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/*
* This program is free software; you can redistribute it
* and/or modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later
* version.
*
* This program is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the Free
* Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
/*
* Base64 handling elsewhere in mutt should be modified to call
* these routines. These routines were written because IMAP's
* AUTHENTICATE protocol required them, and base64 handling
* elsewhere wasn't sufficiently generic.
*
*/
/*
* This code is heavily modified from fetchmail (also GPL'd, of
* course) by Brendan Cully <brendan@kublai.com>.
*
* Original copyright notice:
*
* The code in the fetchmail distribution is Copyright 1997 by Eric
* S. Raymond. Portions are also copyrighted by Carl Harris, 1993
* and 1995. Copyright retained for the purpose of protecting free
* redistribution of source.
*
*/
#if HAVE_CONFIG_H
# include "config.h"
#endif
#include "mutt.h"
#include "mime.h"
#define BAD -1
/* raw bytes to null-terminated base 64 string */
void mutt_to_base64 (unsigned char *out, const unsigned char *in, size_t len,
size_t olen)
{
while (len >= 3 && olen > 10)
{
*out++ = B64Chars[in[0] >> 2];
*out++ = B64Chars[((in[0] << 4) & 0x30) | (in[1] >> 4)];
*out++ = B64Chars[((in[1] << 2) & 0x3c) | (in[2] >> 6)];
*out++ = B64Chars[in[2] & 0x3f];
olen -= 4;
len -= 3;
in += 3;
}
/* clean up remainder */
if (len > 0 && olen > 4)
{
unsigned char fragment;
*out++ = B64Chars[in[0] >> 2];
fragment = (in[0] << 4) & 0x30;
if (len > 1)
fragment |= in[1] >> 4;
*out++ = B64Chars[fragment];
*out++ = (len < 2) ? '=' : B64Chars[(in[1] << 2) & 0x3c];
*out++ = '=';
}
*out = '\0';
}
/* Convert '\0'-terminated base 64 string to raw bytes.
* Returns length of returned buffer, or -1 on error */
int mutt_from_base64 (char *out, const char *in)
{
int len = 0;
register unsigned char digit1, digit2, digit3, digit4;
do
{
digit1 = in[0];
if (digit1 > 127 || base64val (digit1) == BAD)
return -1;
digit2 = in[1];
if (digit2 > 127 || base64val (digit2) == BAD)
return -1;
digit3 = in[2];
if (digit3 > 127 || ((digit3 != '=') && (base64val (digit3) == BAD)))
return -1;
digit4 = in[3];
if (digit4 > 127 || ((digit4 != '=') && (base64val (digit4) == BAD)))
return -1;
in += 4;
/* digits are already sanity-checked */
*out++ = (base64val(digit1) << 2) | (base64val(digit2) >> 4);
len++;
if (digit3 != '=')
{
*out++ = ((base64val(digit2) << 4) & 0xf0) | (base64val(digit3) >> 2);
len++;
if (digit4 != '=')
{
*out++ = ((base64val(digit3) << 6) & 0xc0) | base64val(digit4);
len++;
}
}
}
while (*in && digit4 != '=');
return len;
}
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