add python mime inject

mime-inject.py

@@ -0,0 +1,30 @@
+#!/usr/bin/env python3
+import sys
+import email
+m = email.message_from_bytes(sys.stdin.buffer.read())
+
+INJECTED = {
+  'text/plain': False,
+  'text/html': False,
+}
+
+def inject(m):
+  c = m.get_content_type()
+  payload = m.get_payload()
+  if c == 'text/plain':
+    payload = 'BANNER\r' + payload
+  if c == 'text/html':
+    payload = payload.replace('</body>', '<p>BANNER</p></body>')
+  m.set_payload(payload)
+
+def visit(m):
+  c = m.get_content_type()
+  if c in ('text/plain', 'text/html'):
+    if INJECTED[c]: return
+    inject(m)
+    INJECTED[c] = True
+
+for _m in m.walk():
+  visit(_m)
+
+sys.stdout.buffer.write(m.as_bytes())