encrypt.c

00001 #include <stdio.h>
00002 #include <string.h>
00003 #include <math.h>
00004 #include "mycrypt.h"
00005 #define SCRAMBLE_LENGTH_323 8
00006 
00007 typedef unsigned long ulong;
00008 typedef unsigned int uint;
00009 typedef unsigned char uchar;
00010 
00011 struct rand_struct {
00012   unsigned long seed1,seed2,max_value;
00013   double max_value_dbl;
00014 };
00015 
00016 void hash_password(ulong *result, const char *password, uint password_len)
00017 {
00018   register ulong nr=1345345333L, add=7, nr2=0x12345671L;
00019   ulong tmp;
00020   const char *password_end= password + password_len;
00021   for (; password < password_end; password++)
00022   {
00023     if (*password == ' ' || *password == '\t')
00024       continue;                                 /* skip space in password */
00025     tmp= (ulong) (uchar) *password;
00026     nr^= (((nr & 63)+add)*tmp)+ (nr << 8);
00027     nr2+=(nr2 << 8) ^ nr;
00028     add+=tmp;
00029   }
00030   result[0]=nr & (((ulong) 1L << 31) -1L); /* Don't use sign bit (str2int) */;
00031   result[1]=nr2 & (((ulong) 1L << 31) -1L);
00032 }
00033 
00034 void randominit(struct rand_struct *rand_st, ulong seed1, ulong seed2)
00035 {                                               /* For mysql 3.21.# */
00036 #ifdef HAVE_purify
00037   bzero((char*) rand_st,sizeof(*rand_st));      /* Avoid UMC varnings */
00038 #endif
00039   rand_st->max_value= 0x3FFFFFFFL;
00040   rand_st->max_value_dbl=(double) rand_st->max_value;
00041   rand_st->seed1=seed1%rand_st->max_value ;
00042   rand_st->seed2=seed2%rand_st->max_value;
00043 }
00044 
00045 double my_rnd(struct rand_struct *rand_st)
00046 {
00047   rand_st->seed1=(rand_st->seed1*3+rand_st->seed2) % rand_st->max_value;
00048   rand_st->seed2=(rand_st->seed1+rand_st->seed2+33) % rand_st->max_value;
00049   return (((double) rand_st->seed1)/rand_st->max_value_dbl);
00050 }
00051 
00052 void scramble_323(char *to, const char *message, const char *password)
00053 {
00054   struct rand_struct rand_st;
00055   ulong hash_pass[2], hash_message[2];
00056 
00057   if (password && password[0])
00058   {
00059     char extra, *to_start=to;
00060     const char *message_end= message + SCRAMBLE_LENGTH_323;
00061     hash_password(hash_pass,password, (uint) strlen(password));
00062     hash_password(hash_message, message, SCRAMBLE_LENGTH_323);
00063     randominit(&rand_st,hash_pass[0] ^ hash_message[0],
00064                hash_pass[1] ^ hash_message[1]);
00065     for (; message < message_end; message++)
00066       *to++= (char) (floor(my_rnd(&rand_st)*31)+64);
00067     extra=(char) (floor(my_rnd(&rand_st)*31));
00068     while (to_start != to)
00069       *(to_start++)^=extra;
00070   }
00071   *to= 0;
00072 }