Subversion Repositories or1k

#include <features.h>

#include <stdlib.h>

/* TEA based crypt(), version 0.0 <ndf@linux.mit.edu>

 * It looks like there are problems with key bits carrying through

 * to the encryted data, and I want to get rid of that libc call..

 * This is just so rob could see it ;) */

char *

crypt(const char * key, const char * salt)

{

  /* n is the number of rounds, delta is a golden # derivative,

   k is the key, v is the data to be encrypted. */

  unsigned long v[2], sum=0, delta=0x9e3779b9, n=64, k[4];

  static char rkey[16];

  unsigned char i;

  /* Our constant string will be a string of zeros .. */

  v[0]=v[1]=k[0]=k[1]=k[2]=k[3]=0;

  for(i=0;i<16;i++) rkey[i]=0;

  rkey[0]=*salt;

  rkey[1]=salt[1];

  for (i=0;key[i];i++) rkey[i+1]=key[i];

  memcpy(k, rkey, 4*sizeof(long));

  while (n-->0)  {

    sum += delta;

    v[0] += (v[1]<<4)+k[0] ^ v[1]+sum ^ (v[1]>>5)+k[1];

    v[1] += (v[0]<<4)+k[2] ^ v[0]+sum ^ (v[0]>>5)+k[3];

  }

  *rkey=*salt; rkey[1]=salt[1];

  /* Now we need to unpack the bits and map it to "A-Za-z0-9./" for printing

     in /etc/passwd */

  for (i=2;i<13;i++)

    {

      /* This unpacks the 6 bit data, each cluster into its own byte */

      if (i==8) v[0]|=v[1]>>28;

      rkey[i]=v[(i-2)/6]&0x3F;

      v[(i-2)/6]>>=6;

      /* Now we map to the proper chars */

      if (rkey[i]>=0 && rkey[i]<12) rkey[i]+=46;

      else if (rkey[i]>11 && rkey[i]<38) rkey[i]+=53;

      else if (rkey[i]>37 && rkey[i]<64) rkey[i]+=59;

      else return NULL;

    }

  rkey[13]='\0';

  return rkey;

}