jcs.org
mutt stable branch with some hacks
1/*
2 * This program is free software; you can redistribute it
3 * and/or modify it under the terms of the GNU General Public
4 * License as published by the Free Software Foundation; either
5 * version 2 of the License, or (at your option) any later
6 * version.
7 *
8 * This program is distributed in the hope that it will be
9 * useful, but WITHOUT ANY WARRANTY; without even the implied
10 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
11 * PURPOSE. See the GNU General Public License for more
12 * details.
13 *
14 * You should have received a copy of the GNU General Public
15 * License along with this program; if not, write to the Free
16 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 *
19 */
20
21/*
22 * Base64 handling elsewhere in mutt should be modified to call
23 * these routines. These routines were written because IMAP's
24 * AUTHENTICATE protocol required them, and base64 handling
25 * elsewhere wasn't sufficiently generic.
26 *
27 */
28
29/*
30 * This code is heavily modified from fetchmail (also GPL'd, of
31 * course) by Brendan Cully <brendan@kublai.com>.
32 *
33 * Original copyright notice:
34 *
35 * The code in the fetchmail distribution is Copyright 1997 by Eric
36 * S. Raymond. Portions are also copyrighted by Carl Harris, 1993
37 * and 1995. Copyright retained for the purpose of protecting free
38 * redistribution of source.
39 *
40 */
41
42#if HAVE_CONFIG_H
43# include "config.h"
44#endif
45
46#include "mutt.h"
47#include "mime.h"
48
49#define BAD -1
50
51/* raw bytes to null-terminated base 64 string */
52void mutt_to_base64 (unsigned char *out, const unsigned char *in, size_t len,
53 size_t olen)
54{
55 while (len >= 3 && olen > 10)
56 {
57 *out++ = B64Chars[in[0] >> 2];
58 *out++ = B64Chars[((in[0] << 4) & 0x30) | (in[1] >> 4)];
59 *out++ = B64Chars[((in[1] << 2) & 0x3c) | (in[2] >> 6)];
60 *out++ = B64Chars[in[2] & 0x3f];
61 olen -= 4;
62 len -= 3;
63 in += 3;
64 }
65
66 /* clean up remainder */
67 if (len > 0 && olen > 4)
68 {
69 unsigned char fragment;
70
71 *out++ = B64Chars[in[0] >> 2];
72 fragment = (in[0] << 4) & 0x30;
73 if (len > 1)
74 fragment |= in[1] >> 4;
75 *out++ = B64Chars[fragment];
76 *out++ = (len < 2) ? '=' : B64Chars[(in[1] << 2) & 0x3c];
77 *out++ = '=';
78 }
79 *out = '\0';
80}
81
82/* Convert '\0'-terminated base 64 string to raw bytes.
83 * Returns length of returned buffer, or -1 on error */
84int mutt_from_base64 (char *out, const char *in)
85{
86 int len = 0;
87 register unsigned char digit1, digit2, digit3, digit4;
88
89 do
90 {
91 digit1 = in[0];
92 if (digit1 > 127 || base64val (digit1) == BAD)
93 return -1;
94 digit2 = in[1];
95 if (digit2 > 127 || base64val (digit2) == BAD)
96 return -1;
97 digit3 = in[2];
98 if (digit3 > 127 || ((digit3 != '=') && (base64val (digit3) == BAD)))
99 return -1;
100 digit4 = in[3];
101 if (digit4 > 127 || ((digit4 != '=') && (base64val (digit4) == BAD)))
102 return -1;
103 in += 4;
104
105 /* digits are already sanity-checked */
106 *out++ = (base64val(digit1) << 2) | (base64val(digit2) >> 4);
107 len++;
108 if (digit3 != '=')
109 {
110 *out++ = ((base64val(digit2) << 4) & 0xf0) | (base64val(digit3) >> 2);
111 len++;
112 if (digit4 != '=')
113 {
114 *out++ = ((base64val(digit3) << 6) & 0xc0) | base64val(digit4);
115 len++;
116 }
117 }
118 }
119 while (*in && digit4 != '=');
120
121 return len;
122}