check that pyopenssl > 0.12 is installed before using fonctions available after this version

src/common/check_X509.py

@@ -4,6 +4,10 @@ log = logging.getLogger('gajim.c.check_X509')
 try:
     import OpenSSL.SSL
     import OpenSSL.crypto
+    ver = OpenSSL.__version__
+    ver_l = [int(i) for i in ver.split('.')]
+    if ver_l < [0, 12]:
+        raise ImportError
     from pyasn1.type import univ, constraint, char, namedtype, tag
     from pyasn1.codec.der.decoder import decode
     from common.helpers import prep, InvalidFormat

src/features_window.py

@@ -49,8 +49,8 @@ class FeaturesWindow:
         self.features = {
             _('SSL certificate validation'): (self.pyopenssl_available,
                 _('A library used to validate server certificates to ensure a secure connection.'),
-                _('Requires python-pyopenssl.'),
-                _('Requires python-pyopenssl.')),
+                _('Requires python-pyopenssl > 0.12 and pyasn1.'),
+                _('Requires python-pyopenssl > 0.12 and pyasn1.')),
             _('Bonjour / Zeroconf'): (self.zeroconf_available,
                 _('Serverless chatting with autodetected clients in a local network.'),
                 _('Requires python-avahi.'),