aboutsummaryrefslogtreecommitdiff
path: root/perl/Wallet
diff options
context:
space:
mode:
Diffstat (limited to 'perl/Wallet')
-rw-r--r--perl/Wallet/Config.pm21
-rw-r--r--perl/Wallet/Kadmin.pm43
-rw-r--r--perl/Wallet/Kadmin/Heimdal.pm74
-rw-r--r--perl/Wallet/Kadmin/MIT.pm68
-rw-r--r--perl/Wallet/Object/Keytab.pm49
5 files changed, 169 insertions, 86 deletions
diff --git a/perl/Wallet/Config.pm b/perl/Wallet/Config.pm
index c59d3e3..396bf7d 100644
--- a/perl/Wallet/Config.pm
+++ b/perl/Wallet/Config.pm
@@ -26,7 +26,8 @@ Wallet::Config - Configuration handling for the wallet server
=for stopwords
DBI DSN SQLite subdirectories KEYTAB keytab kadmind KDC add-ons kadmin DNS
SRV kadmin keytabs remctl backend lowercased NETDB ACL NetDB unscoped
-usernames rekey hostnames Allbery wallet-backend keytab-backend
+usernames rekey hostnames Allbery wallet-backend keytab-backend Heimdal
+rekeys
=head1 SYNOPSIS
@@ -313,11 +314,19 @@ our $KEYTAB_TMP;
=head2 Retrieving Existing Keytabs
-The keytab object backend optionally supports retrieving existing keys,
-and hence keytabs, for Kerberos principals by contacting the KDC via
-remctl and talking to B<keytab-backend>. This is enabled by setting the
-C<unchanging> flag on keytab objects. To configure that support, set the
-following variables.
+Heimdal provides the choice, over the network protocol, of either
+downloading the existing keys for a principal or generating new random
+keys. MIT Kerberos does not; downloading a keytab over the kadmin
+protocol always rekeys the principal.
+
+For MIT Kerberos, the keytab object backend therefore optionally supports
+retrieving existing keys, and hence keytabs, for Kerberos principals by
+contacting the KDC via remctl and talking to B<keytab-backend>. This is
+enabled by setting the C<unchanging> flag on keytab objects. To configure
+that support, set the following variables.
+
+This is not required for Heimdal; for Heimdal, setting the C<unchanging>
+flag is all that's needed.
=over 4
diff --git a/perl/Wallet/Kadmin.pm b/perl/Wallet/Kadmin.pm
index 3ca531e..f3c2895 100644
--- a/perl/Wallet/Kadmin.pm
+++ b/perl/Wallet/Kadmin.pm
@@ -83,10 +83,12 @@ Wallet::Kadmin - Kerberos administration API for wallet keytab backend
=head1 SYNOPSIS
my $kadmin = Wallet::Kadmin->new;
- $kadmin->create ("host/foo.example.com");
- $kadmin->keytab ("host/foo.example.com", "aes256-cts-hmac-sha1-96");
- my $exists = $kadmin->exists ("host/oldshell.example.com");
- $kadmin->destroy ("host/oldshell.example.com") if $exists;
+ $kadmin->create ('host/foo.example.com');
+ $kadmin->keytab_rekey ('host/foo.example.com', 'keytab',
+ 'aes256-cts-hmac-sha1-96');
+ my $data = $kadmin->keytab ('host/foo.example.com');
+ my $exists = $kadmin->exists ('host/oldshell.example.com');
+ $kadmin->destroy ('host/oldshell.example.com') if $exists;
=head1 DESCRIPTION
@@ -162,19 +164,26 @@ kadmin command-line client, the sub CALLBACK will be called in the child
process before running the program. This can be used to, for example,
properly clean up shared database handles.
-=item keytab(PRINCIPAL, FILE [, ENCTYPE ... ])
-
-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.
-
-ktadd() creates a new keytab for the given principal, storing it in the
-given file and limited to the enctypes supplied. The enctype values must
-be enctype strings recognized by the Kerberos implementation (strings like
-C<aes256-cts-hmac-sha1-96> or C<des-cbc-crc>). Returns true on success
-and false on failure.
+=item keytab(PRINCIPAL)
+
+keytab() creates a keytab for the given principal, storing it in the given
+file. 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 have previously been
+created in the Kerberos KDC. Returns the keytab as binary data on success
+and undef on failure.
+
+=item keytab_rekey(PRINCIPAL, FILE [, ENCTYPE ...])
+
+Like keytab(), but randomizes the key for the principal before generating
+the keytab and writes it to the given file. This will invalidate any
+existing keytabs for that principal. This method can also limit the
+encryption types of the keys for that principal via the optional ENCTYPE
+arguments. The enctype values must be enctype strings recognized by the
+Kerberos implementation (strings like C<aes256-cts-hmac-sha1-96> or
+C<des-cbc-crc>). If none are given, the KDC defaults will be used.
+Returns true on success and false on failure.
=back
diff --git a/perl/Wallet/Kadmin/Heimdal.pm b/perl/Wallet/Kadmin/Heimdal.pm
index 0ac8cd9..e066006 100644
--- a/perl/Wallet/Kadmin/Heimdal.pm
+++ b/perl/Wallet/Kadmin/Heimdal.pm
@@ -39,6 +39,23 @@ sub canonicalize_principal {
return $principal;
}
+# Read the entirety of a possibly binary file and return the contents. If
+# reading the file fails, set the error message and return undef.
+sub slurp_file {
+ my ($self, $file) = @_;
+ unless (open (TMPFILE, '<', $file)) {
+ $self->error ("cannot open temporary file $file: $!");
+ return;
+ }
+ local $/;
+ my $data = <TMPFILE>;
+ unless (close TMPFILE) {
+ $self->error ("cannot read temporary file $file: $!");
+ return;
+ }
+ return $data;
+}
+
##############################################################################
# Public interfaces
##############################################################################
@@ -93,11 +110,38 @@ sub create {
return 1;
}
-# Create a keytab from a principal. Takes the principal, the file, and
-# optionally a list of encryption types to which to limit the keytab. Return
-# true if successful, false otherwise. If the keytab creation fails, sets the
-# error.
+# Create a keytab for a principal. Returns the keytab as binary data or undef
+# on failure, setting the error.
sub keytab {
+ my ($self, $principal) = @_;
+ $principal = $self->canonicalize_principal ($principal);
+ my $kadmin = $self->{client};
+ my $file = $Wallet::Config::KEYTAB_TMP . "/keytab.$$";
+ unlink $file;
+ my $princdata = eval { $kadmin->getPrincipal ($principal) };
+ if ($@) {
+ $self->error ("error creating keytab for $principal: $@");
+ return;
+ } elsif (!$princdata) {
+ $self->error ("error creating keytab for $principal: principal does"
+ . " not exist");
+ return;
+ }
+ eval { $kadmin->extractKeytab ($princdata, $file) };
+ if ($@) {
+ $self->error ("error creating keytab for principal: $@");
+ return;
+ }
+ my $data = $self->slurp_file ($file);
+ unlink $file;
+ return $data;
+}
+
+# Create a keytab for a principal, randomizing the keys for that principal at
+# the same time. 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 keytab_rekey {
my ($self, $principal, $file, @enctypes) = @_;
$principal = $self->canonicalize_principal ($principal);
@@ -213,10 +257,12 @@ Wallet::Kadmin::Heimdal - Wallet Kerberos administration API for Heimdal
=head1 SYNOPSIS
my $kadmin = Wallet::Kadmin::Heimdal->new;
- $kadmin->create ("host/foo.example.com");
- $kadmin->keytab ("host/foo.example.com", "aes256-cts-hmac-sha1-96");
- my $exists = $kadmin->exists ("host/oldshell.example.com");
- $kadmin->destroy ("host/oldshell.example.com") if $exists;
+ $kadmin->create ('host/foo.example.com');
+ $kadmin->keytab_rekey ('host/foo.example.com', 'keytab',
+ 'aes256-cts-hmac-sha1-96');
+ my $data = $kadmin->keytab ('host/foo.example.com');
+ my $exists = $kadmin->exists ('host/oldshell.example.com');
+ $kadmin->destroy ('host/oldshell.example.com') if $exists;
=head1 DESCRIPTION
@@ -228,6 +274,18 @@ To use this object, several configuration parameters must be set. See
Wallet::Config(3) for details on those configuration parameters and
information about how to set wallet configuration.
+=head1 FILES
+
+=over 4
+
+=item KEYTAB_TMP/keytab.<pid>
+
+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 SEE ALSO
kadmin(8), Wallet::Config(3), Wallet::Kadmin(3),
diff --git a/perl/Wallet/Kadmin/MIT.pm b/perl/Wallet/Kadmin/MIT.pm
index 9ab575c..1c6d2c1 100644
--- a/perl/Wallet/Kadmin/MIT.pm
+++ b/perl/Wallet/Kadmin/MIT.pm
@@ -137,11 +137,52 @@ sub create {
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.
+# 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 {
+ my ($self, $principal) = @_;
+ my $host = $Wallet::Config::KEYTAB_REMCTL_HOST;
+ unless ($host and $Wallet::Config::KEYTAB_REMCTL_CACHE) {
+ $self->error ('keytab unchanging support not configured');
+ return;
+ }
+ eval { require Net::Remctl };
+ if ($@) {
+ $self->error ("keytab unchanging support not available: $@");
+ return;
+ }
+ if ($principal !~ /\@/ && $Wallet::Config::KEYTAB_REALM) {
+ $principal .= '@' . $Wallet::Config::KEYTAB_REALM;
+ }
+ local $ENV{KRB5CCNAME} = $Wallet::Config::KEYTAB_REMCTL_CACHE;
+ my $port = $Wallet::Config::KEYTAB_REMCTL_PORT || 0;
+ my $remctl_princ = $Wallet::Config::KEYTAB_REMCTL_PRINCIPAL || '';
+ my @command = ('keytab', 'retrieve', $principal);
+ my $result = Net::Remctl::remctl ($host, $port, $remctl_princ, @command);
+ if ($result->error) {
+ $self->error ("cannot retrieve keytab for $principal: ",
+ $result->error);
+ return;
+ } elsif ($result->status != 0) {
+ my $error = $result->stderr;
+ $error =~ s/\s+$//;
+ $error =~ s/\n/ /g;
+ $self->error ("cannot retrieve keytab for $principal: $error");
+ return;
+ } else {
+ return $result->stdout;
+ }
+}
+
+# Create a keytab for a principal, randomizing the keys for that principal
+# in the process. 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 keytab_rekey {
my ($self, $principal, $file, @enctypes) = @_;
unless ($self->valid_principal ($principal)) {
$self->error ("invalid principal name: $principal");
@@ -210,7 +251,7 @@ __END__
##############################################################################
=for stopwords
-keytabs keytab kadmin KDC API Allbery
+rekeying rekeys remctl backend keytabs keytab kadmin KDC API Allbery
=head1 NAME
@@ -219,10 +260,12 @@ Wallet::Kadmin::MIT - Wallet Kerberos administration API for MIT
=head1 SYNOPSIS
my $kadmin = Wallet::Kadmin::MIT->new;
- $kadmin->create ("host/foo.example.com");
- $kadmin->keytab ("host/foo.example.com", "aes256-cts-hmac-sha1-96");
- my $exists = $kadmin->exists ("host/oldshell.example.com");
- $kadmin->destroy ("host/oldshell.example.com") if $exists;
+ $kadmin->create ('host/foo.example.com');
+ $kadmin->keytab_rekey ('host/foo.example.com', 'keytab',
+ 'aes256-cts-hmac-sha1-96');
+ my $data = $kadmin->keytab ('host/foo.example.com');
+ my $exists = $kadmin->exists ('host/oldshell.example.com');
+ $kadmin->destroy ('host/oldshell.example.com') if $exists;
=head1 DESCRIPTION
@@ -231,6 +274,13 @@ providing an interface to create and delete principals and create keytabs.
It provides the API documented in Wallet::Kadmin(3) for an MIT Kerberos
KDC.
+MIT Kerberos does not provide any method via the kadmin network protocol
+to retrieve a keytab for a principal without rekeying it, so the keytab()
+method (as opposed to keytab_rekey(), which rekeys the principal) is
+implemented using a remctl backend. For that method (used for unchanging
+keytab objects) to work, the necessary wallet configuration and remctl
+interface on the KDC must be set up.
+
To use this object, several configuration parameters must be set. See
Wallet::Config(3) for details on those configuration parameters and
information about how to set wallet configuration.
diff --git a/perl/Wallet/Object/Keytab.pm b/perl/Wallet/Object/Keytab.pm
index 44ee003..5c66967 100644
--- a/perl/Wallet/Object/Keytab.pm
+++ b/perl/Wallet/Object/Keytab.pm
@@ -180,49 +180,6 @@ sub sync_list {
}
##############################################################################
-# Keytab retrieval
-##############################################################################
-
-# 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');
- return;
- }
- eval { require Net::Remctl };
- if ($@) {
- $self->error ("keytab unchanging support not available: $@");
- 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;
- } else {
- return $result->stdout;
- }
-}
-
-##############################################################################
# Core methods
##############################################################################
@@ -365,8 +322,9 @@ sub get {
$self->error ("cannot get $id: object is locked");
return;
}
+ my $kadmin = $self->{kadmin};
if ($self->flag_check ('unchanging')) {
- my $result = $self->keytab_retrieve ($self->{name});
+ my $result = $kadmin->keytab ($self->{name});
if (defined $result) {
$self->log_action ('get', $user, $host, $time);
}
@@ -379,8 +337,7 @@ sub get {
my $file = $Wallet::Config::KEYTAB_TMP . "/keytab.$$";
unlink $file;
my @enctypes = $self->attr ('enctypes');
- my $kadmin = $self->{kadmin};
- if (not $kadmin->keytab ($self->{name}, $file, @enctypes)) {
+ if (not $kadmin->keytab_rekey ($self->{name}, $file, @enctypes)) {
$self->error ($kadmin->error);
return;
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-02-06 10:46:04 +0000