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--- a/perl/lib/Wallet/Config.pm
+++ b/perl/lib/Wallet/Config.pm
@@ -765,11 +765,42 @@ with this ACL type. This variable must
=cut
+our $LDAP_SECRET;
+
+=item LDAP_SECRET
+
+Specifies an LDAP URL that is used to retrieve the secret to use when
+encrypting and decrypting file objects. The url must not include the
+hostname. LDAP_HOST will be used as the hostname to bind to. The
+Kerberos ticket cache specified in LDAP_CACHE is used when connecting
+to the LDAP server. GSS-API authentication is always used; there is
+currently no support for any other type of bind. The ticket cache
+must be for a principal with access to retrieve the secret. This
+variable and LDAP_CACHE must be set to use file object encryption.
+
+=cut
+
+our $LDAP_SECRET_PREFIX;
+
+=item LDAP_SECRET_PREFIX
+
+Specifies the prefix to be used when generating storing an encrypted
+file object. The prefix is used to determine whether or not a file
+object has been stored encrypted. This allows the gradual transition
+from unencrypted file objects to encrypted file objects. When file
+object encryption is enable any "get" of an unencyrpted file object
+will result in the replacement of the unencrypted object with an
+encrypted object.
+
+=cut
+
our $LDAP_CACHE;
=back
-Finally, depending on the structure of the LDAP directory being queried,
+=head2 LDAP Principal Mapping
+
+Depending on the structure of the LDAP directory being queried,
there may not be any attribute in the directory whose value exactly
matches the Kerberos principal. The attribute designated by
LDAP_FILTER_ATTR may instead hold a transformation of the principal name
@@ -794,6 +825,27 @@ Note that this example only removes the
Any principal from some other realm will be left fully qualified, and then
presumably will not be found in the directory.
+=head2 File Object Encryption
+
+The default encryption method use is based on the twofish cypher. If
+another encryption method is desired then the perl function file_crypt
+should be defined. The function must accept three parameters: the
+action to preform, the encryption secret, and the string to encrypt or
+decrypt. For example:
+
+ sub file_crypt {
+ use Crypt::RC4;
+ my ($action, $secret, $string) = @_;
+
+ my $return_string;
+ if ($action eq 'encrypt') {
+ $return_string = RC4($secret, $string);
+ } elsif ($action eq 'decrypt') {
+ $return_string = RC4($secret, $string);
+ }
+ return $return_string;
+ }
+
=head1 NETDB ACL CONFIGURATION
These configuration variables are only needed if you intend to use the
--- a/perl/lib/Wallet/Object/File.pm
+++ b/perl/lib/Wallet/Object/File.pm
@@ -20,6 +20,7 @@ use warnings;
use Digest::MD5 qw(md5_hex);
use File::Copy qw(move);
use File::Slurp;
+use Wallet::ACL::LDAP::Attribute;
use Wallet::Config;
use Wallet::Object::Base;
@@ -107,6 +108,114 @@ sub rename {
}
##############################################################################
+# Encyption and decryption
+##############################################################################
+
+sub _get_crypt_key {
+ my ($self) = @_;
+
+ # ldap:///basedn?attr?scope?filter
+ my $url = $Wallet::Config::LDAP_SECRET;
+ $url =~ s{^ldap:///}{}xmsi;
+ if ($url eq $Wallet::Config::LDAP_SECRET) {
+ self->error("ERROR: Invalid LDAP URL $url");
+ exit 1;
+ }
+ my @parts = split /\?/, $url;
+ my $base = $parts[0];
+ my $attr = $parts[1];
+ my $scope = $parts[2];
+ my $filter = $parts[3];
+
+ # Search for the secret in the LDAP directory
+ my $ldap_obj = Wallet::ACL::LDAP::Attribute->new;
+ my $ldap = $ldap_obj->{ldap};
+ my $entry;
+ eval {
+ my @options = (base => $base,
+ filter => $filter,
+ scope => $scope,
+ attrs => [ $attr ]
+ );
+ my $search = $ldap->search (@options);
+ if ($search->count == 1) {
+ $entry = $search->pop_entry;
+ } elsif ($search->count > 1) {
+ die 'ERROR: ' . $search->count . " LDAP entries found for $filter";
+ } else {
+ die "ERROR: No entry found for $url";
+ }
+ };
+ if ($@ || !$entry) {
+ die "ERROR: LDAP search failed for $url";
+ }
+
+ my $return_val;
+ my $cnt = 0;
+ foreach my $return_attr ($entry->attributes) {
+ if (lc($return_attr) eq lc($attr)) {
+ $return_val = $entry->get_value($return_val);
+ $cnt++;
+ }
+ }
+ if (!$return_val) {
+ die "ERROR: LDAP search failed for $url";
+ }
+ if ($cnt !=1) {
+ die "ERROR: LDAP search return too many values ($url)";
+ }
+ return $return_val;
+}
+
+sub _file_crypt {
+ my ($self, $action, $string) = @_;
+
+ use Crypt::CBC;
+ use MIME::Base64;
+
+ my $return_string;
+ my $pre = $Wallet::Config::LDAP_SECRET_PREFIX;
+ my $key = $self->_get_crypt_key();
+
+ my $cipher = Crypt::CBC->new(
+ -key => $key,
+ -cipher => 'Twofish',
+ -padding => 'space',
+ -add_header => 1
+ );
+ if ($action eq 'encrypt') {
+ $return_string = $pre . encode_base64($cipher->encrypt($string));
+ } elsif ($action eq 'decrypt') {
+ if ($string =~ s/^$pre//xms) {
+ $return_string = $cipher->decrypt(decode_base64($string));
+ } else {
+ $return_string = $string;
+ }
+ } else {
+ my $msg = "ERROR: invalid action ($action)\n ";
+ $msg .= "INFO: action must be 'encrypt' or 'decrypt'\n";
+ $self->error($msg);
+ return;
+ }
+ return $return_string;
+}
+
+sub _file_decrypt {
+ my ($self, $data, $user, $host, $time) = @_;
+ my $undata = $self->_file_crypt('decrypt', $data);
+ if ($undata eq $data) {
+ $self->store($data, $user, $host, $time) = @_;
+ }
+ return $undata;
+}
+
+sub _file_encrypt {
+ my ($self, $data) = @_;
+ my $endata = $self->_file_crypt('encrypt', $data);
+ return $endata;
+}
+
+##############################################################################
# Core methods
##############################################################################
@@ -143,6 +253,9 @@ sub get {
$self->error ("cannot get $id: $!");
return;
}
+ if ($Wallet::LDAP::SECRET) {
+ $data = self->_file_decrypt($user, $host, $time, $data);
+ }
$self->log_action ('get', $user, $host, $time);
return $data;
}
@@ -158,10 +271,17 @@ sub checksum {
}
my $path = $self->file_path;
my $this_checksum;
+ my $this_data;
+ my $this_endata = read_file($path);
+ if ($Wallet::Config::LDAP_SECRET) {
+ $this_data = $self->_file_decrypt($this_endata, $user, $host, $time)
+ } else {
+ $this_data = $this_endata;
+ }
if (defined (&Wallet::Config::file_checksum)) {
- $this_checksum = Wallet::Config::file_checksum($path);
+ $this_checksum = Wallet::Config::file_checksum($this_data);
} else {
- $this_checksum = md5_hex(read_file($path));
+ $this_checksum = md5_hex($this_data);
}
$self->log_action ('checksum', $user, $host, $time);
return $this_checksum;
@@ -189,6 +309,9 @@ sub store {
$self->error ("cannot store $id: $!");
return;
}
+ if ($Wallet::Config::LDAP_SECRET) {
+ $data = $self->_file_encrypt($data);
+ }
unless (print FILE ($data) and close FILE) {
$self->error ("cannot store $id: $!");
close FILE;
|
