encrypt.c raw

   1  #include <stdint.h>
   2  #include <stdlib.h>
   3  #include <unistd.h>
   4  
   5  #include "crypt_des.h"
   6  
   7  static struct expanded_key __encrypt_key;
   8  
   9  void setkey(const char *key)
  10  {
  11  	unsigned char bkey[8];
  12  	int i, j;
  13  
  14  	for (i = 0; i < 8; i++) {
  15  		bkey[i] = 0;
  16  		for (j = 7; j >= 0; j--, key++)
  17  			bkey[i] |= (uint32_t)(*key & 1) << j;
  18  	}
  19  
  20  	__des_setkey(bkey, &__encrypt_key);
  21  }
  22  
  23  void encrypt(char *block, int edflag)
  24  {
  25  	struct expanded_key decrypt_key, *key;
  26  	uint32_t b[2];
  27  	int i, j;
  28  	char *p;
  29  
  30  	p = block;
  31  	for (i = 0; i < 2; i++) {
  32  		b[i] = 0;
  33  		for (j = 31; j >= 0; j--, p++)
  34  			b[i] |= (uint32_t)(*p & 1) << j;
  35  	}
  36  
  37  	key = &__encrypt_key;
  38  	if (edflag) {
  39  		key = &decrypt_key;
  40  		for (i = 0; i < 16; i++) {
  41  			decrypt_key.l[i] = __encrypt_key.l[15-i];
  42  			decrypt_key.r[i] = __encrypt_key.r[15-i];
  43  		}
  44  	}
  45  
  46  	__do_des(b[0], b[1], b, b + 1, 1, 0, key);
  47  
  48  	p = block;
  49  	for (i = 0; i < 2; i++)
  50  		for (j = 31; j >= 0; j--)
  51  			*p++ = b[i]>>j & 1;
  52  }
  53