Annotation of libwww/Library/src/HTUU.c, revision 2.6.2.1
2.6 frystyk 1: /* HTUU.c
2: ** UUENCODE AND UUDECODE
3: **
4: ** (c) COPYRIGHT CERN 1994.
5: ** Please first read the full copyright statement in the file COPYRIGH.
2.1 luotonen 6: **
7: ** ACKNOWLEDGEMENT:
8: ** This code is taken from rpem distribution, and was originally
9: ** written by Mark Riordan.
10: **
11: ** AUTHORS:
12: ** MR Mark Riordan riordanmr@clvax1.cl.msu.edu
13: ** AL Ari Luotonen luotonen@dxcern.cern.ch
14: **
15: ** HISTORY:
16: ** Added as part of the WWW library and edited to conform
17: ** with the WWW project coding standards by: AL 5 Aug 1993
18: ** Originally written by: MR 12 Aug 1990
19: ** Original header text:
20: ** -------------------------------------------------------------
21: ** File containing routines to convert a buffer
22: ** of bytes to/from RFC 1113 printable encoding format.
23: **
24: ** This technique is similar to the familiar Unix uuencode
25: ** format in that it maps 6 binary bits to one ASCII
26: ** character (or more aptly, 3 binary bytes to 4 ASCII
27: ** characters). However, RFC 1113 does not use the same
28: ** mapping to printable characters as uuencode.
29: **
30: ** Mark Riordan 12 August 1990 and 17 Feb 1991.
31: ** This code is hereby placed in the public domain.
32: ** -------------------------------------------------------------
33: **
34: ** BUGS:
35: **
36: **
37: */
38:
2.6.2.1 ! frystyk 39: /* Library include files */
! 40: #include "tcp.h"
2.1 luotonen 41: #include "HTUtils.h"
42: #include "HTUU.h"
43:
44:
45: PRIVATE char six2pr[64] = {
46: 'A','B','C','D','E','F','G','H','I','J','K','L','M',
47: 'N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
48: 'a','b','c','d','e','f','g','h','i','j','k','l','m',
49: 'n','o','p','q','r','s','t','u','v','w','x','y','z',
50: '0','1','2','3','4','5','6','7','8','9','+','/'
51: };
52:
53: PRIVATE unsigned char pr2six[256];
54:
55:
56: /*--- function HTUU_encode -----------------------------------------------
57: *
58: * Encode a single line of binary data to a standard format that
59: * uses only printing ASCII characters (but takes up 33% more bytes).
60: *
61: * Entry bufin points to a buffer of bytes. If nbytes is not
62: * a multiple of three, then the byte just beyond
63: * the last byte in the buffer must be 0.
64: * nbytes is the number of bytes in that buffer.
65: * This cannot be more than 48.
66: * bufcoded points to an output buffer. Be sure that this
67: * can hold at least 1 + (4*nbytes)/3 characters.
68: *
69: * Exit bufcoded contains the coded line. The first 4*nbytes/3 bytes
70: * contain printing ASCII characters representing
71: * those binary bytes. This may include one or
72: * two '=' characters used as padding at the end.
73: * The last byte is a zero byte.
74: * Returns the number of ASCII characters in "bufcoded".
75: */
76: PUBLIC int HTUU_encode ARGS3(unsigned char *, bufin,
77: unsigned int, nbytes,
78: char *, bufcoded)
79: {
80: /* ENC is the basic 1 character encoding function to make a char printing */
81: #define ENC(c) six2pr[c]
82:
83: register char *outptr = bufcoded;
84: unsigned int i;
2.4 luotonen 85:
2.1 luotonen 86: for (i=0; i<nbytes; i += 3) {
87: *(outptr++) = ENC(*bufin >> 2); /* c1 */
2.2 luotonen 88: *(outptr++) = ENC(((*bufin << 4) & 060) | ((bufin[1] >> 4) & 017)); /*c2*/
89: *(outptr++) = ENC(((bufin[1] << 2) & 074) | ((bufin[2] >> 6) & 03));/*c3*/
2.1 luotonen 90: *(outptr++) = ENC(bufin[2] & 077); /* c4 */
91:
92: bufin += 3;
93: }
94:
95: /* If nbytes was not a multiple of 3, then we have encoded too
96: * many characters. Adjust appropriately.
97: */
98: if(i == nbytes+1) {
99: /* There were only 2 bytes in that last group */
100: outptr[-1] = '=';
101: } else if(i == nbytes+2) {
102: /* There was only 1 byte in that last group */
103: outptr[-1] = '=';
104: outptr[-2] = '=';
105: }
106: *outptr = '\0';
107: return(outptr - bufcoded);
108: }
109:
110:
111: /*--- function HTUU_decode ------------------------------------------------
112: *
113: * Decode an ASCII-encoded buffer back to its original binary form.
114: *
115: * Entry bufcoded points to a uuencoded string. It is
116: * terminated by any character not in
117: * the printable character table six2pr, but
118: * leading whitespace is stripped.
119: * bufplain points to the output buffer; must be big
120: * enough to hold the decoded string (generally
121: * shorter than the encoded string) plus
122: * as many as two extra bytes used during
123: * the decoding process.
124: * outbufsize is the maximum number of bytes that
125: * can fit in bufplain.
126: *
127: * Exit Returns the number of binary bytes decoded.
128: * bufplain contains these bytes.
129: */
130: PUBLIC int HTUU_decode ARGS3(char *, bufcoded,
131: unsigned char *, bufplain,
132: int, outbufsize)
133: {
134: /* single character decode */
2.3 luotonen 135: #define DEC(c) pr2six[(int)c]
2.1 luotonen 136: #define MAXVAL 63
137:
138: static int first = 1;
139:
140: int nbytesdecoded, j;
141: register char *bufin = bufcoded;
142: register unsigned char *bufout = bufplain;
143: register int nprbytes;
144:
145: /* If this is the first call, initialize the mapping table.
146: * This code should work even on non-ASCII machines.
147: */
148: if(first) {
149: first = 0;
150: for(j=0; j<256; j++) pr2six[j] = MAXVAL+1;
151:
2.3 luotonen 152: for(j=0; j<64; j++) pr2six[(int)six2pr[j]] = (unsigned char) j;
2.1 luotonen 153: #if 0
154: pr2six['A']= 0; pr2six['B']= 1; pr2six['C']= 2; pr2six['D']= 3;
155: pr2six['E']= 4; pr2six['F']= 5; pr2six['G']= 6; pr2six['H']= 7;
156: pr2six['I']= 8; pr2six['J']= 9; pr2six['K']=10; pr2six['L']=11;
157: pr2six['M']=12; pr2six['N']=13; pr2six['O']=14; pr2six['P']=15;
158: pr2six['Q']=16; pr2six['R']=17; pr2six['S']=18; pr2six['T']=19;
159: pr2six['U']=20; pr2six['V']=21; pr2six['W']=22; pr2six['X']=23;
160: pr2six['Y']=24; pr2six['Z']=25; pr2six['a']=26; pr2six['b']=27;
161: pr2six['c']=28; pr2six['d']=29; pr2six['e']=30; pr2six['f']=31;
162: pr2six['g']=32; pr2six['h']=33; pr2six['i']=34; pr2six['j']=35;
163: pr2six['k']=36; pr2six['l']=37; pr2six['m']=38; pr2six['n']=39;
164: pr2six['o']=40; pr2six['p']=41; pr2six['q']=42; pr2six['r']=43;
165: pr2six['s']=44; pr2six['t']=45; pr2six['u']=46; pr2six['v']=47;
166: pr2six['w']=48; pr2six['x']=49; pr2six['y']=50; pr2six['z']=51;
167: pr2six['0']=52; pr2six['1']=53; pr2six['2']=54; pr2six['3']=55;
168: pr2six['4']=56; pr2six['5']=57; pr2six['6']=58; pr2six['7']=59;
169: pr2six['8']=60; pr2six['9']=61; pr2six['+']=62; pr2six['/']=63;
170: #endif
171: }
172:
173: /* Strip leading whitespace. */
174:
175: while(*bufcoded==' ' || *bufcoded == '\t') bufcoded++;
176:
177: /* Figure out how many characters are in the input buffer.
178: * If this would decode into more bytes than would fit into
179: * the output buffer, adjust the number of input bytes downwards.
180: */
181: bufin = bufcoded;
2.3 luotonen 182: while(pr2six[(int)*(bufin++)] <= MAXVAL);
2.1 luotonen 183: nprbytes = bufin - bufcoded - 1;
184: nbytesdecoded = ((nprbytes+3)/4) * 3;
185: if(nbytesdecoded > outbufsize) {
186: nprbytes = (outbufsize*4)/3;
187: }
188:
189: bufin = bufcoded;
190:
191: while (nprbytes > 0) {
192: *(bufout++) = (unsigned char) (DEC(*bufin) << 2 | DEC(bufin[1]) >> 4);
193: *(bufout++) = (unsigned char) (DEC(bufin[1]) << 4 | DEC(bufin[2]) >> 2);
194: *(bufout++) = (unsigned char) (DEC(bufin[2]) << 6 | DEC(bufin[3]));
195: bufin += 4;
196: nprbytes -= 4;
197: }
198:
199: if(nprbytes & 03) {
2.3 luotonen 200: if(pr2six[(int)bufin[-2]] > MAXVAL) {
2.1 luotonen 201: nbytesdecoded -= 2;
202: } else {
203: nbytesdecoded -= 1;
204: }
205: }
206:
207: return(nbytesdecoded);
208: }
209:
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