NAME

GSSAPI - Perl extension providing access to the GSSAPIv2 library

SYNOPSIS

use GSSAPI;
my $targethostname = 'HTTP@moerbsen.grolmsnet.lan';
my $status;
 TRY: {
     my ($target, $tname, $ttl );
     $status = GSSAPI::Name->import( $target,
                                     $server,
                                     GSSAPI::OID::gss_nt_hostbased_service)
             or last;
     $status = $target->display($tname) or last;
     print "\n using Name $tname";
     my $ctx = GSSAPI::Context->new();
     my $imech = GSSAPI::OID::gss_mech_krb5;
     my $iflags = 0 ;
     my $bindings = GSS_C_NO_CHANNEL_BINDINGS;
     my $creds = GSS_C_NO_CREDENTIAL;
     my $itime = 0;
     my $itoken = q{};
     my $otoken;
     $status = $ctx->init($creds,$target,
                          $imech,$iflags,$itime,$bindings,$itoken,
                          undef, $otoken,undef,undef) or last;
     $status = $ctx->valid_time_left($ttl) or last;
     print "\n Security context's time to live $ttl secs";
 }
 unless ($status->major == GSS_S_COMPLETE  ) {
    print "\nErrors: ", $status;
 } else {
    print "\n seems everything is fine, type klist to see the ticket\n";

DESCRIPTION

This module gives access to the routines of the GSSAPI library, as described in rfc2743 and rfc2744 and implemented by the Kerberos-1.2 distribution from MIT.

Since 0.14 it also compiles and works with Heimdal. Lacks of Heimdal support are gss_release_oid(), gss_str_to_oid() and fail of some tests. Have a look at the tests in t/ directory too see what tests fail on Heimdal ( the *.t tests are just skipping them at the moment)

The API presented by this module is a mildly object oriented reinterpretation of the C API, where opaque C structures are Perl objects, but the style of function call has been left mostly untouched. As a result, most routines modify one or more of the parameters passed to them, reflecting the C call-by-reference (or call-by-value-return) semantics.

All users of this module are therefore strongly advised to localize all usage of these routines to minimize pain if and when the API changes.

USAGE

This module wraps the GSSAPI C-Bindings. If you are new to GSSAPI it is a good idea to read RFC2743 and RFC2744, the documentation requires you to be familiar with the concept and the wordings of GSSAPI programming.

the examples directory holds some working examples of usage:

getcred_hostbased.pl: gets a GSSAPI Token for a service specified on commandline. (like kgetcred on Heimdal or kvno on MIT)
gss-client.pl: a simple GSSAPI TCP client.
gss-server.pl: a simple GSSAPI TCP server. Use both as templates if you need quickhacking GSSAPI enabeled GSSAPI TCP services.

GSSAPI::Name

GSSAPI internal representation of principalname

Methods

import( $gssapinameobj, $servicename, $mechnism_oid );: converts stringrepresentation $servicename of service into a GSSAPI internal format and stores it in $gssapiservicename.

input

servicename: Scalar value, like 'HTTP@moerbsen.grolmsnet.lan'.
mechnism_oid: Chose one of the predefines mechanism OIDs from GSSAPI::OID

output

$gssapinameobj: GSSAPI internal representation of servicename

return value

returns GSSAPI::Status Object

Example:

$status = GSSAPI::Name->import( $gssapinameobj,
                                'HTTP@moerbsen.grolmsnet.lan',
                                GSSAPI::OID::gss_nt_hostbased_service);

display($tname);: converts the GSSAPI internal format into a humanreadable string and stores it into $tname.

output

humanreadable string will be stored into $tname.

return value

returns GSSAPI::Status Object

Example:

my $tname;
$status = $gssapinameobj->display($tname);
die 'hmm, error...' if($status->major != GSS_S_COMPLETE );
print "\n  Name is $tname";

compare( nameobj, ret): Wraps gss_compare_name().

Input

nameobj: the 2nd GSSAPI::Name to be compared to

output

ret

value is non-zero: names refer to same entity
value is zero: names refer to different entities.

return value: returns GSSAPI::Status Object

EXPORT

GSS_C_ACCEPT
GSS_C_AF_APPLETALK
GSS_C_AF_BSC
GSS_C_AF_CCITT
GSS_C_AF_CHAOS
GSS_C_AF_DATAKIT
GSS_C_AF_DECnet
GSS_C_AF_DLI
GSS_C_AF_DSS
GSS_C_AF_ECMA
GSS_C_AF_HYLINK
GSS_C_AF_IMPLINK
GSS_C_AF_INET
GSS_C_AF_LAT
GSS_C_AF_LOCAL
GSS_C_AF_NBS
GSS_C_AF_NS
GSS_C_AF_NULLADDR
GSS_C_AF_OSI
GSS_C_AF_PUP
GSS_C_AF_SNA
GSS_C_AF_UNSPEC
GSS_C_AF_X25
GSS_C_ANON_FLAG
GSS_C_BOTH
GSS_C_CALLING_ERROR_MASK
GSS_C_CALLING_ERROR_OFFSET
GSS_C_CONF_FLAG
GSS_C_DELEG_FLAG
GSS_C_EMPTY_BUFFER
GSS_C_GSS_CODE
GSS_C_INDEFINITE
GSS_C_INITIATE
GSS_C_INTEG_FLAG
GSS_C_MECH_CODE
GSS_C_MUTUAL_FLAG
GSS_C_NO_BUFFER
GSS_C_NO_CHANNEL_BINDINGS
GSS_C_NO_CONTEXT
GSS_C_NO_CREDENTIAL
GSS_C_NO_NAME
GSS_C_NO_OID
GSS_C_NO_OID_SET
GSS_C_PROT_READY_FLAG
GSS_C_QOP_DEFAULT
GSS_C_REPLAY_FLAG
GSS_C_ROUTINE_ERROR_MASK
GSS_C_ROUTINE_ERROR_OFFSET
GSS_C_SEQUENCE_FLAG
GSS_C_SUPPLEMENTARY_MASK
GSS_C_SUPPLEMENTARY_OFFSET
GSS_C_TRANS_FLAG
GSS_S_BAD_BINDINGS
GSS_S_BAD_MECH
GSS_S_BAD_NAME
GSS_S_BAD_NAMETYPE
GSS_S_BAD_QOP
GSS_S_BAD_SIG
GSS_S_BAD_STATUS
GSS_S_CALL_BAD_STRUCTURE
GSS_S_CALL_INACCESSIBLE_READ
GSS_S_CALL_INACCESSIBLE_WRITE
GSS_S_COMPLETE
GSS_S_CONTEXT_EXPIRED
GSS_S_CONTINUE_NEEDED
GSS_S_CREDENTIALS_EXPIRED
GSS_S_CRED_UNAVAIL
GSS_S_DEFECTIVE_CREDENTIAL
GSS_S_DEFECTIVE_TOKEN
GSS_S_DUPLICATE_ELEMENT
GSS_S_DUPLICATE_TOKEN
GSS_S_FAILURE
GSS_S_GAP_TOKEN
GSS_S_NAME_NOT_MN
GSS_S_NO_CONTEXT
GSS_S_NO_CRED
GSS_S_OLD_TOKEN
GSS_S_UNAUTHORIZED
GSS_S_UNAVAILABLE
GSS_S_UNSEQ_TOKEN

Exportable functions

$status = indicate_mechs($oidset)

Example

use GSSAPI qw(:all);
my $oidset;
my $isin = 0;
my $status = indicate_mechs( $oidset );
$status->major == GSS_S_COMPLETE || die 'error';
$status = $oidset->contains( gss_mech_krb5_old, $isin );
$status->major == GSS_S_COMPLETE || die 'error';
if ( $isin ) {
  print 'Support of Kerberos 5 old mechtype';
} else {
  print 'No Support of Kerberos 5 old mechtype';
}

Constant OIDs provided:

# Constant OIDs provided:
$oid = gss_nt_user_name;
$oid = gss_nt_machine_uid_name;
$oid = gss_nt_string_uid_name;
$oid = gss_nt_service_name;
$oid = gss_nt_exported_name;
$oid = gss_nt_service_name_v2;
$oid = gss_nt_krb5_name;
$oid = gss_nt_krb5_principal;
$oid = gss_mech_krb5;
$oid = gss_mech_krb5_old;
$oid = gss_mech_spnego;

All other functions are class or instance methods.