des.h

用C语言实现des加密算法

#ifndef CRYPT_H_
#define CRYPT_H_
#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <ctype.h>
#include <limits.h>

#ifdef __cplusplus
extern "C" {
#endif

/* version */
#define CRYPT   0x0096
#define SCRYPT  "0.96"

/* error codes [will be expanded in future releases] */
enum {
   CRYPT_OK=0,             /* Result OK */
   
   CRYPT_INVALID_KEYSIZE,  /* Invalid key size given */
   CRYPT_INVALID_ROUNDS,   /* Invalid number of rounds */
   CRYPT_FAIL_TESTVECTOR,  /* Algorithm failed test vectors */
  
};
#define DES
/* Use small code where possible */
#define SMALL_CODE

/* Enable self-test test vector checking */
#define LTC_TEST

/* type of argument checking, 0=default, 1=fatal and 2=none */
#define ARGTYPE  0
/* ch1-01-1 */

/* Controls endianess and size of registers.  Leave uncommented to get platform neutral [slower] code */
/* detect x86-32 machines somewhat */
#if defined(INTEL_CC) || (defined(_MSC_VER) && defined(WIN32)) || (defined(__GNUC__) && (defined(__DJGPP__) || defined(__CYGWIN__) || defined(__MINGW32__) || defined(__i386__)))
   #define ENDIAN_LITTLE
   #define ENDIAN_32BITWORD
#endif

/* detects MIPS R5900 processors (PS2) */
#if (defined(__R5900) || defined(R5900) || defined(__R5900__)) && (defined(_mips) || defined(__mips__) || defined(mips))
   #define ENDIAN_LITTLE
   #define ENDIAN_64BITWORD
#endif

/* #define ENDIAN_LITTLE */
/* #define ENDIAN_BIG */

/* #define ENDIAN_32BITWORD */
/* #define ENDIAN_64BITWORD */

#if (defined(ENDIAN_BIG) || defined(ENDIAN_LITTLE)) && !(defined(ENDIAN_32BITWORD) || defined(ENDIAN_64BITWORD))
    #error You must specify a word size as well as endianess 
#endif

#if !(defined(ENDIAN_BIG) || defined(ENDIAN_LITTLE))
   #define ENDIAN_NEUTRAL
#endif

/* fix for MSVC ...evil! */
#ifdef _MSC_VER
   #define CONST64(n) n ## ui64
   typedef unsigned __int64 ulong64;
#else
   #define CONST64(n) n ## ULL
   typedef unsigned long long ulong64;
#endif

/* this is the "32-bit at least" data type 
 * Re-define it to suit your platform but it must be at least 32-bits 
 */
typedef unsigned long ulong32;

/* ---- HELPER MACROS ---- */
#ifdef ENDIAN_NEUTRAL

#define STORE32L(x, y)                                                                     \
     { (y)[3] = (unsigned char)(((x)>>24)&255); (y)[2] = (unsigned char)(((x)>>16)&255);   \
       (y)[1] = (unsigned char)(((x)>>8)&255); (y)[0] = (unsigned char)((x)&255); }

#define LOAD32L(x, y)                            \
     { x = ((unsigned long)((y)[3] & 255)<<24) | \
           ((unsigned long)((y)[2] & 255)<<16) | \
           ((unsigned long)((y)[1] & 255)<<8)  | \
           ((unsigned long)((y)[0] & 255)); }


#define STORE32H(x, y)                                                                     \
     { (y)[0] = (unsigned char)(((x)>>24)&255); (y)[1] = (unsigned char)(((x)>>16)&255);   \
       (y)[2] = (unsigned char)(((x)>>8)&255); (y)[3] = (unsigned char)((x)&255); }

#define LOAD32H(x, y)                            \
     { x = ((unsigned long)((y)[0] & 255)<<24) | \
           ((unsigned long)((y)[1] & 255)<<16) | \
           ((unsigned long)((y)[2] & 255)<<8)  | \
           ((unsigned long)((y)[3] & 255)); }


#endif /* ENDIAN_NEUTRAL */

#ifdef ENDIAN_LITTLE

#define STORE32H(x, y)                                                                     \
     { (y)[0] = (unsigned char)(((x)>>24)&255); (y)[1] = (unsigned char)(((x)>>16)&255);   \
       (y)[2] = (unsigned char)(((x)>>8)&255); (y)[3] = (unsigned char)((x)&255); }

#define LOAD32H(x, y)                            \
     { x = ((unsigned long)((y)[0] & 255)<<24) | \
           ((unsigned long)((y)[1] & 255)<<16) | \
           ((unsigned long)((y)[2] & 255)<<8)  | \
           ((unsigned long)((y)[3] & 255)); }


#ifdef ENDIAN_32BITWORD 

#define STORE32L(x, y)        \
     { unsigned long __t = (x); memcpy(y, &__t, 4); }

#define LOAD32L(x, y)         \
     memcpy(&(x), y, 4);

#else /* 64-bit words then  */

#define STORE32L(x, y)        \
     { unsigned long __t = (x); memcpy(y, &__t, 4); }

#define LOAD32L(x, y)         \
     { memcpy(&(x), y, 4); x &= 0xFFFFFFFF; }

#endif /* ENDIAN_64BITWORD */

#endif /* ENDIAN_LITTLE */

#ifdef ENDIAN_BIG
#define STORE32L(x, y)                                                                     \
     { (y)[0] = (unsigned char)(((x)>>24)&255); (y)[1] = (unsigned char)(((x)>>16)&255);   \
       (y)[2] = (unsigned char)(((x)>>8)&255); (y)[3] = (unsigned char)((x)&255); }

#define LOAD32L(x, y)                            \
     { x = ((unsigned long)((y)[0] & 255)<<24) | \
           ((unsigned long)((y)[1] & 255)<<16) | \
           ((unsigned long)((y)[2] & 255)<<8)  | \
           ((unsigned long)((y)[3] & 255)); }

#ifdef ENDIAN_32BITWORD 

#define STORE32H(x, y)        \
     { unsigned long __t = (x); memcpy(y, &__t, 4); }

#define LOAD32H(x, y)         \
     memcpy(&(x), y, 4);

#else /* 64-bit words then  */

#define STORE32H(x, y)        \
     { unsigned long __t = (x); memcpy(y, &__t, 4); }

#define LOAD32H(x, y)         \
     { memcpy(&(x), y, 4); x &= 0xFFFFFFFF; }

#endif /* ENDIAN_64BITWORD */
#endif /* ENDIAN_BIG */

#define BSWAP(x)  ( ((x>>24)&0x000000FFUL) | ((x<<24)&0xFF000000UL)  | \
                    ((x>>8)&0x0000FF00UL)  | ((x<<8)&0x00FF0000UL) )

#ifdef _MSC_VER

#pragma intrinsic(_lrotr,_lrotl)
#define ROR(x,n) _lrotr(x,n)
#define ROL(x,n) _lrotl(x,n)

#elif defined(__GNUC__) && defined(__i386__) && !defined(INTEL_CC)

static inline unsigned long ROL(unsigned long word, int i)
{
   __asm__("roll %%cl,%0"
      :"=r" (word)
      :"0" (word),"c" (i));
   return word;
}

static inline unsigned long ROR(unsigned long word, int i)
{
   __asm__("rorl %%cl,%0"
      :"=r" (word)
      :"0" (word),"c" (i));
   return word;
}

#else
/* rotates the hard way */
#define ROL(x, y) ( (((unsigned long)(x)<<(unsigned long)((y)&31)) | (((unsigned long)(x)&0xFFFFFFFFUL)>>(unsigned long)(32-((y)&31)))) & 0xFFFFFFFFUL)
#define ROR(x, y) ( ((((unsigned long)(x)&0xFFFFFFFFUL)>>(unsigned long)((y)&31)) | ((unsigned long)(x)<<(unsigned long)(32-((y)&31)))) & 0xFFFFFFFFUL)

#endif

/* extract a byte portably */
#ifdef _MSC_VER
   #define byte(x, n) ((unsigned char)((x) >> (8 * (n))))
#else
   #define byte(x, n) (((x) >> (8 * (n))) & 255)
#endif   

typedef struct des_key {
    ulong32 ek[32], dk[32];
}symmetric_key;

extern int des_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey);
extern void des_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *key);
extern void des_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *key);
extern int des_test(void);
extern int des_keysize(int *desired_keysize);


#if ARGTYPE == 0
#include <signal.h>

/* this is the default LibTomCrypt macro  */
extern void crypt_argchk(char *v, char *s, int d);
#define _ARGCHK(x) if (!(x)) { crypt_argchk(#x, __FILE__, __LINE__); }

#elif ARGTYPE == 1

/* fatal type of error */
#define _ARGCHK(x) assert((x))

#elif ARGTYPE == 2

#define _ARGCHK(x) 

#endif
void zeromem(void *dst, size_t len);
void burn_stack(unsigned long len);

#ifdef __cplusplus
   }
#endif

#endif /* CRYPT_H_ */