280 lines
8.1 KiB
C
280 lines
8.1 KiB
C
/*
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This file was derived from the libwww code, version 2.15, from CERN.
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A number of modifications have been made by Spyglass.
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eric@spyglass.com
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This file was removed from LibWWW and placed into the
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Security Protocol Module.
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jeff@spyglass.com
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*/
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/* MODULE HTUU.c
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** UUENCODE AND UUDECODE
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**
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** ACKNOWLEDGEMENT:
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** This code is taken from rpem distribution, and was originally
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** written by Mark Riordan.
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**
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** AUTHORS:
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** MR Mark Riordan riordanmr@clvax1.cl.msu.edu
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** AL Ari Luotonen luotonen@dxcern.cern.ch
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**
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** HISTORY:
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** Added as part of the WWW library and edited to conform
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** with the WWW project coding standards by: AL 5 Aug 1993
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** Originally written by: MR 12 Aug 1990
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** Original header text:
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** -------------------------------------------------------------
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** File containing routines to convert a buffer
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** of bytes to/from RFC 1113 printable encoding format.
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**
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** This technique is similar to the familiar Unix uuencode
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** format in that it maps 6 binary bits to one ASCII
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** character (or more aptly, 3 binary bytes to 4 ASCII
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** characters). However, RFC 1113 does not use the same
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** mapping to printable characters as uuencode.
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**
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** Mark Riordan 12 August 1990 and 17 Feb 1991.
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** This code is hereby placed in the public domain.
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** -------------------------------------------------------------
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**
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** BUGS:
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**
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**
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*/
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const static char six2pr[64] =
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{
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'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
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'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
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'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
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'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
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'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
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};
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static unsigned char pr2six[256];
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/*--- function HTUU_encode -----------------------------------------------
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*
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* Encode a single line of binary data to a standard format that
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* uses only printing ASCII characters (but takes up 33% more bytes).
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*
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* Entry bufin points to a buffer of bytes. If nbytes is not
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* a multiple of three, then the byte just beyond
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* the last byte in the buffer must be 0.
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* nbytes is the number of bytes in that buffer.
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* This cannot be more than 48.
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* bufcoded points to an output buffer. Be sure that this
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* can hold at least 1 + (4*nbytes)/3 characters.
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* outbufmax maximum size of the buffer bufcoded.
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*
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* Exit bufcoded contains the coded line. The first 4*nbytes/3 bytes
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* contain printing ASCII characters representing
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* those binary bytes. This may include one or
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* two '=' characters used as padding at the end.
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* The last byte is a zero byte.
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* Returns the number of ASCII characters in "bufcoded".
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*/
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int HTUU_encode(unsigned char *bufin, unsigned int nbytes, char *bufcoded,
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long outbufmax)
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{
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/* ENC is the basic 1 character encoding function to make a char printing */
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#define ENC(c) six2pr[c]
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register char *outptr = bufcoded;
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unsigned int i;
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for (i = 0; i < nbytes; i += 3)
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{
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if ( (outptr - bufcoded + 4) > outbufmax )
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return (-1);
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*(outptr++) = ENC(*bufin >> 2); /* c1 */
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*(outptr++) = ENC(((*bufin << 4) & 060) | ((bufin[1] >> 4) & 017)); /*c2 */
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*(outptr++) = ENC(((bufin[1] << 2) & 074) | ((bufin[2] >> 6) & 03)); /*c3 */
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*(outptr++) = ENC(bufin[2] & 077); /* c4 */
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bufin += 3;
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}
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/* If nbytes was not a multiple of 3, then we have encoded too
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* many characters. Adjust appropriately.
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*/
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if (i == nbytes + 1)
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{
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/* There were only 2 bytes in that last group */
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outptr[-1] = '=';
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}
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else if (i == nbytes + 2)
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{
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/* There was only 1 byte in that last group */
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outptr[-1] = '=';
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outptr[-2] = '=';
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}
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if ( (outptr - bufcoded) + 1 < outbufmax )
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*outptr = '\0';
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return ((int)(outptr - bufcoded));
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}
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/*--- function HTUU_decode ------------------------------------------------
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*
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* Decode an ASCII-encoded buffer back to its original binary form.
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*
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* Entry bufcoded points to a uuencoded string. It is
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* terminated by any character not in
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* the printable character table six2pr, but
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* leading whitespace is stripped.
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* bufplain points to the output buffer; must be big
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* enough to hold the decoded string (generally
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* shorter than the encoded string) plus
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* as many as two extra bytes used during
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* the decoding process.
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* outbufsize is the maximum number of bytes that
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* can fit in bufplain.
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*
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* Exit Returns the number of binary bytes decoded.
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* bufplain contains these bytes.
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*/
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int HTUU_decode(char *bufcoded, unsigned char *bufplain, int outbufsize)
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{
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/* single character decode */
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#define DEC(c) pr2six[(int)c]
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#define MAXVAL 63
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static int first = 1;
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int nbytesdecoded, j;
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register char *bufin = bufcoded;
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register unsigned char *bufout = bufplain;
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register int nprbytes;
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/* If this is the first call, initialize the mapping table.
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* This code should work even on non-ASCII machines.
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*/
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if (first)
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{
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first = 0;
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for (j = 0; j < 256; j++)
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pr2six[j] = MAXVAL + 1;
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for (j = 0; j < 64; j++)
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pr2six[(int) six2pr[j]] = (unsigned char) j;
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#if 0
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pr2six['A'] = 0;
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pr2six['B'] = 1;
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pr2six['C'] = 2;
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pr2six['D'] = 3;
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pr2six['E'] = 4;
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pr2six['F'] = 5;
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pr2six['G'] = 6;
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pr2six['H'] = 7;
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pr2six['I'] = 8;
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pr2six['J'] = 9;
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pr2six['K'] = 10;
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pr2six['L'] = 11;
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pr2six['M'] = 12;
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pr2six['N'] = 13;
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pr2six['O'] = 14;
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pr2six['P'] = 15;
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pr2six['Q'] = 16;
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pr2six['R'] = 17;
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pr2six['S'] = 18;
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pr2six['T'] = 19;
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pr2six['U'] = 20;
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pr2six['V'] = 21;
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pr2six['W'] = 22;
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pr2six['X'] = 23;
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pr2six['Y'] = 24;
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pr2six['Z'] = 25;
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pr2six['a'] = 26;
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pr2six['b'] = 27;
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pr2six['c'] = 28;
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pr2six['d'] = 29;
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pr2six['e'] = 30;
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pr2six['f'] = 31;
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pr2six['g'] = 32;
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pr2six['h'] = 33;
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pr2six['i'] = 34;
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pr2six['j'] = 35;
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pr2six['k'] = 36;
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pr2six['l'] = 37;
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pr2six['m'] = 38;
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pr2six['n'] = 39;
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pr2six['o'] = 40;
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pr2six['p'] = 41;
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pr2six['q'] = 42;
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pr2six['r'] = 43;
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pr2six['s'] = 44;
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pr2six['t'] = 45;
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pr2six['u'] = 46;
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pr2six['v'] = 47;
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pr2six['w'] = 48;
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pr2six['x'] = 49;
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pr2six['y'] = 50;
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pr2six['z'] = 51;
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pr2six['0'] = 52;
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pr2six['1'] = 53;
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pr2six['2'] = 54;
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pr2six['3'] = 55;
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pr2six['4'] = 56;
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pr2six['5'] = 57;
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pr2six['6'] = 58;
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pr2six['7'] = 59;
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pr2six['8'] = 60;
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pr2six['9'] = 61;
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pr2six['+'] = 62;
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pr2six['/'] = 63;
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#endif
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}
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/* Strip leading whitespace. */
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while (*bufcoded == ' ' || *bufcoded == '\t')
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bufcoded++;
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/* Figure out how many characters are in the input buffer.
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* If this would decode into more bytes than would fit into
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* the output buffer, adjust the number of input bytes downwards.
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*/
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bufin = bufcoded;
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while (pr2six[(int) *(bufin++)] <= MAXVAL) ;
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nprbytes = (int)(bufin - bufcoded) - 1;
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nbytesdecoded = ((nprbytes + 3) / 4) * 3;
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if (nbytesdecoded > outbufsize)
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{
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nprbytes = (outbufsize * 4) / 3;
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}
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bufin = bufcoded;
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while (nprbytes > 0)
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{
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*(bufout++) = (unsigned char) (DEC(*bufin) << 2 | DEC(bufin[1]) >> 4);
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*(bufout++) = (unsigned char) (DEC(bufin[1]) << 4 | DEC(bufin[2]) >> 2);
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*(bufout++) = (unsigned char) (DEC(bufin[2]) << 6 | DEC(bufin[3]));
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bufin += 4;
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nprbytes -= 4;
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}
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if (nprbytes & 03)
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{
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if (pr2six[(int) bufin[-2]] > MAXVAL)
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{
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nbytesdecoded -= 2;
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}
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else
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{
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nbytesdecoded -= 1;
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}
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}
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return (nbytesdecoded);
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}
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