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
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
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.
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.
30 * This code is heavily modified from fetchmail (also GPL'd, of
31 * course) by Brendan Cully <brendan@kublai.com>.
33 * Original copyright notice:
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.
46 #include <lib-mime/mime.h>
50 /* raw bytes to null-terminated base 64 string */
51 void mutt_to_base64 (unsigned char *out, const unsigned char *in, size_t len,
54 while (len >= 3 && olen > 10) {
55 *out++ = __m_b64chars[in[0] >> 2];
56 *out++ = __m_b64chars[((in[0] << 4) & 0x30) | (in[1] >> 4)];
57 *out++ = __m_b64chars[((in[1] << 2) & 0x3c) | (in[2] >> 6)];
58 *out++ = __m_b64chars[in[2] & 0x3f];
64 /* clean up remainder */
65 if (len > 0 && olen > 4) {
66 unsigned char fragment;
68 *out++ = __m_b64chars[in[0] >> 2];
69 fragment = (in[0] << 4) & 0x30;
71 fragment |= in[1] >> 4;
72 *out++ = __m_b64chars[fragment];
73 *out++ = (len < 2) ? '=' : __m_b64chars[(in[1] << 2) & 0x3c];
79 /* Convert '\0'-terminated base 64 string to raw bytes.
80 * Returns length of returned buffer, or -1 on error */
81 int mutt_from_base64 (char *out, const char *in)
84 register unsigned char digit1, digit2, digit3, digit4;
88 if (base64val(digit1) < 0)
91 if (base64val(digit2) < 0)
94 if (digit3 != '=' && base64val(digit3) < 0)
97 if (digit4 != '=' && base64val(digit4) < 0)
101 /* digits are already sanity-checked */
102 *out++ = (base64val(digit1) << 2) | (base64val(digit2) >> 4);
105 *out++ = ((base64val(digit2) << 4) & 0xf0) | (base64val(digit3) >> 2);
108 *out++ = ((base64val(digit3) << 6) & 0xc0) | base64val(digit4);
112 } while (*in && digit4 != '=');