[PATCH cluster v4 0/3] fix #6701: Add keyUsage extension to root CA

[PATCH cluster v4 0/3] fix #6701: Add keyUsage extension to root CA

[Arthur Bied-Charreton]

The main fix (1/3) adds the keyUsage extension to PVE's root CA, which
is required by RFC 5280.

{2,3}/3 address review feedback [0] by eliminating temporary config
files and moving temp file creation from /tmp to /run/pve-cluster to prevent symlink
races.

More details in the commit messages.

Changes since v2:
Create temp file in /run/pve-cluster instead of /run, as suggested by
Maximiliano here [1]

Changes since v3:
Clarify commit messages for {2,3}/3

[0]
https://lore.proxmox.com/pve-devel/20260123195300.0ae7fcc9@rosa.proxmox.com/T/#t
[1]
https://lore.proxmox.com/pve-devel/s8o7brad0e6.fsf@toolbox/


pve-cluster:

Arthur Bied-Charreton (3):
  fix #6701: Add keyUsage extension to root CA
  setup: Replace temp OpenSSL config file with CLI arguments
  Create temporary CSR file in /run instead of /tmp

 src/PVE/Cluster/Setup.pm | 45 +++++++++++-----------------------------
 1 file changed, 12 insertions(+), 33 deletions(-)


Summary over all repositories:
  1 files changed, 12 insertions(+), 33 deletions(-)

-- 
Generated by murpp 0.10.0

[PATCH pve-cluster v4 1/3] fix #6701: Add keyUsage extension to root CA

[Arthur Bied-Charreton]

Add the keyUsage[0] extension to the PVE root CA to comply with RFC
5280, which Python decided to enforce as of 3.13 by adding the
VERIFY_X509_STRICT flag from its `ssl` module [1], which breaks some
clients like Ansible. This change of behavior is documented by
`create_default_context` [2].

The authorityKeyIdentifier [3] and subjectKeyIdentifier [4] extensions are
required by RFC 5280 as well, however OpenSSL adds them in by default
based on /etc/ssl/openssl.cnf, so there is no need for explicitly
passing them.

Test script:
```
import socket, ssl

ctx = ssl.create_default_context(cafile="/etc/pve/pve-root-ca.pem")
ctx.wrap_socket(socket.create_connection(("localhost", 8006)),
server_hostname="localhost")
print("success")
```

[0] https://www.rfc-editor.org/rfc/rfc5280#section-4.2.1.3
[1] https://docs.python.org/3/library/ssl.html
[2] https://docs.python.org/3/library/ssl.html#ssl.create_default_context
[3] https://www.rfc-editor.org/rfc/rfc5280#section-4.2.1.1
[4] https://www.rfc-editor.org/rfc/rfc5280#section-4.2.1.2

Signed-off-by: Arthur Bied-Charreton <a.bied-charreton@proxmox.com>
---
 src/PVE/Cluster/Setup.pm | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/PVE/Cluster/Setup.pm b/src/PVE/Cluster/Setup.pm
index 75d3507..4f528ba 100644
--- a/src/PVE/Cluster/Setup.pm
+++ b/src/PVE/Cluster/Setup.pm
@@ -439,6 +439,8 @@ sub gen_pveca_cert {
             '-new',
             '-x509',
             '-nodes',
+            '-addext',
+            'keyUsage=critical,keyCertSign,cRLSign',
             '-key',
             $pveca_key_fn,
             '-out',
-- 
2.47.3

[PATCH pve-cluster v4 2/3] setup: Replace temp OpenSSL config file with CLI arguments

[Arthur Bied-Charreton]

Using a temporary config file for SSL cert generation is fragile:
it requires cleanup and uses a predictable path in /tmp. OpenSSL's
'-subj', '-addext', and '-copy_extensions copyall' flags cover all
required fields directly on the command line, which removes the
need for a config file.

The 'default_bits = 2048' from the old config is not carried over, as
it matches OpenSSL's default (see /etc/ssl/openssl.cnf).

'string_mask = nombstr' has no CLI equivalent and is also not kept in.
The encoding difference is negligible, since all DN values are pure
ASCII: the 2 hardcoded strings ("PVE Cluster Node" and "Proxmox Virtual
Environment") and the node name, which is sanitized by the 'pve-node'
format.

[0]
https://lore.proxmox.com/pve-devel/20260123195300.0ae7fcc9@rosa.proxmox.com/T/#t

Suggested-by: Stoiko Ivanov <s.ivanov@proxmox.com>
Signed-off-by: Arthur Bied-Charreton <a.bied-charreton@proxmox.com>
---
 src/PVE/Cluster/Setup.pm | 41 +++++++++-------------------------------
 1 file changed, 9 insertions(+), 32 deletions(-)

diff --git a/src/PVE/Cluster/Setup.pm b/src/PVE/Cluster/Setup.pm
index 4f528ba..b9cacfd 100644
--- a/src/PVE/Cluster/Setup.pm
+++ b/src/PVE/Cluster/Setup.pm
@@ -504,33 +504,6 @@ sub gen_pve_ssl_cert {
         $names .= ",DNS:$fqdn";
     }
 
-    my $sslconf = <<__EOD;
-RANDFILE = /root/.rnd
-extensions = v3_req
-
-[ req ]
-default_bits = 2048
-distinguished_name = req_distinguished_name
-req_extensions = v3_req
-prompt = no
-string_mask = nombstr
-
-[ req_distinguished_name ]
-organizationalUnitName = PVE Cluster Node
-organizationName = Proxmox Virtual Environment
-commonName = $fqdn
-
-[ v3_req ]
-basicConstraints = CA:FALSE
-extendedKeyUsage = serverAuth
-subjectAltName = $names
-__EOD
-
-    my $cfgfn = "/tmp/pvesslconf-$$.tmp";
-    my $fh = IO::File->new($cfgfn, "w");
-    print $fh $sslconf;
-    close($fh);
-
     my $reqfn = "/tmp/pvecertreq-$$.tmp";
     unlink $reqfn;
 
@@ -541,18 +514,23 @@ __EOD
             'req',
             '-batch',
             '-new',
-            '-config',
-            $cfgfn,
             '-key',
             $pvessl_key_fn,
             '-out',
             $reqfn,
+            '-subj',
+            "/OU=PVE Cluster Node/O=Proxmox Virtual Environment/CN=$fqdn",
+            '-addext',
+            'basicConstraints=CA:FALSE',
+            '-addext',
+            'extendedKeyUsage=serverAuth',
+            '-addext',
+            "subjectAltName=$names",
         ]);
     };
 
     if (my $err = $@) {
         unlink $reqfn;
-        unlink $cfgfn;
         die "unable to generate pve certificate request:\n$err";
     }
 
@@ -581,13 +559,12 @@ __EOD
             'openssl', 'x509', '-req', '-in', $reqfn, '-days', $daysleft, '-out',
             $pvessl_cert_fn,
             '-CAkey', $pveca_key_fn, '-CA', $pveca_cert_fn, '-CAserial', $pveca_srl_fn,
-            '-extfile', $cfgfn,
+            '-copy_extensions', 'copyall',
         ]);
     };
     my $err = $@;
 
     unlink $reqfn or $!{ENOENT} or warn "failed to clean up '$reqfn' - $!";
-    unlink $cfgfn or $!{ENOENT} or warn "failed to clean up '$cfgfn' - $!";
 
     die "unable to generate pve ssl certificate:\n$err" if $err;
 }
-- 
2.47.3

[PATCH pve-cluster v4 3/3] Create temporary CSR file in /run instead of /tmp

[Arthur Bied-Charreton]

As suggested here [0], creating temp files in a world-writable directory
such as /tmp could expose the config generation to symlink races. Use
the /run/pve-cluster directory instead, which is the rundir created by
the cluster filesystem for this purpose [1].

[0]
https://lore.proxmox.com/pve-devel/20260123195300.0ae7fcc9@rosa.proxmox.com/T/#t
[1]
https://lore.proxmox.com/pve-devel/s8o7brad0e6.fsf@toolbox/

Suggested-by: Stoiko Ivanov <s.ivanov@proxmox.com>
Suggested-by: Maximiliano Sandoval <m.sandoval@proxmox.com>
Signed-off-by: Arthur Bied-Charreton <a.bied-charreton@proxmox.com>
---
 src/PVE/Cluster/Setup.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/PVE/Cluster/Setup.pm b/src/PVE/Cluster/Setup.pm
index b9cacfd..e718611 100644
--- a/src/PVE/Cluster/Setup.pm
+++ b/src/PVE/Cluster/Setup.pm
@@ -504,7 +504,7 @@ sub gen_pve_ssl_cert {
         $names .= ",DNS:$fqdn";
     }
 
-    my $reqfn = "/tmp/pvecertreq-$$.tmp";
+    my $reqfn = "/run/pve-cluster/pvecertreq-$$.tmp";
     unlink $reqfn;
 
     my $pvessl_key_fn = "$pmxcfs_base_dir/nodes/$nodename/pve-ssl.key";
-- 
2.47.3