[pve-devel] [PATCH pve-storage] fix #6900: correctly detect PBS API tokens in storage plugin

[Robert Obkircher]

The PBS storage plugin used PVE code to detect if an API token was
entered in the username field. This lead to bad requests for some
valid PBS tokens which are not valid PVE tokens.

Relax the token pattern to allow token names that start with numbers
or underscores. Also allow single character names, which are
technically allowed on the Rust side even though they can't be created
through the PBS Web UI.

Signed-off-by: Robert Obkircher <r.obkircher at proxmox.com>
---
 src/PVE/Storage/PBSPlugin.pm | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/PVE/Storage/PBSPlugin.pm b/src/PVE/Storage/PBSPlugin.pm
index 5842004..892b4d5 100644
--- a/src/PVE/Storage/PBSPlugin.pm
+++ b/src/PVE/Storage/PBSPlugin.pm
@@ -14,6 +14,7 @@ use POSIX qw(mktime strftime ENOENT);
 use POSIX::strptime;
 
 use PVE::APIClient::LWP;
+use PVE::Auth::Plugin;
 use PVE::JSONSchema qw(get_standard_option);
 use PVE::Network;
 use PVE::PBSClient;
@@ -701,6 +702,27 @@ my sub snapshot_files_encrypted {
     return $any && $all;
 }
 
+# On the Rust side this is TOKEN_NAME_REGEX_STR: = SAFE_ID_REGEX_STR
+# which is = r"(?:[A-Za-z0-9_][A-Za-z0-9._\-]*)";
+our $token_subid_regex = qr/[A-Za-z0-9_][A-Za-z0-9\.\-_]*/;
+
+our $token_full_regex =
+    qr/((${PVE::Auth::Plugin::user_regex})\@(${PVE::Auth::Plugin::realm_regex}))!(${token_subid_regex})/;
+
+# Similar to PVE::AccessControl::pve_verify_tokenid, except that this
+# also allows the subid to start with numbers or underscores.
+sub pbs_verify_tokenid {
+    my ($tokenid, $noerr) = @_;
+
+    if ($tokenid =~ /^${token_full_regex}$/) {
+        return wantarray ? ($tokenid, $2, $3, $4) : $tokenid;
+    }
+
+    die "value '$tokenid' does not look like a valid token ID\n" if !$noerr;
+
+    return undef;
+}
+
 # TODO: use a client with native rust/proxmox-backup bindings to profit from
 # API schema checks and types
 my sub pbs_api_connect {
@@ -710,7 +732,7 @@ my sub pbs_api_connect {
 
     my $user = $scfg->{username} // 'root at pam';
 
-    if (my $tokenid = PVE::AccessControl::pve_verify_tokenid($user, 1)) {
+    if (my $tokenid = pbs_verify_tokenid($user, 1)) {
         $params->{apitoken} = "PBSAPIToken=${tokenid}:${password}";
     } else {
         $params->{password} = $password;
-- 
2.47.3