Adds taint visualizer which reveals bitmaps of nudge dumps

Issue #1
Fixes #3

drtaint_shadow.c

@@ -298,7 +298,7 @@ shadow_memory_iter_func(umbra_map_t *map, umbra_shadow_memory_info_t *info,
 {
     if (info->shadow_type == UMBRA_SHADOW_MEMORY_TYPE_NORMAL) {
         FILE *fp = (FILE *)user_data;
-        fprintf(fp, "APP %08x SHADOW %08x:",
+        fprintf(fp, "APP %08x SHADOW %08x ",
                 info->app_base,
                 info->shadow_base);
         fwrite(info->shadow_base, 1, info->shadow_size, fp);

scripts/vis.py

@@ -0,0 +1,28 @@
+import numpngw
+import operator
+import sys
+import numpy
+
+file = sys.argv[1]
+
+file = open(file).read()
+file = file.split("\n")
+
+# make sure it's the right type of file
+assert file[0].rstrip() == "TAINT DUMP"
+file = file[1:-1]
+def parse_line(i):
+    i = i.rstrip().split(" ")
+    assert i[0] == "APP" and \
+           i[2] == "SHADOW"
+    return int(i[1], 16), i[4]
+mappings = map(parse_line, file)
+
+for n,shadow in mappings:
+    shadow = map(ord, shadow)
+    shadow = numpy.asarray(shadow,
+                dtype=numpy.uint8)
+    shadow.resize(256, 64)
+
+    numpngw.write_png("app_{:x}.png".format(n),
+            shadow, bitdepth=1)