/* * $LynxId: HTUU.c,v 1.11 2010/09/21 23:55:12 tom Exp $ * * MODULE HTUU.c * UUENCODE AND UUDECODE * * 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: * ------------------------------------------------------------- * 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. * ------------------------------------------------------------- */ #include #include #include static 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', '+', '/' }; static 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 1 + (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". */ int HTUU_encode(unsigned char *bufin, size_t 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; size_t i; /* This doesn't seem to be needed (AL): register unsigned char *inptr = bufin; */ 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 (int) (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. */ 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; 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[UCH(six2pr[j])] = UCH(j); #if 0 /* *INDENT-OFF* */ 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; /* *INDENT-ON* */ #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[UCH(*(bufin++))] <= MAXVAL) ; nprbytes = (int) (bufin - bufcoded - 1); nbytesdecoded = ((nprbytes + 3) / 4) * 3; if (nbytesdecoded > outbufsize) { nprbytes = (outbufsize * 4) / 3; } bufin = bufcoded; while (nprbytes > 0) { *(bufout++) = UCH((DEC(bufin[0]) << 2) | (DEC(bufin[1]) >> 4)); *(bufout++) = UCH((DEC(bufin[1]) << 4) | (DEC(bufin[2]) >> 2)); *(bufout++) = UCH((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); }