Handle PGP signed messages

mbox2web

@@ -7,7 +7,9 @@ import html.parser
 import mailbox
 import os
 import re
+import subprocess
 import sys
+import tempfile
 import urllib.parse
 
 import jinja2
@@ -142,6 +144,29 @@ def render_body(msg):
         }
         bodyhtml = bodytmpl.render(context)
 
+    elif content_type == "multipart/signed":
+        content, signature = msg.get_payload()
+        with tempfile.NamedTemporaryFile(buffering=0) as content_fh:
+            content_fh.write(content.as_bytes())
+            with tempfile.NamedTemporaryFile(buffering=0, suffix=".asc") as signature_fh:
+                signature_fh.write(signature.get_payload(decode=True))
+
+                r = subprocess.run(["gpg", "--verify", signature_fh.name, content_fh.name],
+                                   stdout=subprocess.PIPE,
+                                   stderr=subprocess.PIPE,
+                                   universal_newlines=True)
+                gpgresult = r.stderr
+                # Analyze gpgresult or just use r,returncode?
+                gpgstatus = "dubious"
+
+        contenthtml = render_message(content)
+        bodytmpl = jenv.get_template("body_multipart_signed.html")
+        context = {
+            "content": contenthtml,
+            "gpgresult": gpgresult,
+            "gpgstatus": gpgstatus,
+        }
+        bodyhtml = bodytmpl.render(context)
 
     else:
         raise RuntimeError("Content-type " + content_type + " not implemented yet")