claws-mail/src/base64.c
2002-08-09 08:16:29 +00:00

168 lines
4.2 KiB
C

/*
* Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
* Copyright (C) 1999-2002 Hiroyuki Yamamoto
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <glib.h>
#include <ctype.h>
#include <string.h>
#include "base64.h"
static const gchar base64char[64] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static const gchar base64val[128] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1
};
#define BASE64VAL(c) (isascii(c) ? base64val[(gint)(c)] : -1)
void base64_encode(gchar *out, const guchar *in, gint inlen)
{
const guchar *inp = in;
gchar *outp = out;
while (inlen >= 3) {
*outp++ = base64char[(inp[0] >> 2) & 0x3f];
*outp++ = base64char[((inp[0] & 0x03) << 4) |
((inp[1] >> 4) & 0x0f)];
*outp++ = base64char[((inp[1] & 0x0f) << 2) |
((inp[2] >> 6) & 0x03)];
*outp++ = base64char[inp[2] & 0x3f];
inp += 3;
inlen -= 3;
}
if (inlen > 0) {
*outp++ = base64char[(inp[0] >> 2) & 0x3f];
if (inlen == 1) {
*outp++ = base64char[(inp[0] & 0x03) << 4];
*outp++ = '=';
} else {
*outp++ = base64char[((inp[0] & 0x03) << 4) |
((inp[1] >> 4) & 0x0f)];
*outp++ = base64char[((inp[1] & 0x0f) << 2)];
}
*outp++ = '=';
}
*outp = '\0';
}
gint base64_decode(guchar *out, const gchar *in, gint inlen)
{
const gchar *inp = in;
guchar *outp = out;
gchar buf[4];
if (inlen < 0)
inlen = G_MAXINT;
while (inlen >= 4 && *inp != '\0') {
buf[0] = *inp++;
inlen--;
if (BASE64VAL(buf[0]) == -1) break;
buf[1] = *inp++;
inlen--;
if (BASE64VAL(buf[1]) == -1) break;
buf[2] = *inp++;
inlen--;
if (buf[2] != '=' && BASE64VAL(buf[2]) == -1) break;
buf[3] = *inp++;
inlen--;
if (buf[3] != '=' && BASE64VAL(buf[3]) == -1) break;
*outp++ = ((BASE64VAL(buf[0]) << 2) & 0xfc) |
((BASE64VAL(buf[1]) >> 4) & 0x03);
if (buf[2] != '=') {
*outp++ = ((BASE64VAL(buf[1]) & 0x0f) << 4) |
((BASE64VAL(buf[2]) >> 2) & 0x0f);
if (buf[3] != '=') {
*outp++ = ((BASE64VAL(buf[2]) & 0x03) << 6) |
(BASE64VAL(buf[3]) & 0x3f);
}
}
}
return outp - out;
}
Base64Decoder *base64_decoder_new(void)
{
Base64Decoder *decoder;
decoder = g_new0(Base64Decoder, 1);
return decoder;
}
void base64_decoder_free(Base64Decoder *decoder)
{
g_free(decoder);
}
gint base64_decoder_decode(Base64Decoder *decoder,
const gchar *in, guchar *out)
{
gint len, total_len = 0;
gint buf_len;
gchar buf[4];
g_return_val_if_fail(decoder != NULL, -1);
g_return_val_if_fail(in != NULL, -1);
g_return_val_if_fail(out != NULL, -1);
buf_len = decoder->buf_len;
memcpy(buf, decoder->buf, sizeof(buf));
for (;;) {
while (buf_len < 4) {
gchar c = *in;
in++;
if (c == '\0') break;
if (c == '\r' || c == '\n') continue;
if (c != '=' && BASE64VAL(c) == -1)
return -1;
buf[buf_len++] = c;
}
if (buf_len < 4 || buf[0] == '=' || buf[1] == '=') {
decoder->buf_len = buf_len;
memcpy(decoder->buf, buf, sizeof(buf));
return total_len;
}
len = base64_decode(out, buf, 4);
out += len;
total_len += len;
buf_len = 0;
if (len < 3) {
decoder->buf_len = 0;
return total_len;
}
}
}