verify accounts gpg_key upon startup

This introduces a custom config check that
tests if the given gpg_key value points to a
valid private key. If so, the property
Account.gpg_key is a pyme.pygpgme._gpgme_key object.

1 files changed, 18 insertions, 0 deletions

diff --git a/alot/settings/checks.py b/alot/settings/checks.py
index 4943daa3..ff1ad3a8 100644
--- a/alot/settings/checks.py
+++ b/alot/settings/checks.py
@@ -2,6 +2,10 @@ import mailbox
 import re
 from urlparse import urlparse
 from validate import VdtTypeError
+from validate import ValidateError
+
+from alot import crypto
+from alot.errors import GPGProblem
 
 
 def mail_container(value):
@@ -21,3 +25,17 @@ def mail_container(value):
     else:
         raise VdtTypeError(value)
     return box
+
+
+def gpg_key(value):
+    """
+    test if value points to a known gpg key
+    and return that key as :class:`pyme.pygpgme._gpgme_key`.
+    """
+    try:
+        key = crypto.CryptoContext().get_key(value)
+        if key == None:
+            raise ValidateError('No key found for hint %s' % value)
+        return key
+    except GPGProblem, e:
+        raise ValidateError(e.message)