* add (non-working) Xanga decoder skeleton.

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/pwntcha/trunk@444 92316355-f0b4-4df1-b90c-862c8a59935f

src/Makefile.am

@@ -13,6 +13,7 @@ pwntcha_SOURCES = \
     scode.c \
     slashdot.c \
     vbulletin.c \
+    xanga.c \
     test.c
 pwntcha_CFLAGS = $(ADDITIONAL_CFLAGS) -Wall -O6
 pwntcha_LDFLAGS = $(ADDITIONAL_LDFLAGS)

src/main.c

@@ -146,6 +146,8 @@ int main(int argc, char *argv[])
             result = decode_slashdot(img);
         else if(!strcmp(mode, "vbulletin"))
             result = decode_vbulletin(img);
+        else if(!strcmp(mode, "xanga"))
+            result = decode_xanga(img);
         else
         {
             if(img->width == 155 && img->height == 50)
@@ -163,6 +165,11 @@ int main(int argc, char *argv[])
                 dprintf("autodetected phpBB captcha\n");
                 result = decode_phpbb(img);
             }
+            else if(img->width == 170 && img->height == 50)
+            {
+                dprintf("autodetected Xanga captcha\n");
+                result = decode_xanga(img);
+            }
             else if(img->height <= 40 && count < 10)
             {
                 dprintf("autodetected scode/trencaspammers captcha\n");

src/xanga.c

@@ -0,0 +1,131 @@
+/*
+ * xanga.c: decode Xanga captchas
+ * $Id$
+ *
+ * Copyright: (c) 2005 Sam Hocevar <sam@zoy.org>
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the Do What The Fuck You Want To
+ *   Public License as published by Banlu Kemiyatorn. See
+ *   http://sam.zoy.org/projects/COPYING.WTFPL for more details.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <math.h>
+
+#include "config.h"
+#include "common.h"
+
+static struct image *fill_white_holes(struct image *img);
+static struct image *rotate(struct image *img);
+static struct image *cut_cells(struct image *img);
+static struct image *find_glyphs(struct image *img);
+
+/* Our macros */
+#define FACTOR 1
+#define FONTNAME "font_xanga.png" // use with FACTOR = 1
+//#define FONTNAME "font.png" // use with FACTOR = 2
+//#define FONTNAME "font_dilated.png" // use with FACTOR = 2
+static struct image *font = NULL;
+
+/* Global stuff */
+struct { int xmin, ymin, xmax, ymax; } objlist[100];
+int objects, first, last;
+char *result;
+
+/* Main function */
+char *decode_xanga(struct image *img)
+{
+    struct image *tmp1, *tmp2, *tmp3, *tmp4, *tmp5, *tmp6, *tmp7;
+
+    /* Initialise local data */
+    objects = 0;
+    first = -1;
+    last = -1;
+
+    /* Xanga captchas have 7 characters */
+    result = malloc(8 * sizeof(char));
+    strcpy(result, "       ");
+
+image_save(img, "xanga1.bmp");
+    /* Clean image a bit */
+//    tmp1 = filter_equalize(img, 200);
+    tmp1 = filter_contrast(img);
+    //tmp1 = filter_detect_lines(img);
+image_save(tmp1, "xanga2.bmp");
+    tmp2 = fill_white_holes(tmp1);
+//    tmp2 = filter_fill_holes(tmp1);
+image_save(tmp2, "xanga3.bmp");
+    //tmp3 = filter_detect_lines(tmp2);
+//    tmp3 = filter_median(tmp2);
+//image_save(tmp3, "xanga4.bmp");
+    tmp3 = filter_equalize(tmp2, 128);
+image_save(tmp3, "xanga4.bmp");
+return NULL;
+
+    /* Detect small objects to guess image orientation */
+    tmp3 = filter_median(tmp2);
+    tmp4 = filter_equalize(tmp3, 200);
+
+    /* Invert rotation and find glyphs */
+    tmp5 = rotate(tmp2);
+    tmp6 = filter_median(tmp5);
+
+    /* Clean up our mess */
+    image_free(tmp1);
+    image_free(tmp2);
+    image_free(tmp3);
+    image_free(tmp4);
+    image_free(tmp5);
+    image_free(tmp6);
+    image_free(tmp7);
+
+    /* aaaaaaa means decoding failed */
+    if(!strcmp(result, "aaaaaaa"))
+        result[0] = '\0';
+
+    return result;
+}
+
+/* The following functions are local */
+
+static struct image *fill_white_holes(struct image *img)
+{
+    struct image *dst;
+    int x, y, i;
+    int r, g, b;
+
+    dst = image_new(img->width, img->height);
+
+    for(y = 0; y < img->height; y++)
+        for(x = 0; x < img->width; x++)
+        {
+            getpixel(img, x, y, &r, &g, &b);
+            setpixel(dst, x, y, r, g, b);
+        }
+
+    for(y = 1; y < img->height - 1; y++)
+        for(x = 1; x < img->width - 1; x++)
+        {
+            int count = 0;
+            getpixel(img, x, y, &r, &g, &b);
+            if(r <= 16)
+                continue;
+            getpixel(img, x + 1, y, &r, &g, &b);
+            count += r;
+            getpixel(img, x - 1, y, &r, &g, &b);
+            count += r;
+            getpixel(img, x, y + 1, &r, &g, &b);
+            count += r;
+            getpixel(img, x, y - 1, &r, &g, &b);
+            count += r;
+            if(count > 600)
+                continue;
+            setpixel(dst, x, y, count / 5, count / 5, count / 5);
+        }
+
+    return dst;
+}
+