1 files changed, 50 insertions, 20 deletions

diff --git a/src/mailman_pgp/pgp/inline.py b/src/mailman_pgp/pgp/inline.py
index fe5b2c3..ca83e89 100644
--- a/src/mailman_pgp/pgp/inline.py
+++ b/src/mailman_pgp/pgp/inline.py
@@ -159,11 +159,10 @@ class InlineWrapper:
             if not part.is_multipart() and self._is_signed(part):
                 yield self._verify(part, key)
 
-    def _sign(self, part, key, hash):
-        payload = str(part.get_payload())
-        pmsg = PGPMessage.new(payload, cleartext=True)
-        pmsg |= key.sign(pmsg, hash=hash)
-        part.set_payload(str(pmsg))
+    def _sign(self, pmsg, key, hash):
+        smsg = copy.copy(pmsg)
+        smsg |= key.sign(smsg, hash=hash)
+        return smsg
 
     def sign(self, key, hash=None):
         """
@@ -179,7 +178,10 @@ class InlineWrapper:
         out = copy.deepcopy(self.msg)
         for part in walk(out):
             if not part.is_multipart():
-                self._sign(part, key, hash)
+                payload = str(part.get_payload())
+                pmsg = PGPMessage.new(payload, cleartext=True)
+                smsg = self._sign(pmsg, key, hash)
+                part.set_payload(str(smsg))
         return out
 
     def _decrypt(self, part, key):
@@ -202,12 +204,17 @@ class InlineWrapper:
                 self._decrypt(part, key)
         return out
 
-    def _encrypt(self, part, *keys, **kwargs):
-        payload = str(part.get_payload())
-        pmsg = PGPMessage.new(payload)
-        for key in keys:
-            pmsg = key.encrypt(pmsg, **kwargs)
-        part.set_payload(str(pmsg))
+    def _encrypt(self, pmsg, *keys, cipher):
+        emsg = copy.copy(pmsg)
+        if len(keys) == 1:
+            emsg = keys[0].encrypt(emsg, cipher=cipher)
+        else:
+            session_key = cipher.gen_key()
+            for key in keys:
+                emsg = key.encrypt(emsg, cipher=cipher,
+                                   session_key=session_key)
+            del session_key
+        return emsg
 
     def encrypt(self, *keys, cipher=SymmetricKeyAlgorithm.AES256):
         """
@@ -225,12 +232,35 @@ class InlineWrapper:
         out = copy.deepcopy(self.msg)
         for part in walk(out):
             if not part.is_multipart():
-                if len(keys) == 1:
-                    self._encrypt(part, *keys, cipher=cipher)
-                else:
-                    session_key = cipher.gen_key()
-                    for key in keys:
-                        self._encrypt(part, key, cipher=cipher,
-                                      session_key=session_key)
-                    del session_key
+                payload = str(part.get_payload())
+                pmsg = PGPMessage.new(payload)
+                emsg = self._encrypt(pmsg, *keys, cipher=cipher)
+                part.set_payload(str(emsg))
         return out
+
+    def sign_encrypt(self, key, *keys, hash=None,
+                     cipher=SymmetricKeyAlgorithm.AES256):
+        """
+
+        :param key:
+        :param keys:
+        :param hash:
+        :param cipher:
+        :return:
+        """
+        if len(keys) == 0:
+            raise ValueError('At least one key necessary.')
+
+        out = copy.deepcopy(self.msg)
+        for part in walk(out):
+            if not part.is_multipart():
+                payload = str(part.get_payload())
+                pmsg = PGPMessage.new(payload)
+                smsg = self._sign(pmsg, key, hash=hash)
+                emsg = self._encrypt(smsg, *keys, cipher=cipher)
+                part.set_payload(str(emsg))
+        return out
+
+    def sign_then_encrypt(self, key, *keys, hash=None,
+                          cipher=SymmetricKeyAlgorithm.AES256):
+        return self.sign_encrypt(key, *keys, hash=hash, cipher=cipher)
\ No newline at end of file