* scode captcha decoder

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/pwntcha/trunk@400 92316355-f0b4-4df1-b90c-862c8a59935f

src/Makefile.am

@@ -3,7 +3,15 @@ NULL =
 bin_PROGRAMS = pwntcha
 pwntcha_CFLAGS = $(ADDITIONAL_CFLAGS) -Wall -O6
 pwntcha_LDFLAGS = $(ADDITIONAL_LDFLAGS)
-pwntcha_SOURCES = main.c image.c filters.c common.h slashdot.c phpbb.c test.c
+pwntcha_SOURCES = \
+    main.c \
+    image.c \
+    filters.c \
+    common.h \
+    phpbb.c \
+    scode.c \
+    slashdot.c \
+    test.c
 
 if USE_OPENCV
 ADDITIONAL_CFLAGS = `opencv-config --cflags`

src/main.c

@@ -31,12 +31,11 @@ int debug = 1;
 int main(int argc, char *argv[])
 {
     char *mode = "auto";
-
-    argv0 = argv[0];
-
     int c;
     int digit_optind = 0;
 
+    argv0 = argv[0];
+
     for(;;)
     {
         int this_option_optind = optind ? optind : 1;
@@ -122,6 +121,8 @@ int main(int argc, char *argv[])
             result = decode_test(img);
         else if(!strcmp(mode, "phpbb"))
             result = decode_phpbb(img);
+        else if(!strcmp(mode, "scode"))
+            result = decode_scode(img);
         else if(!strcmp(mode, "slashdot"))
             result = decode_slashdot(img);
         else
@@ -131,6 +132,11 @@ int main(int argc, char *argv[])
                 dprintf("autodetecting phpBB captcha\n");
                 result = decode_phpbb(img);
             }
+            else if(img->height == 25)
+            {
+                dprintf("autodetecting scode captcha\n");
+                result = decode_scode(img);
+            }
             else if(img->height == 69)
             {
                 dprintf("autodetecting slashdot captcha\n");

src/scode.c

@@ -0,0 +1,144 @@
+/*
+ * scode.c: decode scode captchas
+ * $Id$
+ *
+ * Copyright: (c) 2004 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 "config.h"
+#include "common.h"
+
+static char find_glyph(struct image *img, int xmin, int xmax);
+
+/* Main function */
+char *decode_scode(struct image *img)
+{
+    char *result;
+    int stats[256];
+    int x, y, i, incell = 0, cur = 0, xmin = 0;
+    int r, g, b;
+    struct image *tmp1;
+
+    /* allocate enough place */
+    result = malloc(1024 * sizeof(char));
+
+    /* Detect background: first 3 lines */
+    for(i = 0; i < 256; i++)
+        stats[i] = 0;
+
+    for(y = 0; y < 3; y++)
+        for(x = 0; x < img->width; x++)
+        {
+            getpixel(img, x, y, &r, &g, &b);
+            stats[r]++;
+        }
+
+    /* Set non-background colours to 0 */
+    tmp1 = 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);
+            if(stats[r])
+                setpixel(tmp1, x, y, 255, 255, 255);
+            else
+                setpixel(tmp1, x, y, 0, 0, 0);
+        }
+
+    /* Decode glyphs */
+    for(x = 0; x < img->width; x++)
+    {
+        int found = 0;
+        for(y = 0; y < img->height; y++)
+        {
+            getpixel(tmp1, x, y, &r, &g, &b);
+            if(!r)
+            {
+                found = 1;
+                break;
+            }
+        }
+        if(found && !incell)
+        {
+            incell = 1;
+            xmin = x;
+        }
+        else if(!found && incell)
+        {
+            incell = 0;
+            /* Find glyph */
+            result[cur++] = find_glyph(tmp1, xmin, x);
+        }
+    }
+
+    image_free(tmp1);
+
+    result[cur] = 0;
+    return result;
+}
+
+static char find_glyph(struct image *img, int xmin, int xmax)
+{
+    int ymin = -1, ymax = -1;
+    int x, y, count = 0;
+    int r, g, b;
+
+    /* Compute vertical bounds of glyph */
+    for(y = 0; y < img->height; y++)
+    {
+        int found = 0;
+        for(x = xmin; x < xmax; x++)
+        {
+            getpixel(img, x, y, &r, &g, &b);
+            if(!r)
+            {
+                found = 1;
+                break;
+            }
+        }
+        if(found)
+        {
+            if(ymin == -1)
+                ymin = y;
+            else
+                ymax = y + 1;
+        }
+    }
+
+    for(x = xmin; x < xmax; x++)
+    {
+        for(y = ymin; y < ymax; y++)
+        {
+            getpixel(img, x, y, &r, &g, &b);
+            if(!r)
+                count += y - ymin;
+        }
+    }
+
+    switch(count)
+    {
+        case 162: return '0';
+        case 131: return '1';
+        case 150: return '2';
+        case 139: return '3';
+        case 155: return '4';
+        case 159: return '5';
+        case 181: return '6';
+        case  90: return '7';
+        case 180: return '8';
+        case 170: return '9';
+        default:
+            dprintf("don't know about checksum %i\n", count);
+            return '?';
+    }
+}
+

src/slashdot.c

@@ -34,7 +34,7 @@ int objects, first, last;
 char *result;
 
 /* Main function */
-char * decode_slashdot(struct image *img)
+char *decode_slashdot(struct image *img)
 {
     struct image *tmp1, *tmp2, *tmp3, *tmp4, *tmp5, *tmp6, *tmp7;
 

src/test.c

@@ -28,7 +28,7 @@ int objects, first, last;
 char *result;
 
 /* Main function */
-char * decode_test(struct image *img)
+char *decode_test(struct image *img)
 {
     struct image *tmp1, *tmp2, *tmp3, *tmp4, *tmp5, *tmp6, *tmp7;