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/*
** Copyright 2003-2004 Double Precision, Inc. See COPYING for
** distribution information.
*/
/*
*/
#include "encode.h"
#include <string.h>
#include <stdlib.h>
static int quoted_printable(struct libmail_encode_info *,
const char *, size_t);
static int base64(struct libmail_encode_info *,
const char *, size_t);
static int eflush(struct libmail_encode_info *,
const char *, size_t);
void libmail_encode_start(struct libmail_encode_info *info,
const char *transfer_encoding,
int (*callback_func)(const char *, size_t, void *),
void *callback_arg)
{
info->output_buf_cnt=0;
info->input_buf_cnt=0;
switch (*transfer_encoding) {
case 'q':
case 'Q':
info->encoding_func=quoted_printable;
info->input_buffer[0]=0; /* Recycle for qp encoding */
break;
case 'b':
case 'B':
info->encoding_func=base64;
break;
default:
info->encoding_func=eflush;
break;
}
info->callback_func=callback_func;
info->callback_arg=callback_arg;
}
int libmail_encode(struct libmail_encode_info *info,
const char *ptr,
size_t cnt)
{
return ((*info->encoding_func)(info, ptr, cnt));
}
int libmail_encode_end(struct libmail_encode_info *info)
{
int rc=(*info->encoding_func)(info, NULL, 0);
if (rc == 0 && info->output_buf_cnt > 0)
{
rc= (*info->callback_func)(info->output_buffer,
info->output_buf_cnt,
info->callback_arg);
info->output_buf_cnt=0;
}
return rc;
}
static int eflush(struct libmail_encode_info *info, const char *ptr, size_t n)
{
while (n > 0)
{
size_t i;
if (info->output_buf_cnt == sizeof(info->output_buffer))
{
int rc= (*info->callback_func)(info->output_buffer,
info->output_buf_cnt,
info->callback_arg);
info->output_buf_cnt=0;
if (rc)
return rc;
}
i=n;
if (i > sizeof(info->output_buffer) - info->output_buf_cnt)
i=sizeof(info->output_buffer) - info->output_buf_cnt;
memcpy(info->output_buffer + info->output_buf_cnt, ptr, i);
info->output_buf_cnt += i;
ptr += i;
n -= i;
}
return 0;
}
static int base64_flush(struct libmail_encode_info *);
static int base64(struct libmail_encode_info *info,
const char *buf, size_t n)
{
if (!buf)
{
int rc=0;
if (info->input_buf_cnt > 0)
rc=base64_flush(info);
return rc;
}
while (n)
{
size_t i;
if (info->input_buf_cnt == sizeof(info->input_buffer))
{
int rc=base64_flush(info);
if (rc != 0)
return rc;
}
i=n;
if (i > sizeof(info->input_buffer) - info->input_buf_cnt)
i=sizeof(info->input_buffer) - info->input_buf_cnt;
memcpy(info->input_buffer + info->input_buf_cnt,
buf, i);
info->input_buf_cnt += i;
buf += i;
n -= i;
}
return 0;
}
static const char base64tab[]=
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static int base64_flush(struct libmail_encode_info *info)
{
int a=0,b=0,c=0;
int i, j;
int d, e, f, g;
char output_buf[ sizeof(info->input_buffer) / 3 * 4+1];
for (j=i=0; i<info->input_buf_cnt; i += 3)
{
a=(unsigned char)info->input_buffer[i];
b= i+1 < info->input_buf_cnt ?
(unsigned char)info->input_buffer[i+1]:0;
c= i+2 < info->input_buf_cnt ?
(unsigned char)info->input_buffer[i+2]:0;
d=base64tab[ a >> 2 ];
e=base64tab[ ((a & 3 ) << 4) | (b >> 4)];
f=base64tab[ ((b & 15) << 2) | (c >> 6)];
g=base64tab[ c & 63 ];
if (i + 1 >= info->input_buf_cnt) f='=';
if (i + 2 >= info->input_buf_cnt) g='=';
output_buf[j++]=d;
output_buf[j++]=e;
output_buf[j++]=f;
output_buf[j++]=g;
}
info->input_buf_cnt=0;
output_buf[j++]='\n';
return eflush(info, output_buf, j);
}
static const char xdigit[]="0123456789ABCDEF";
static int quoted_printable(struct libmail_encode_info *info,
const char *p, size_t n)
{
char local_buf[256];
int local_buf_cnt=0;
#define QPUT(c) do { if (local_buf_cnt == sizeof(local_buf)) \
{ int rc=eflush(info, local_buf, local_buf_cnt); \
local_buf_cnt=0; if (rc) return (rc); } \
local_buf[local_buf_cnt]=(c); ++local_buf_cnt; } while(0)
if (!p)
return (0);
while (n)
{
/*
** Repurpose input_buffer[0] as a flag whether the previous
** character was a space.
**
** A space before a newline gets escaped.
*/
if (info->input_buffer[0])
{
if (*p == '\n')
{
QPUT('=');
QPUT('2');
QPUT('0');
}
else
{
QPUT(' ');
}
++info->input_buf_cnt;
}
info->input_buffer[0]=0;
if (*p == ' ')
{
info->input_buffer[0]=1;
p++;
--n;
continue;
}
if (info->input_buf_cnt > 72 && *p != '\n')
{
QPUT('=');
QPUT('\n');
info->input_buf_cnt=0;
}
if ( *p == '\n')
info->input_buf_cnt=0;
else if (*p < ' ' || *p == '=' || *p >= 0x7F)
{
QPUT('=');
QPUT(xdigit[ (*p >> 4) & 15]);
QPUT(xdigit[ *p & 15 ]);
info->input_buf_cnt += 3;
p++;
--n;
continue;
}
else info->input_buf_cnt++;
QPUT( *p);
p++;
--n;
}
if (local_buf_cnt > 0)
return eflush(info, local_buf, local_buf_cnt);
return 0;
}
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