Warn the user if is using an old app version.

[Closes #4636]

2 files changed, 39 insertions, 0 deletions

diff --git a/src/leap/bitmask/provider/__init__.py b/src/leap/bitmask/provider/__init__.py
index 53587d65..68f3ded0 100644
--- a/src/leap/bitmask/provider/__init__.py
+++ b/src/leap/bitmask/provider/__init__.py
@@ -18,6 +18,10 @@
 Module initialization for leap.bitmask.provider
 """
 import os
+
+from distutils.version import LooseVersion
+
+from leap.bitmask import __version__ as BITMASK_VERSION
 from leap.common.check import leap_assert
 
 
@@ -32,3 +36,21 @@ def get_provider_path(domain):
     """
     leap_assert(domain is not None, "get_provider_path: We need a domain")
     return os.path.join("leap", "providers", domain, "provider.json")
+
+
+class SupportedClient(object):
+    """
+    Class responsible of checking for client compatibility.
+    """
+
+    @classmethod
+    def supports(self, minimum_version):
+        """
+        :param minimum_version: the version number of the client that
+                                we need to check.
+        :type minimum_version: str
+
+        :returns: True if that version is supported or False otherwise.
+        :return type: bool
+        """
+        return LooseVersion(minimum_version) <= LooseVersion(BITMASK_VERSION)
diff --git a/src/leap/bitmask/provider/providerbootstrapper.py b/src/leap/bitmask/provider/providerbootstrapper.py
index 947ba0c9..695b1593 100644
--- a/src/leap/bitmask/provider/providerbootstrapper.py
+++ b/src/leap/bitmask/provider/providerbootstrapper.py
@@ -30,6 +30,7 @@ from leap.bitmask import util
 from leap.bitmask.util.constants import REQUEST_TIMEOUT
 from leap.bitmask.services.abstractbootstrapper import AbstractBootstrapper
 from leap.bitmask.provider.supportedapis import SupportedAPIs
+from leap.bitmask.provider import SupportedClient
 from leap.common import ca_bundle
 from leap.common.certs import get_digest
 from leap.common.files import check_and_fix_urw_only, get_mtime, mkdir_p
@@ -45,6 +46,14 @@ class UnsupportedProviderAPI(Exception):
     pass
 
 
+class UnsupportedClientVersionError(Exception):
+    """
+    Raised when attempting to use a provider with an older
+    client than supported.
+    """
+    pass
+
+
 class WrongFingerprint(Exception):
     """
     Raised when a fingerprint comparison does not match.
@@ -59,6 +68,8 @@ class ProviderBootstrapper(AbstractBootstrapper):
     If a check fails, the subsequent checks are not executed
     """
 
+    MIN_CLIENT_VERSION = 'x-minimum-client-version'
+
     def __init__(self, signaler=None, bypass_checks=False):
         """
         Constructor for provider bootstrapper object
@@ -187,6 +198,8 @@ class ProviderBootstrapper(AbstractBootstrapper):
         res.raise_for_status()
         logger.debug("Request status code: {0}".format(res.status_code))
 
+        min_client_version = res.headers.get(self.MIN_CLIENT_VERSION, '0')
+
         # Not modified
         if res.status_code == 304:
             logger.debug("Provider definition has not been modified")
@@ -194,6 +207,10 @@ class ProviderBootstrapper(AbstractBootstrapper):
         # end refactor, more or less...
         # XXX Watch out, have to check the supported api yet.
         else:
+            if not SupportedClient.supports(min_client_version):
+                self._signaler.signal(self._signaler.PROV_UNSUPPORTED_CLIENT)
+                raise UnsupportedClientVersionError()
+
             provider_definition, mtime = get_content(res)
 
             provider_config = ProviderConfig()