// des.cpp - modified by Wei Dai from Phil Karn's des.c

// The original code and all modifications are in the public domain.

/*

 * This is a major rewrite of my old public domain DES code written

 * circa 1987, which in turn borrowed heavily from Jim Gillogly's 1977

 * public domain code. I pretty much kept my key scheduling code, but

 * the actual encrypt/decrypt routines are taken from from Richard

 * Outerbridge's DES code as printed in Schneier's "Applied Cryptography."

 *

 * This code is in the public domain. I would appreciate bug reports and

 * enhancements.

 *

 * Phil Karn KA9Q, karn@unix.ka9q.ampr.org, August 1994.

 */

#include "pch.h"

#include "misc.h"

#include "des.h"

NAMESPACE_BEGIN(CryptoPP)

typedef BlockGetAndPut<word32, BigEndian> Block;

// Richard Outerbridge's initial permutation algorithm

/*

inline void IPERM(word32 &left, word32 &right)

{

  word32 work;

  work = ((left >> 4) ^ right) & 0x0f0f0f0f;

  right ^= work;

  left ^= work << 4;

  work = ((left >> 16) ^ right) & 0xffff;

  right ^= work;

  left ^= work << 16;

  work = ((right >> 2) ^ left) & 0x33333333;

  left ^= work;

  right ^= (work << 2);

  work = ((right >> 8) ^ left) & 0xff00ff;

  left ^= work;

  right ^= (work << 8);

  right = rotl(right, 1);

  work = (left ^ right) & 0xaaaaaaaa;

  left ^= work;

  right ^= work;

  left = rotl(left, 1);

}

inline void FPERM(word32 &left, word32 &right)

{

  word32 work;

  right = rotr(right, 1);

  work = (left ^ right) & 0xaaaaaaaa;

  left ^= work;

  right ^= work;

  left = rotr(left, 1);

  work = ((left >> 8) ^ right) & 0xff00ff;

  right ^= work;

  left ^= work << 8;

  work = ((left >> 2) ^ right) & 0x33333333;

  right ^= work;

  left ^= work << 2;

  work = ((right >> 16) ^ left) & 0xffff;

  left ^= work;

  right ^= work << 16;

  work = ((right >> 4) ^ left) & 0x0f0f0f0f;

  left ^= work;

  right ^= work << 4;

}

*/

// Wei Dai's modification to Richard Outerbridge's initial permutation

// algorithm, this one is faster if you have access to rotate instructions

// (like in MSVC)

static inline void IPERM(word32 &left, word32 &right)

{

  word32 work;

  right = rotlConstant<4>(right);

  work = (left ^ right) & 0xf0f0f0f0;

  left ^= work;

  right = rotrConstant<20>(right^work);

  work = (left ^ right) & 0xffff0000;

  left ^= work;

  right = rotrConstant<18>(right^work);

  work = (left ^ right) & 0x33333333;

  left ^= work;

  right = rotrConstant<6>(right^work);

  work = (left ^ right) & 0x00ff00ff;

  left ^= work;

  right = rotlConstant<9>(right^work);

  work = (left ^ right) & 0xaaaaaaaa;

  left = rotlConstant<1>(left^work);

  right ^= work;

}

static inline void FPERM(word32 &left, word32 &right)

{

  word32 work;

  right = rotrConstant<1>(right);

  work = (left ^ right) & 0xaaaaaaaa;

  right ^= work;

  left = rotrConstant<9>(left^work);

  work = (left ^ right) & 0x00ff00ff;

  right ^= work;

  left = rotlConstant<6>(left^work);

  work = (left ^ right) & 0x33333333;

  right ^= work;

  left = rotlConstant<18>(left^work);

  work = (left ^ right) & 0xffff0000;

  right ^= work;

  left = rotlConstant<20>(left^work);

  work = (left ^ right) & 0xf0f0f0f0;

  right ^= work;

  left = rotrConstant<4>(left^work);

}

void DES::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &)

{

  AssertValidKeyLength(length);

  RawSetKey(GetCipherDirection(), userKey);

}

#ifndef CRYPTOPP_IMPORTS

/* Tables defined in the Data Encryption Standard documents

 * Three of these tables, the initial permutation, the final

 * permutation and the expansion operator, are regular enough that

 * for speed, we hard-code them. They're here for reference only.

 * Also, the S and P boxes are used by a separate program, gensp.c,

 * to build the combined SP box, Spbox[]. They're also here just

 * for reference.

 */

#ifdef notdef

/* initial permutation IP */

static byte ip[] = {

     58, 50, 42, 34, 26, 18, 10,  2,

     60, 52, 44, 36, 28, 20, 12,  4,

     62, 54, 46, 38, 30, 22, 14,  6,

     64, 56, 48, 40, 32, 24, 16,  8,

     57, 49, 41, 33, 25, 17,  9,  1,

     59, 51, 43, 35, 27, 19, 11,  3,

     61, 53, 45, 37, 29, 21, 13,  5,

     63, 55, 47, 39, 31, 23, 15,  7

};

/* final permutation IP^-1 */

static byte fp[] = {

     40,  8, 48, 16, 56, 24, 64, 32,

     39,  7, 47, 15, 55, 23, 63, 31,

     38,  6, 46, 14, 54, 22, 62, 30,

     37,  5, 45, 13, 53, 21, 61, 29,

     36,  4, 44, 12, 52, 20, 60, 28,

     35,  3, 43, 11, 51, 19, 59, 27,

     34,  2, 42, 10, 50, 18, 58, 26,

     33,  1, 41,  9, 49, 17, 57, 25

};

/* expansion operation matrix */

static byte ei[] = {

     32,  1,  2,  3,  4,  5,

    4,  5,  6,  7,  8,  9,

    8,  9, 10, 11, 12, 13,

     12, 13, 14, 15, 16, 17,

     16, 17, 18, 19, 20, 21,

     20, 21, 22, 23, 24, 25,

     24, 25, 26, 27, 28, 29,

     28, 29, 30, 31, 32,  1

};

/* The (in)famous S-boxes */

static byte sbox[8][64] = {

     /* S1 */

     14,  4, 13,  1,  2, 15, 11,  8,  3, 10,  6, 12,  5,  9,  0,  7,

    0, 15,  7,  4, 14,  2, 13,  1, 10,  6, 12, 11,  9,  5,  3,  8,

    4,  1, 14,  8, 13,  6,  2, 11, 15, 12,  9,  7,  3, 10,  5,  0,

     15, 12,  8,  2,  4,  9,  1,  7,  5, 11,  3, 14, 10,  0,  6, 13,

     /* S2 */

     15,  1,  8, 14,  6, 11,  3,  4,  9,  7,  2, 13, 12,  0,  5, 10,

    3, 13,  4,  7, 15,  2,  8, 14, 12,  0,  1, 10,  6,  9, 11,  5,

    0, 14,  7, 11, 10,  4, 13,  1,  5,  8, 12,  6,  9,  3,  2, 15,

     13,  8, 10,  1,  3, 15,  4,  2, 11,  6,  7, 12,  0,  5, 14,  9,

     /* S3 */

     10,  0,  9, 14,  6,  3, 15,  5,  1, 13, 12,  7, 11,  4,  2,  8,

     13,  7,  0,  9,  3,  4,  6, 10,  2,  8,  5, 14, 12, 11, 15,  1,

     13,  6,  4,  9,  8, 15,  3,  0, 11,  1,  2, 12,  5, 10, 14,  7,

    1, 10, 13,  0,  6,  9,  8,  7,  4, 15, 14,  3, 11,  5,  2, 12,

     /* S4 */

    7, 13, 14,  3,  0,  6,  9, 10,  1,  2,  8,  5, 11, 12,  4, 15,

     13,  8, 11,  5,  6, 15,  0,  3,  4,  7,  2, 12,  1, 10, 14,  9,

     10,  6,  9,  0, 12, 11,  7, 13, 15,  1,  3, 14,  5,  2,  8,  4,

    3, 15,  0,  6, 10,  1, 13,  8,  9,  4,  5, 11, 12,  7,  2, 14,

     /* S5 */

    2, 12,  4,  1,  7, 10, 11,  6,  8,  5,  3, 15, 13,  0, 14,  9,

     14, 11,  2, 12,  4,  7, 13,  1,  5,  0, 15, 10,  3,  9,  8,  6,

    4,  2,  1, 11, 10, 13,  7,  8, 15,  9, 12,  5,  6,  3,  0, 14,

     11,  8, 12,  7,  1, 14,  2, 13,  6, 15,  0,  9, 10,  4,  5,  3,

     /* S6 */

     12,  1, 10, 15,  9,  2,  6,  8,  0, 13,  3,  4, 14,  7,  5, 11,

     10, 15,  4,  2,  7, 12,  9,  5,  6,  1, 13, 14,  0, 11,  3,  8,

    9, 14, 15,  5,  2,  8, 12,  3,  7,  0,  4, 10,  1, 13, 11,  6,

    4,  3,  2, 12,  9,  5, 15, 10, 11, 14,  1,  7,  6,  0,  8, 13,

     /* S7 */

    4, 11,  2, 14, 15,  0,  8, 13,  3, 12,  9,  7,  5, 10,  6,  1,

     13,  0, 11,  7,  4,  9,  1, 10, 14,  3,  5, 12,  2, 15,  8,  6,

    1,  4, 11, 13, 12,  3,  7, 14, 10, 15,  6,  8,  0,  5,  9,  2,

    6, 11, 13,  8,  1,  4, 10,  7,  9,  5,  0, 15, 14,  2,  3, 12,

     /* S8 */

     13,  2,  8,  4,  6, 15, 11,  1, 10,  9,  3, 14,  5,  0, 12,  7,

    1, 15, 13,  8, 10,  3,  7,  4, 12,  5,  6, 11,  0, 14,  9,  2,

    7, 11,  4,  1,  9, 12, 14,  2,  0,  6, 10, 13, 15,  3,  5,  8,

    2,  1, 14,  7,  4, 10,  8, 13, 15, 12,  9,  0,  3,  5,  6, 11

};

/* 32-bit permutation function P used on the output of the S-boxes */

namespace {

  const byte p32i[] = {

     16,  7, 20, 21,

     29, 12, 28, 17,

    1, 15, 23, 26,

    5, 18, 31, 10,

    2,  8, 24, 14,

     32, 27,  3,  9,

     19, 13, 30,  6,

     22, 11,  4, 25

  };

}

#endif

/* permuted choice table (key) */

namespace {

  const byte pc1[] = {

     57, 49, 41, 33, 25, 17,  9,

    1, 58, 50, 42, 34, 26, 18,

     10,  2, 59, 51, 43, 35, 27,

     19, 11,  3, 60, 52, 44, 36,

     63, 55, 47, 39, 31, 23, 15,

    7, 62, 54, 46, 38, 30, 22,

     14,  6, 61, 53, 45, 37, 29,

     21, 13,  5, 28, 20, 12,  4

  };

}

/* number left rotations of pc1 */

namespace {

  const byte totrot[] = {

     1,2,4,6,8,10,12,14,15,17,19,21,23,25,27,28

  };

}

/* permuted choice key (table) */

namespace {

  const byte pc2[] = {

     14, 17, 11, 24,  1,  5,

    3, 28, 15,  6, 21, 10,

     23, 19, 12,  4, 26,  8,

     16,  7, 27, 20, 13,  2,

     41, 52, 31, 37, 47, 55,

     30, 40, 51, 45, 33, 48,

     44, 49, 39, 56, 34, 53,

     46, 42, 50, 36, 29, 32

  };

}

/* End of DES-defined tables */

/* bit 0 is left-most in byte */

namespace {

  const int bytebit[] = {

     0200,0100,040,020,010,04,02,01

  };

}

/* Set key (initialize key schedule array) */

void RawDES::RawSetKey(CipherDir dir, const byte *key)

{

#if (CRYPTOPP_MSC_VERSION >= 1600) || (__cplusplus >= 201103L)

# define REGISTER /* Define to nothing for C++11 and above */

#else

# define REGISTER register

#endif

  SecByteBlock buffer(56+56+8);

  byte *const pc1m=buffer;                 /* place to modify pc1 into */

  byte *const pcr=pc1m+56;                 /* place to rotate pc1 into */

  byte *const ks=pcr+56;

  REGISTER int i,j,l;

  int m;

  for (j=0; j<56; j++) {          /* convert pc1 to bits of key */

    l=pc1[j]-1;             /* integer bit location  */

    m = l & 07;             /* find bit              */

    pc1m[j]=(key[l>>3] &    /* find which key byte l is in */

      bytebit[m])     /* and which bit of that byte */

      ? 1 : 0;        /* and store 1-bit result */

  }

  for (i=0; i<16; i++) {          /* key chunk for each iteration */

    std::memset(ks,0,8);         /* Clear key schedule */

    for (j=0; j<56; j++)    /* rotate pc1 the right amount */

      pcr[j] = pc1m[(l=j+totrot[i])<(j<28? 28 : 56) ? l: l-28];

    /* rotate left and right halves independently */

    for (j=0; j<48; j++){   /* select bits individually */

      /* check bit that goes to ks[j] */

      if (pcr[pc2[j]-1]){

        /* mask it in if it's there */

        l= j % 6;

        ks[j/6] |= bytebit[l] >> 2;

      }

    }

    /* Now convert to odd/even interleaved form for use in F */

    k[2*i] = ((word32)ks[0] << 24)

      | ((word32)ks[2] << 16)

      | ((word32)ks[4] << 8)

      | ((word32)ks[6]);

    k[2*i+1] = ((word32)ks[1] << 24)

      | ((word32)ks[3] << 16)

      | ((word32)ks[5] << 8)

      | ((word32)ks[7]);

  }

  if (dir==DECRYPTION)     // reverse key schedule order

    for (i=0; i<16; i+=2)

    {

      std::swap(k[i], k[32-2-i]);

      std::swap(k[i+1], k[32-1-i]);

    }

}

void RawDES::RawProcessBlock(word32 &l_, word32 &r_) const

{

  word32 l = l_, r = r_;

  const word32 *kptr=k;

  for (unsigned i=0; i<8; i++)

  {

    word32 work = rotrConstant<4>(r) ^ kptr[4 * i + 0];

    l ^= Spbox[6][(work) & 0x3f]

      ^  Spbox[4][(work >> 8) & 0x3f]

      ^  Spbox[2][(work >> 16) & 0x3f]

      ^  Spbox[0][(work >> 24) & 0x3f];

    work = r ^ kptr[4*i+1];

    l ^= Spbox[7][(work) & 0x3f]

      ^  Spbox[5][(work >> 8) & 0x3f]

      ^  Spbox[3][(work >> 16) & 0x3f]

      ^  Spbox[1][(work >> 24) & 0x3f];

    work = rotrConstant<4>(l) ^ kptr[4 * i + 2];

    r ^= Spbox[6][(work) & 0x3f]

      ^  Spbox[4][(work >> 8) & 0x3f]

      ^  Spbox[2][(work >> 16) & 0x3f]

      ^  Spbox[0][(work >> 24) & 0x3f];

    work = l ^ kptr[4*i+3];

    r ^= Spbox[7][(work) & 0x3f]

      ^  Spbox[5][(work >> 8) & 0x3f]

      ^  Spbox[3][(work >> 16) & 0x3f]

      ^  Spbox[1][(work >> 24) & 0x3f];

  }

  l_ = l; r_ = r;

}

void DES_EDE2::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &)

{

  AssertValidKeyLength(length);

  m_des1.RawSetKey(GetCipherDirection(), userKey);

  m_des2.RawSetKey(ReverseCipherDir(GetCipherDirection()), userKey+8);

}

void DES_EDE2::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const

{

  word32 l,r;

  Block::Get(inBlock)(l)(r);

  IPERM(l,r);

  m_des1.RawProcessBlock(l, r);

  m_des2.RawProcessBlock(r, l);

  m_des1.RawProcessBlock(l, r);

  FPERM(l,r);

  Block::Put(xorBlock, outBlock)(r)(l);

}

void DES_EDE3::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &)

{

  AssertValidKeyLength(length);

  m_des1.RawSetKey(GetCipherDirection(), userKey + (IsForwardTransformation() ? 0 : 16));

  m_des2.RawSetKey(ReverseCipherDir(GetCipherDirection()), userKey + 8);

  m_des3.RawSetKey(GetCipherDirection(), userKey + (IsForwardTransformation() ? 16 : 0));

}

void DES_EDE3::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const

{

  word32 l,r;

  Block::Get(inBlock)(l)(r);

  IPERM(l,r);

  m_des1.RawProcessBlock(l, r);

  m_des2.RawProcessBlock(r, l);

  m_des3.RawProcessBlock(l, r);

  FPERM(l,r);

  Block::Put(xorBlock, outBlock)(r)(l);

}

#endif  // #ifndef CRYPTOPP_IMPORTS

static inline bool CheckParity(byte b)

{

  unsigned int a = b ^ (b >> 4);

  return ((a ^ (a>>1) ^ (a>>2) ^ (a>>3)) & 1) == 1;

}

bool DES::CheckKeyParityBits(const byte *key)

{

  for (unsigned int i=0; i<8; i++)

    if (!CheckParity(key[i]))

      return false;

  return true;

}

void DES::CorrectKeyParityBits(byte *key)

{

  for (unsigned int i=0; i<8; i++)

    if (!CheckParity(key[i]))

      key[i] ^= 1;

}

// Encrypt or decrypt a block of data in ECB mode

void DES::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const

{

  word32 l,r;

  Block::Get(inBlock)(l)(r);

  IPERM(l,r);

  RawProcessBlock(l, r);

  FPERM(l,r);

  Block::Put(xorBlock, outBlock)(r)(l);

}

void DES_XEX3::Base::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs &)

{

  AssertValidKeyLength(length);

  if (!m_des.get())

    m_des.reset(new DES::Encryption);

  std::memcpy(m_x1, key + (IsForwardTransformation() ? 0 : 16), BLOCKSIZE);

  m_des->RawSetKey(GetCipherDirection(), key + 8);

  std::memcpy(m_x3, key + (IsForwardTransformation() ? 16 : 0), BLOCKSIZE);

}

void DES_XEX3::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const

{

  xorbuf(outBlock, inBlock, m_x1, BLOCKSIZE);

  m_des->ProcessAndXorBlock(outBlock, xorBlock, outBlock);

  xorbuf(outBlock, m_x3, BLOCKSIZE);

}

NAMESPACE_END