/* DESC.C - Data Encryption Standard routines for RSAREF
     Based on "Karn/Hoey/Outerbridge" implementation (KHODES)
 */

#include "global.h"
#include "rsaref.h"
#include "des.h"

static UINT2 BYTE_BIT[8] = {
  0200, 0100, 040, 020, 010, 04, 02, 01
};

static UINT4 BIG_BYTE[24] = {
  0x800000L, 0x400000L, 0x200000L, 0x100000L,
  0x80000L,  0x40000L,  0x20000L,  0x10000L,
  0x8000L,   0x4000L,   0x2000L,   0x1000L,
  0x800L,    0x400L,    0x200L,    0x100L,
  0x80L,     0x40L,     0x20L,     0x10L,
  0x8L,      0x4L,      0x2L,      0x1L
};

static unsigned char PC1[56] = {
  56, 48, 40, 32, 24, 16,  8,      0, 57, 49, 41, 33, 25, 17,
   9,  1, 58, 50, 42, 34, 26,     18, 10,  2, 59, 51, 43, 35,
  62, 54, 46, 38, 30, 22, 14,      6, 61, 53, 45, 37, 29, 21,
  13,  5, 60, 52, 44, 36, 28,     20, 12,  4, 27, 19, 11,  3
};

static unsigned char TOTAL_ROTATIONS[16] = {
  1, 2, 4, 6, 8, 10, 12, 14, 15, 17, 19, 21, 23, 25, 27, 28
};

static unsigned char PC2[48] = {
  13, 16, 10, 23,  0,  4,  2, 27, 14,  5, 20,  9,
  22, 18, 11,  3, 25,  7, 15,  6, 26, 19, 12,  1,
  40, 51, 30, 36, 46, 54, 29, 39, 50, 44, 32, 47,
  43, 48, 38, 55, 33, 52, 45, 41, 49, 35, 28, 31
};

static UINT4 SP1[64] = {
  0x01010400L, 0x00000000L, 0x00010000L, 0x01010404L,
  0x01010004L, 0x00010404L, 0x00000004L, 0x00010000L,
  0x00000400L, 0x01010400L, 0x01010404L, 0x00000400L,
  0x01000404L, 0x01010004L, 0x01000000L, 0x00000004L,
  0x00000404L, 0x01000400L, 0x01000400L, 0x00010400L,
  0x00010400L, 0x01010000L, 0x01010000L, 0x01000404L,
  0x00010004L, 0x01000004L, 0x01000004L, 0x00010004L,
  0x00000000L, 0x00000404L, 0x00010404L, 0x01000000L,
  0x00010000L, 0x01010404L, 0x00000004L, 0x01010000L,
  0x01010400L, 0x01000000L, 0x01000000L, 0x00000400L,
  0x01010004L, 0x00010000L, 0x00010400L, 0x01000004L,
  0x00000400L, 0x00000004L, 0x01000404L, 0x00010404L,
  0x01010404L, 0x00010004L, 0x01010000L, 0x01000404L,
  0x01000004L, 0x00000404L, 0x00010404L, 0x01010400L,
  0x00000404L, 0x01000400L, 0x01000400L, 0x00000000L,
  0x00010004L, 0x00010400L, 0x00000000L, 0x01010004L
};

static UINT4 SP2[64] = {
  0x80108020L, 0x80008000L, 0x00008000L, 0x00108020L,
  0x00100000L, 0x00000020L, 0x80100020L, 0x80008020L,
  0x80000020L, 0x80108020L, 0x80108000L, 0x80000000L,
  0x80008000L, 0x00100000L, 0x00000020L, 0x80100020L,
  0x00108000L, 0x00100020L, 0x80008020L, 0x00000000L,
  0x80000000L, 0x00008000L, 0x00108020L, 0x80100000L,
  0x00100020L, 0x80000020L, 0x00000000L, 0x00108000L,
  0x00008020L, 0x80108000L, 0x80100000L, 0x00008020L,
  0x00000000L, 0x00108020L, 0x80100020L, 0x00100000L,
  0x80008020L, 0x80100000L, 0x80108000L, 0x00008000L,
  0x80100000L, 0x80008000L, 0x00000020L, 0x80108020L,
  0x00108020L, 0x00000020L, 0x00008000L, 0x80000000L,
  0x00008020L, 0x80108000L, 0x00100000L, 0x80000020L,
  0x00100020L, 0x80008020L, 0x80000020L, 0x00100020L,
  0x00108000L, 0x00000000L, 0x80008000L, 0x00008020L,
  0x80000000L, 0x80100020L, 0x80108020L, 0x00108000L
};

static UINT4 SP3[64] = {
  0x00000208L, 0x08020200L, 0x00000000L, 0x08020008L,
  0x08000200L, 0x00000000L, 0x00020208L, 0x08000200L,
  0x00020008L, 0x08000008L, 0x08000008L, 0x00020000L,
  0x08020208L, 0x00020008L, 0x08020000L, 0x00000208L,
  0x08000000L, 0x00000008L, 0x08020200L, 0x00000200L,
  0x00020200L, 0x08020000L, 0x08020008L, 0x00020208L,
  0x08000208L, 0x00020200L, 0x00020000L, 0x08000208L,
  0x00000008L, 0x08020208L, 0x00000200L, 0x08000000L,
  0x08020200L, 0x08000000L, 0x00020008L, 0x00000208L,
  0x00020000L, 0x08020200L, 0x08000200L, 0x00000000L,
  0x00000200L, 0x00020008L, 0x08020208L, 0x08000200L,
  0x08000008L, 0x00000200L, 0x00000000L, 0x08020008L,
  0x08000208L, 0x00020000L, 0x08000000L, 0x08020208L,
  0x00000008L, 0x00020208L, 0x00020200L, 0x08000008L,
  0x08020000L, 0x08000208L, 0x00000208L, 0x08020000L,
  0x00020208L, 0x00000008L, 0x08020008L, 0x00020200L
};

static UINT4 SP4[64] = {
  0x00802001L, 0x00002081L, 0x00002081L, 0x00000080L,
  0x00802080L, 0x00800081L, 0x00800001L, 0x00002001L,
  0x00000000L, 0x00802000L, 0x00802000L, 0x00802081L,
  0x00000081L, 0x00000000L, 0x00800080L, 0x00800001L,
  0x00000001L, 0x00002000L, 0x00800000L, 0x00802001L,
  0x00000080L, 0x00800000L, 0x00002001L, 0x00002080L,
  0x00800081L, 0x00000001L, 0x00002080L, 0x00800080L,
  0x00002000L, 0x00802080L, 0x00802081L, 0x00000081L,
  0x00800080L, 0x00800001L, 0x00802000L, 0x00802081L,
  0x00000081L, 0x00000000L, 0x00000000L, 0x00802000L,
  0x00002080L, 0x00800080L, 0x00800081L, 0x00000001L,
  0x00802001L, 0x00002081L, 0x00002081L, 0x00000080L,
  0x00802081L, 0x00000081L, 0x00000001L, 0x00002000L,
  0x00800001L, 0x00002001L, 0x00802080L, 0x00800081L,
  0x00002001L, 0x00002080L, 0x00800000L, 0x00802001L,
  0x00000080L, 0x00800000L, 0x00002000L, 0x00802080L
};

static UINT4 SP5[64] = {
  0x00000100L, 0x02080100L, 0x02080000L, 0x42000100L,
  0x00080000L, 0x00000100L, 0x40000000L, 0x02080000L,
  0x40080100L, 0x00080000L, 0x02000100L, 0x40080100L,
  0x42000100L, 0x42080000L, 0x00080100L, 0x40000000L,
  0x02000000L, 0x40080000L, 0x40080000L, 0x00000000L,
  0x40000100L, 0x42080100L, 0x42080100L, 0x02000100L,
  0x42080000L, 0x40000100L, 0x00000000L, 0x42000000L,
  0x02080100L, 0x02000000L, 0x42000000L, 0x00080100L,
  0x00080000L, 0x42000100L, 0x00000100L, 0x02000000L,
  0x40000000L, 0x02080000L, 0x42000100L, 0x40080100L,
  0x02000100L, 0x40000000L, 0x42080000L, 0x02080100L,
  0x40080100L, 0x00000100L, 0x02000000L, 0x42080000L,
  0x42080100L, 0x00080100L, 0x42000000L, 0x42080100L,
  0x02080000L, 0x00000000L, 0x40080000L, 0x42000000L,
  0x00080100L, 0x02000100L, 0x40000100L, 0x00080000L,
  0x00000000L, 0x40080000L, 0x02080100L, 0x40000100L
};

static UINT4 SP6[64] = {
  0x20000010L, 0x20400000L, 0x00004000L, 0x20404010L,
  0x20400000L, 0x00000010L, 0x20404010L, 0x00400000L,
  0x20004000L, 0x00404010L, 0x00400000L, 0x20000010L,
  0x00400010L, 0x20004000L, 0x20000000L, 0x00004010L,
  0x00000000L, 0x00400010L, 0x20004010L, 0x00004000L,
  0x00404000L, 0x20004010L, 0x00000010L, 0x20400010L,
  0x20400010L, 0x00000000L, 0x00404010L, 0x20404000L,
  0x00004010L, 0x00404000L, 0x20404000L, 0x20000000L,
  0x20004000L, 0x00000010L, 0x20400010L, 0x00404000L,
  0x20404010L, 0x00400000L, 0x00004010L, 0x20000010L,
  0x00400000L, 0x20004000L, 0x20000000L, 0x00004010L,
  0x20000010L, 0x20404010L, 0x00404000L, 0x20400000L,
  0x00404010L, 0x20404000L, 0x00000000L, 0x20400010L,
  0x00000010L, 0x00004000L, 0x20400000L, 0x00404010L,
  0x00004000L, 0x00400010L, 0x20004010L, 0x00000000L,
  0x20404000L, 0x20000000L, 0x00400010L, 0x20004010L
};

static UINT4 SP7[64] = {
  0x00200000L, 0x04200002L, 0x04000802L, 0x00000000L,
  0x00000800L, 0x04000802L, 0x00200802L, 0x04200800L,
  0x04200802L, 0x00200000L, 0x00000000L, 0x04000002L,
  0x00000002L, 0x04000000L, 0x04200002L, 0x00000802L,
  0x04000800L, 0x00200802L, 0x00200002L, 0x04000800L,
  0x04000002L, 0x04200000L, 0x04200800L, 0x00200002L,
  0x04200000L, 0x00000800L, 0x00000802L, 0x04200802L,
  0x00200800L, 0x00000002L, 0x04000000L, 0x00200800L,
  0x04000000L, 0x00200800L, 0x00200000L, 0x04000802L,
  0x04000802L, 0x04200002L, 0x04200002L, 0x00000002L,
  0x00200002L, 0x04000000L, 0x04000800L, 0x00200000L,
  0x04200800L, 0x00000802L, 0x00200802L, 0x04200800L,
  0x00000802L, 0x04000002L, 0x04200802L, 0x04200000L,
  0x00200800L, 0x00000000L, 0x00000002L, 0x04200802L,
  0x00000000L, 0x00200802L, 0x04200000L, 0x00000800L,
  0x04000002L, 0x04000800L, 0x00000800L, 0x00200002L
};

static UINT4 SP8[64] = {
  0x10001040L, 0x00001000L, 0x00040000L, 0x10041040L,
  0x10000000L, 0x10001040L, 0x00000040L, 0x10000000L,
  0x00040040L, 0x10040000L, 0x10041040L, 0x00041000L,
  0x10041000L, 0x00041040L, 0x00001000L, 0x00000040L,
  0x10040000L, 0x10000040L, 0x10001000L, 0x00001040L,
  0x00041000L, 0x00040040L, 0x10040040L, 0x10041000L,
  0x00001040L, 0x00000000L, 0x00000000L, 0x10040040L,
  0x10000040L, 0x10001000L, 0x00041040L, 0x00040000L,
  0x00041040L, 0x00040000L, 0x10041000L, 0x00001000L,
  0x00000040L, 0x10040040L, 0x00001000L, 0x00041040L,
  0x10001000L, 0x00000040L, 0x10000040L, 0x10040000L,
  0x10040040L, 0x10000000L, 0x00040000L, 0x10001040L,
  0x00000000L, 0x10041040L, 0x00040040L, 0x10000040L,
  0x10040000L, 0x10001000L, 0x10001040L, 0x00000000L,
  0x10041040L, 0x00041000L, 0x00041000L, 0x00001040L,
  0x00001040L, 0x00040040L, 0x10000000L, 0x10041000L
};

static void Unpack PROTO_LIST ((unsigned char *, UINT4 *));
static void Pack PROTO_LIST ((UINT4 *, unsigned char *));
static void DESKey PROTO_LIST ((UINT4 *, unsigned char *, int));
static void CookKey PROTO_LIST ((UINT4 *, UINT4 *, int));
static void DESFunction PROTO_LIST ((UINT4 *, UINT4 *));

/* Initialize context.  Caller must zeroize the context when finished.
 */
void DES_CBCInit (context, key, iv, encrypt)
DES_CBC_CTX *context;                                            /* context */
unsigned char key[8];                                                /* key */
unsigned char iv[8];                                 /* initializing vector */
int encrypt;                     /* encrypt flag (1 = encrypt, 0 = decrypt) */
{  
  /* Copy encrypt flag to context.
   */
  context->encrypt = encrypt;

  /* Pack initializing vector into context.
   */
  Pack (context->iv, iv);

  /* Save the IV for use in Restart */
  context->originalIV[0] = context->iv[0];
  context->originalIV[1] = context->iv[1];

  /* Precompute key schedule
   */
  DESKey (context->subkeys, key, encrypt);
}

/* DES-CBC block update operation. Continues a DES-CBC encryption
   operation, processing eight-byte message blocks, and updating
   the context.
 */
int DES_CBCUpdate (context, output, input, len)
DES_CBC_CTX *context;                                            /* context */
unsigned char *output;                                      /* output block */
unsigned char *input;                                        /* input block */
unsigned int len;                      /* length of input and output blocks */
{
  UINT4 inputBlock[2], work[2];
  unsigned int i;
  
  if (len % 8)
    return (RE_LEN);

  for (i = 0; i < len/8; i++) {
    Pack (inputBlock, &input[8*i]);
        
    /* Chain if encrypting.
     */
    if (context->encrypt) {
      work[0] = inputBlock[0] ^ context->iv[0];
      work[1] = inputBlock[1] ^ context->iv[1];
    }
    else {
      work[0] = inputBlock[0];
      work[1] = inputBlock[1];         
    }

    DESFunction (work, context->subkeys);

    /* Chain if decrypting, then update IV.
     */
    if (context->encrypt) {
      context->iv[0] = work[0];
      context->iv[1] = work[1];
    }
    else {
      work[0] ^= context->iv[0];
      work[1] ^= context->iv[1];
      context->iv[0] = inputBlock[0];
      context->iv[1] = inputBlock[1];
    }
    Unpack (&output[8*i], work);
  }
  
  /* Zeroize sensitive information.
   */
  R_memset ((POINTER)inputBlock, 0, sizeof (inputBlock));
  R_memset ((POINTER)work, 0, sizeof (work));
  
  return (0);
}

void DES_CBCRestart (context)
DES_CBC_CTX *context;
{
  /* Reset to the original IV */
  context->iv[0] = context->originalIV[0];
  context->iv[1] = context->originalIV[1];
}

/* Initialize context.  Caller must zeroize the context when finished.
   The key has the DES key, input whitener and output whitener concatenated.
 */
void DESX_CBCInit (context, key, iv, encrypt)
DESX_CBC_CTX *context;
unsigned char key[24];                              /* DES key and whiteners */
unsigned char iv[8];                              /* DES initializing vector */
int encrypt;                      /* encrypt flag (1 = encrypt, 0 = decrypt) */
{  
  /* Copy encrypt flag to context.
   */
  context->encrypt = encrypt;

  /* Pack initializing vector and whiteners into context.
   */
  Pack (context->iv, iv);
  Pack (context->inputWhitener, key + 8);
  Pack (context->outputWhitener, key + 16);

  /* Save the IV for use in Restart */
  context->originalIV[0] = context->iv[0];
  context->originalIV[1] = context->iv[1];

  /* Precompute key schedule.
   */
  DESKey (context->subkeys, key, encrypt);
}

/* DESX-CBC block update operation. Continues a DESX-CBC encryption
   operation, processing eight-byte message blocks, and updating
   the context.
 */
int DESX_CBCUpdate (context, output, input, len)
DESX_CBC_CTX *context;                                           /* context */
unsigned char *output;                                      /* output block */
unsigned char *input;                                        /* input block */
unsigned int len;                      /* length of input and output blocks */
{