/*** Copyright (c), The Regents of the University of California            ***
 *** For more information please refer to files in the COPYRIGHT directory ***/
/*
  These routines obfuscate (scramble or sort-of encrypt) passwords.

  These are used to avoid storing plain-text passwords in the files,
  yet still allow automatic authentication.  This is better than
  plain-text passwords sitting around in files and often being
  transmitted on networks in NFS packets.  But, of course, this isn't
  highly secure, particularly since with this source file one can
  defeat it.  But it does stop attackers from finding passwords by
  just searching directories.

  Externally callable routines begin with "obf" and internal routines
  begin with "obfi".

  A timestamp is used with this, which will be gotten from the modify
  time of the authentication file.  This way, a simple copy of the
  file will not successfully authenticate.

  The UID of the running process is also used in the algorithm.

  The same password is obfuscated differently (usually), each time the
  obfuscation is done, so that one will usually be unable to tell by
  looking at the ciphertext whether two passwords are the same or not.
  Also, this makes it more difficult to determine the obfuscation
  algorithm.

  When the iRODS commands authenticate, they first check if this is
  available, and use that if possible.  Otherwise, they prompt for the
  password.

  Returns codes of 0 indicate success, others are iRODS error codes.
*/


#include <stdio.h>
#ifndef windows_platform
#include <sys/types.h>
#include <sys/time.h>
#include <sys/timeb.h>
#include <fcntl.h>
#include <sys/stat.h>
#endif
#include <stdlib.h>

#include "rods.h"
#include "rodsPath.h"

#ifdef _WIN32
#include "Unix2Nt.h"  /* May need something like this for Windows */ 
#include "iRODSNtUtil.h"    /* May need something like this for Windows */
#include "rcGlobalExtern.h"
#endif

#define TMP_FLAG "%TEMPORARY_PW%"

#define AUTH_FILENAME_DEFAULT ".irods/.irodsA" /* under the HOME dir */

int obfDebug=0;
int timeVal=0;
int isTemp=0;
int doTemp=0;

int cipherBlockChaining=0;

/* 
  What can be a main routine for some simple tests.
 */
int
obftestmain(int argc, char *argv[])
{
   char p3[MAX_PASSWORD_LEN];
   int i;

   obfDebug = 2;

   if (argc < 2) {
     printf("Usage: -d|-e\n");
     exit(-1);
   }

   if (strcmp(argv[1],"-d")==0) {
     i = obfGetPw(p3);
     if (obfDebug)  printf("val  = %d \n",i);
   }

   if (strcmp(argv[1],"-e")==0) {
     i = obfSavePw(1, 0, 1, "");
     if (obfDebug)  printf("val  = %d \n",i);
   }
   return (0);
}

int 
obfSetDebug(int opt)
{
  obfDebug = opt;
  return (0);
}

int
obfiGetFilename(char *fileName)
{
   char *envVar = NULL;

   envVar = getRodsEnvAuthFileName();
   if (envVar != NULL && *envVar!='\0') {
      strcpy(fileName,envVar);
      return(0);
   }

#ifdef windows_platform
   if(ProcessType != CLIENT_PT)
   {
	   char *tmpstr1;
	   int t;
	   tmpstr1 = iRODSNtGetServerConfigPath();
	   sprintf(fileName, "%s\\irodsA.txt", tmpstr1);
	   return 0;
   }

   /* for clients */
   envVar = iRODSNt_gethome();
#else
   envVar =  getenv ("HOME");
#endif
   if (envVar == NULL) {
      return(ENVIRONMENT_VAR_HOME_NOT_DEFINED);
   }
   strncpy(fileName, envVar, MAX_NAME_LEN);
   strncat(fileName, "/", MAX_NAME_LEN);
   strncat(fileName, AUTH_FILENAME_DEFAULT, MAX_NAME_LEN);

#ifdef windows_platform
   if(envVar != NULL)
	   free(envVar);
#endif

   return(0);
}

int
obfGetPw(char *pw)
{
  char myPw[MAX_PASSWORD_LEN+10];
  char myPwD[MAX_PASSWORD_LEN+10];
  char fileName[MAX_NAME_LEN+10];
  char *cp;

  int i;
  int envVal;

  strcpy(pw, "");

  envVal = obfiGetEnvKey();

  i = obfiGetFilename(fileName);
  if (i < 0) return(i);

  i = obfiGetTv(fileName);
  if (i < 0) return(i);

  i = obfiGetPw(fileName, myPw);
  if (i < 0) return(i);

  i = obfiDecode(myPw, myPwD, envVal);
  if (i < 0) return(i);

  isTemp=0;
  cp = strstr(myPwD,TMP_FLAG);
  if (cp != 0) {
    isTemp=1;
    *cp='\0';
  }

  if (obfDebug) printf("out:%s\n",myPwD);
  strcpy(pw, myPwD);

  return 0;
}

/* 
 remove the password file
 opt: if non-zero, don't ask and don't print error;just remove it if it exists.
*/
int 
obfRmPw(int opt)
{
   int i;
   char fileName[MAX_NAME_LEN+10];
   char inbuf[MAX_NAME_LEN+10];
   int fd;

   i = obfiGetFilename(fileName);
   if (i != 0) return(i);

#ifdef windows_platform
   fd = iRODSNt_open(fileName,O_RDONLY,1);
#else
   fd = open(fileName,O_RDONLY,0);
#endif
   if (fd < 0) {
      if (opt==0) printf("%s does not exist\n", fileName);
      return(AUTH_FILE_DOES_NOT_EXIST);
   }
   close(fd);
   if (opt==0) {
      printf("Remove %s?:", fileName);
      fgets(inbuf, MAX_NAME_LEN, stdin);
      i = strlen(inbuf);
      if (i < 2) return 0;
      if (inbuf[0]=='y') {
	 i = unlink(fileName);
      }
   }
   else {
      i = unlink(fileName);
   }
   if (i==0) return(0);
   return (UNLINK_FAILED);
}

/* Set timeVal from a fstat of the file after writing to it.
   Could just use system time, but if it's way off from the file
   system (NFS on a VM host, for example), it would fail. */
int
obfiSetTimeFromFile(int fd) {
#ifndef windows_platform
   struct stat statBuf;
#else
	struct irodsntstat statBuf;
#endif
   int wval, fval, lval;  
   wval = write(fd," ",1);
   if (wval != 1) return FILE_WRITE_ERR;
#ifndef windows_platform
   fval = fstat(fd, &statBuf);
#else
   fval = _fstat64(fd, &statBuf);
#endif
   if (fval<0) {
      timeVal=0;
      return UNABLE_TO_STAT_FILE;
   } 
   lval = lseek (fd, 0, SEEK_SET);
   if (lval < 0) return UNABLE_TO_STAT_FILE;

   timeVal = statBuf.st_mtime & 0xffff;   /* keep it bounded */
   return 0;
}



/* int promptOpt; if 1, echo password as typed, else no echo */
/* int fileOpt; if 1, ask permission before writing file */
/* int printOpt; if 1, display an updated file msg on success */
/* char *pwArg; if non-0-length, this is the new password */
int
obfSavePw(int promptOpt, int fileOpt, int printOpt, char *pwArg)
{
  char fileName[MAX_NAME_LEN+10];
  char inbuf[MAX_PASSWORD_LEN+100];
  char myPw[MAX_PASSWORD_LEN+10];
  int i, fd, envVal;
#ifndef USE_BOOST_FS
  struct stat statbuf;
#endif

  i = obfiGetFilename(fileName);
  if (i != 0) return(i);

  envVal = obfiGetEnvKey();

  if (strlen(pwArg)==0) {

#ifdef windows_platform
	 iRODSNtGetUserPasswdInputInConsole(inbuf, "Enter your current iRODS password:", promptOpt);
#else
    if (promptOpt != 1) {
#ifdef USE_BOOST_FS
      path p ("/bin/stty");
      if (exists(p))
#else
      if (stat ("/bin/stty", &statbuf) == 0)
#endif
        system("/bin/stty -echo");
    }

    printf("Enter your current iRODS password:");
    fgets(inbuf, MAX_PASSWORD_LEN+50, stdin);

    if (promptOpt != 1) {
      system("/bin/stty echo");
      printf("\n");
    }
#endif

  }
  else {
    strncpy(inbuf, pwArg, MAX_PASSWORD_LEN); 
  }
  i = strlen(inbuf);
  if (i < 1) return NO_PASSWORD_ENTERED;
  if (strlen(inbuf) > MAX_PASSWORD_LEN-2) return (PASSWORD_EXCEEDS_MAX_SIZE);
  if (inbuf[i-1]=='\n') inbuf[i-1]='\0';  /* remove trailing \n */

  if (doTemp) {
    strcat(inbuf,TMP_FLAG);
  }
  
  fd = obfiOpenOutFile(fileName, fileOpt);
  if (fd < 0) return (FILE_OPEN_ERR);

  if (fd == 0) return(0); /* user canceled */

  i = obfiSetTimeFromFile(fd);
  if (i<0) return(i);

  obfiEncode(inbuf,myPw, envVal);
  if (obfDebug > 1) printf(" in:%s out:%s\n",inbuf, myPw);

  i = obfiWritePw(fd, myPw);
  if (i < 0) return (i);

  if (obfDebug || printOpt) printf("Successfully wrote %s\n",fileName);

  return 0;
}

/* various options for temporary auth files/pws */
int obfTempOps(int tmpOpt)
{
  char fileName[MAX_NAME_LEN+10];
  char pw[MAX_PASSWORD_LEN+10];
  int i;
  if (tmpOpt==1) {  /* store pw flagged as temporary */
    doTemp=1;    
  }

  if (tmpOpt==2) {  /* remove the pw file if temporary */
    i = obfGetPw(pw);
    strcpy(pw,"           ");
    if (i != 0) return i;
    if (isTemp) {
      i = obfiGetFilename(fileName);
      if (i != 0) return(i);
      unlink(fileName);
    }
  }
  return 0;
}

int
obfiGetTv(char *fileName)
{
#ifndef windows_platform
   struct stat statBuf;
#else
	struct irodsntstat statBuf;
#endif
   int fval;

#ifndef windows_platform
   fval = stat(fileName,&statBuf); 
#else
   fval = iRODSNt_stat(fileName,&statBuf);
#endif

   if (fval<0) {
      timeVal=0;
      return UNABLE_TO_STAT_FILE;
   } 

   timeVal = statBuf.st_mtime & 0xffff;   /* keep it bounded */
   return 0;
}

int
obfiGetPw(char *fileName, char *pw)
{
   int fd_in, rval;
   char buf1[500];

#ifdef windows_platform
   fd_in = iRODSNt_open(fileName,O_RDONLY,1);
#else
   fd_in = open(fileName,O_RDONLY,0);
#endif

   if (fd_in<0) {
      return FILE_OPEN_ERR;
   }
   
   rval = read(fd_in, buf1, 500);
   close(fd_in);

   if (rval < 0) {
      return FILE_READ_ERR;
   }
   if (strlen(buf1)< MAX_PASSWORD_LEN) {
     strcpy(pw, buf1);
     return 0;
   }
   else {
     return PASSWORD_EXCEEDS_MAX_SIZE;
   }

}

int 
obfiOpenOutFile(char *fileName, int fileOpt)
{
   char inbuf[MAX_NAME_LEN];
   int i, fd_out;

#ifdef _WIN32
   fd_out = iRODSNt_open(fileName,O_CREAT|O_WRONLY|O_EXCL, 1);
#else
   fd_out = open(fileName,O_CREAT|O_WRONLY|O_EXCL,0600);
#endif

   if (fd_out<0) {
     if (errno != EEXIST) {
       return FILE_OPEN_ERR;
     }
     if (fileOpt > 0) {
       printf("Overwrite '%s'?:",fileName);
       fgets(inbuf, MAX_NAME_LEN, stdin);
       i = strlen(inbuf);
       if (i < 2) return 0;
     }
     else {
       strcpy(inbuf, "y");
     }
     if (inbuf[0]=='y') {
#ifdef windows_platform
       fd_out = iRODSNt_open(fileName, O_CREAT|O_WRONLY|O_TRUNC, 1);
#else
       fd_out = open(fileName, O_CREAT|O_WRONLY|O_TRUNC, 0600);
#endif
       if (fd_out<0) return FILE_OPEN_ERR;
     }
     else {
       return 0;
     }
   }
   return(fd_out);
}

int
obfiWritePw(int fd, char *pw)
{
   int wval, len;
   len = strlen(pw);
   wval = write(fd,pw,len+1);
   if (wval != len+1) {
     return FILE_WRITE_ERR;
   }
   close(fd);
   return 0;
}
 
int obfiTimeval()
{
   long sec;
   int val;  

   struct timeval nowtime;

   (void)gettimeofday(&nowtime, (struct timezone *)0);
   sec = nowtime.tv_sec;

   val = sec;
   val = val & 0xffff;      /* keep it bounded */
   if (obfDebug > 1)  printf("val  = %d %x\n",val,val);
   return(val);
}


/*
  Obfuscate a password
*/
void
obfiEncode(char *in, char *out, int extra)
{
   int i;
   long seq;
   char *my_in;

   /*   struct timeb timeb_time; */
   struct timeval nowtime;

   int rval;
   int wheel_len;
   int wheel[26+26+10+15];
   int j, addin, addin_i, found;
   int ii;
   int now;
   char headstring[10];
#ifndef _WIN32
   int uid;
#endif
/*
 Set up an array of characters that we will transpose.
*/

   wheel_len=26+26+10+15;
   j=0;
   for (i=0;i<10;i++) wheel[j++]=(int)'0' + i;
   for (i=0;i<26;i++) wheel[j++]=(int)'A' + i;
   for (i=0;i<26;i++) wheel[j++]=(int)'a' + i;
   for (i=0;i<15;i++) wheel[j++]=(int)'!' + i;

/*
 get uid to use as part of the key
*/
#ifndef _WIN32
   uid = getuid();
   uid = uid &0xf5f;  /* keep it fairly small and not exactly uid */
#endif

/*
 get a pseudo random number
*/

   (void)gettimeofday(&nowtime, (struct timezone *)0);
   rval = nowtime.tv_usec & 0xf;

/*
 and use it to pick a pattern for ascii offsets
*/
   seq = 0;
   if (rval==0) seq = 0xd768b678;
   if (rval==1) seq = 0xedfdaf56;
   if (rval==2) seq = 0x2420231b;
   if (rval==3) seq = 0x987098d8;
   if (rval==4) seq = 0xc1bdfeee;
   if (rval==5) seq = 0xf572341f;
   if (rval==6) seq = 0x478def3a;
   if (rval==7) seq = 0xa830d343;
   if (rval==8) seq = 0x774dfa2a;
   if (rval==9) seq = 0x6720731e;
   if (rval==10)seq = 0x346fa320;
   if (rval==11)seq = 0x6ffdf43a;
   if (rval==12)seq = 0x7723a320;
   if (rval==13)seq = 0xdf67d02e;
   if (rval==14)seq = 0x86ad240a;
   if (rval==15)seq = 0xe76d342e;

/*
 get the timestamp and other id
*/
   if (timeVal != 0) {
      now = timeVal; /* from file, normally */
   }
   else {
      now = obfiTimeval();
   }
   headstring[1] = ((now>>4) & 0xf) + 'a';
   headstring[2] = (now & 0xf) + 'a';
   headstring[3] = ((now>>12) & 0xf) + 'a';
   headstring[4] = ((now>>8) & 0xf) + 'a';
   headstring[5] = '\0';
   headstring[0]='S' - ( (rval&0x7)*2);  /* another check value */

  *out++ = '.';          /* store our initial, human-readable identifier */

  addin_i=0;
  my_in = headstring;    /* start with head string */
  for (ii=0;;) {
     ii++;
     if (ii==6) {
        *out++ = rval + 'e';  /* store the key */
        my_in=in;     /* now start using the input string */
     }
     found=0;
     addin = (seq>>addin_i)&0x1f;
     addin += extra;
#ifndef _WIN32
     addin += uid;
     addin_i+=3;
#else
     addin_i+=2;
#endif
     if (addin_i>28)addin_i=0;
     for (i=0;i<wheel_len;i++) {
        if (*my_in == (char)wheel[i]) {
           j = i + addin;
           if (obfDebug>1) printf("j1=%d ",j);
           j = j % wheel_len;
           if (obfDebug>1) printf ("j2=%d \n",j);
           *out++ = (char)wheel[j];
           found = 1;
           break;
        }
     }
     if (found==0) {
        if (*my_in == '\0') {
           *out++ = '\0'; 
           return;
        }
        else {*out++=*my_in;}
     }
     my_in++;
  }
}


int
obfiTimeCheck(int time1, int time2)
{
  int fudge=20;
  int delta;

  /*  printf("time1=%d time2=%d\n",time1, time2); */

  delta=time1-time2;
  if (delta < 0) delta = 0-delta;
  if (delta < fudge) return(0);

  if (time1<65000) time1+=65535;
  if (time2<65000) time2+=65535;

  delta=time1-time2;
  if (delta < 0) delta = 0-delta;
  if (delta < fudge) return(0);

  return(1);
}



int
obfiDecode(char *in, char *out, int extra)
{
   int i;
   long seq;
   char *p1;

   int rval;
   int wheel_len;
   int wheel[26+26+10+15];
   int j, addin, addin_i, kpos, found, nout;
   char headstring[10];
   int ii, too_short;
   char *my_out, *my_in;
   int not_en, encodedTime;
#ifndef _WIN32
   int uid;
#endif

   wheel_len=26+26+10+15;

/*
 get uid to use as part of the key
*/
#ifndef _WIN32
   uid = getuid();
   uid = uid &0xf5f;  /* keep it fairly small and not exactly uid */
#endif

/*
 Set up an array of characters that we will transpose.
*/
   j=0;
   for (i=0;i<10;i++) wheel[j++]=(int)'0' + i;
   for (i=0;i<26;i++) wheel[j++]=(int)'A' + i;
   for (i=0;i<26;i++) wheel[j++]=(int)'a' + i;
   for (i=0;i<15;i++) wheel[j++]=(int)'!' + i;

   too_short=0;
   for (p1=in,i=0;i<6;i++) {
      if (*p1++ == '\0') too_short=1;
   }

   kpos=6;
   p1=in;
   for (i=0;i<kpos;i++,p1++);
   rval = (int)*p1;
   rval = rval - 'e';

   if (rval > 15 || rval < 0 || too_short==1) {  /* invalid key or too short */
      while ((*out++ = *in++) != '\0')  ;   /* return input string */
      return AUTH_FILE_NOT_ENCRYPTED;
   }

   seq = 0;
   if (rval==0) seq = 0xd768b678;
   if (rval==1) seq = 0xedfdaf56;
   if (rval==2) seq = 0x2420231b;
   if (rval==3) seq = 0x987098d8;
   if (rval==4) seq = 0xc1bdfeee;
   if (rval==5) seq = 0xf572341f;
   if (rval==6) seq = 0x478def3a;
   if (rval==7) seq = 0xa830d343;
   if (rval==8) seq = 0x774dfa2a;
   if (rval==9) seq = 0x6720731e;
   if (rval==10)seq = 0x346fa320;
   if (rval==11)seq = 0x6ffdf43a;
   if (rval==12)seq = 0x7723a320;
   if (rval==13)seq = 0xdf67d02e;
   if (rval==14)seq = 0x86ad240a;
   if (rval==15)seq = 0xe76d342e;

   addin_i=0;
   my_out = headstring;
   my_in = in;
   my_in++;   /* skip leading '.' */
   for (ii=0;;) {
      ii++;
      if (ii==6) {
         not_en = 0;
         if (*in != '.') { 
            not_en = 1;  /* is not 'encrypted' */
         }
         if (headstring[0] !='S' - ( (rval&0x7)*2)) {
           not_en=1; 
           if (obfDebug) printf("not s\n");
         }

         if (timeVal==0) {
            timeVal = obfiTimeval();
         }
         encodedTime = ((headstring[1] - 'a')<<4) + (headstring[2]-'a') +
                       ((headstring[3] - 'a')<<12) + ((headstring[4]-'a')<<8);

#ifndef _WIN32
	 if (obfiTimeCheck(encodedTime, timeVal)) not_en=1;
#else    /* The file always contains an encrypted password in Windows. */
         not_en = 0;
#endif

         if (obfDebug) printf("timeVal=%d encodedTime=%d\n",timeVal,encodedTime);

         my_out = out;   /* start outputing for real */
         if (not_en == 1) {
             while ((*out++ = *in++) != '\0')  ;   /* return input string */
	     return AUTH_FILE_NOT_ENCRYPTED;
         }
         my_in++;   /* skip key */
      }
      else {
         found=0;
         addin = (seq>>addin_i)&0x1f;
         addin += extra;
#ifndef _WIN32
          addin += uid;
         addin_i+=3;
#else
          addin_i+=2;
#endif
         if (addin_i>28)addin_i=0;
         for (i=0;i<wheel_len;i++) {
            if (*my_in == (char)wheel[i]) {
               j = i - addin;
               if (obfDebug) printf ("j=%d ",j);

               while (j<0) {
                 j+=wheel_len;
               }
               if (obfDebug) printf ("j2=%d \n",j);

               *my_out++ = (char)wheel[j];
               nout++;
               found = 1;
               break;
            }
         }
         if (found==0) {
            if (*my_in == '\0') {
               *my_out++ = '\0'; 
               return 0;
            }
            else {*my_out++=*my_in; nout++;}
         }
         my_in++;
      }
   }
}

int
obfiGetEnvKey()
{
#if 0
  char *envVar;
  char *chr;
  int i;
#endif
  /* May want to do this someday, but at least not for now */
  return 0;
}


/*
  Obfuscate a string using an input key
*/
void
obfEncodeByKey(char *in, char *key, char *out) {
/*
 Set up an array of characters that we will transpose.
*/
   MD5_CTX context;

   int wheel_len=26+26+10+15;
   int wheel[26+26+10+15];

   int i, j;
   int pc;    /* previous character */

   unsigned char buffer[65]; /* each digest is 16 bytes, 4 of them */
   char keyBuf[100];
   char *cpIn, *cpOut;
   unsigned char *cpKey;

   j=0;
   for (i=0;i<10;i++) wheel[j++]=(int)'0' + i;
   for (i=0;i<26;i++) wheel[j++]=(int)'A' + i;
   for (i=0;i<26;i++) wheel[j++]=(int)'a' + i;
   for (i=0;i<15;i++) wheel[j++]=(int)'!' + i;

   memset(keyBuf, 0, 100);
   strncpy(keyBuf, key, 100);
   memset(buffer, 0, 17);

/* 
  Get the MD5 digest of the key to get some bytes with many different values
*/

   MD5Init (&context);
   MD5Update (&context, (unsigned char*)keyBuf, 100);
   MD5Final (buffer, &context);

   MD5Init (&context);
   MD5Update (&context, buffer, 16);  /* MD5 of the MD5 */
   MD5Final (buffer+16, &context);

   MD5Init (&context);
   MD5Update (&context, buffer, 32);  /* MD5 of 2 MD5s */
   MD5Final (buffer+32, &context);

   MD5Init (&context);
   MD5Update (&context, buffer, 32);  /* MD5 of 2 MD5s */
   MD5Final (buffer+48, &context);


   cpIn=in;
   cpOut=out;
   cpKey=buffer;
   pc = 0;
   for (;;cpIn++) {
      int k, found;
      k = (int)*cpKey++;
      if (cpKey > buffer+60) cpKey=buffer;
      found=0;
      for (i=0;i<wheel_len;i++) {
	 if (*cpIn == (char)wheel[i]) {
	    j = i + k + pc;
	    j = j % wheel_len;
	    *cpOut++ = (char)wheel[j];
	    if (cipherBlockChaining) {
	       pc = *(cpOut-1);
	       pc = pc & 0xff;
	    }
	    found = 1;
	    break;
	 }
      }
      if (found==0) {
	 if (*cpIn == '\0') {
	    *cpOut++ = '\0'; 
	    return;
	 }
	 else {*cpOut++=*cpIn;}
      }
   }
}

/*
  Obfuscate a string using an input key, version 2.  Version two is
  like the original but uses two key and a hash of them instead of the
  key itself (to keep the key itself even more undiscoverable).  The
  second key is a session signiture (based on the challenge) (not
  secret but known to both client and server and unique for each
  connection).  It also uses a quasi-cipher-block-chaining alrogithm
  and adds a random character (so the 'out' is different even with the
  same 'in' each time).
*/
#define V2_Prefix "A.ObfV2"

void
obfEncodeByKeyV2(char *in, char *key, char *key2, char *out) {
   struct timeval nowtime;
   char *myKey2;
   char myKey[200];
   char myIn[200];
   int rval;

   strncpy(myIn, V2_Prefix, 10);
   strncat(myIn, in, 150);

   strncpy(myKey, key, 90);
   strncat(myKey, key2, 100);

/*
 get a pseudo random number
*/
   (void)gettimeofday(&nowtime, (struct timezone *)0);
   rval = nowtime.tv_usec & 0x1f;
   myIn[0]+=rval;  /* and add it to the leading character */


   myKey2 = obfGetMD5Hash(myKey);

   cipherBlockChaining=1;
   obfEncodeByKey(myIn, myKey2, out);
   cipherBlockChaining=0;
   return;
}  


/*
  De-obfuscate a string using an input key
*/
void
obfDecodeByKey(char *in, char *key, char *out) {
/*
 Set up an array of characters that we will transpose.
*/
   MD5_CTX context;
   int wheel_len=26+26+10+15;
   int wheel[26+26+10+15];

   int i, j;
   int pc;
   unsigned char buffer[65]; /* each digest is 16 bytes, 4 of them */
   char keyBuf[100];
   char *cpIn, *cpOut;
   unsigned char *cpKey;

   j=0;
   for (i=0;i<10;i++) wheel[j++]=(int)'0' + i;
   for (i=0;i<26;i++) wheel[j++]=(int)'A' + i;
   for (i=0;i<26;i++) wheel[j++]=(int)'a' + i;
   for (i=0;i<15;i++) wheel[j++]=(int)'!' + i;

   memset(keyBuf, 0, 100);
   strncpy(keyBuf, key, 100);

   memset(buffer, 0, 65);

/* 
  Get the MD5 digest of the key to get some bytes with many different values
*/
   MD5Init (&context);
   MD5Update (&context, (unsigned char*)keyBuf, 100);
   MD5Final (buffer, &context);

   MD5Init (&context);
   MD5Update (&context, buffer, 16);  /* MD5 of the MD5 */
   MD5Final (buffer+16, &context);

   MD5Init (&context);
   MD5Update (&context, buffer, 32);  /* MD5 of 2 MD5s */
   MD5Final (buffer+32, &context);

   MD5Init (&context);
   MD5Update (&context, buffer, 32);  /* MD5 of 2 MD5s */
   MD5Final (buffer+48, &context);

   cpIn=in;
   cpOut=out;
   cpKey=buffer;
   pc = 0;
   for (;;cpIn++) {
      int k, found;
      k = (int)*cpKey++;
      if (cpKey > buffer+60) cpKey=buffer;
      found=0;
      for (i=0;i<wheel_len;i++) {
	 if (*cpIn == (char)wheel[i]) {
	    j = i - k - pc;
	    while (j<0) {
	       j+=wheel_len;
	    }
	    *cpOut++ = (char)wheel[j];
	    if (cipherBlockChaining) {
	       pc = *cpIn;
	       pc = pc & 0xff;
	    }
	    found = 1;
	    break;
	 }
      }
      if (found==0) {
	 if (*cpIn == '\0') {
	    *cpOut++ = '\0'; 
	    return;
	 }
	 else {*cpOut++=*cpIn;}
      }
   }
}

/* Version 2, undoes V2 encoding.
   If encoding is not V2, handles is at V1 (original)
*/
void
obfDecodeByKeyV2(char *in, char *key, char *key2, char *out) {
   char *myKey2;
   static char myOut[200];
   int i, len, matches;
   char match[60];
   char myKey[200];

   strncpy(myKey, key, 90);
   strncat(myKey, key2, 100);

   myKey2 = obfGetMD5Hash(myKey);
   cipherBlockChaining=1;
   obfDecodeByKey(in, myKey2, myOut);
   cipherBlockChaining=0;

   strncpy(match, V2_Prefix, 10);
   len=strlen(V2_Prefix);
   matches=1;
   for (i=1;i<len;i++) {
      if (match[i]!=myOut[i]) matches=0;
   }
   if (matches==0) {
      obfDecodeByKey(in, key, out);
      return;
   }

   strncpy(out, myOut+len, MAX_PASSWORD_LEN); /* skip prefix */
   return;
}

/*
  Hash an input string
*/
char *
obfGetMD5Hash(char *stringToHash) {
/*
 Set up an array of characters that we will transpose.
*/
   MD5_CTX context;

   unsigned char buffer[20]; /* the digest is 16 bytes */
   char keyBuf[100];

   static char outBuf[50];

   memset(keyBuf, 0, 100);
   strncpy(keyBuf, stringToHash, 100);

   memset(buffer, 0, 20);

/* 
  Get the MD5 digest of the key
*/
   MD5Init (&context);
   MD5Update (&context, (unsigned char*)keyBuf, 100);
   MD5Final (buffer, &context);

   sprintf(outBuf,"%2.2x%2.2x%2.2x%2.2x%2.2x%2.2x%2.2x%2.2x%2.2x%2.2x%2.2x%2.2x%2.2x%2.2x%2.2x%2.2x",
	   buffer[0], buffer[1], buffer[2], buffer[3], 
	   buffer[4], buffer[5], buffer[6], buffer[7], 
	   buffer[8], buffer[9], buffer[10], buffer[11], 
	   buffer[12], buffer[13], buffer[14], buffer[15]);
   return(outBuf);
}