[pve-devel] [PATCH access-control 2/2] Implement u2f authentication
Wolfgang Bumiller
w.bumiller at proxmox.com
Thu May 24 15:28:49 CEST 2018
Signed-off-by: Wolfgang Bumiller <w.bumiller at proxmox.com>
---
PVE/API2/AccessControl.pm | 215 ++++++++++++++++++++++++++++++++++++++++++++--
PVE/AccessControl.pm | 65 ++++++++++++--
PVE/Auth/AD.pm | 4 +-
PVE/Auth/LDAP.pm | 3 +-
PVE/Auth/PAM.pm | 3 +-
PVE/Auth/PVE.pm | 69 ++++++++++++---
PVE/Auth/Plugin.pm | 16 ++++
7 files changed, 346 insertions(+), 29 deletions(-)
diff --git a/PVE/API2/AccessControl.pm b/PVE/API2/AccessControl.pm
index e48f0cb..f236651 100644
--- a/PVE/API2/AccessControl.pm
+++ b/PVE/API2/AccessControl.pm
@@ -3,6 +3,8 @@ package PVE::API2::AccessControl;
use strict;
use warnings;
+use JSON;
+
use PVE::Exception qw(raise raise_perm_exc);
use PVE::SafeSyslog;
use PVE::RPCEnvironment;
@@ -16,6 +18,12 @@ use PVE::API2::Group;
use PVE::API2::Role;
use PVE::API2::ACL;
+my $u2f_available = 0;
+eval {
+ require PVE::U2F;
+ $u2f_available = 1;
+};
+
use base qw(PVE::RESTHandler);
__PACKAGE__->register_method ({
@@ -113,21 +121,33 @@ my $verify_auth = sub {
my $create_ticket = sub {
my ($rpcenv, $username, $pw_or_ticket, $otp) = @_;
- my $ticketuser;
+ my ($ticketuser, $u2fdata);
if (($ticketuser = PVE::AccessControl::verify_ticket($pw_or_ticket, 1)) &&
($ticketuser eq 'root at pam' || $ticketuser eq $username)) {
# valid ticket. Note: root at pam can create tickets for other users
} else {
- $username = PVE::AccessControl::authenticate_user($username, $pw_or_ticket, $otp);
+ ($username, $u2fdata) = PVE::AccessControl::authenticate_user($username, $pw_or_ticket, $otp);
}
- my $ticket = PVE::AccessControl::assemble_ticket($username);
+ my %extra;
+ my $ticket_data = $username;
+ if (defined($u2fdata)) {
+ my $u2f = get_u2f_instance($u2fdata->@{qw(publicKey keyHandle)});
+ my $challenge = $u2f->auth_challenge()
+ or die "failed to get u2f challenge\n";
+ $challenge = decode_json($challenge);
+ $extra{U2FChallenge} = $challenge;
+ $ticket_data = "u2f!$username!$challenge->{challenge}";
+ }
+
+ my $ticket = PVE::AccessControl::assemble_ticket($ticket_data);
my $csrftoken = PVE::AccessControl::assemble_csrf_prevention_token($username);
return {
ticket => $ticket,
username => $username,
CSRFPreventionToken => $csrftoken,
+ %extra,
};
};
@@ -246,6 +266,8 @@ __PACKAGE__->register_method ({
username => { type => 'string' },
ticket => { type => 'string', optional => 1},
CSRFPreventionToken => { type => 'string', optional => 1 },
+ challenge => { type => 'string', optional => 1 },
+ # cap => computed api permissions, unless there's a u2f challenge
}
},
code => sub {
@@ -275,7 +297,8 @@ __PACKAGE__->register_method ({
die PVE::Exception->new("authentication failure\n", code => 401);
}
- $res->{cap} = &$compute_api_permission($rpcenv, $username);
+ $res->{cap} = &$compute_api_permission($rpcenv, $username)
+ if !defined($res->{U2FChallenge});
PVE::Cluster::log_msg('info', 'root at pam', "successful auth for user '$username'");
@@ -287,7 +310,7 @@ __PACKAGE__->register_method ({
path => 'password',
method => 'PUT',
permissions => {
- description => "Each user is allowed to change his own password. A user can change the password of another user if he has 'Realm.AllocateUser' (on the realm of user <userid>) and 'User.Modify' permission on /access/groups/<group> on a group where user <userid> is member of.",
+ description => "Each user is allowed to change their own password. A user can change the password of another user if they have 'Realm.AllocateUser' (on the realm of user <userid>) and 'User.Modify' permission on /access/groups/<group> on a group where user <userid> is member of.",
check => [ 'or',
['userid-param', 'self'],
[ 'and',
@@ -344,4 +367,186 @@ __PACKAGE__->register_method ({
return undef;
}});
+sub get_u2f_config() {
+ die "u2f support not available\n" if !$u2f_available;
+
+ my $dc = cfs_read_file('datacenter.cfg');
+ my $u2f = $dc->{u2f};
+ die "u2f not configured in datacenter.cfg\n" if !$u2f;
+ $u2f = PVE::JSONSchema::parse_property_string($PVE::Cluster::u2f_format, $u2f);
+ return $u2f;
+}
+
+sub get_u2f_instance {
+ my ($publicKey, $keyHandle) = @_;
+
+ my $u2fconfig = get_u2f_config();
+ my $u2f = PVE::U2F->new();
+ $u2f->set_appid($u2fconfig->{appid});
+ $u2f->set_origin($u2fconfig->{origin});
+ $u2f->set_publicKey($publicKey) if defined($publicKey);
+ $u2f->set_keyHandle($keyHandle) if defined($keyHandle);
+ return $u2f;
+}
+
+__PACKAGE__->register_method ({
+ name => 'change_u2f',
+ path => 'u2f',
+ method => 'PUT',
+ permissions => {
+ description => 'A user can change their own u2f token.',
+ check => [ 'or',
+ ['userid-param', 'self'],
+ [ 'and',
+ [ 'userid-param', 'Realm.AllocateUser'],
+ [ 'userid-group', ['User.Modify']]
+ ]
+ ],
+ },
+ protected => 1, # else we can't access shadow files
+ description => "Change user u2f authentication.",
+ parameters => {
+ additionalProperties => 0,
+ properties => {
+ userid => get_standard_option('userid', {
+ completion => \&PVE::AccessControl::complete_username,
+ }),
+ password => {
+ optional => 1, # Only required if not root at pam
+ description => "The current password.",
+ type => 'string',
+ minLength => 5,
+ maxLength => 64,
+ },
+ action => {
+ description => 'The action to perform',
+ type => 'string',
+ enum => [qw(delete new confirm)],
+ },
+ response => {
+ optional => 1,
+ description => 'The response to the current registration challenge.',
+ type => 'string',
+ },
+ }
+ },
+ returns => { type => 'object' },
+ code => sub {
+ my ($param) = @_;
+
+ my $rpcenv = PVE::RPCEnvironment::get();
+ my $authuser = $rpcenv->get_user();
+
+ my $action = delete $param->{action};
+ my $response = delete $param->{response};
+ my $password = delete($param->{password}) // '';
+
+ my ($userid, $ruid, $realm) = PVE::AccessControl::verify_username($param->{userid});
+ $rpcenv->check_user_exist($userid);
+
+ # Only root may modify root
+ raise_perm_exc() if $userid eq 'root at pam' && $authuser ne 'root at pam';
+
+ # Regular users need to confirm their password to change u2f settings.
+ if ($authuser ne 'root at pam') {
+ raise_param_exc('password' => 'password is required to modify u2f data')
+ if !defined($password);
+ my $domain_cfg = cfs_read_file('domains.cfg');
+ my $cfg = $domain_cfg->{ids}->{$realm};
+ die "auth domain '$realm' does not exists\n" if !$cfg;
+ my $plugin = PVE::Auth::Plugin->lookup($cfg->{type});
+ $plugin->authenticate_user($cfg, $realm, $ruid, $password);
+ }
+
+ if ($action eq 'delete') {
+ PVE::AccessControl::domain_set_u2f($realm, $ruid, undef);
+ PVE::Cluster::log_msg('info', $authuser, "deleted u2f data for user '$userid'");
+ } elsif ($action eq 'new') {
+ my $u2f = get_u2f_instance();
+ my $challenge = $u2f->registration_challenge()
+ or raise("failed to get u2f challenge");
+ $challenge = decode_json($challenge);
+ PVE::AccessControl::domain_set_u2f($realm, $ruid, $challenge);
+ return $challenge;
+ } elsif ($action eq 'confirm') {
+ raise_param_exc('response' => "confirm action requires the 'response' parameter to be set")
+ if !defined($response);
+ my $data = PVE::AccessControl::domain_get_u2f($realm, $ruid);
+ my $challenge = $data->{challenge}
+ or raise("no active challenge");
+ my $u2f = get_u2f_instance();
+ $u2f->set_challenge($challenge);
+ my ($keyHandle, $publicKey) = $u2f->registration_verify($response);
+ PVE::AccessControl::domain_set_u2f($realm, $ruid, {
+ keyHandle => $keyHandle,
+ publicKey => $publicKey,
+ });
+ } else {
+ die "invalid action: $action\n";
+ }
+
+ return {};
+ }});
+
+__PACKAGE__->register_method({
+ name => 'verify_u2f',
+ path => 'u2f',
+ method => 'POST',
+ permissions => { user => 'all' },
+ protected => 1, # else we can't access shadow files
+ description => 'Finish a u2f challenge.',
+ parameters => {
+ additionalProperties => 0,
+ properties => {
+ response => {
+ type => 'string',
+ description => 'The response to the current authentication challenge.',
+ },
+ }
+ },
+ returns => {
+ type => 'object',
+ properties => {
+ ticket => { type => 'string' },
+ # cap
+ }
+ },
+ code => sub {
+ my ($param) = @_;
+
+ my $rpcenv = PVE::RPCEnvironment::get();
+ my $challenge = $rpcenv->get_u2f_challenge()
+ or raise('no active challenge');
+ my $authuser = $rpcenv->get_user();
+ my ($userid, $ruid, $realm) = PVE::AccessControl::verify_username($authuser);
+
+ my $u2fdata = PVE::AccessControl::domain_get_u2f($realm, $ruid)
+ or raise('no u2f data available');
+
+ my $keyHandle = $u2fdata->{keyHandle};
+ my $publicKey = $u2fdata->{publicKey};
+ raise("incomplete u2f setup")
+ if !defined($keyHandle) || !defined($publicKey);
+
+ my $u2f = get_u2f_instance($publicKey, $keyHandle);
+ $u2f->set_challenge($challenge);
+
+ eval {
+ my ($counter, $present) = $u2f->auth_verify($param->{response});
+ # Do we want to do anything with these?
+ };
+ if (my $err = $@) {
+ my $clientip = $rpcenv->get_client_ip() || '';
+ syslog('err', "authentication verification failure; rhost=$clientip user=$authuser msg=$err");
+ die PVE::Exception->new("authentication failure\n", code => 401);
+ }
+
+ # create a new ticket for the user:
+ my $ticket_data = "u2f!$authuser!verified";
+ return {
+ ticket => PVE::AccessControl::assemble_ticket($ticket_data),
+ cap => &$compute_api_permission($rpcenv, $authuser),
+ }
+ }});
+
1;
diff --git a/PVE/AccessControl.pm b/PVE/AccessControl.pm
index f0fb7dc..4e53504 100644
--- a/PVE/AccessControl.pm
+++ b/PVE/AccessControl.pm
@@ -9,6 +9,7 @@ use Net::SSLeay;
use Net::IP;
use MIME::Base64;
use Digest::SHA;
+use JSON;
use PVE::OTP;
use PVE::Ticket;
@@ -113,11 +114,11 @@ sub get_privkey {
}
sub assemble_ticket {
- my ($username) = @_;
+ my ($data) = @_;
my $rsa_priv = get_privkey();
- return PVE::Ticket::assemble_rsa_ticket($rsa_priv, 'PVE', $username);
+ return PVE::Ticket::assemble_rsa_ticket($rsa_priv, 'PVE', $data);
}
sub verify_ticket {
@@ -125,14 +126,32 @@ sub verify_ticket {
my $rsa_pub = get_pubkey();
- my ($username, $age) = PVE::Ticket::verify_rsa_ticket(
+ my ($data, $age) = PVE::Ticket::verify_rsa_ticket(
$rsa_pub, 'PVE', $ticket, undef, -300, $ticket_lifetime, $noerr);
- return undef if $noerr && !defined($username);
+ return undef if $noerr && !defined($data);
+
+ my ($username, $challenge);
+ if ($data =~ m{^u2f!([^!]+)!([0-9a-zA-Z/.=_\-+]+)$}) {
+ ($username, $challenge) = ($1, $2);
+ if ($challenge eq 'verified') {
+ $challenge = undef;
+ } else {
+ if (!wantarray) {
+ # A ticket awaiting 2nd factor verification is only valid if
+ # the caller is aware there could be one...
+ return undef if $noerr;
+ # Get the same error we'd get from an invalid ticket:
+ PVE::Ticket::verify_rsa_ticket(undef, 'PVE');
+ }
+ }
+ } else {
+ $username = $data;
+ }
return undef if !PVE::Auth::Plugin::verify_username($username, $noerr);
- return wantarray ? ($username, $age) : $username;
+ return wantarray ? ($username, $age, $challenge) : $username;
}
# VNC tickets
@@ -314,14 +333,19 @@ sub authenticate_user {
my $cfg = $domain_cfg->{ids}->{$realm};
die "auth domain '$realm' does not exists\n" if !$cfg;
my $plugin = PVE::Auth::Plugin->lookup($cfg->{type});
- $plugin->authenticate_user($cfg, $realm, $ruid, $password);
+ my $u2f = $plugin->authenticate_user($cfg, $realm, $ruid, $password);
+
+ if (defined($u2f) && exists($u2f->{challenge})) {
+ # u2f setup was not completed, discard
+ $u2f = undef;
+ }
if ($cfg->{tfa}) {
my $tfa_cfg = PVE::Auth::Plugin::parse_tfa_config($cfg->{tfa});
verify_one_time_pw($usercfg, $username, $tfa_cfg, $otp);
}
- return $username;
+ return wantarray ? ($username, $u2f) : $username;
}
sub domain_set_password {
@@ -1076,6 +1100,33 @@ sub remove_vm_from_pool {
lock_user_config($delVMfromPoolFn, "pool cleanup for VM $vmid failed");
}
+sub domain_set_u2f {
+ my ($realm, $username, $u2f) = @_;
+
+ die "no auth domain specified" if !$realm;
+
+ my $domain_cfg = cfs_read_file('domains.cfg');
+
+ my $cfg = $domain_cfg->{ids}->{$realm};
+ die "auth domain '$realm' does not exist\n" if !$cfg;
+ my $plugin = PVE::Auth::Plugin->lookup($cfg->{type});
+ $plugin->store_u2f($cfg, $realm, $username, $u2f);
+}
+
+sub domain_get_u2f {
+ my ($realm, $username) = @_;
+
+ die "no auth domain specified" if !$realm;
+
+ my $domain_cfg = cfs_read_file('domains.cfg');
+
+ my $cfg = $domain_cfg->{ids}->{$realm};
+ die "auth domain '$realm' does not exist\n" if !$cfg;
+ my $plugin = PVE::Auth::Plugin->lookup($cfg->{type});
+ return $plugin->get_u2f($cfg, $realm, $username);
+}
+
+
# bash completion helpers
sub complete_username {
diff --git a/PVE/Auth/AD.pm b/PVE/Auth/AD.pm
index b924b02..d000940 100755
--- a/PVE/Auth/AD.pm
+++ b/PVE/Auth/AD.pm
@@ -128,10 +128,10 @@ sub authenticate_user {
eval { &$authenticate_user_ad($config, $config->{server1}, $username, $password); };
my $err = $@;
- return 1 if !$err;
+ return undef if !$err;
die $err if !$config->{server2};
&$authenticate_user_ad($config, $config->{server2}, $username, $password);
- return 1;
+ return undef;
}
1;
diff --git a/PVE/Auth/LDAP.pm b/PVE/Auth/LDAP.pm
index 9f08504..9a04de5 100755
--- a/PVE/Auth/LDAP.pm
+++ b/PVE/Auth/LDAP.pm
@@ -143,9 +143,10 @@ sub authenticate_user {
eval { &$authenticate_user_ldap($config, $config->{server1}, $username, $password, $realm); };
my $err = $@;
- return 1 if !$err;
+ return undef if !$err;
die $err if !$config->{server2};
&$authenticate_user_ldap($config, $config->{server2}, $username, $password, $realm);
+ return undef;
}
1;
diff --git a/PVE/Auth/PAM.pm b/PVE/Auth/PAM.pm
index 42feba8..65c7512 100755
--- a/PVE/Auth/PAM.pm
+++ b/PVE/Auth/PAM.pm
@@ -56,8 +56,7 @@ sub authenticate_user {
}
$pamh = 0; # call destructor
-
- return 1;
+ return undef;
}
diff --git a/PVE/Auth/PVE.pm b/PVE/Auth/PVE.pm
index de39d35..bdaa29b 100755
--- a/PVE/Auth/PVE.pm
+++ b/PVE/Auth/PVE.pm
@@ -4,6 +4,9 @@ use strict;
use warnings;
use Encode;
+use MIME::Base64;
+use JSON;
+
use PVE::Tools;
use PVE::Auth::Plugin;
use PVE::Cluster qw(cfs_register_file cfs_read_file cfs_write_file cfs_lock_file);
@@ -26,13 +29,14 @@ sub parse_shadow_passwd {
while ($raw =~ /^\s*(.+?)\s*$/gm) {
my $line = $1;
- if ($line !~ m/^\S+:\S+:$/) {
+ if ($line !~ m@^\S+:\S+:(?:([A-Za-z0-9+/.=]+):)?$@) {
warn "pve shadow password: ignore invalid line $.\n";
next;
}
- my ($userid, $crypt_pass) = split (/:/, $line);
+ my ($userid, $crypt_pass, $u2f) = split (/:/, $line);
$shadow->{users}->{$userid}->{shadow} = $crypt_pass;
+ $shadow->{users}->{$userid}->{u2f} = length($u2f) ? $u2f : undef;
}
return $shadow;
@@ -44,7 +48,8 @@ sub write_shadow_config {
my $data = '';
foreach my $userid (keys %{$cfg->{users}}) {
my $crypt_pass = $cfg->{users}->{$userid}->{shadow};
- $data .= "$userid:$crypt_pass:\n";
+ my $u2f = $cfg->{users}->{$userid}->{u2f} // '';
+ $data .= "$userid:$crypt_pass:$u2f:\n";
}
return $data
@@ -72,22 +77,33 @@ sub options {
};
}
+my $decode_u2f = sub {
+ my ($u2f) = @_;
+ $u2f = decode_json(decode_base64($u2f));
+ if (defined(my $pubkey = $u2f->{publicKey})) {
+ $u2f->{publicKey} = decode_base64($pubkey);
+ }
+ return $u2f;
+};
+
sub authenticate_user {
my ($class, $config, $realm, $username, $password) = @_;
die "no password\n" if !$password;
my $shadow_cfg = cfs_read_file($shadowconfigfile);
-
- if ($shadow_cfg->{users}->{$username}) {
- my $encpw = crypt(Encode::encode('utf8', $password),
- $shadow_cfg->{users}->{$username}->{shadow});
- die "invalid credentials\n" if ($encpw ne $shadow_cfg->{users}->{$username}->{shadow});
- } else {
- die "no password set\n";
- }
- return 1;
+ die "no password set\n"
+ if !$shadow_cfg->{users}->{$username};
+
+ my $userdata = $shadow_cfg->{users}->{$username};
+
+ my $encpw = crypt(Encode::encode('utf8', $password), $userdata->{shadow});
+ die "invalid credentials\n" if ($encpw ne $userdata->{shadow});
+ if (defined(my $u2f = $userdata->{u2f})) {
+ return $decode_u2f->($u2f);
+ }
+ return undef;
}
sub store_password {
@@ -113,4 +129,33 @@ sub delete_user {
});
}
+sub store_u2f {
+ my ($class, $config, $realm, $username, $u2f) = @_;
+
+ if (defined($u2f)) {
+ if (defined(my $pubkey = $u2f->{publicKey})) {
+ $u2f->{publicKey} = encode_base64($pubkey, '');
+ }
+ $u2f = encode_base64(encode_json($u2f), '');
+ $u2f =~ s/\n//g;
+ }
+
+ lock_shadow_config(sub {
+ my $shadow_cfg = cfs_read_file($shadowconfigfile);
+ $shadow_cfg->{users}->{$username}->{u2f} = $u2f;
+ cfs_write_file($shadowconfigfile, $shadow_cfg);
+ });
+}
+
+sub get_u2f {
+ my ($class, $config, $realm, $username) = @_;
+
+ my $u2f;
+ lock_shadow_config(sub {
+ my $shadow_cfg = cfs_read_file($shadowconfigfile);
+ $u2f = $shadow_cfg->{users}->{$username}->{u2f};
+ });
+ return defined($u2f) ? $decode_u2f->($u2f) : undef;
+}
+
1;
diff --git a/PVE/Auth/Plugin.pm b/PVE/Auth/Plugin.pm
index d5d2c06..14909c2 100755
--- a/PVE/Auth/Plugin.pm
+++ b/PVE/Auth/Plugin.pm
@@ -223,4 +223,20 @@ sub delete_user {
# do nothing by default
}
+sub store_u2f {
+ my ($class, $config, $realm, $username, $token) = @_;
+
+ my $type = $class->type();
+
+ die "can't modify u2f data on auth type '$type'\n";
+}
+
+sub get_u2f {
+ my ($class, $config, $realm, $username) = @_;
+
+ my $type = $class->type();
+
+ die "can't get u2f data on auth type '$type'\n";
+}
+
1;
--
2.11.0
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