# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1389142557 -3600
# Node ID 5798c36178755fc40116f408f8b789df3da98d45
# Parent  40886b6893b42e4706d7851e84075cd20bd22a84
Added support for "authorship" verification of transferred content.

diff -r 40886b6893b4 -r 5798c3617875 scripts/getfiles.py
--- a/scripts/getfiles.py	Wed Jan 08 01:07:30 2014 +0100
+++ b/scripts/getfiles.py	Wed Jan 08 01:55:57 2014 +0100
@@ -7,7 +7,6 @@
 """
 
 from MoinMessage import *
-from email.mime.application import MIMEApplication
 from email.mime.text import MIMEText
 from email.parser import Parser
 from os.path import join, exists
@@ -21,6 +20,13 @@
     finally:
         f.close()
 
+def decrypt(gpg, content):
+    if is_encrypted(content):
+        text = gpg.decryptMessage(content)
+        return Parser().parsestr(text)
+    else:
+        return content
+
 if __name__ == "__main__":
     try:
         service = sys.argv[1]
@@ -46,29 +52,22 @@
 
     # Get the e-mail message itself.
 
-    message = message.get_payload()
+    email_message = message.get_payload()
 
-    # Encrypt, sign and send the message.
+    # Encrypt, sign and send the request.
 
     gpg = GPG()
-    message = gpg.encryptMessage(message, service)
-    message = gpg.signMessage(message, signer)
-    resp = sendMessageForReading(message, url)
+    encrypted_message = gpg.encryptMessage(email_message, service)
+    signed_message = gpg.signMessage(encrypted_message, signer)
+    resp = sendMessageForReading(signed_message, url)
 
-    # Verify, decrypt and unpack the message.
+    # Verify the response after possible transport encryption.
 
     try:
-        if not is_signed(message):
-            print >>sys.stderr, "Incoming message was not signed."
-            sys.exit(1)
-
         message = Parser().parse(resp)
+        message = decrypt(gpg, message)
         fingerprint, identity, content = gpg.verifyMessage(message)
 
-        if is_encrypted(content):
-            text = gpg.decryptMessage(content)
-            content = Parser().parsestr(text)
-
     except MoinMessageDecodingError:
         print >>sys.stderr, "Incoming message was improperly encoded."
         sys.exit(1)
@@ -86,20 +85,17 @@
         # file, even though the eventual filename in the directory may be
         # different.
 
-        filename = part["Content-Disposition"]
-        directory, leafname = filename.split("/")
+        directory = part["Content-Disposition"]
 
-        # The data may be encrypted.
+        # The retrieved content may be encrypted.
+
+        part = decrypt(gpg, part)
 
-        try:
-            data = gpg.decryptMessage(part)
-        except MoinMessageError:
-            print >>sys.stderr, "Message part was not decrypted."
-            data = part.get_payload(decode=True)
+        # The original sender may now be verified.
 
-        # Parse the decoded data.
-
-        content = Parser().parsestr(data)
+        if is_signed(part):
+            fingerprint, identity, content = gpg.verifyMessage(part)
+            print >>sys.stderr, "Content signed by %s." % identity
 
         if content.is_multipart():
             files = content.get_payload()
@@ -111,8 +107,8 @@
         for file in files:
             data = file.get_payload(decode=True)
 
-            realname = file.get("Content-Disposition")
-            filename = join(directory, realname or leafname)
+            realname = file["Content-Disposition"]
+            filename = join(directory, realname)
 
             dirpath = join(target_dir, directory)
             if not exists(dirpath):
diff -r 40886b6893b4 -r 5798c3617875 scripts/sendfiles.py
--- a/scripts/sendfiles.py	Wed Jan 08 01:07:30 2014 +0100
+++ b/scripts/sendfiles.py	Wed Jan 08 01:55:57 2014 +0100
@@ -48,7 +48,8 @@
 
     email_message = message.get_payload()
 
-    # Sign, encrypt, sign and send the message.
+    # Sign (for authorship), encrypt (for privacy), sign (for authentication),
+    # and send the message.
 
     gpg = GPG()
     signed_message = gpg.signMessage(email_message, signer)