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/* Copyright (c) 2010, Vsevolod Stakhov
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY AUTHOR ''AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "images.h"
#include "main.h"
#include "message.h"
static const guint8 png_signature[] = {137, 80, 78, 71, 13, 10, 26, 10};
static const guint8 jpg_sig1[] = {0xff, 0xd8};
static const guint8 jpg_sig2[] = {'J', 'F', 'I', 'F'};
static const guint8 gif_signature[] = {'G', 'I', 'F', '8'};
static const guint8 bmp_signature[] = {'B', 'M'};
static void process_image (struct rspamd_task *task, struct mime_part *part);
void
process_images (struct rspamd_task *task)
{
GList *cur;
struct mime_part *part;
cur = task->parts;
while (cur) {
part = cur->data;
if (g_mime_content_type_is_type (part->type, "image", "*") && part->content->len > 0) {
process_image (task, part);
}
cur = g_list_next (cur);
}
}
static enum known_image_types
detect_image_type (GByteArray *data)
{
if (data->len > sizeof (png_signature) / sizeof (png_signature[0])) {
if (memcmp (data->data, png_signature, sizeof (png_signature)) == 0) {
return IMAGE_TYPE_PNG;
}
}
if (data->len > 10) {
if (memcmp (data->data, jpg_sig1, sizeof (jpg_sig1)) == 0) {
if (memcmp (data->data + 6, jpg_sig2, sizeof (jpg_sig2)) == 0) {
return IMAGE_TYPE_JPG;
}
}
}
if (data->len > sizeof (gif_signature) / sizeof (gif_signature[0])) {
if (memcmp (data->data, gif_signature, sizeof (gif_signature)) == 0) {
return IMAGE_TYPE_GIF;
}
}
if (data->len > sizeof (bmp_signature) / sizeof (bmp_signature[0])) {
if (memcmp (data->data, bmp_signature, sizeof (bmp_signature)) == 0) {
return IMAGE_TYPE_BMP;
}
}
return IMAGE_TYPE_UNKNOWN;
}
static struct rspamd_image *
process_png_image (struct rspamd_task *task, GByteArray *data)
{
struct rspamd_image *img;
guint32 t;
guint8 *p;
if (data->len < 24) {
msg_info ("bad png detected (maybe striped): <%s>", task->message_id);
return NULL;
}
/* In png we should find iHDR section and get data from it */
/* Skip signature and read header section */
p = data->data + 12;
if (memcmp (p, "IHDR", 4) != 0) {
msg_info ("png doesn't begins with IHDR section", task->message_id);
return NULL;
}
img = rspamd_mempool_alloc (task->task_pool, sizeof (struct rspamd_image));
img->type = IMAGE_TYPE_PNG;
img->data = data;
p += 4;
memcpy (&t, p, sizeof (guint32));
img->width = ntohl (t);
p += 4;
memcpy (&t, p, sizeof (guint32));
img->height = ntohl (t);
return img;
}
static struct rspamd_image *
process_jpg_image (struct rspamd_task *task, GByteArray *data)
{
guint8 *p;
guint16 t;
gsize remain;
struct rspamd_image *img;
img = rspamd_mempool_alloc (task->task_pool, sizeof (struct rspamd_image));
img->type = IMAGE_TYPE_JPG;
img->data = data;
p = data->data;
remain = data->len;
/* In jpeg we should find any data stream (ff c0 .. ff c3) and extract its height and width */
while (remain --) {
if (*p == 0xFF && remain > 8 && (*(p + 1) >= 0xC0 && *(p + 1) <= 0xC3)) {
memcpy (&t, p + 5, sizeof (guint16));
img->height = ntohs (t);
memcpy (&t, p + 7, sizeof (guint16));
img->width = ntohs (t);
return img;
}
p ++;
}
return NULL;
}
static struct rspamd_image *
process_gif_image (struct rspamd_task *task, GByteArray *data)
{
struct rspamd_image *img;
guint8 *p;
guint16 t;
if (data->len < 10) {
msg_info ("bad gif detected (maybe striped): <%s>", task->message_id);
return NULL;
}
img = rspamd_mempool_alloc (task->task_pool, sizeof (struct rspamd_image));
img->type = IMAGE_TYPE_GIF;
img->data = data;
p = data->data + 6;
memcpy (&t, p, sizeof (guint16));
img->width = GUINT16_FROM_LE (t);
memcpy (&t, p + 2, sizeof (guint16));
img->height = GUINT16_FROM_LE (t);
return img;
}
static struct rspamd_image *
process_bmp_image (struct rspamd_task *task, GByteArray *data)
{
struct rspamd_image *img;
gint32 t;
guint8 *p;
if (data->len < 28) {
msg_info ("bad bmp detected (maybe striped): <%s>", task->message_id);
return NULL;
}
img = rspamd_mempool_alloc (task->task_pool, sizeof (struct rspamd_image));
img->type = IMAGE_TYPE_BMP;
img->data = data;
p = data->data + 18;
memcpy (&t, p, sizeof (gint32));
img->width = abs (GINT32_FROM_LE (t));
memcpy (&t, p + 4, sizeof (gint32));
img->height = abs (GINT32_FROM_LE (t));
return img;
}
static void
process_image (struct rspamd_task *task, struct mime_part *part)
{
enum known_image_types type;
struct rspamd_image *img = NULL;
if ((type = detect_image_type (part->content)) != IMAGE_TYPE_UNKNOWN) {
switch (type) {
case IMAGE_TYPE_PNG:
img = process_png_image (task, part->content);
break;
case IMAGE_TYPE_JPG:
img = process_jpg_image (task, part->content);
break;
case IMAGE_TYPE_GIF:
img = process_gif_image (task, part->content);
break;
case IMAGE_TYPE_BMP:
img = process_bmp_image (task, part->content);
break;
default:
img = NULL;
break;
}
}
if (img != NULL) {
debug_task ("detected %s image of size %ud x %ud in message <%s>",
image_type_str (img->type),
img->width, img->height,
task->message_id);
img->filename = part->filename;
task->images = g_list_prepend (task->images, img);
}
}
const gchar *
image_type_str (enum known_image_types type)
{
switch (type) {
case IMAGE_TYPE_PNG:
return "PNG";
break;
case IMAGE_TYPE_JPG:
return "JPEG";
break;
case IMAGE_TYPE_GIF:
return "GIF";
break;
case IMAGE_TYPE_BMP:
return "BMP";
break;
default:
return "unknown";
}
return "unknown";
}
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