des.c

python的加密库

/*
 *  des.c : Source code for the DES block cipher
 *
 * Part of the Python Cryptography Toolkit
 *
 * Distribute and use freely; there are no restrictions on further 
 * dissemination and usage except those imposed by the laws of your 
 * country of residence.
 *
 */

#include "Python.h"
  
/* des.c */
/* Copyright (C) 1993 Eric Young */
/* Integrated into the PCT by A.M. Kuchling, November 1994 */

#define MODULE_NAME DES
#define BLOCK_SIZE 8
#define KEY_SIZE 8


typedef unsigned char des_cblock[8];

/* ecb_enc.c */
/* Copyright (C) 1993 Eric Young - see README for more details */

#define c2l(c,l)	(l =((unsigned long)(*((c)++)))    , \
			 l|=((unsigned long)(*((c)++)))<< 8, \
			 l|=((unsigned long)(*((c)++)))<<16, \
			 l|=((unsigned long)(*((c)++)))<<24)

/* NOTE - c is not incremented as per c2l */
#define c2ln(c,l1,l2,n)	{ \
			c+=n; \
			l1=l2=0; \
			switch (n) { \
			case 8: l2|=((unsigned long)(*(--(c))))<<24; \
			case 7: l2|=((unsigned long)(*(--(c))))<<16; \
			case 6: l2|=((unsigned long)(*(--(c))))<< 8; \
			case 5: l2|=((unsigned long)(*(--(c))));     \
			case 4: l1|=((unsigned long)(*(--(c))))<<24; \
			case 3: l1|=((unsigned long)(*(--(c))))<<16; \
			case 2: l1|=((unsigned long)(*(--(c))))<< 8; \
			case 1: l1|=((unsigned long)(*(--(c))));     \
				} \
			}

#define l2c(l,c)	(*((c)++)=(unsigned char)(((l)    )&0xff), \
			 *((c)++)=(unsigned char)(((l)>> 8)&0xff), \
			 *((c)++)=(unsigned char)(((l)>>16)&0xff), \
			 *((c)++)=(unsigned char)(((l)>>24)&0xff))

/* replacements for htonl and ntohl since I have no idea what to do
 * when faced with machines with 8 byte longs. */
#define HDRSIZE 4

#define n2l(c,l)	(l =((unsigned long)(*((c)++)))<<24, \
			 l|=((unsigned long)(*((c)++)))<<16, \
			 l|=((unsigned long)(*((c)++)))<< 8, \
			 l|=((unsigned long)(*((c)++))))

#define l2n(l,c)	(*((c)++)=(unsigned char)(((l)>>24)&0xff), \
			 *((c)++)=(unsigned char)(((l)>>16)&0xff), \
			 *((c)++)=(unsigned char)(((l)>> 8)&0xff), \
			 *((c)++)=(unsigned char)(((l)    )&0xff))

/* NOTE - c is not incremented as per l2c */
#define l2cn(l1,l2,c,n)	{ \
			c+=n; \
			switch (n) { \
			case 8: *(--(c))=(unsigned char)(((l2)>>24)&0xff); \
			case 7: *(--(c))=(unsigned char)(((l2)>>16)&0xff); \
			case 6: *(--(c))=(unsigned char)(((l2)>> 8)&0xff); \
			case 5: *(--(c))=(unsigned char)(((l2)    )&0xff); \
			case 4: *(--(c))=(unsigned char)(((l1)>>24)&0xff); \
			case 3: *(--(c))=(unsigned char)(((l1)>>16)&0xff); \
			case 2: *(--(c))=(unsigned char)(((l1)>> 8)&0xff); \
			case 1: *(--(c))=(unsigned char)(((l1)    )&0xff); \
				} \
			}

#define D_ENCRYPT(L,R,S)	\
	u=(R^s[S  ]); \
	t=R^s[S+1]; \
	t=((t>>4)+(t<<28)); \
	L^=	des_SPtrans[1][(t    )&0x3f]| \
		des_SPtrans[3][(t>> 8)&0x3f]| \
		des_SPtrans[5][(t>>16)&0x3f]| \
		des_SPtrans[7][(t>>24)&0x3f]| \
		des_SPtrans[0][(u    )&0x3f]| \
		des_SPtrans[2][(u>> 8)&0x3f]| \
		des_SPtrans[4][(u>>16)&0x3f]| \
		des_SPtrans[6][(u>>24)&0x3f];

	/* IP and FP
	 * The problem is more of a geometric problem that random bit fiddling.
	 0  1  2  3  4  5  6  7      62 54 46 38 30 22 14  6
	 8  9 10 11 12 13 14 15      60 52 44 36 28 20 12  4
	16 17 18 19 20 21 22 23      58 50 42 34 26 18 10  2
	24 25 26 27 28 29 30 31  to  56 48 40 32 24 16  8  0

	32 33 34 35 36 37 38 39      63 55 47 39 31 23 15  7
	40 41 42 43 44 45 46 47      61 53 45 37 29 21 13  5
	48 49 50 51 52 53 54 55      59 51 43 35 27 19 11  3
	56 57 58 59 60 61 62 63      57 49 41 33 25 17  9  1

	The output has been subject to swaps of the form
	0 1 -> 3 1 but the odd and even bits have been put into
	2 3    2 0
	different words.  The main trick is to remember that
	t=((l>>size)^r)&(mask);
	r^=t;
	l^=(t<<size);
	can be used to swap and move bits between words.

	So l =  0  1  2  3  r = 16 17 18 19
	        4  5  6  7      20 21 22 23
	        8  9 10 11      24 25 26 27
	       12 13 14 15      28 29 30 31
	becomes (for size == 2 and mask == 0x3333)
	   t =   2^16  3^17 -- --   l =  0  1 16 17  r =  2  3 18 19
		 6^20  7^21 -- --        4  5 20 21       6  7 22 23
		10^24 11^25 -- --        8  9 24 25      10 11 24 25
		14^28 15^29 -- --       12 13 28 29      14 15 28 29

	Thanks for hints from Richard Outerbridge - he told me IP&FP
	could be done in 15 xor, 10 shifts and 5 ands.
	When I finally started to think of the problem in 2D
	I first got ~42 operations without xors.  When I remembered
	how to use xors :-) I got it to its final state.
	*/
#define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
	(b)^=(t),\
	(a)^=((t)<<(n)))



/* spr.h */
/* Copyright (C) 1993 Eric Young - see README for more details */
static unsigned long des_SPtrans[8][64]={
/* nibble 0 */
	{0x00820200, 0x00020000, 0x80800000, 0x80820200,
	 0x00800000, 0x80020200, 0x80020000, 0x80800000,
	 0x80020200, 0x00820200, 0x00820000, 0x80000200,
	 0x80800200, 0x00800000, 0x00000000, 0x80020000,
	 0x00020000, 0x80000000, 0x00800200, 0x00020200,
	 0x80820200, 0x00820000, 0x80000200, 0x00800200,
	 0x80000000, 0x00000200, 0x00020200, 0x80820000,
	 0x00000200, 0x80800200, 0x80820000, 0x00000000,
	 0x00000000, 0x80820200, 0x00800200, 0x80020000,
	 0x00820200, 0x00020000, 0x80000200, 0x00800200,
	 0x80820000, 0x00000200, 0x00020200, 0x80800000,
	 0x80020200, 0x80000000, 0x80800000, 0x00820000,
	 0x80820200, 0x00020200, 0x00820000, 0x80800200,
	 0x00800000, 0x80000200, 0x80020000, 0x00000000,
	 0x00020000, 0x00800000, 0x80800200, 0x00820200,
	 0x80000000, 0x80820000, 0x00000200, 0x80020200},

/* nibble 1 */
	{0x10042004, 0x00000000, 0x00042000, 0x10040000,
	 0x10000004, 0x00002004, 0x10002000, 0x00042000,
	 0x00002000, 0x10040004, 0x00000004, 0x10002000,
	 0x00040004, 0x10042000, 0x10040000, 0x00000004,
	 0x00040000, 0x10002004, 0x10040004, 0x00002000,
	 0x00042004, 0x10000000, 0x00000000, 0x00040004,
	 0x10002004, 0x00042004, 0x10042000, 0x10000004,
	 0x10000000, 0x00040000, 0x00002004, 0x10042004,
	 0x00040004, 0x10042000, 0x10002000, 0x00042004,
	 0x10042004, 0x00040004, 0x10000004, 0x00000000,
	 0x10000000, 0x00002004, 0x00040000, 0x10040004,
	 0x00002000, 0x10000000, 0x00042004, 0x10002004,
	 0x10042000, 0x00002000, 0x00000000, 0x10000004,
	 0x00000004, 0x10042004, 0x00042000, 0x10040000,
	 0x10040004, 0x00040000, 0x00002004, 0x10002000,
	 0x10002004, 0x00000004, 0x10040000, 0x00042000},

/* nibble 2 */
	{0x41000000, 0x01010040, 0x00000040, 0x41000040,
	 0x40010000, 0x01000000, 0x41000040, 0x00010040,
	 0x01000040, 0x00010000, 0x01010000, 0x40000000,
	 0x41010040, 0x40000040, 0x40000000, 0x41010000,
	 0x00000000, 0x40010000, 0x01010040, 0x00000040,
	 0x40000040, 0x41010040, 0x00010000, 0x41000000,
	 0x41010000, 0x01000040, 0x40010040, 0x01010000,
	 0x00010040, 0x00000000, 0x01000000, 0x40010040,
	 0x01010040, 0x00000040, 0x40000000, 0x00010000,
	 0x40000040, 0x40010000, 0x01010000, 0x41000040,
	 0x00000000, 0x01010040, 0x00010040, 0x41010000,
	 0x40010000, 0x01000000, 0x41010040, 0x40000000,
	 0x40010040, 0x41000000, 0x01000000, 0x41010040,
	 0x00010000, 0x01000040, 0x41000040, 0x00010040,
	 0x01000040, 0x00000000, 0x41010000, 0x40000040,
	 0x41000000, 0x40010040, 0x00000040, 0x01010000},

/* nibble 3 */
	{0x00100402, 0x04000400, 0x00000002, 0x04100402,
	 0x00000000, 0x04100000, 0x04000402, 0x00100002,
	 0x04100400, 0x04000002, 0x04000000, 0x00000402,
	 0x04000002, 0x00100402, 0x00100000, 0x04000000,
	 0x04100002, 0x00100400, 0x00000400, 0x00000002,
	 0x00100400, 0x04000402, 0x04100000, 0x00000400,
	 0x00000402, 0x00000000, 0x00100002, 0x04100400,
	 0x04000400, 0x04100002, 0x04100402, 0x00100000,
	 0x04100002, 0x00000402, 0x00100000, 0x04000002,
	 0x00100400, 0x04000400, 0x00000002, 0x04100000,
	 0x04000402, 0x00000000, 0x00000400, 0x00100002,
	 0x00000000, 0x04100002, 0x04100400, 0x00000400,
	 0x04000000, 0x04100402, 0x00100402, 0x00100000,
	 0x04100402, 0x00000002, 0x04000400, 0x00100402,
	 0x00100002, 0x00100400, 0x04100000, 0x04000402,
	 0x00000402, 0x04000000, 0x04000002, 0x04100400},

/* nibble 4 */
	{0x02000000, 0x00004000, 0x00000100, 0x02004108,
	 0x02004008, 0x02000100, 0x00004108, 0x02004000,
	 0x00004000, 0x00000008, 0x02000008, 0x00004100,
	 0x02000108, 0x02004008, 0x02004100, 0x00000000,
	 0x00004100, 0x02000000, 0x00004008, 0x00000108,
	 0x02000100, 0x00004108, 0x00000000, 0x02000008,
	 0x00000008, 0x02000108, 0x02004108, 0x00004008,
	 0x02004000, 0x00000100, 0x00000108, 0x02004100,
	 0x02004100, 0x02000108, 0x00004008, 0x02004000,
	 0x00004000, 0x00000008, 0x02000008, 0x02000100,
	 0x02000000, 0x00004100, 0x02004108, 0x00000000,
	 0x00004108, 0x02000000, 0x00000100, 0x00004008,
	 0x02000108, 0x00000100, 0x00000000, 0x02004108,
	 0x02004008, 0x02004100, 0x00000108, 0x00004000,
	 0x00004100, 0x02004008, 0x02000100, 0x00000108,
	 0x00000008, 0x00004108, 0x02004000, 0x02000008},

/* nibble 5 */
	{0x20000010, 0x00080010, 0x00000000, 0x20080800,
	 0x00080010, 0x00000800, 0x20000810, 0x00080000,
	 0x00000810, 0x20080810, 0x00080800, 0x20000000,
	 0x20000800, 0x20000010, 0x20080000, 0x00080810,
	 0x00080000, 0x20000810, 0x20080010, 0x00000000,
	 0x00000800, 0x00000010, 0x20080800, 0x20080010,
	 0x20080810, 0x20080000, 0x20000000, 0x00000810,
	 0x00000010, 0x00080800, 0x00080810, 0x20000800,
	 0x00000810, 0x20000000, 0x20000800, 0x00080810,
	 0x20080800, 0x00080010, 0x00000000, 0x20000800,
	 0x20000000, 0x00000800, 0x20080010, 0x00080000,
	 0x00080010, 0x20080810, 0x00080800, 0x00000010,
	 0x20080810, 0x00080800, 0x00080000, 0x20000810,
	 0x20000010, 0x20080000, 0x00080810, 0x00000000,
	 0x00000800, 0x20000010, 0x20000810, 0x20080800,
	 0x20080000, 0x00000810, 0x00000010, 0x20080010},

/* nibble 6 */
	{0x00001000, 0x00000080, 0x00400080, 0x00400001,
	 0x00401081, 0x00001001, 0x00001080, 0x00000000,
	 0x00400000, 0x00400081, 0x00000081, 0x00401000,
	 0x00000001, 0x00401080, 0x00401000, 0x00000081,
	 0x00400081, 0x00001000, 0x00001001, 0x00401081,
	 0x00000000, 0x00400080, 0x00400001, 0x00001080,
	 0x00401001, 0x00001081, 0x00401080, 0x00000001,
	 0x00001081, 0x00401001, 0x00000080, 0x00400000,
	 0x00001081, 0x00401000, 0x00401001, 0x00000081,
	 0x00001000, 0x00000080, 0x00400000, 0x00401001,
	 0x00400081, 0x00001081, 0x00001080, 0x00000000,
	 0x00000080, 0x00400001, 0x00000001, 0x00400080,
	 0x00000000, 0x00400081, 0x00400080, 0x00001080,
	 0x00000081, 0x00001000, 0x00401081, 0x00400000,
	 0x00401080, 0x00000001, 0x00001001, 0x00401081,
	 0x00400001, 0x00401080, 0x00401000, 0x00001001},

/* nibble 7 */
	{0x08200020, 0x08208000, 0x00008020, 0x00000000,
	 0x08008000, 0x00200020, 0x08200000, 0x08208020,
	 0x00000020, 0x08000000, 0x00208000, 0x00008020,
	 0x00208020, 0x08008020, 0x08000020, 0x08200000,
	 0x00008000, 0x00208020, 0x00200020, 0x08008000,
	 0x08208020, 0x08000020, 0x00000000, 0x00208000,
	 0x08000000, 0x00200000, 0x08008020, 0x08200020,
	 0x00200000, 0x00008000, 0x08208000, 0x00000020,
	 0x00200000, 0x00008000, 0x08000020, 0x08208020,
	 0x00008020, 0x08000000, 0x00000000, 0x00208000,
	 0x08200020, 0x08008020, 0x08008000, 0x00200020,
	 0x08208000, 0x00000020, 0x00200020, 0x08008000,
	 0x08208020, 0x00200000, 0x08200000, 0x08000020,
	 0x00208000, 0x00008020, 0x08008020, 0x08200000,
	 0x00000020, 0x08208000, 0x00208020, 0x00000000,
	 0x08000000, 0x08200020, 0x00008000, 0x00208020}};

static unsigned long des_skb[8][64]={
/* for C bits (numbered as per FIPS 46) 1 2 3 4 5 6 */
	{0x00000000,0x00000010,0x20000000,0x20000010,
	 0x00010000,0x00010010,0x20010000,0x20010010,
	 0x00000800,0x00000810,0x20000800,0x20000810,
	 0x00010800,0x00010810,0x20010800,0x20010810,
	 0x00000020,0x00000030,0x20000020,0x20000030,
	 0x00010020,0x00010030,0x20010020,0x20010030,
	 0x00000820,0x00000830,0x20000820,0x20000830,
	 0x00010820,0x00010830,0x20010820,0x20010830,
	 0x00080000,0x00080010,0x20080000,0x20080010,
	 0x00090000,0x00090010,0x20090000,0x20090010,
	 0x00080800,0x00080810,0x20080800,0x20080810,
	 0x00090800,0x00090810,0x20090800,0x20090810,
	 0x00080020,0x00080030,0x20080020,0x20080030,
	 0x00090020,0x00090030,0x20090020,0x20090030,
	 0x00080820,0x00080830,0x20080820,0x20080830,
	 0x00090820,0x00090830,0x20090820,0x20090830},
/* for C bits (numbered as per FIPS 46) 7 8 10 11 12 13 */
	{0x00000000,0x02000000,0x00002000,0x02002000,
	 0x00200000,0x02200000,0x00202000,0x02202000,
	 0x00000004,0x02000004,0x00002004,0x02002004,
	 0x00200004,0x02200004,0x00202004,0x02202004,
	 0x00000400,0x02000400,0x00002400,0x02002400,
	 0x00200400,0x02200400,0x00202400,0x02202400,
	 0x00000404,0x02000404,0x00002404,0x02002404,
	 0x00200404,0x02200404,0x00202404,0x02202404,
	 0x10000000,0x12000000,0x10002000,0x12002000,
	 0x10200000,0x12200000,0x10202000,0x12202000,
	 0x10000004,0x12000004,0x10002004,0x12002004,
	 0x10200004,0x12200004,0x10202004,0x12202004,
	 0x10000400,0x12000400,0x10002400,0x12002400,
	 0x10200400,0x12200400,0x10202400,0x12202400,
	 0x10000404,0x12000404,0x10002404,0x12002404,
	 0x10200404,0x12200404,0x10202404,0x12202404},
/* for C bits (numbered as per FIPS 46) 14 15 16 17 19 20 */
	{0x00000000,0x00000001,0x00040000,0x00040001,
	 0x01000000,0x01000001,0x01040000,0x01040001,
	 0x00000002,0x00000003,0x00040002,0x00040003,
	 0x01000002,0x01000003,0x01040002,0x01040003,
	 0x00000200,0x00000201,0x00040200,0x00040201,
	 0x01000200,0x01000201,0x01040200,0x01040201,
	 0x00000202,0x00000203,0x00040202,0x00040203,
	 0x01000202,0x01000203,0x01040202,0x01040203,
	 0x08000000,0x08000001,0x08040000,0x08040001,
	 0x09000000,0x09000001,0x09040000,0x09040001,
	 0x08000002,0x08000003,0x08040002,0x08040003,
	 0x09000002,0x09000003,0x09040002,0x09040003,