Added support for complex operators in type fields

src/binwalk/core/magic.py

@@ -60,7 +60,10 @@ class SignatureLine(object):
             if operator in parts[1]:
                 (self.type, self.opvalue) = parts[1].split(operator, 1)
                 self.operator = operator
+                try:
                     self.opvalue = int(self.opvalue, 0)
+                except ValueError as e:
+                    pass
                 break
 
         if parts[2][0] in ['=', '!', '>', '<', '&', '|']:
@@ -241,20 +244,10 @@ class Magic(object):
 
         return filtered
 
-    def parse(self, signature, offset):
-        description = []
-        tag_strlen = None
-        max_line_level = 0
-        tags = {'id' : signature.id, 'offset' : offset, 'invalid' : False}
-
-        for line in signature.lines:
-            if line.level <= max_line_level:
-                if isinstance(line.offset, int):
-                    line_offset = line.offset
-                else:
+    def do_math(self, offset, expression):
         # (4.l+12)
-                    if '.' in line.offset:
-                        (o, t) = line.offset.split('.', 1)
+        if '.' in expression:
+            (o, t) = expression.split('.', 1)
             o = offset + int(o.split('(', 1)[1], 0)
             t = t[0]
 
@@ -272,13 +265,26 @@ class Magic(object):
             except struct.error as e:
                 v = 0
 
-                        v = "(%d%s" % (v, line.offset.split(t, 1)[1])
+            v = "(%d%s" % (v, expression.split(t, 1)[1])
         # (32+0x20)
         else:
-                        v = line.offset
+            v = expression
 
-                    #print ("Converted offset '%s' to '%s'" % (line.offset, v))
-                    line_offset = binwalk.core.common.MathExpression(v).value
+        #print ("Converted offset '%s' to '%s'" % (expression, v))
+        return binwalk.core.common.MathExpression(v).value
+
+    def parse(self, signature, offset):
+        description = []
+        tag_strlen = None
+        max_line_level = 0
+        tags = {'id' : signature.id, 'offset' : offset, 'invalid' : False}
+
+        for line in signature.lines:
+            if line.level <= max_line_level:
+                if isinstance(line.offset, int):
+                    line_offset = line.offset
+                else:
+                    line_offset = self.do_math(offset, line.offset)
 
                 start = offset + line_offset
                 end = start + line.size
@@ -299,18 +305,23 @@ class Magic(object):
                         dvalue = self.data[start:end]
 
                 if isinstance(dvalue, int) and line.operator:
+                    if isinstance(line.opvalue, int):
+                        opval = line.opvalue
+                    else:
+                        opval = self.do_math(offset, line.opvalue)
+
                     if line.operator == '&':
-                        dvalue &= line.opvalue
+                        dvalue &= opval
                     elif line.operator == '|':
-                        dvalue |= line.opvalue
+                        dvalue |= opval
                     elif line.operator == '*':
-                        dvalue *= line.opvalue
+                        dvalue *= opval
                     elif line.operator == '+':
-                        dvalue += line.opvalue
+                        dvalue += opval
                     elif line.operator == '-':
-                        dvalue -= line.opvalue
+                        dvalue -= opval
                     elif line.operator == '/':
-                        dvalue /= line.opvalue
+                        dvalue /= opval
 
                 if ((line.value is None) or
                     (line.condition == '=' and dvalue == line.value) or