NAME

Authen::Krb5 - Perl extension for Kerberos 5

SYNOPSIS

use Authen::Krb5;

Authen::Krb5::init_context();

DESCRIPTION

Authen::Krb5 is an object oriented interface to the Kerberos 5 API. Both the implementation and documentation are nowhere near complete, and may require previous experience with Kerberos 5 programming. Most of the functions here are documented in detail in the Kerberos 5 API documentation.

FUNCTIONS

error(n): Returns the error code from the most recent Authen::Krb5 call. If provided with an error code 'n', this function will return a textual description of the error.
init_context(): Initializes a context for the application. Returns a Authen::Krb5::Context object, or undef if there was an error.
init_ets() (DEPRECATED): Initializes the Kerberos error tables. Should be called along with init_context at the beginning of a script.
get_default_realm(): Returns the default realm of your host.
get_host_realm(host): Returns the realm of the specified host.
get_krbhst(realm): Returns a list of the Kerberos servers from the specified realm.
build_principal_ext(p): Not like the actual krb5_build_principal_ext. This is legacy code from Malcolm's code, which I'll probably change in future releases. In any case, it creates a 'server' principal for use in getting a TGT. Pass it the principal for which you would like a TGT.
parse_name(name): Converts a string representation of a principal to a principal object. You can use this to create a principal from your username.
sname_to_principal(hostname,sname,type): Generates a server principal from the given hostname, service, and type. Type can be one of the following: NT_UNKNOWN, NT_PRINCIPAL, NT_SRV_INST, NT_SRV_HST, NT_SRV_XHST, NT_UID. See the Kerberos documentation for details.
cc_resolve(name): Returns a credentials cache identifier which corresponds to the given name. 'name' must be in the form TYPE:RESIDUAL. See the Kerberos documentation for more information.
cc_default_name(): Returns the name of the default credentials cache, which may be equivalent to KRB5CCACHE.
cc_default(): Returns a Authen::Krb5::Ccache object representing the default credentials cache.
kt_resolve(name): Returns a Authen::Krb5::Keytab object representing the specified keytab name.
kt_default_name(): Returns a sting containing the default keytab name.
kt_default(): Returns an Authen::Krb5::Keytab object representing the default keytab.
kt_read_service_key(name, principal[, kvno, enctype]): Searches the keytab specified by name (the default keytab if name is undef) for a key matching principal (and optionally kvno and enctype) and returns the key in the form of an Authen::Krb5::Keyblock object.
get_init_creds_password(client, password[, service]): Attempt to get an initial ticket for the client. 'client' is a principal object for which you want an initial ticket. 'password' is the password for the client. 'service', if given, is the string representation (not a principal object) for the ticket to acquire. If not given, it defaults to krbtgt/REALM@REALM for the local realm. Returns an Authen::Krb5::Creds object or undef on failure.
get_init_creds_keytab(client, keytab[, service]): Attempt to get an inintial ticket for the client using a keytab. 'client' is a principal object for which you want an initial ticket. 'keytab' is a keytab object created with kt_resolve. 'service', if given, is the string representation (not a principal object) for the ticket to acquire. If not given, it defaults to krbtgt/REALM@REALM for the local realm. Returns an Authen::Krb5::Creds object or undef on failure.
get_in_tkt_with_password(client,server,password,cc): Attempt to get an initial ticket for the client. 'client' is a principal object for which you want an initial ticket. 'server' is a principal object for the service (usually krbtgt/REALM@REALM). 'password' is the password for the client, and 'cc' is a Authen::Krb5::Ccache object representing the current credentials cache. Returns a Kerberos error code.
Although this interface is deprecated in the Kerberos C libraries, it's supported in the Perl module. In this module, it's implemented in terms of krb5_get_init_creds_password, krb5_cc_initialize, and krb5_cc_store_cred.
get_in_tkt_with_keytab(client,server,keytab,cc): Obtain an initial ticket for the client using a keytab. 'client' is a principal object for which you want an initial ticket. 'server' is a principal object for the service (usually krbtgt/REALM@REALM). 'keytab' is a keytab object createed with kt_resolve. 'cc' is a Authen::Krb5::Ccache object representing the current credentials cache. Returns a Kerberos error code.
Although this interface is deprecated in the Kerberos C libraries, it's supported in the Perl module. In this module, it's implemented in terms of krb5_get_init_creds_keytab, krb5_cc_initialize, and krb5_cc_store_cred.
mk_req(auth_context,ap_req_options,service,hostname,in,cc): Obtains a ticket for a specified service and returns a KRB_AP_REQ message suitable for passing to rd_req. 'auth_context' is the Authen::Krb5::AuthContext object you want to use for this connection, 'ap_req_options' is an OR'ed representation of the possible options (see Kerberos docs), 'service' is the name of the service for which you want a ticket (like 'host'), hostname is the hostname of the server, 'in' can be any user-specified data that can be verified at the server end, and 'cc' is your credentials cache object.
rd_req(auth_context,in,server,keytab): Parses a KRB_AP_REQ message and returns its contents in a Authen::Krb5::Ticket object. 'auth_context' is the connection's Authen::Krb5::AuthContext object, 'in' is the KRB_AP_REQ message (usually from mk_req), and server is the expected server's name for the ticket. 'keytab' is a Authen::Krb5::Keytab object for the keytab you want to use. Specify 'undef' or leave off to use the default keytab.
mk_priv(auth_context,in): Encrypts 'in' using parameters specified in auth_context, and returns the encrypted data. Requires use of a replay cache.
rd_priv(auth_context,in): Decrypts 'in' using parameters specified in auth_context, and returns the decrypted data.
sendauth(auth_context,fh,version,client,server,options,in,in_creds,cc): Obtains and sends an authenticated ticket from a client program to a server program using the filehandle 'fh'. 'version' is an application-defined version string that recvauth compares to its own version string. 'client' is the client principal, e.g. username@REALM. 'server' is the service principal to which you are authenticating, e.g. service.hostname@REALM. The only useful option right now is AP_OPTS_MUTUAL_REQUIRED, which forces sendauth to perform mutual authentication with the server. 'in' is a string that will be received by recvauth and verified by the server--it's up to the application. 'in_creds' is not yet supported, so just use 'undef' here. 'cc' should be set to the current credentials cache. sendauth returns true on success and undefined on failure.
recvauth(auth_context,fh,version,server,keytab): Receives authentication data from a client using the sendauth function through the filehandle 'fh'. 'version' is as described in the sendauth section. 'server' is the server principal to which the client will be authenticating. 'keytab' is a Authen::Krb5::Keytab object specifying the keytab to use for this service. recvauth returns a Authen::Krb5::Ticket object on success or undefined on failure.
genaddrs(auth_context,fh,flags): Uses the open socket filehandle 'fh' to generate local and remote addresses for auth_context. Flags should be one of the following, depending on the type of address you want to generate (flags can be OR'ed):
KRB5_AUTH_CONTEXT_GENERATE_LOCAL_ADDR KRB5_AUTH_CONTEXT_GENERATE_LOCAL_FULL_ADDR KRB5_AUTH_CONTEXT_GENERATE_REMOTE_ADDR KRB5_AUTH_CONTEXT_GENERATE_REMOTE_FULL_ADDR
gen_portaddr(addr,port): Generates a local port address that can be used to name a replay cache. 'addr' is a Authen::Krb5::Address object, and port is a port number in network byte order. For generateing a replay cache name, you should supply the local address of the client and the socket's local port number. Returns a Authen::Krb5::Address object containing the address.
gen_replay_name(addr,string): Generate a unique replay cache name. 'addr' is a Authen::Krb5::Address object created by gen_portaddr. 'string' is used as a unique identifier for the replay cache. Returns the replay cache name.
get_server_rcache(name): Returns a Authen::Krb5::Rcache object using the replay cache name 'name.'

CLASSES & METHODS

Authen::Krb5::Principal: Kerberos 5 princpal object.

o realm: Returns the realm of the principal.
o type: Returns the type of the principal.
o data: Returns a list containing the components of the principal (everything before the realm).

Authen::Krb5::Ccache: Kerberos 5 credentials cache object.

o initialize(p): Creates/refreshes a credentials cache for the primary principal 'p'. If the cache already exists, its contents are destroyed.
o store_cred(creds): Stores the given credentials, which should be an Authen::Krb5::Creds object as returned from get_init_creds_password() or get_init_creds_keytab(), in the cache.
o get_name: Returns the name of the credentials cache.
o get_principal: Returns the primary principal of the credentials cache.
o destroy: Destroys the credentials cache and releases all resources it used.
o start_seq_get(): Returns a cursor that can be passed to next_cred() to read in turn every credential in the cache.
o next_cred(cursor): Returns the next credential in the cache as an Authen::Krb5::Creds object.
o end_seq_get(cursor): Perform cleanup opreations after next_cred() and invalidates cursor.

Authen::Krb5::KeyBlock: Kerberos 5 keyblock object.

o enctype(): Returns the encryption type ID.
o enctype_string(): Returns a text description of the encryption type.
o length(): Returns the length of the session key.
o contents(): Returns the actual contents of the keyblock (the session key).

Authen::Krb5::AuthContext: Kerberos 5 auth_context object.

o new: Allocates memory for a new Authen::Krb5::AuthContext object and returns it.
o setaddrs(localaddr,remoteaddr): Sets the local and remote addresses for the AuthContext object. 'localaddr' and 'remoteaddr' are Authen::Krb5::Address objects, usually of type ADDRTYPE_INET.
o getaddrs(): Returns a list containing the local and the remote address of the AuthContext object.
o setrcache(rc): Sets the replay cache for auth_context. 'rc' is a Authen::Krb5::Rcache object generated by get_server_rcache.
o getkey(): Retrieves the session key as an Authen::Krb5::KeyBlock object.

Authen::Krb5::Ticket: Kerberos 5 ticket object.

o server: Returns the server stored in the ticket.
o enc_part2: Returns a Authen::Krb5::EncTktPart object representation of the ticket data. See below.

Authen::Krb5::EncTktPart: Object representation of the krb5_enc_tkt_part structure.

o client: The client principal contained in the ticket.

Authen::Krb5::Keyblock: Object representation of the krb5_keyblock structure.

o enctype: The integral enctype of the key.
o length: Length of the key.
o contents: Contents of the key itself, as a string.

Authen::Krb5::Keytab

o add_entry(entry): Adds entry to the keytab.
o remove_entry(entry): Removes entry from the keytab.
o get_name(): Returns the name of the keytab.
o get_entry(principal[, kvno, enctype]): Returns an Authen::Krb5::KeytabEntry object representing an entry in the keytab matching principal and optionally kvno and enctype.
o start_seq_get(): Returns a cursor that can be passed to next_entry() to read in turn every key in the keytab.
o next_entry(cursor): Returns the next entry in the keytab as an Authen::Krb5::KeytabEntry object.
o end_seq_get(cursor): Perform cleanup opreations after next_entry() and invalidates cursor.

Authen::Krb5::KeytabEntry

o new(principal, kvno, keyblock): Create a new Authen::Krb5::KeytabEntry object from an Authen::Krb5::Principal object, a key version number, and an Authen::Krb5::Keyblock object.
o principal: An Authen::Krb5::Principal object representing the principal contained in the entry.
o timestamp: The timestamp of the entry.
o kvno: The key version number of the key contained in the entry.
o key: An Authen::Krb5::Keyblock object representing a copy of the keyblock contained in the entry.

Authen::Krb5::Creds: Object representing a credential.

o starttime(): Returns the starttime time property of the credential.
o authtime(): Returns the authtime time property of the credential.
o endtime(): Returns the endtime time property of the credential.
o renew_till(): Returns the renew_till time property of the credential.
o server(): Returns the name of the service principal the credential is for.
o client(): Returns the client principal name (will usually be identical for all credentials in a credential cache).
o ticket(): Returns the Authen::Krb5::Ticket for this credential.
o keyblock(): Returns the keyblock of the credential.

AUTHOR

Jeff Horwitz (jeff@smashing.org)

ACKNOWLEDGEMENTS

Based on the original work by Doug MacEachern and Malcolm Beattie. Code contributions from Scott Hutton (shutton@indiana.edu).

POD ERRORS

Hey! The above document had some coding errors, which are explained below:

Around line 602:: You forgot a '=back' before '=head1'