3, 16>(m_x.begin(), m_rk.begin(), i+3);
CHAM_EncRound< 4, 16>(m_x.begin(), m_rk.begin(), i+4);
CHAM_EncRound< 5, 16>(m_x.begin(), m_rk.begin(), i+5);
CHAM_EncRound< 6, 16>(m_x.begin(), m_rk.begin(), i+6);
CHAM_EncRound< 7, 16>(m_x.begin(), m_rk.begin(), i+7);
CHAM_EncRound< 8, 16>(m_x.begin(), m_rk.begin(), i+8);
CHAM_EncRound< 9, 16>(m_x.begin(), m_rk.begin(), i+9);
CHAM_EncRound<10, 16>(m_x.begin(), m_rk.begin(), i+10);
CHAM_EncRound<11, 16>(m_x.begin(), m_rk.begin(), i+11);
CHAM_EncRound<12, 16>(m_x.begin(), m_rk.begin(), i+12);
CHAM_EncRound<13, 16>(m_x.begin(), m_rk.begin(), i+13);
CHAM_EncRound<14, 16>(m_x.begin(), m_rk.begin(), i+14);
CHAM_EncRound<15, 16>(m_x.begin(), m_rk.begin(), i+15);
}
break;
}
default:
CRYPTOPP_ASSERT(0);
}
PutBlock<word32, BigEndian> oblock(xorBlock, outBlock);
oblock(m_x[0])(m_x[1])(m_x[2])(m_x[3]);
}
void CHAM128::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
// Do not cast the buffer. It will SIGBUS on some ARM and SPARC.
GetBlock<word32, BigEndian> iblock(inBlock);
iblock(m_x[0])(m_x[1])(m_x[2])(m_x[3]);
switch (m_kw)
{
case 4: // 128-bit key
{
const int R = 80;
for (int i = R-1; i >= 0; i-=8)
{
CHAM_DecRound<7, 8>(m_x.begin(), m_rk.begin(), i-0);
CHAM_DecRound<6, 8>(m_x.begin(), m_rk.begin(), i-1);
CHAM_DecRound<5, 8>(m_x.begin(), m_rk.begin(), i-2);
CHAM_DecRound<4, 8>(m_x.begin(), m_rk.begin(), i-3);
CHAM_DecRound<3, 8>(m_x.begin(), m_rk.begin(), i-4);
CHAM_DecRound<2, 8>(m_x.begin(), m_rk.begin(), i-5);
CHAM_DecRound<1, 8>(m_x.begin(), m_rk.begin(), i-6);
CHAM_DecRound<0, 8>(m_x.begin(), m_rk.begin(), i-7);
}
break;
}
case 8: // 256-bit key
{
const int R = 96;
for (int i = R-1; i >= 0; i-=16)
{
CHAM_DecRound<15, 16>(m_x.begin(), m_rk.begin(), i-0);
CHAM_DecRound<14, 16>(m_x.begin(), m_rk.begin(), i-1);
CHAM_DecRound<13, 16>(m_x.begin(), m_rk.begin(), i-2);
CHAM_DecRound<12, 16>(m_x.begin(), m_rk.begin(), i-3);
CHAM_DecRound<11, 16>(m_x.begin(), m_rk.begin(), i-4);
CHAM_DecRound<10, 16>(m_x.begin(), m_rk.begin(), i-5);
CHAM_DecRound< 9, 16>(m_x.begin(), m_rk.begin(), i-6);
CHAM_DecRound< 8, 16>(m_x.begin(), m_rk.begin(), i-7);
CHAM_DecRound< 7, 16>(m_x.begin(), m_rk.begin(), i-8);
CHAM_DecRound< 6, 16>(m_x.begin(), m_rk.begin(), i-9);
CHAM_DecRound< 5, 16>(m_x.begin(), m_rk.begin(), i-10);
CHAM_DecRound< 4, 16>(m_x.begin(), m_rk.begin(), i-11);
CHAM_DecRound< 3, 16>(m_x.begin(), m_rk.begin(), i-12);
CHAM_DecRound< 2, 16>(m_x.begin(), m_rk.begin(), i-13);
CHAM_DecRound< 1, 16>(m_x.begin(), m_rk.begin(), i-14);
CHAM_DecRound< 0, 16>(m_x.begin(), m_rk.begin(), i-15);
}
break;
}
default:
CRYPTOPP_ASSERT(0);
}
PutBlock<word32, BigEndian> oblock(xorBlock, outBlock);
oblock(m_x[0])(m_x[1])(m_x[2])(m_x[3]);
}
#if CRYPTOPP_CHAM128_ADVANCED_PROCESS_BLOCKS
size_t CHAM128::Enc::AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks,
byte *outBlocks, size_t length, word32 flags) const
{
# if (CRYPTOPP_SSSE3_AVAILABLE)
if (HasSSSE3()) {
const size_t rounds = (m_kw == 4 ? 80 : 96);
return CHAM128_Enc_AdvancedProcessBlocks_SSSE3(m_rk, rounds,
inBlocks, xorBlocks, outBlocks, length, flags);
}
# endif // CRYPTOPP_SSSE3_AVAILABLE
return BlockTransformation::AdvancedProcessBlocks(inBlocks, xorBlocks, outBlocks, length, flags);
}
size_t CHAM128::Dec::AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks,
byte *outBlocks, size_t length, word32 flags) const
{
# if (CRYPTOPP_SSSE3_AVAILABLE)
if (HasSSSE3()) {
const size_t rounds = (m_kw == 4 ? 80 : 96);
return CHAM128_Dec_AdvancedProcessBlocks_SSSE3(m_rk, rounds,
inBlocks, xorBlocks, outBlocks, length, flags);
}
# endif // CRYPTOPP_SSSE3_AVAILABLE
return BlockTransformation::AdvancedProcessBlocks(inBlocks, xorBlocks, outBlocks, length, flags);
}
#endif // CRYPTOPP_CHAM128_ADVANCED_PROCESS_BLOCKS
NAMESPACE_END
cham.h
Classes for the CHAM block cipher.
BlockTransformation::AdvancedProcessBlocks
virtual size_t AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags) const
Encrypt and xor multiple blocks using additional flags.
NameValuePairs
Interface for retrieving values given their names.
Definition cryptlib.h:327
config.h
Library configuration file.
word32
unsigned int word32
32-bit unsigned datatype
Definition config_int.h:72
word16
unsigned short word16
16-bit unsigned datatype
Definition config_int.h:69
cpu.h
Functions for CPU features and intrinsics.
BIG_ENDIAN_ORDER
@ BIG_ENDIAN_ORDER
byte order is big-endian
Definition cryptlib.h:152
misc.h
Utility functions for the Crypto++ library.
rotlConstant
T rotlConstant(T x)
Performs a left rotate.
Definition misc.h:1757
GetWord
T GetWord(bool assumeAligned, ByteOrder order, const byte *block)
Access a block of memory.
Definition misc.h:2906
rotrConstant
T rotrConstant(T x)
Performs a right rotate.
Definition misc.h:1783
CryptoPP
Crypto++ library namespace.
pch.h
Precompiled header file.
CRYPTOPP_ASSERT
#define CRYPTOPP_ASSERT(exp)
Debugging and diagnostic assertion.
Definition trap.h:68