update

phishing/decode-spam-headers.py

@@ -868,6 +868,7 @@ Results will be unsound. Make sure you have pasted your headers with correct spa
         self.results['SpamAssassin Spam Report']                = self.testSpamAssassinSpamReport()
         self.results['Message Feedback Loop']                   = self.testMSFBL()
         self.results['Other interesting headers']               = self.testInterestingHeaders()
+        self.results['OVH\'s X-VR-SPAMCAUSE']                   = self.testSpamCause()
 
         return {k: v for k, v in self.results.items() if v}
 
@@ -887,6 +888,41 @@ Results will be unsound. Make sure you have pasted your headers with correct spa
         parts = fqdn.split('.')
         return '.'.join(parts[-2:])
 
+    @staticmethod
+    def decodeSpamcause(msg):
+        text = []
+        for i in range(0, len(msg), 2):
+            text.append(SMTPHeadersAnalysis.unrotSpamcause(msg[i: i + 2]))
+        return str.join('', text)
+
+    @staticmethod
+    def unrotSpamcause(pair, key=ord('x')):
+        offset = 0
+        for c in 'cdefgh':
+            if c in pair:
+                offset = (ord('g') - ord(c)) * 16
+                break
+        return chr(sum(ord(c) for c in pair) - key - offset)
+
+    def testSpamCause(self):
+        (num, header, value) = self.getHeader('X-VR-SPAMCAUSE')
+        if num == -1: return []
+
+        result = ''
+        value = SMTPHeadersAnalysis.flattenLine(value).replace(' ', '').replace('\t', '')
+
+        decoded = SMTPHeadersAnalysis.decodeSpamcause(value)
+        result = decoded
+
+        if len(result) == 0:
+            return []
+
+        return {
+            'header' : header,
+            'value': value,
+            'analysis' : result
+        }
+
     def testMSFBL(self):
         (num, header, value) = self.getHeader('X-MSFBL')
         if num == -1: return []