From: Wolfgang Bumiller Date: Tue, 2 Apr 2019 10:21:51 +0000 (+0200) Subject: more general 2FA configuration via priv/tfa.cfg X-Git-Url: https://git.proxmox.com/?p=pve-access-control.git;a=commitdiff_plain;h=fda8ca85d312be337c8980994867f37b29b4eebd;hp=e235ae390310ac8445c76c7055fb2508f314f441 more general 2FA configuration via priv/tfa.cfg Adds a priv/tfa.cfg file usable in place of user.cfg. (Otherwise the user.cfg can potentially grow too big with u2f keys.) Also contains some preparation code for u2f and user-opt-in totp. Signed-off-by: Wolfgang Bumiller --- diff --git a/PVE/AccessControl.pm b/PVE/AccessControl.pm index 51ef3ee..655f306 100644 --- a/PVE/AccessControl.pm +++ b/PVE/AccessControl.pm @@ -11,6 +11,7 @@ use MIME::Base64; use Digest::SHA; use IO::File; use File::stat; +use JSON; use PVE::OTP; use PVE::Ticket; @@ -55,6 +56,9 @@ Crypt::OpenSSL::RSA->import_random_seed(); cfs_register_file('user.cfg', \&parse_user_config, \&write_user_config); +cfs_register_file('priv/tfa.cfg', + \&parse_priv_tfa_config, + \&write_priv_tfa_config); sub verify_username { PVE::Auth::Plugin::verify_username(@_); @@ -446,9 +450,7 @@ sub check_user_enabled { } sub verify_one_time_pw { - my ($usercfg, $username, $tfa_cfg, $otp) = @_; - - my $type = $tfa_cfg->{type}; + my ($type, $username, $keys, $tfa_cfg, $otp) = @_; die "missing one time password for two-factor authentication '$type'\n" if !$otp; @@ -456,11 +458,9 @@ sub verify_one_time_pw { my $proxy; if ($type eq 'yubico') { - my $keys = $usercfg->{users}->{$username}->{keys}; PVE::OTP::yubico_verify_otp($otp, $keys, $tfa_cfg->{url}, $tfa_cfg->{id}, $tfa_cfg->{key}, $proxy); } elsif ($type eq 'oath') { - my $keys = $usercfg->{users}->{$username}->{keys}; PVE::OTP::oath_verify_otp($otp, $keys, $tfa_cfg->{step}, $tfa_cfg->{digits}); } else { die "unknown tfa type '$type'\n"; @@ -494,12 +494,22 @@ sub authenticate_user { my $plugin = PVE::Auth::Plugin->lookup($cfg->{type}); $plugin->authenticate_user($cfg, $realm, $ruid, $password); - if ($cfg->{tfa}) { - my $tfa_cfg = PVE::Auth::Plugin::parse_tfa_config($cfg->{tfa}); - verify_one_time_pw($usercfg, $username, $tfa_cfg, $otp); + my $u2f; + + my ($type, $tfa_data) = user_get_tfa($username, $realm); + if ($type) { + if ($type eq 'u2f') { + # Note that if the user did not manage to complete the initial u2f registration + # challenge we have a hash containing a 'challenge' entry in the user's tfa.cfg entry: + $u2f = $tfa_data if !exists $tfa_data->{challenge}; + } else { + my $keys = $tfa_data->{keys}; + my $tfa_cfg = $tfa_data->{config}; + verify_one_time_pw($type, $username, $keys, $tfa_cfg, $otp); + } } - return $username; + return wantarray ? ($username, $u2f) : $username; } sub domain_set_password { @@ -1083,6 +1093,64 @@ sub write_user_config { return $data; } +# The TFA configuration in priv/tfa.cfg format contains one line per user of +# the form: +# USER:TYPE:DATA +# DATA is a base64 encoded json string and its format depends on the type. +sub parse_priv_tfa_config { + my ($filename, $raw) = @_; + + my $users = {}; + my $cfg = { users => $users }; + + $raw = '' if !defined($raw); + while ($raw =~ /^\s*(.+?)\s*$/gm) { + my $line = $1; + my ($user, $type, $data) = split(/:/, $line, 3); + + my (undef, undef, $realm) = PVE::Auth::Plugin::verify_username($user, 1); + if (!$realm) { + warn "user tfa config - ignore user '$user' - invalid user name\n"; + next; + } + + $data = decode_json(decode_base64($data)); + + $users->{$user} = { + type => $type, + data => $data, + }; + } + + return $cfg; +} + +sub write_priv_tfa_config { + my ($filename, $cfg) = @_; + + my $output = ''; + + my $users = $cfg->{users}; + foreach my $user (sort keys %$users) { + my $info = $users->{$user}; + next if !%$info; # skip empty entries + + $info = {%$info}; # copy to verify contents: + + my $type = delete $info->{type}; + my $data = delete $info->{data}; + + if (my @keys = keys %$info) { + die "invalid keys in TFA config for user $user: " . join(', ', @keys) . "\n"; + } + + $data = encode_base64(encode_json($data), ''); + $output .= "${user}:${type}:${data}\n"; + } + + return $output; +} + sub roles { my ($cfg, $user, $path) = @_; @@ -1265,6 +1333,118 @@ sub remove_vm_from_pool { lock_user_config($delVMfromPoolFn, "pool cleanup for VM $vmid failed"); } +my $CUSTOM_TFA_TYPES = { + u2f => 1, + oath => 1, +}; + +# Delete an entry by setting $data=undef in which case $type is ignored. +# Otherwise both must be valid. +sub user_set_tfa { + my ($userid, $realm, $type, $data, $cached_usercfg, $cached_domaincfg) = @_; + + if (defined($data) && !defined($type)) { + # This is an internal usage error and should not happen + die "cannot set tfa data without a type\n"; + } + + my $user_cfg = $cached_usercfg || cfs_read_file('user.cfg'); + my $user = $user_cfg->{users}->{$userid} + or die "user '$userid' not found\n"; + + my $domain_cfg = $cached_domaincfg || cfs_read_file('domains.cfg'); + my $realm_cfg = $domain_cfg->{ids}->{$realm}; + die "auth domain '$realm' does not exist\n" if !$realm_cfg; + + my $realm_tfa = $realm_cfg->{tfa}; + if (defined($realm_tfa)) { + $realm_tfa = PVE::Auth::Plugin::parse_tfa_config($realm_tfa); + # If the realm has a TFA setting, we're only allowed to use that. + if (defined($data)) { + my $required_type = $realm_tfa->{type}; + if ($required_type ne $type) { + die "realm '$realm' only allows TFA of type '$required_type\n"; + } + + if (defined($data->{config})) { + # XXX: Is it enough if the type matches? Or should the configuration also match? + } + + # realm-configured tfa always uses a simple key list, so use the user.cfg + $user->{keys} = $data->{keys}; + } else { + die "realm '$realm' does not allow removing the 2nd factor\n"; + } + } else { + # Without a realm-enforced TFA setting the user can add a u2f or totp entry by themselves. + # The 'yubico' type requires yubico server settings, which have to be configured on the + # realm, so this is not supported here: + die "domain '$realm' does not support TFA type '$type'\n" + if defined($data) && !$CUSTOM_TFA_TYPES->{$type}; + } + + # Custom TFA entries are stored in priv/tfa.cfg as they can be more complet: u2f uses a + # public key and a key handle, TOTP requires the usual totp settings... + + my $tfa_cfg = cfs_read_file('priv/tfa.cfg'); + my $tfa = ($tfa_cfg->{users}->{$userid} //= {}); + + if (defined($data)) { + $tfa->{type} = $type; + $tfa->{data} = $data; + cfs_write_file('priv/tfa.cfg', $tfa_cfg); + + $user->{keys} = 'x'; + } else { + delete $tfa_cfg->{users}->{$userid}; + cfs_write_file('priv/tfa.cfg', $tfa_cfg); + + delete $user->{keys}; + } + + cfs_write_file('user.cfg', $user_cfg); +} + +sub user_get_tfa { + my ($username, $realm) = @_; + + my $user_cfg = cfs_read_file('user.cfg'); + my $user = $user_cfg->{users}->{$username} + or die "user '$username' not found\n"; + + my $keys = $user->{keys}; + return if !$keys; + + my $domain_cfg = cfs_read_file('domains.cfg'); + my $realm_cfg = $domain_cfg->{ids}->{$realm}; + die "auth domain '$realm' does not exist\n" if !$realm_cfg; + + my $realm_tfa = $realm_cfg->{tfa}; + $realm_tfa = PVE::Auth::Plugin::parse_tfa_config($realm_tfa) + if $realm_tfa; + + if ($keys ne 'x') { + # old style config, find the type via the realm + return if !$realm_tfa; + return ($realm_tfa->{type}, { + keys => $keys, + config => $realm_tfa, + }); + } else { + my $tfa_cfg = cfs_read_file('priv/tfa.cfg'); + my $tfa = $tfa_cfg->{users}->{$username}; + return if !$tfa; # should not happen (user.cfg wasn't cleaned up?) + + if ($realm_tfa) { + # if the realm has a tfa setting we need to verify the type: + die "auth domain '$realm' and user have mismatching TFA settings\n" + if $realm_tfa && $realm_tfa->{type} ne $tfa->{type}; + } + + return ($tfa->{type}, $tfa->{data}); + } +} + # bash completion helpers register_standard_option('userid-completed',