diff options
Diffstat (limited to 'perl/Wallet/Object/Keytab.pm')
| -rw-r--r-- | perl/Wallet/Object/Keytab.pm | 756 |
1 files changed, 186 insertions, 570 deletions
diff --git a/perl/Wallet/Object/Keytab.pm b/perl/Wallet/Object/Keytab.pm index 8739f89..edb26b3 100644 --- a/perl/Wallet/Object/Keytab.pm +++ b/perl/Wallet/Object/Keytab.pm @@ -1,8 +1,8 @@ # Wallet::Object::Keytab -- Keytab object implementation for the wallet. -# $Id$ # # Written by Russ Allbery <rra@stanford.edu> -# Copyright 2007, 2008 Board of Trustees, Leland Stanford Jr. University +# Copyright 2007, 2008, 2009, 2010 +# Board of Trustees, Leland Stanford Jr. University # # See LICENSE for licensing terms. @@ -18,390 +18,14 @@ use vars qw(@ISA $VERSION); use Wallet::Config (); use Wallet::Object::Base; +use Wallet::Kadmin; @ISA = qw(Wallet::Object::Base); # This version should be increased on any code change to this module. Always # use two digits for the minor version with a leading zero if necessary so # that it will sort properly. -$VERSION = '0.06'; - -############################################################################## -# kadmin Interaction -############################################################################## - -# Make sure that principals are well-formed and don't contain characters that -# will cause us problems when talking to kadmin. Takes a principal and -# returns true if it's okay, false otherwise. Note that we do not permit -# realm information here. -sub valid_principal { - my ($self, $principal) = @_; - return scalar ($principal =~ m,^[\w-]+(/[\w_.-]+)?\z,); -} - -# Run a kadmin command and capture the output. Returns the output, either as -# a list of lines or, in scalar context, as one string. The exit status of -# kadmin is often worthless. -sub kadmin { - my ($self, $command) = @_; - unless (defined ($Wallet::Config::KEYTAB_PRINCIPAL) - and defined ($Wallet::Config::KEYTAB_FILE) - and defined ($Wallet::Config::KEYTAB_REALM)) { - die "keytab object implementation not configured\n"; - } - my @args = ('-p', $Wallet::Config::KEYTAB_PRINCIPAL, '-k', '-t', - $Wallet::Config::KEYTAB_FILE, '-q', $command); - push (@args, '-s', $Wallet::Config::KEYTAB_HOST) - if $Wallet::Config::KEYTAB_HOST; - push (@args, '-r', $Wallet::Config::KEYTAB_REALM) - if $Wallet::Config::KEYTAB_REALM; - my $pid = open (KADMIN, '-|'); - if (not defined $pid) { - die "cannot fork: $!\n"; - } elsif ($pid == 0) { - # Don't use die here; it will get trapped as an exception. Also be - # careful about our database handles. (We still lose if there's some - # other database handle open we don't know about.) - $self->{dbh}->{InactiveDestroy} = 1; - unless (open (STDERR, '>&STDOUT')) { - warn "wallet: cannot dup stdout: $!\n"; - exit 1; - } - unless (exec ($Wallet::Config::KEYTAB_KADMIN, @args)) { - warn "wallet: cannot run $Wallet::Config::KEYTAB_KADMIN: $!\n"; - exit 1; - } - } - local $_; - my @output; - while (<KADMIN>) { - if (/^wallet: cannot /) { - s/^wallet: //; - die $_; - } - push (@output, $_) unless /Authenticating as principal/; - } - close KADMIN; - return wantarray ? @output : join ('', @output); -} - -# Check whether a given principal already exists in Kerberos. Returns true if -# so, false otherwise. Throws an exception if kadmin fails. -sub kadmin_exists { - my ($self, $principal) = @_; - return unless $self->valid_principal ($principal); - if ($Wallet::Config::KEYTAB_REALM) { - $principal .= '@' . $Wallet::Config::KEYTAB_REALM; - } - my $output = $self->kadmin ("getprinc $principal"); - if ($output =~ /^get_principal: /) { - return; - } else { - return 1; - } -} - -# Create a principal in Kerberos. Since this is only called by create, it -# throws an exception on failure rather than setting the error and returning -# undef. -sub kadmin_addprinc { - my ($self, $principal) = @_; - unless ($self->valid_principal ($principal)) { - die "invalid principal name $principal\n"; - } - return 1 if $self->kadmin_exists ($principal); - if ($Wallet::Config::KEYTAB_REALM) { - $principal .= '@' . $Wallet::Config::KEYTAB_REALM; - } - my $flags = $Wallet::Config::KEYTAB_FLAGS || ''; - my $output = $self->kadmin ("addprinc -randkey $flags $principal"); - if ($output =~ /^add_principal: (.*)/m) { - die "error adding principal $principal: $1\n"; - } - return 1; -} - -# Create a keytab from a principal. Takes the principal, the file, and -# optionally a list of encryption types to which to limit the keytab. Return -# true if successful, false otherwise. If the keytab creation fails, sets the -# error. -sub kadmin_ktadd { - my ($self, $principal, $file, @enctypes) = @_; - unless ($self->valid_principal ($principal)) { - $self->error ("invalid principal name: $principal"); - return; - } - if ($Wallet::Config::KEYTAB_REALM) { - $principal .= '@' . $Wallet::Config::KEYTAB_REALM; - } - my $command = "ktadd -q -k $file"; - if (@enctypes) { - @enctypes = map { /:/ ? $_ : "$_:normal" } @enctypes; - $command .= ' -e "' . join (' ', @enctypes) . '"'; - } - my $output = eval { $self->kadmin ("$command $principal") }; - if ($@) { - $self->error ($@); - return; - } elsif ($output =~ /^(?:kadmin|ktadd): (.*)/m) { - $self->error ("error creating keytab for $principal: $1"); - return; - } - return 1; -} - -# Delete a principal from Kerberos. Return true if successful, false -# otherwise. If the deletion fails, sets the error. If the principal doesn't -# exist, return success; we're bringing reality in line with our expectations. -sub kadmin_delprinc { - my ($self, $principal) = @_; - unless ($self->valid_principal ($principal)) { - $self->error ("invalid principal name: $principal"); - return; - } - my $exists = eval { $self->kadmin_exists ($principal) }; - if ($@) { - $self->error ($@); - return; - } elsif (not $exists) { - return 1; - } - if ($Wallet::Config::KEYTAB_REALM) { - $principal .= '@' . $Wallet::Config::KEYTAB_REALM; - } - my $output = eval { $self->kadmin ("delprinc -force $principal") }; - if ($@) { - $self->error ($@); - return; - } elsif ($output =~ /^delete_principal: (.*)/m) { - $self->error ("error deleting $principal: $1"); - return; - } - return 1; -} - -############################################################################## -# AFS kaserver synchronization -############################################################################## - -# Given a Kerberos v5 principal name, convert it to a Kerberos v4 principal -# name. Returns undef if it can't convert the name for some reason (right -# now, only if the principal has more than two parts). Note that this mapping -# does not guarantee a unique result; multiple hosts in different domains can -# be mapped to the same Kerberos v4 principal name using this function. -sub kaserver_name { - my ($self, $k5) = @_; - my %host = map { $_ => 1 } qw(host ident imap pop smtp); - $k5 =~ s/\@.*//; - my @parts = split ('/', $k5); - if (@parts > 2) { - return; - } elsif (@parts == 2 and $host{$parts[0]}) { - $parts[1] =~ s/\..*//; - $parts[0] = 'rcmd' if $parts[0] eq 'host'; - } - my $k4 = join ('.', @parts); - if ($Wallet::Config::KEYTAB_AFS_REALM) { - $k4 .= '@' . $Wallet::Config::KEYTAB_AFS_REALM; - } - return $k4; -} - -# Run kasetkey with the given arguments. Returns true on success and false on -# failure. On failure, sets the internal error to the error from kasetkey. -sub kaserver_kasetkey { - my ($self, @args) = @_; - my $admin = $Wallet::Config::KEYTAB_AFS_ADMIN; - my $admin_srvtab = $Wallet::Config::KEYTAB_AFS_SRVTAB; - my $kasetkey = $Wallet::Config::KEYTAB_AFS_KASETKEY; - unless ($kasetkey and $admin and $admin_srvtab) { - $self->error ('kaserver synchronization not configured'); - return; - } - my $pid = open (KASETKEY, '-|'); - if (not defined $pid) { - $self->error ("cannot fork: $!"); - return; - } elsif ($pid == 0) { - # Don't use die here; it will get trapped as an exception. Also be - # careful about our database handles. (We still lose if there's some - # other database handle open we don't know about.) - $self->{dbh}->{InactiveDestroy} = 1; - unless (open (STDERR, '>&STDOUT')) { - warn "cannot redirect stderr: $!\n"; - exit 1; - } - unless (exec ($kasetkey, '-k', $admin_srvtab, '-a', $admin, @args)) { - warn "cannot exec $kasetkey: $!\n"; - exit 1; - } - } else { - local $/; - my $output = <KASETKEY>; - close KASETKEY; - if ($? != 0) { - $output =~ s/\s+\z//; - $output =~ s/\n/, /g; - $output = ': ' . $output if $output; - $self->error ("cannot synchronize key with kaserver$output"); - return; - } - } - return 1; -} - -# Given a keytab file name, the Kerberos v5 principal that's stored in that -# keytab, a srvtab file name, and the corresponding Kerberos v4 principal, -# write out a srvtab file containing the DES key in that keytab. Fails if -# there is no DES key in the keytab. -sub kaserver_srvtab { - my ($self, $keytab, $k5, $srvtab, $k4) = @_; - - # Gah. Someday I will write Perl bindings for Kerberos that are less - # broken. - eval { require Authen::Krb5 }; - if ($@) { - $self->error ("kaserver synchronization support not available: $@"); - return; - } - eval { Authen::Krb5::init_context() }; - if ($@ and not $@ =~ /^Authen::Krb5 already initialized/) { - $self->error ('Kerberos initialization failed'); - return; - } - undef $@; - - # Do the interface dance. We call kt_read_service_key with 0 for the kvno - # to get any kvno, which works with MIT Kerberos at least. Assume a DES - # enctype of 1. This code won't work with any enctype other than - # des-cbc-crc. - my $princ = Authen::Krb5::parse_name ($k5); - unless (defined $princ) { - my $error = Authen::Krb5::error(); - $self->error ("cannot parse $k5: $error"); - return; - } - my $key = Authen::Krb5::kt_read_service_key ($keytab, $princ, 0, 1); - unless (defined $key) { - my $error = Authen::Krb5::error(); - $self->error ("cannot find des-cbc-crc key in $keytab: $error"); - return; - } - unless (open (SRVTAB, '>', $srvtab)) { - $self->error ("cannot create $srvtab: $!"); - return; - } - - # srvtab format is nul-terminated name, nul-terminated instance, - # nul-terminated realm, single character kvno (which we always set to 0), - # and DES keyblock. - my ($principal, $realm) = split ('@', $k4); - $realm ||= ''; - my ($name, $inst) = split (/\./, $principal, 2); - $inst ||= ''; - my $data = join ("\0", $name, $inst, $realm); - $data .= "\0\0" . $key->contents; - print SRVTAB $data; - unless (close SRVTAB) { - unlink $srvtab; - $self->error ("cannot write to $srvtab: $!"); - return; - } - return 1; -} - -# Given a principal name and a path to the keytab, synchronizes the key with a -# principal in an AFS kaserver. Returns true on success and false on failure. -# On failure, sets the internal error. -sub kaserver_sync { - my ($self, $principal, $keytab) = @_; - if ($Wallet::Config::KEYTAB_REALM) { - $principal .= '@' . $Wallet::Config::KEYTAB_REALM; - } - my $k4 = $self->kaserver_name ($principal); - if (not defined $k4) { - $self->error ("cannot convert $principal to Kerberos v4"); - return; - } - my $srvtab = $Wallet::Config::KEYTAB_TMP . "/srvtab.$$"; - unless ($self->kaserver_srvtab ($keytab, $principal, $srvtab, $k4)) { - return; - } - unless ($self->kaserver_kasetkey ('-c', $srvtab, '-s', $k4)) { - unlink $srvtab; - return; - } - unlink $srvtab; - return 1; -} - -# Given a principal name, destroy the corresponding principal in the AFS -# kaserver. Returns true on success and false on failure, setting the object -# error if it fails. -sub kaserver_destroy { - my ($self, $principal) = @_; - my $k4 = $self->kaserver_name ($principal); - if (not defined $k4) { - $self->error ("cannot convert $principal to Kerberos v4"); - return; - } - return $self->kaserver_kasetkey ('-D', $k4); -} - -# Set the kaserver sync attribute. Called by attr(). Returns true on success -# and false on failure, setting the object error if it fails. -sub kaserver_set { - my ($self, $user, $host, $time) = @_; - $time ||= time; - my @trace = ($user, $host, $time); - my $name = $self->{name}; - eval { - my $sql = "select ks_name from keytab_sync where ks_name = ? and - ks_target = 'kaserver'"; - my $result = $self->{dbh}->selectrow_array ($sql, undef, $name); - if ($result) { - die "kaserver synchronization already set\n"; - } - $sql = "insert into keytab_sync (ks_name, ks_target) - values (?, 'kaserver')"; - $self->{dbh}->do ($sql, undef, $name); - $self->log_set ('type_data sync', undef, 'kaserver', @trace); - $self->{dbh}->commit; - }; - if ($@) { - $self->error ($@); - $self->{dbh}->rollback; - return; - } - return 1; -} - -# Clear the kaserver sync attribute. Called by attr(). Returns true on -# success and false on failure, setting the object error if it fails. -sub kaserver_clear { - my ($self, $user, $host, $time) = @_; - $time ||= time; - my @trace = ($user, $host, $time); - my $name = $self->{name}; - eval { - my $sql = "select ks_name from keytab_sync where ks_name = ? and - ks_target = 'kaserver'"; - my $result = $self->{dbh}->selectrow_array ($sql, undef, $name); - unless ($result) { - die "kaserver synchronization not set\n"; - } - $sql = 'delete from keytab_sync where ks_name = ?'; - $self->{dbh}->do ($sql, undef, $name); - $self->log_set ('type_data sync', 'kaserver', undef, @trace); - $self->{dbh}->commit; - }; - if ($@) { - $self->error ($@); - $self->{dbh}->rollback; - return; - } - return 1; -} +$VERSION = '0.08'; ############################################################################## # Enctype restriction @@ -487,55 +111,86 @@ sub enctypes_list { } ############################################################################## -# Keytab retrieval +# Synchronization ############################################################################## -# Retrieve an existing keytab from the KDC via a remctl call. The KDC needs -# to be running the keytab-backend script and support the keytab retrieve -# remctl command. In addition, the user must have configured us with the path -# to a ticket cache and the host to which to connect with remctl. Returns the -# keytab on success and undef on failure. -sub keytab_retrieve { - my ($self, $keytab) = @_; - my $host = $Wallet::Config::KEYTAB_REMCTL_HOST; - unless ($host and $Wallet::Config::KEYTAB_REMCTL_CACHE) { - $self->error ('keytab unchanging support not configured'); +# Set a synchronization target or clear the targets if $targets is an +# empty list. Returns true on success and false on failure. +# +# Currently, no synchronization targets are supported, but we preserve the +# ability to clear synchronization and the basic structure of the code so +# that they can be added later. +sub sync_set { + my ($self, $targets, $user, $host, $time) = @_; + $time ||= time; + my @trace = ($user, $host, $time); + if (@$targets > 1) { + $self->error ('only one synchronization target supported'); return; - } - eval { require Net::Remctl }; - if ($@) { - $self->error ("keytab unchanging support not available: $@"); + } elsif (@$targets) { + my $target = $targets->[0]; + $self->error ("unsupported synchronization target $target"); return; + } else { + eval { + my $sql = 'select ks_target from keytab_sync where ks_name = ?'; + my $dbh = $self->{dbh}; + my $name = $self->{name}; + my ($result) = $dbh->selectrow_array ($sql, undef, $name); + if ($result) { + my $sql = 'delete from keytab_sync where ks_name = ?'; + $self->{dbh}->do ($sql, undef, $name); + $self->log_set ('type_data sync', $result, undef, @trace); + } + $self->{dbh}->commit; + }; + if ($@) { + $self->error ($@); + $self->{dbh}->rollback; + return; + } } - if ($Wallet::Config::KEYTAB_REALM) { - $keytab .= '@' . $Wallet::Config::KEYTAB_REALM; - } - local $ENV{KRB5CCNAME} = $Wallet::Config::KEYTAB_REMCTL_CACHE; - my $port = $Wallet::Config::KEYTAB_REMCTL_PORT || 0; - my $principal = $Wallet::Config::KEYTAB_REMCTL_PRINCIPAL || ''; - my @command = ('keytab', 'retrieve', $keytab); - my $result = Net::Remctl::remctl ($host, $port, $principal, @command); - if ($result->error) { - $self->error ("cannot retrieve keytab for $keytab: ", $result->error); - return; - } elsif ($result->status != 0) { - my $error = $result->stderr; - $error =~ s/\s+$//; - $error =~ s/\n/ /g; - $self->error ("cannot retrieve keytab for $keytab: $error"); + return 1; +} + +# Return a list of the current synchronization targets. Returns the empty +# list on failure or on an empty list of enctype restrictions, but sets +# the object error on failure so the caller should use that to determine +# success. +sub sync_list { + my ($self) = @_; + my @targets; + eval { + my $sql = 'select ks_target from keytab_sync where ks_name = ? + order by ks_target'; + my $sth = $self->{dbh}->prepare ($sql); + $sth->execute ($self->{name}); + my $target; + while (defined ($target = $sth->fetchrow_array)) { + push (@targets, $target); + } + $self->{dbh}->commit; + }; + if ($@) { + $self->error ($@); + $self->{dbh}->rollback; return; - } else { - return $result->stdout; } + return @targets; } ############################################################################## # Core methods ############################################################################## -# Override attr to support setting the enctypes and sync attributes. +# Override attr to support setting the enctypes and sync attributes. Note +# that the sync attribute has no supported targets at present and hence will +# always return an error, but the code is still here so that it doesn't have +# to be rewritten once a new sync target is added. sub attr { my ($self, $attribute, $values, $user, $host, $time) = @_; + $time ||= time; + my @trace = ($user, $host, $time); my %known = map { $_ => 1 } qw(enctypes sync); undef $self->{error}; unless ($known{$attribute}) { @@ -544,43 +199,15 @@ sub attr { } if ($values) { if ($attribute eq 'enctypes') { - $self->enctypes_set ($values, $user, $host, $time); + return $self->enctypes_set ($values, $user, $host, $time); } elsif ($attribute eq 'sync') { - if (@$values > 1) { - $self->error ('only one synchronization target supported'); - return; - } elsif (@$values and $values->[0] ne 'kaserver') { - my $target = $values->[0]; - $self->error ("unsupported synchronization target $target"); - return; - } elsif (@$values) { - return $self->kaserver_set ($user, $host, $time); - } else { - return $self->kaserver_clear ($user, $host, $time); - } + return $self->sync_set ($values, $user, $host, $time); } } else { if ($attribute eq 'enctypes') { return $self->enctypes_list; } elsif ($attribute eq 'sync') { - my @targets; - eval { - my $sql = 'select ks_target from keytab_sync where ks_name = ? - order by ks_target'; - my $sth = $self->{dbh}->prepare ($sql); - $sth->execute ($self->{name}); - my $target; - while (defined ($target = $sth->fetchrow_array)) { - push (@targets, $target); - } - $self->{dbh}->commit; - }; - if ($@) { - $self->error ($@); - $self->{dbh}->rollback; - return; - } - return @targets; + return $self->sync_list; } } } @@ -608,16 +235,53 @@ sub attr_show { return $output; } +# Override new to start by creating a handle for the kadmin module we're +# using. +sub new { + my ($class, $type, $name, $dbh) = @_; + my $self = { + dbh => $dbh, + kadmin => undef, + }; + bless $self, $class; + my $kadmin = Wallet::Kadmin->new (); + $self->{kadmin} = $kadmin; + + # Set a callback for things to do after a fork, specifically for the MIT + # kadmin module which forks to kadmin. + my $callback = sub { $self->{dbh}->{InactiveDestroy} = 1 }; + $kadmin->fork_callback ($callback); + + $self = $class->SUPER::new ($type, $name, $dbh); + $self->{kadmin} = $kadmin; + return $self; +} + # Override create to start by creating the principal in Kerberos and only # create the entry in the database if that succeeds. Error handling isn't # great here since we don't have a way to communicate the error back to the # caller. sub create { my ($class, $type, $name, $dbh, $creator, $host, $time) = @_; - my $self = { dbh => $dbh }; + my $self = { + dbh => $dbh, + kadmin => undef, + }; bless $self, $class; - $self->kadmin_addprinc ($name); - return $class->SUPER::create ($type, $name, $dbh, $creator, $host, $time); + my $kadmin = Wallet::Kadmin->new (); + $self->{kadmin} = $kadmin; + + # Set a callback for things to do after a fork, specifically for the MIT + # kadmin module which forks to kadmin. + my $callback = sub { $self->{dbh}->{InactiveDestroy} = 1 }; + $kadmin->fork_callback ($callback); + + if (not $kadmin->create ($name)) { + die $kadmin->error, "\n"; + } + $self = $class->SUPER::create ($type, $name, $dbh, $creator, $host, $time); + $self->{kadmin} = $kadmin; + return $self; } # Override destroy to delete the principal out of Kerberos as well. @@ -628,12 +292,6 @@ sub destroy { $self->error ("cannot destroy $id: object is locked"); return; } - my @sync = $self->attr ('sync'); - if (grep { $_ eq 'kaserver' } @sync) { - unless ($self->kaserver_destroy ($self->{name})) { - return; - } - } eval { my $sql = 'delete from keytab_sync where ks_name = ?'; $self->{dbh}->do ($sql, undef, $self->{name}); @@ -646,7 +304,11 @@ sub destroy { $self->{dbh}->rollback; return; } - return if not $self->kadmin_delprinc ($self->{name}); + my $kadmin = $self->{kadmin}; + if (not $kadmin->destroy ($self->{name})) { + $self->error ($kadmin->error); + return; + } return $self->SUPER::destroy ($user, $host, $time); } @@ -660,49 +322,20 @@ sub get { $self->error ("cannot get $id: object is locked"); return; } + my $kadmin = $self->{kadmin}; + my $result; if ($self->flag_check ('unchanging')) { - my $result = $self->keytab_retrieve ($self->{name}); - if (defined $result) { - $self->log_action ('get', $user, $host, $time); - } - return $result; - } - unless (defined ($Wallet::Config::KEYTAB_TMP)) { - $self->error ('KEYTAB_TMP configuration variable not set'); - return; - } - my $file = $Wallet::Config::KEYTAB_TMP . "/keytab.$$"; - unlink $file; - my @enctypes = $self->attr ('enctypes'); - return if not $self->kadmin_ktadd ($self->{name}, $file, @enctypes); - local *KEYTAB; - unless (open (KEYTAB, '<', $file)) { - my $princ = $self->{name}; - $self->error ("error opening keytab for principal $princ: $!"); - return; - } - local $/; - undef $!; - my $data = <KEYTAB>; - if ($!) { - my $princ = $self->{name}; - $self->error ("error reading keytab for principal $princ: $!"); - unlink $file; - return; + $result = $kadmin->keytab ($self->{name}); + } else { + my @enctypes = $self->attr ('enctypes'); + $result = $kadmin->keytab_rekey ($self->{name}, @enctypes); } - close KEYTAB; - my @sync = $self->attr ('sync'); - if (grep { $_ eq 'kaserver' } @sync) { - unless ($self->kaserver_sync ($self->{name}, $file)) { - unlink $file; - return; - } - } elsif ($Wallet::Config::KEYTAB_AFS_DESTROY) { - $self->kaserver_destroy ($self->{name}); + if (defined $result) { + $self->log_action ('get', $user, $host, $time); + } else { + $self->error ($kadmin->error); } - unlink $file; - $self->log_action ('get', $user, $host, $time); - return $data; + return $result; } 1; @@ -712,6 +345,10 @@ __END__ # Documentation ############################################################################## +=for stopwords +keytab API KDC keytabs HOSTNAME DATETIME enctypes enctype DBH metadata +unmanaged kadmin Allbery + =head1 NAME Wallet::Object::Keytab - Keytab object implementation for wallet @@ -726,17 +363,17 @@ Wallet::Object::Keytab - Keytab object implementation for wallet =head1 DESCRIPTION -Wallet::Object::Keytab is a representation of Kerberos keytab objects in the -wallet. It implements the wallet object API and provides the necessary -glue to create principals in a Kerberos KDC, create and return keytabs for -those principals, and delete them out of Kerberos when the wallet object is -destroyed. +Wallet::Object::Keytab is a representation of Kerberos keytab objects in +the wallet. It implements the wallet object API and provides the +necessary glue to create principals in a Kerberos KDC, create and return +keytabs for those principals, and delete them out of Kerberos when the +wallet object is destroyed. A keytab is an on-disk store for the key or keys for a Kerberos principal. -Keytabs are used by services to verify incoming authentication from clients -or by automated processes that need to authenticate to Kerberos. To create -a keytab, the principal has to be created in Kerberos and then a keytab is -generated and stored in a file on disk. +Keytabs are used by services to verify incoming authentication from +clients or by automated processes that need to authenticate to Kerberos. +To create a keytab, the principal has to be created in Kerberos and then a +keytab is generated and stored in a file on disk. This implementation generates a new random key (and hence invalidates all existing keytabs) each time the keytab is retrieved with the get() method. @@ -748,14 +385,15 @@ information about how to set wallet configuration. =head1 METHODS This object mostly inherits from Wallet::Object::Base. See the -documentation for that class for all generic methods. Below are only those -methods that are overridden or behave specially for this implementation. +documentation for that class for all generic methods. Below are only +those methods that are overridden or behave specially for this +implementation. =over 4 =item attr(ATTRIBUTE [, VALUES, PRINCIPAL, HOSTNAME [, DATETIME]]) -Sets or retrieves a given object attribute. The following attributes are +Sets or retrieves a given object attribute. The following attribute is supported: =over 4 @@ -764,15 +402,15 @@ supported: Restricts the generated keytab to a specific set of encryption types. The values of this attribute must be enctype strings recognized by Kerberos -(strings like C<aes256-cts> or C<des-cbc-crc>). Encryption types must also -be present in the list of supported enctypes stored in the database database -or the attr() method will reject them. Note that the salt should not be -included; since the salt is irrelevant for keytab keys, it will always be -set to C<normal> by the wallet. +(strings like C<aes256-cts-hmac-sha1-96> or C<des-cbc-crc>). Encryption +types must also be present in the list of supported enctypes stored in the +database database or the attr() method will reject them. Note that the +salt should not be included; since the salt is irrelevant for keytab keys, +it will always be set to the default by the wallet. -If this attribute is set, the specified enctype list will be passed to -ktadd when get() is called for that keytab. If it is not set, the default -set in the KDC will be used. +If this attribute is set, the principal will be restricted to that +specific enctype list when get() is called for that keytab. If it is not +set, the default set in the KDC will be used. This attribute is ignored if the C<unchanging> flag is set on a keytab. Keytabs retrieved with C<unchanging> set will contain all keys present in @@ -781,33 +419,21 @@ enctypes than those requested by this attribute. =item sync -Sets the external systems to which the key of a given principal is -synchronized. The only supported value for this attribute is C<kaserver>, -which says to synchronize the key with an AFS Kerberos v4 kaserver. - -If this attribute is set on a keytab, whenever get() is called for that -keytab, the new DES key will be extracted from that keytab and set in the -configured AFS kaserver. The Kerberos v4 principal name will be the same as -the Kerberos v5 principal name except that the components are separated by -C<.> instead of C</>; the second component is truncated after the first C<.> -if the first component is one of C<host>, C<ident>, C<imap>, C<pop>, or -C<smtp>; and the first component is C<rcmd> if the Kerberos v5 principal -component is C<host>. The principal name must not contain more than two -components. - -If this attribute is set, calling destroy() will also destroy the principal -from the AFS kaserver, with a principal mapping determined as above. +This attribute is intended to set a list of external systems with which +data about this keytab is synchronized, but there are no supported targets +currently. However, there is support for clearing this attribute or +returning its current value. =back If no other arguments besides ATTRIBUTE are given, returns the values of that attribute, if any, as a list. On error, returns the empty list. To -distinguish between an error and an empty return, call error() afterwards. +distinguish between an error and an empty return, call error() afterward. It is guaranteed to return undef unless there was an error. If other arguments are given, sets the given ATTRIBUTE values to VALUES, -which must be a reference to an array (even if only one value is being set). -Pass a reference to an empty array to clear the attribute values. +which must be a reference to an array (even if only one value is being +set). Pass a reference to an empty array to clear the attribute values. PRINCIPAL, HOSTNAME, and DATETIME are stored as history information. PRINCIPAL should be the user who is destroying the object. If DATETIME isn't given, the current time is used. @@ -816,20 +442,20 @@ isn't given, the current time is used. This is a class method and should be called on the Wallet::Object::Keytab class. It creates a new object with the given TYPE and NAME (TYPE is -normally C<keytab> and must be for the rest of the wallet system to use the -right class, but this module doesn't check for ease of subclassing), using -DBH as the handle to the wallet metadata database. PRINCIPAL, HOSTNAME, and -DATETIME are stored as history information. PRINCIPAL should be the user -who is creating the object. If DATETIME isn't given, the current time is -used. +normally C<keytab> and must be for the rest of the wallet system to use +the right class, but this module doesn't check for ease of subclassing), +using DBH as the handle to the wallet metadata database. PRINCIPAL, +HOSTNAME, and DATETIME are stored as history information. PRINCIPAL +should be the user who is creating the object. If DATETIME isn't given, +the current time is used. When a new keytab object is created, the Kerberos principal designated by NAME is also created in the Kerberos realm determined from the wallet -configuration. If the principal already exists, create() still succeeds (so -that a previously unmanaged principal can be imported into the wallet). -Otherwise, if the Kerberos principal could not be created, create() fails. -The principal is created with the C<-randkey> option to randomize its keys. -NAME must not contain the realm; instead, the KEYTAB_REALM configuration +configuration. If the principal already exists, create() still succeeds +(so that a previously unmanaged principal can be imported into the +wallet). Otherwise, if the Kerberos principal could not be created, +create() fails. The principal is created with the randomized keys. NAME +must not contain the realm; instead, the KEYTAB_REALM configuration variable should be set. See Wallet::Config(3) for more information. If create() fails, it throws an exception. @@ -847,18 +473,14 @@ destroying the object. If DATETIME isn't given, the current time is used. =item get(PRINCIPAL, HOSTNAME [, DATETIME]) -Retrieves a keytab for this object and returns the keytab data or undef -on error. The caller should call error() to get the error message if -get() returns undef. The keytab is created with C<ktadd>, invalidating -any existing keytabs for that principal, unless the unchanging flag is set -on the object. PRINCIPAL, HOSTNAME, and DATETIME are stored as history -information. PRINCIPAL should be the user who is downloading the keytab. -If DATETIME isn't given, the current time is used. - -If the configuration variable $KEYTAB_AFS_DESTROY is set and the C<sync> -attribute is not set to C<kaserver>, calling get() on a keytab object will -cause the corresponding Kerberos v4 principal to be destroyed. This -variable is not set by default. +Retrieves a keytab for this object and returns the keytab data or undef on +error. The caller should call error() to get the error message if get() +returns undef. The keytab is created with new randomized keys, +invalidating any existing keytabs for that principal, unless the +unchanging flag is set on the object. PRINCIPAL, HOSTNAME, and DATETIME +are stored as history information. PRINCIPAL should be the user who is +downloading the keytab. If DATETIME isn't given, the current time is +used. =back @@ -868,30 +490,24 @@ variable is not set by default. =item KEYTAB_TMP/keytab.<pid> -The keytab is created in this file using C<ktadd> and then read into memory. -KEYTAB_TMP is set in the wallet configuration, and <pid> is the process ID -of the current process. The file is unlinked after being read. +The keytab is created in this file and then read into memory. KEYTAB_TMP +is set in the wallet configuration, and <pid> is the process ID of the +current process. The file is unlinked after being read. =back =head1 LIMITATIONS -Currently, this implementation only supports MIT Kerberos and needs -modifications to support Heimdal. It calls an external B<kadmin> program -rather than using a native Perl module and therefore requires B<kadmin> be -installed and parses its output. It may miss some error conditions if the -output of B<kadmin> ever changes. - Only one Kerberos realm is supported for a given wallet implementation and -all keytab objects stored must be in that realm. Keytab names in the wallet -database do not have realm information. +all keytab objects stored must be in that realm. Keytab names in the +wallet database do not have realm information. =head1 SEE ALSO kadmin(8), Wallet::Config(3), Wallet::Object::Base(3), wallet-backend(8) -This module is part of the wallet system. The current version is available -from L<http://www.eyrie.org/~eagle/software/wallet/>. +This module is part of the wallet system. The current version is +available from L<http://www.eyrie.org/~eagle/software/wallet/>. =head1 AUTHOR |