validate key before adding to encryption list

we check whether a key is
 - revoked
 - expired
 - invalid
 - unable to encrypt
 - unable to sign

1 files changed, 12 insertions, 0 deletions

diff --git a/alot/crypto.py b/alot/crypto.py
index 55b9e30c..9000d15b 100644
--- a/alot/crypto.py
+++ b/alot/crypto.py
@@ -198,3 +198,15 @@ def hash_key(key):
     for tmp_key in key.subkeys:
         hash_str += tmp_key.keyid
     return hash_str
+
+def validate_key(key, sign=False, encrypt=False):
+    if key.revoked:
+        raise GPGProblem("The key \"" + key.uids[0].uid + "\" is revoked.")
+    elif key.expired:
+        raise GPGProblem("The key \"" + key.uids[0].uid + "\" is expired.")
+    elif key.invalid:
+        raise GPGProblem("The key \"" + key.uids[0].uid + "\" is invalid.")
+    if encrypt and not key.can_encrypt:
+        raise GPGProblem("The key \"" + key.uids[0].uid + "\" can not encrypt.")
+    if sign and not key.can_sign:
+        raise GPGProblem("The key \"" + key.uids[0].uid + "\" can not sign.")