[pve-devel] [PATCH v3 manager 1/3] fix #4552: certhelpers: check if custom cert and key match on change

[Max Carrara <m.carrara@proxmox.com>]

It is now checked whether the new custom SSL certificate actually
matches the provided or existing custom key.

Also, the new custom certificate and key pair is now validated
*before* it is used or replaced with the existing pair. Safety copies
are still made; if a pair is currently in use, it is therefore left
untouched until the new one is valid.

Signed-off-by: Max Carrara <m.carrara@proxmox.com>
---
 NOTE: This patch requies a version bump+upload of pve-common.

 PVE/CertHelpers.pm | 70 +++++++++++++++++++++++++++++++++++++---------
 1 file changed, 57 insertions(+), 13 deletions(-)

diff --git a/PVE/CertHelpers.pm b/PVE/CertHelpers.pm
index 7e088cb9..e97331b8 100644
--- a/PVE/CertHelpers.pm
+++ b/PVE/CertHelpers.pm
@@ -53,12 +53,15 @@ sub cert_lock {
 sub set_cert_files {
     my ($cert, $key, $path_prefix, $force) = @_;
 
-    my ($old_cert, $old_key, $info);
+    my $info;
 
     my $cert_path = "${path_prefix}.pem";
     my $cert_path_tmp = "${path_prefix}.pem.old";
+    my $cert_path_new = "${path_prefix}.pem.new";
+
     my $key_path = "${path_prefix}.key";
     my $key_path_tmp = "${path_prefix}.key.old";
+    my $key_path_new = "${path_prefix}.key.new";
 
     die "Custom certificate file exists but force flag is not set.\n"
 	if !$force && -e $cert_path;
@@ -69,26 +72,67 @@ sub set_cert_files {
     PVE::Tools::file_copy($key_path, $key_path_tmp) if -e $key_path;
 
     eval {
-	PVE::Tools::file_set_contents($cert_path, $cert);
-	PVE::Tools::file_set_contents($key_path, $key) if $key;
+	PVE::Tools::file_set_contents($cert_path_new, $cert);
+
+	if ($key) {
+	    PVE::Tools::file_set_contents($key_path_new, $key);
+	} elsif (-e $key_path) {
+	    PVE::Tools::file_copy($key_path, $key_path_new);
+	} else {
+	    die "Cannot set custom certificate without key.\n";
+	}
+
+	die "Custom certificate does not match provided key.\n"
+	    if !PVE::Certificate::certificate_matches_key($cert_path_new, $key_path_new);
+
+	PVE::Tools::file_copy($cert_path_new, $cert_path);
+	PVE::Tools::file_copy($key_path_new, $key_path);
+
 	$info = PVE::Certificate::get_certificate_info($cert_path);
     };
     my $err = $@;
 
     if ($err) {
-	if (-e $cert_path_tmp && -e $key_path_tmp) {
-	    eval {
-		warn "Attempting to restore old certificate files..\n";
-		PVE::Tools::file_copy($cert_path_tmp, $cert_path);
-		PVE::Tools::file_copy($key_path_tmp, $key_path);
-	    };
-	    warn "$@\n" if $@;
+	warn $err . "\n";
+
+	# remove PID from front
+	$err =~ s|^(\d+:\s)||;
+
+	if (-e $cert_path_tmp || -e $key_path_tmp) {
+	    warn "Beginning to restore previous files.\n";
+
+	    if (-e $cert_path_tmp) {
+		eval {
+		    warn "Restoring previous certificate...\n";
+		    PVE::Tools::file_copy($cert_path_tmp, $cert_path);
+		};
+		warn "$@\n" if $@;
+	    }
+
+	    if (-e $key_path_tmp) {
+		eval {
+		    warn "Restoring previous key...\n";
+		    PVE::Tools::file_copy($key_path_tmp, $key_path);
+		};
+		warn "$@\n" if $@;
+	    }
+
+	    warn "Finished restoring previous files!\n";
+	}
+    }
+
+    for my $path (
+	$cert_path_tmp,
+	$cert_path_new,
+	$key_path_tmp,
+	$key_path_new,
+    ) {
+	if (-e $path) {
+	    unlink $path or warn "Failed to remove temporary file: '$path' - $!\n";
 	}
-	die "Setting certificate files failed - $err\n"
     }
 
-    unlink $cert_path_tmp;
-    unlink $key_path_tmp;
+    die "Setting certificate files failed due to the following error: $err" if $err;
 
     return $info;
 }
-- 
2.39.2