www.pudn.com > RSA-MD2-MD5-source_code.rar > desc.c, change:1994-03-26,size:21984b


/* 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 */ 
{ 
  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, and xor with whitener. 
     */ 
    if (context->encrypt) { 
      work[0] = 
        inputBlock[0] ^ context->iv[0] ^ context->inputWhitener[0]; 
      work[1] = 
        inputBlock[1] ^ context->iv[1] ^ context->inputWhitener[1]; 
    } 
    else { 
      work[0] = inputBlock[0] ^ context->outputWhitener[0]; 
      work[1] = inputBlock[1] ^ context->outputWhitener[1];          
    } 
 
    DESFunction (work, context->subkeys); 
 
    /* Xor with whitener, chain if decrypting, then update IV. 
     */ 
    if (context->encrypt) { 
      work[0] ^= context->outputWhitener[0]; 
      work[1] ^= context->outputWhitener[1]; 
      context->iv[0] = work[0]; 
      context->iv[1] = work[1]; 
    } 
    else { 
      work[0] ^= context->iv[0] ^ context->inputWhitener[0]; 
      work[1] ^= context->iv[1] ^ context->inputWhitener[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 DESX_CBCRestart (context) 
DESX_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. 
 */ 
void DES3_CBCInit(context, key, iv, encrypt) 
DES3_CBC_CTX *context;                                           /* context */ 
unsigned char key[24];                                               /* 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 schedules. 
   */ 
  DESKey (context->subkeys[0], encrypt ? key : &key[16], encrypt); 
  DESKey (context->subkeys[1], &key[8], !encrypt); 
  DESKey (context->subkeys[2], encrypt ? &key[16] : key, encrypt); 
} 
 
int DES3_CBCUpdate (context, output, input, len) 
DES3_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[0]); 
    DESFunction (work, context->subkeys[1]); 
    DESFunction (work, context->subkeys[2]); 
 
    /* 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 DES3_CBCRestart (context) 
DES3_CBC_CTX *context; 
{ 
  /* Reset to the original IV */ 
  context->iv[0] = context->originalIV[0]; 
  context->iv[1] = context->originalIV[1]; 
} 
 
static void Pack (into, outof) 
UINT4 *into; 
unsigned char *outof; 
{ 
  *into    = (*outof++ & 0xffL) << 24; 
  *into   |= (*outof++ & 0xffL) << 16; 
  *into   |= (*outof++ & 0xffL) << 8; 
  *into++ |= (*outof++ & 0xffL); 
  *into    = (*outof++ & 0xffL) << 24; 
  *into   |= (*outof++ & 0xffL) << 16; 
  *into   |= (*outof++ & 0xffL) << 8; 
  *into   |= (*outof   & 0xffL); 
} 
 
static void Unpack (into, outof) 
unsigned char *into; 
UINT4 *outof; 
{ 
  *into++ = (unsigned char)((*outof >> 24) & 0xffL); 
  *into++ = (unsigned char)((*outof >> 16) & 0xffL); 
  *into++ = (unsigned char)((*outof >>  8) & 0xffL); 
  *into++ = (unsigned char)( *outof++      & 0xffL); 
  *into++ = (unsigned char)((*outof >> 24) & 0xffL); 
  *into++ = (unsigned char)((*outof >> 16) & 0xffL); 
  *into++ = (unsigned char)((*outof >>  8) & 0xffL); 
  *into   = (unsigned char)( *outof        & 0xffL); 
} 
 
static void DESKey (subkeys, key, encrypt) 
UINT4 subkeys[32]; 
unsigned char key[8]; 
int encrypt; 
{ 
  UINT4 kn[32]; 
  int i, j, l, m, n; 
  unsigned char pc1m[56], pcr[56]; 
 
  for (j = 0; j < 56; j++) { 
    l = PC1[j]; 
    m = l & 07; 
    pc1m[j] = (unsigned char)((key[l >> 3] & BYTE_BIT[m]) ? 1 : 0); 
  } 
  for (i = 0; i < 16; i++) { 
    m = i << 1; 
    n = m + 1; 
    kn[m] = kn[n] = 0L; 
    for (j = 0; j < 28; j++) { 
      l = j + TOTAL_ROTATIONS[i]; 
      if (l < 28) 
        pcr[j] = pc1m[l]; 
      else 
        pcr[j] = pc1m[l - 28]; 
    } 
    for (j = 28; j < 56; j++) { 
      l = j + TOTAL_ROTATIONS[i]; 
      if (l < 56) 
        pcr[j] = pc1m[l]; 
      else 
        pcr[j] = pc1m[l - 28]; 
    } 
    for (j = 0; j < 24; j++) { 
      if (pcr[PC2[j]]) 
        kn[m] |= BIG_BYTE[j]; 
      if (pcr[PC2[j+24]]) 
        kn[n] |= BIG_BYTE[j]; 
    } 
  } 
  CookKey (subkeys, kn, encrypt); 
 
  /* Zeroize sensitive information. 
   */ 
  R_memset ((POINTER)pc1m, 0, sizeof (pc1m)); 
  R_memset ((POINTER)pcr, 0, sizeof (pcr)); 
  R_memset ((POINTER)kn, 0, sizeof (kn)); 
} 
 
static void CookKey (subkeys, kn, encrypt) 
UINT4 *subkeys; 
UINT4 *kn; 
int encrypt; 
{ 
  UINT4 *cooked, *raw0, *raw1; 
  int increment; 
  unsigned int i; 
 
  raw1 = kn; 
  cooked = encrypt ? subkeys : &subkeys[30]; 
  increment = encrypt ? 1 : -3; 
 
  for (i = 0; i < 16; i++, raw1++) { 
    raw0 = raw1++; 
    *cooked    = (*raw0 & 0x00fc0000L) << 6; 
    *cooked   |= (*raw0 & 0x00000fc0L) << 10; 
    *cooked   |= (*raw1 & 0x00fc0000L) >> 10; 
    *cooked++ |= (*raw1 & 0x00000fc0L) >> 6; 
    *cooked    = (*raw0 & 0x0003f000L) << 12; 
    *cooked   |= (*raw0 & 0x0000003fL) << 16; 
    *cooked   |= (*raw1 & 0x0003f000L) >> 4; 
    *cooked   |= (*raw1 & 0x0000003fL); 
    cooked += increment; 
  } 
} 
 
static void DESFunction (block, subkeys) 
UINT4 *block; 
UINT4 *subkeys; 
{ 
  register UINT4 fval, work, right, left; 
  register int round; 
   
  left = block[0]; 
  right = block[1]; 
  work = ((left >> 4) ^ right) & 0x0f0f0f0fL; 
  right ^= work; 
  left ^= (work << 4); 
  work = ((left >> 16) ^ right) & 0x0000ffffL; 
  right ^= work; 
  left ^= (work << 16); 
  work = ((right >> 2) ^ left) & 0x33333333L; 
  left ^= work; 
  right ^= (work << 2); 
  work = ((right >> 8) ^ left) & 0x00ff00ffL; 
  left ^= work; 
  right ^= (work << 8); 
  right = ((right << 1) | ((right >> 31) & 1L)) & 0xffffffffL; 
  work = (left ^ right) & 0xaaaaaaaaL; 
  left ^= work; 
  right ^= work; 
  left = ((left << 1) | ((left >> 31) & 1L)) & 0xffffffffL; 
   
  for (round = 0; round < 8; round++) { 
    work  = (right << 28) | (right >> 4); 
    work ^= *subkeys++; 
    fval  = SP7[ work        & 0x3fL]; 
    fval |= SP5[(work >>  8) & 0x3fL]; 
    fval |= SP3[(work >> 16) & 0x3fL]; 
    fval |= SP1[(work >> 24) & 0x3fL]; 
    work  = right ^ *subkeys++; 
    fval |= SP8[ work        & 0x3fL]; 
    fval |= SP6[(work >>  8) & 0x3fL]; 
    fval |= SP4[(work >> 16) & 0x3fL]; 
    fval |= SP2[(work >> 24) & 0x3fL]; 
    left ^= fval; 
    work  = (left << 28) | (left >> 4); 
    work ^= *subkeys++; 
    fval  = SP7[ work        & 0x3fL]; 
    fval |= SP5[(work >>  8) & 0x3fL]; 
    fval |= SP3[(work >> 16) & 0x3fL]; 
    fval |= SP1[(work >> 24) & 0x3fL]; 
    work  = left ^ *subkeys++; 
    fval |= SP8[ work        & 0x3fL]; 
    fval |= SP6[(work >>  8) & 0x3fL]; 
    fval |= SP4[(work >> 16) & 0x3fL]; 
    fval |= SP2[(work >> 24) & 0x3fL]; 
    right ^= fval; 
  } 
   
  right = (right << 31) | (right >> 1); 
  work = (left ^ right) & 0xaaaaaaaaL; 
  left ^= work; 
  right ^= work; 
  left = (left << 31) | (left >> 1); 
  work = ((left >> 8) ^ right) & 0x00ff00ffL; 
  right ^= work; 
  left ^= (work << 8); 
  work = ((left >> 2) ^ right) & 0x33333333L; 
  right ^= work; 
  left ^= (work << 2); 
  work = ((right >> 16) ^ left) & 0x0000ffffL; 
  left ^= work; 
  right ^= (work << 16); 
  work = ((right >> 4) ^ left) & 0x0f0f0f0fL; 
  left ^= work; 
  right ^= (work << 4); 
  *block++ = right; 
  *block = left; 
}