rsync: Issue an explicit warning if Manifest timestamp is >24hr old

Issue an explicit warning if the Manifest timestamp for Gentoo
repository is 24 hours behind the system clock. This is meant to detect
attacks based on preventing the user from upgrading.

Reviewed-by: Zac Medico <zmedico@gentoo.org>

4 files changed, 27 insertions, 0 deletions

diff --git a/cnf/repos.conf b/cnf/repos.conf
index 4a40ff4fc..984ecd220 100644
--- a/cnf/repos.conf
+++ b/cnf/repos.conf
@@ -7,6 +7,7 @@ sync-type = rsync
 sync-uri = rsync://rsync.gentoo.org/gentoo-portage
 auto-sync = yes
 sync-rsync-verify-metamanifest = yes
+sync-rsync-verify-max-age = 24
 sync-openpgp-key-path = /var/lib/gentoo/gkeys/keyrings/gentoo/release/pubring.gpg
 
 # for daily squashfs snapshots
diff --git a/man/portage.5 b/man/portage.5
index d4f755f51..54ce7eec9 100644
--- a/man/portage.5
+++ b/man/portage.5
@@ -1086,6 +1086,10 @@ directories if appropriate.
 Number of parallel jobs to use when verifying nested Manifests. Defaults
 to the apparent number of processors.
 .TP
+.B sync\-rsync\-verify\-max\-age
+Warn if repository is older than the specified number of days. Disabled
+when 0. Defaults to disabled.
+.TP
 .B sync\-rsync\-verify\-metamanifest = yes|no
 Require the repository to contain a signed MetaManifest and verify
 it using \fBapp\-portage/gemato\fR. Defaults to no.
diff --git a/pym/portage/sync/modules/rsync/__init__.py b/pym/portage/sync/modules/rsync/__init__.py
index 27a2548c0..cb80f6d66 100644
--- a/pym/portage/sync/modules/rsync/__init__.py
+++ b/pym/portage/sync/modules/rsync/__init__.py
@@ -29,6 +29,7 @@ module_spec = {
 				'sync-rsync-extra-opts',
 				'sync-rsync-vcs-ignore',
 				'sync-rsync-verify-jobs',
+				'sync-rsync-verify-max-age',
 				'sync-rsync-verify-metamanifest',
 				),
 			}
diff --git a/pym/portage/sync/modules/rsync/rsync.py b/pym/portage/sync/modules/rsync/rsync.py
index dc4674548..ac841545d 100644
--- a/pym/portage/sync/modules/rsync/rsync.py
+++ b/pym/portage/sync/modules/rsync/rsync.py
@@ -6,6 +6,7 @@ import logging
 import time
 import signal
 import socket
+import datetime
 import io
 import re
 import random
@@ -109,6 +110,20 @@ class RsyncSync(NewBase):
 				writemsg_level("!!! sync-rsync-verify-jobs not a positive integer: %s\n" % (self.verify_jobs,),
 					level=logging.WARNING, noiselevel=-1)
 				self.verify_jobs = None
+		# Support overriding max age.
+		self.max_age = self.repo.module_specific_options.get(
+				'sync-rsync-verify-max-age', '')
+		if self.max_age:
+			try:
+				self.max_age = int(self.max_age)
+				if self.max_age < 0:
+					raise ValueError(self.max_age)
+			except ValueError:
+				writemsg_level("!!! sync-rsync-max-age must be a non-negative integer: %s\n" % (self.max_age,),
+					level=logging.WARNING, noiselevel=-1)
+				self.max_age = 0
+		else:
+			self.max_age = 0
 
 		openpgp_env = None
 		if self.verify_metamanifest and gemato is not None:
@@ -339,6 +354,12 @@ class RsyncSync(NewBase):
 						ts = m.find_timestamp()
 						if ts is None:
 							raise RuntimeError('Timestamp not found in Manifest')
+						if (self.max_age != 0 and
+								(datetime.datetime.utcnow() - ts.ts).days > self.max_age):
+							out.ewarn('Manifest is over %d days old, this is suspicious!' % (self.max_age,))
+							out.ewarn('You may want to try using another mirror and/or reporting this one:')
+							out.ewarn('  %s' % (dosyncuri,))
+							out.ewarn('')
 
 						out.einfo('Manifest timestamp: %s UTC' % (ts.ts,))
 						out.einfo('Valid OpenPGP signature found:')