ltable_generation.cpp

在cdma2000移动通信系统使用ORYX流密码算法实现空中接口部分的数据加密。

/* The header for LTable_Generation is the same as for
3 DataKey_Generation (see Exhibit 2-46).*/
 

#define LTable_Generation_SOURCE_FILE
#include "cavei.h" /* see Exhibit 2-3 */
#include "oryx.h" /* see Exhibit 2-45 */
#define high(x) (unsigned char)(0xffU&(x>>24)) /* leftmost octet */
#define FA1 000460216667 /* Peterson & Weldon prim 32 */
#define FA2 001760427607 /* Peterson & Weldon prim 32 */
#define FB 020014300113 /* P&W prim 31 020004100071 times z+1 */
#define FK 030634530010 /* reverse of P&W prim 32 04200324714328 */
static 
unsigned long K; /* 32-bit K register */
static
unsigned long A, B; /* 32-bit LFSRs */
unsigned char L[256]; /* look up table */
unsigned long DataKey; /* data encryption key */
static
void kstep(void);
static
unsigned char keygen(void);
void LTable_Generation(const unsigned char RAND[4])
 {
 int i,j;
 unsigned char tempc;

K = 0;
K = (K<<8) + (unsigned long)RAND[i];
 for (i=0; i<256; i++)
L[i] = (unsigned char)i;

/* use high octet of K to permute 0 through 255 */
 for (i=0; i< 256; i++)
 {
 kstep();
 tempc = L[i];
 L[i] = L[j];
 L[j] = tempc;
 }
 }
static
 void kstep(void)
 {
 if(K==0) K = 0x31415926;
 if(K&1)
 {
 K = (K>>1) ^ FK;
 }
 else
 {
 K = (K>>1);
 }
 K &= 0xffffffff;
 }