cloud-init/SOURCES/ci-cc_ssh.py-fix-private-key-group-owner-and-permission.patch

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2021-12-07 17:10:01 +00:00
From 2a6b3b5afb20a7856ad81b3ec3da621571c3bec3 Mon Sep 17 00:00:00 2001
From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Date: Wed, 20 Oct 2021 10:41:36 +0200
Subject: [PATCH] cc_ssh.py: fix private key group owner and permissions
(#1070)
RH-Author: Emanuele Giuseppe Esposito <eesposit@redhat.com>
RH-MergeRequest: 12: cc_ssh.py: fix private key group owner and permissions (#1070)
RH-Commit: [1/1] b2dc9cfd18ac0a8e1e22a37b1585d22dbde11536 (eesposit/cloud-init-centos-)
RH-Bugzilla: 2015974
RH-Acked-by: Vitaly Kuznetsov <vkuznets@redhat.com>
RH-Acked-by: Mohamed Gamal Morsy <mmorsy@redhat.com>
commit ee296ced9c0a61b1484d850b807c601bcd670ec1
Author: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Date: Tue Oct 19 21:32:10 2021 +0200
cc_ssh.py: fix private key group owner and permissions (#1070)
When default host keys are created by sshd-keygen (/etc/ssh/ssh_host_*_key)
in RHEL/CentOS/Fedora, openssh it performs the following:
// create new keys
if ! $KEYGEN -q -t $KEYTYPE -f $KEY -C '' -N '' >&/dev/null; then
exit 1
fi
// sanitize permissions
/usr/bin/chgrp ssh_keys $KEY
/usr/bin/chmod 640 $KEY
/usr/bin/chmod 644 $KEY.pub
Note that the group ssh_keys exists only in RHEL/CentOS/Fedora.
Now that we disable sshd-keygen to allow only cloud-init to create
them, we miss the "sanitize permissions" part, where we set the group
owner as ssh_keys and the private key mode to 640.
According to https://bugzilla.redhat.com/show_bug.cgi?id=2013644#c8, failing
to set group ownership and permissions like openssh does makes the RHEL openscap
tool generate an error.
Signed-off-by: Emanuele Giuseppe Esposito eesposit@redhat.com
RHBZ: 2013644
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
cloudinit/config/cc_ssh.py | 7 +++++++
cloudinit/util.py | 14 ++++++++++++++
2 files changed, 21 insertions(+)
diff --git a/cloudinit/config/cc_ssh.py b/cloudinit/config/cc_ssh.py
index 05a16dbc..4e986c55 100755
--- a/cloudinit/config/cc_ssh.py
+++ b/cloudinit/config/cc_ssh.py
@@ -240,6 +240,13 @@ def handle(_name, cfg, cloud, log, _args):
try:
out, err = subp.subp(cmd, capture=True, env=lang_c)
sys.stdout.write(util.decode_binary(out))
+
+ gid = util.get_group_id("ssh_keys")
+ if gid != -1:
+ # perform same "sanitize permissions" as sshd-keygen
+ os.chown(keyfile, -1, gid)
+ os.chmod(keyfile, 0o640)
+ os.chmod(keyfile + ".pub", 0o644)
except subp.ProcessExecutionError as e:
err = util.decode_binary(e.stderr).lower()
if (e.exit_code == 1 and
diff --git a/cloudinit/util.py b/cloudinit/util.py
index 343976ad..fe37ae89 100644
--- a/cloudinit/util.py
+++ b/cloudinit/util.py
@@ -1831,6 +1831,20 @@ def chmod(path, mode):
os.chmod(path, real_mode)
+def get_group_id(grp_name: str) -> int:
+ """
+ Returns the group id of a group name, or -1 if no group exists
+
+ @param grp_name: the name of the group
+ """
+ gid = -1
+ try:
+ gid = grp.getgrnam(grp_name).gr_gid
+ except KeyError:
+ LOG.debug("Group %s is not a valid group name", grp_name)
+ return gid
+
+
def get_permissions(path: str) -> int:
"""
Returns the octal permissions of the file/folder pointed by the path,
--
2.27.0