updated signature verification code

edward-bot now prints a helpful note about signature validity.

i've also added some caveats in comment form regarding the remaining
issues with the verification code i've written so far. there are more
important considerations that need to be made when verifying signatures.

diff --git a/edward-bot b/edward-bot
index d83f70be4fdf0979739a5f5d309fb9f865746f61..1ca0f9b7a13c050f8fde632085eac4c318d89989 100755 (executable)
--- a/edward-bot
+++ b/edward-bot
@@ -107,16 +107,17 @@ def print_decrypted (message):
 
 def print_sig (sig):
 
-        if sig.summary != 0:
-            print("bad sig: " + str(sig.summary))
-            #continue
-        
         fprint = sig.fpr
         timestamp = time.localtime(sig.timestamp)
 
         g = gpgme.Context()
         key = g.get_key(fprint)
 
+        # right now i'm just choosing the first user id, even if that id isn't
+        # signed by the user yet another is. if a user id is printed, it should
+        # at least be one that is signed, and/or correspond to the From:
+        # field's email address and full name.
+
         name = key.uids[0].name
         e_addr = key.uids[0].email
         comment = key.uids[0].comment
@@ -124,8 +125,21 @@ def print_sig (sig):
         date = time.strftime("%a %d %b %Y %I:%M:%S %p %Z", timestamp)
         fprint_short = re.search("[0-9A-Fa-f]{32}([0-9A-Fa-f]{8})", fprint).groups()[0]
 
-        print("Signature Made " + date + " using key " + fprint_short)
-        print("From " + name + " (" + comment + ") <" \
+        # this section needs some work. signature summary, validity, status,
+        # and wrong_key_usage all complicate the picture. their enum/#define
+        # values overlap, which makes things more complicated.
+
+        validity = sig.validity
+        if validity == gpgme.VALIDITY_ULTIMATE \
+                or validity == gpgme.VALIDITY_FULL:
+            status = "Good Signature "
+        elif validity == gpgme.VALIDITY_MARGINAL:
+            status = "Marginal Signature "
+        else:
+            status = "BAD Signature "
+
+        print("Signature Made " + date + " using key ID " + fprint_short)
+        print(status + "from " + name + " (" + comment + ") <" \
                 + e_addr + ">")