/*
This file was derived from the libwww code, version 2.15, from CERN.
A number of modifications have been made by Spyglass.
eric@spyglass.com
This file was removed from LibWWW and placed into the
Security Protocol Module.
jeff@spyglass.com
*/
/* 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.
** -------------------------------------------------------------
**
** BUGS:
**
**
*/
const 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.
* outbufmax maximum size of the buffer bufcoded.
*
* 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, unsigned int nbytes, char *bufcoded,
long outbufmax)
{
/* 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)
{
if ( (outptr - bufcoded + 4) > outbufmax )
return (-1);
*(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] = '=';
}
if ( (outptr - bufcoded) + 1 < outbufmax )
*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 = 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 = (int)(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);
}