/*									 HTUU.c**	UUENCODE AND UUDECODE****	(c) COPYRIGHT MIT 1995.**	Please first read the full copyright statement in the file COPYRIGH.**	@(#) $Id: HTUU.c,v 2.14 2000/06/16 08:07:23 kahan Exp $**** ACKNOWLEDGEMENT:**	This code is taken from rpem distribution, and was originally**	written by Mark Riordan.**** AUTHORS:**	MR	Mark Riordan	riordanmr@clvax1.cl.msu.edu**	AL	Ari Luotonen	luotonen@dxcern.cern.ch**** HISTORY:**	Added as part of the WWW library and edited to conform**	with the WWW project coding standards by:	AL  5 Aug 1993**	Originally written by:				MR 12 Aug 1990**	Original header text:****      06 Jun 2000 Heiner KallWeit changed the proposed size of the **              of the buffer for HTUU_Encode to avoid SIGSEV problems.** ** -------------------------------------------------------------**  File containing routines to convert a buffer**  of bytes to/from RFC 1113 printable encoding format.****  This technique is similar to the familiar Unix uuencode**  format in that it maps 6 binary bits to one ASCII**  character (or more aptly, 3 binary bytes to 4 ASCII**  characters).  However, RFC 1113 does not use the same**  mapping to printable characters as uuencode.****  Mark Riordan   12 August 1990 and 17 Feb 1991.**  This code is hereby placed in the public domain.** -------------------------------------------------------------**** BUGS:*****//* Library include files */#include "wwwsys.h"#include "HTUtils.h"#include "HTUU.h"PRIVATE char six2pr[64] = {    'A','B','C','D','E','F','G','H','I','J','K','L','M',    'N','O','P','Q','R','S','T','U','V','W','X','Y','Z',    'a','b','c','d','e','f','g','h','i','j','k','l','m',    'n','o','p','q','r','s','t','u','v','w','x','y','z',    '0','1','2','3','4','5','6','7','8','9','+','/'};PRIVATE unsigned char pr2six[256];/*--- function HTUU_encode ----------------------------------------------- * *   Encode a single line of binary data to a standard format that *   uses only printing ASCII characters (but takes up 33% more bytes). * *    Entry    bufin    points to a buffer of bytes.  If nbytes is not *                      a multiple of three, then the byte just beyond *                      the last byte in the buffer must be 0. *             nbytes   is the number of bytes in that buffer. *                      This cannot be more than 48. *             bufcoded points to an output buffer.  Be sure that this *                      can hold at least 5 + 4 * (nbytes/3) characters. * *    Exit     bufcoded contains the coded line.  The first 4*nbytes/3 bytes *                      contain printing ASCII characters representing *                      those binary bytes. This may include one or *                      two '=' characters used as padding at the end. *                      The last byte is a zero byte. *             Returns the number of ASCII characters in "bufcoded". */PUBLIC int HTUU_encode (unsigned char *	bufin,			unsigned int	nbytes,			char *		bufcoded){/* ENC is the basic 1 character encoding function to make a char printing */#define ENC(c) six2pr[c]   register char *outptr = bufcoded;   unsigned int i;   for (i=0; i<nbytes; i += 3) {      *(outptr++) = ENC(*bufin >> 2);            /* c1 */      *(outptr++) = ENC(((*bufin << 4) & 060) | ((bufin[1] >> 4) & 017)); /*c2*/      *(outptr++) = ENC(((bufin[1] << 2) & 074) | ((bufin[2] >> 6) & 03));/*c3*/      *(outptr++) = ENC(bufin[2] & 077);         /* c4 */      bufin += 3;   }   /* If nbytes was not a multiple of 3, then we have encoded too    * many characters.  Adjust appropriately.    */   if(i == nbytes+1) {      /* There were only 2 bytes in that last group */      outptr[-1] = '=';   } else if(i == nbytes+2) {      /* There was only 1 byte in that last group */      outptr[-1] = '=';      outptr[-2] = '=';   }   *outptr = '\0';   return(outptr - bufcoded);}/*--- function HTUU_decode ------------------------------------------------ * *  Decode an ASCII-encoded buffer back to its original binary form. * *    Entry    bufcoded    points to a uuencoded string.  It is  *                         terminated by any character not in *                         the printable character table six2pr, but *                         leading whitespace is stripped. *             bufplain    points to the output buffer; must be big *                         enough to hold the decoded string (generally *                         shorter than the encoded string) plus *                         as many as two extra bytes used during *                         the decoding process. *             outbufsize  is the maximum number of bytes that *                         can fit in bufplain. * *    Exit     Returns the number of binary bytes decoded. *             bufplain    contains these bytes. */PUBLIC int HTUU_decode (char *		bufcoded,			unsigned char *	bufplain,			int		outbufsize){/* single character decode */#define DEC(c) pr2six[(int)c]#define MAXVAL 63   static int first = 1;   int nbytesdecoded, j;   register char *bufin = bufcoded;   register unsigned char *bufout = bufplain;   register int nprbytes;   /* If this is the first call, initialize the mapping table.    * This code should work even on non-ASCII machines.    */   if(first) {      first = 0;      for(j=0; j<256; j++) pr2six[j] = MAXVAL+1;      for(j=0; j<64; j++) pr2six[(int)six2pr[j]] = (unsigned char) j;#if 0      pr2six['A']= 0; pr2six['B']= 1; pr2six['C']= 2; pr2six['D']= 3;       pr2six['E']= 4; pr2six['F']= 5; pr2six['G']= 6; pr2six['H']= 7;       pr2six['I']= 8; pr2six['J']= 9; pr2six['K']=10; pr2six['L']=11;       pr2six['M']=12; pr2six['N']=13; pr2six['O']=14; pr2six['P']=15;       pr2six['Q']=16; pr2six['R']=17; pr2six['S']=18; pr2six['T']=19;       pr2six['U']=20; pr2six['V']=21; pr2six['W']=22; pr2six['X']=23;       pr2six['Y']=24; pr2six['Z']=25; pr2six['a']=26; pr2six['b']=27;       pr2six['c']=28; pr2six['d']=29; pr2six['e']=30; pr2six['f']=31;       pr2six['g']=32; pr2six['h']=33; pr2six['i']=34; pr2six['j']=35;       pr2six['k']=36; pr2six['l']=37; pr2six['m']=38; pr2six['n']=39;       pr2six['o']=40; pr2six['p']=41; pr2six['q']=42; pr2six['r']=43;       pr2six['s']=44; pr2six['t']=45; pr2six['u']=46; pr2six['v']=47;       pr2six['w']=48; pr2six['x']=49; pr2six['y']=50; pr2six['z']=51;       pr2six['0']=52; pr2six['1']=53; pr2six['2']=54; pr2six['3']=55;       pr2six['4']=56; pr2six['5']=57; pr2six['6']=58; pr2six['7']=59;       pr2six['8']=60; pr2six['9']=61; pr2six['+']=62; pr2six['/']=63;#endif   }   /* Strip leading whitespace. */   while(*bufcoded==' ' || *bufcoded == '\t') bufcoded++;   /* Figure out how many characters are in the input buffer.    * If this would decode into more bytes than would fit into    * the output buffer, adjust the number of input bytes downwards.    */   bufin = bufcoded;   while(pr2six[(int)*(bufin++)] <= MAXVAL);   nprbytes = bufin - bufcoded - 1;   nbytesdecoded = ((nprbytes+3)/4) * 3;   if(nbytesdecoded > outbufsize) {      nprbytes = (outbufsize*4)/3;   }   bufin = bufcoded;      while (nprbytes > 0) {      *(bufout++) = (unsigned char) (DEC(*bufin) << 2 | DEC(bufin[1]) >> 4);      *(bufout++) = (unsigned char) (DEC(bufin[1]) << 4 | DEC(bufin[2]) >> 2);      *(bufout++) = (unsigned char) (DEC(bufin[2]) << 6 | DEC(bufin[3]));      bufin += 4;      nprbytes -= 4;   }      if(nprbytes & 03) {      if(pr2six[(int)bufin[-2]] > MAXVAL) {         nbytesdecoded -= 2;      } else {         nbytesdecoded -= 1;      }   }   return(nbytesdecoded);}