man Pages(3): Library Routines

rpcsec_gss(3N)

NAME

rpcsec_gss- security flavor incorporating

SYNOPSIS

cc [ flag... ] file...- lnsl [ library... ]#include <rpc/rpcsec_gss.h>

DESCRIPTION

RPCSEC_GSS is a security flavor which sits "on top" of the GSS-API (Generic Security Service API) for network transmissions. Applications using RPCSEC_GSS can take advantage of GSS-API security features; moreover, they can use any security mechanism (such as RSA public key or Kerberos) that works with the GSS-API.

The GSS-API offers two security services beyond the traditional authentication services (AUTH_DES, AUTH_SYS, and AUTH_KERB): integrity and privacy. With integrity, the system uses cryptographic checksumming to ensure the authenticity of a message (authenticity of originator, recipient, and data); privacy provides additional security by encrypting data. Applications using RPCSEC_GSS specify which service they wish to use. Type of security service is mechanism-independent.

Before exchanging data with a peer, an application must establish a context for the exchange. RPCSEC_GSS provides a single function for this purpose, rpc_gss_seccreate(), which allows the application to specify the security mechanism, Quality of Protection (QOP), and type of service at context creation. (The QOP parameter sets the cryptographic algorithms to be used with integrity or privacy, and is mechanism-dependent.) Once a context is established, applications can reset the QOP and type of service for each data unit exchanged, if desired.

Valid mechanisms and QOPs may be obtained from configuration files or from the name service. Each mechanism has a default QOP.

Contexts are destroyed with the usual RPC auth_destroy() call.

Data Structures

Some of the data structures used by the RPCSEC_GSS package are shown below.

`rpc_gss_service_t`

This enum defines the types of security services the context may have. rpc_gss_seccreate() takes this as one argument when setting the service type for a session.

typedef enum {
   rpc_gss_svc_default = 0,
   rpc_gss_svc_none = 1,
   rpc_gss_svc_integrity = 2,
   rpc_gss_svc_privacy = 3
} rpc_gss_service_t ;

`rpc_gss_options_req_t`

Structure containing options passed directly through to the GSS-API. rpc_gss_seccreate() takes this as an argument when creating a context. (Because the GSS-API is not currently exposed, this data type is mentioned for informational purposes only. The programmer should set this to NULL.

typedef struct {
   int				  req_flags;	GSS request bits   
   int				  time_req;	requested credential lifetime   
   gss_cred_id_t	  my_cred;	GSS credential struct   
   gss_channel_bindings_t; 	
   input_channel_bindings;	
} rpc_gss_options_req_t ;

`rpc_gss_OID`

This data type is used by in-kernel RPC routines, and thus is mentioned here for informational purposes only.

typedef struct {
   u_int	length;			
   void	*elements		
} *rpc_gss_OID;

`rpc_gss_options_ret_t`

Structure containing GSS-API options returned to the calling function, rpc_gss_seccreate(). MAX_GSS_MECH is defined as 128. (Because the GSS-API is not currently exposed, this data type is mentioned for informational purposes only. Set this to NULL in order to use default values.)

typedef struct {
   int		major_status;		
   int		minor_status;	
   u_int		rpcsec_version		vers. of RPCSEC_GSS
   int		ret_flags
   int		time_req
   gss_ctx_id_t	gss_context;
   char actual_mechanism[MAX_GSS_MECH];		mechanism used
} rpc_gss_options_ret_t;

`rpc_gss_principal_t`

The (mechanism-dependent, opaque) client principal type. Used as an argument to the rpc_gss_get_principal_name() function, and in the gsscred table. Also referenced by the rpc_gss_rawcred_t structure for raw credentials (see below).

typedef struct {
   int	len;			
   char	name[1];	
} *rpc_gss_principal_t;

`rpc_gss_rawcred_t`

Structure for raw credentials. Used by rpc_gss_getcred() and rpc_gss_set_callback().

typedef struct {
  u_int			version;			RPC version #  
  char			*mechanism;		security mechanism  
  char			*qop;			Quality of Protection  
  rpc_gss_principal_t	client_principal;		client name  
  char			*svc_principal;		server name  
  rpc_gss_service_t	service;			service (integrity, etc.)
rpc_gss_rawcred_t;

`rpc_gss_ucred_t`

Structure for UNIX credentials. Used by rpc_gss_getcred() as an alternative to rpc_gss_rawcred_t.

typedef struct {
   uid_t		uid;		user ID   
   gid_t		gid;		group ID   
   short		gidlen;		
   git_t		*gidlist;		list of groups
} rpc_gss_ucred_t;

`rpc_gss_callback_t`

Callback structure used by rpc_gss_set_callback().

typedef struct {
   u_int		program;    	RPC program #   
   u_int		version;		   RPC version #   
   bool_t	(*callback)();	user-defined callback routine
} rpc_gss_callback_t;

`rpc_gss_lock_t`

Structure used by a callback routine to enforce a particular QOP and service for a session. The locked field is normally set to FALSE; the server sets it to TRUE in order to lock the session. (A locked context will reject all requests having different QOP and service values than those found in the raw_cred structure.) For more information, see the rpc_gss_set_callback(3N) man page.

typedef struct {
   bool_t		locked;
   rpc_gss_rawcred_t	*raw_cred;
} rpc_gss_lock_t;

`rpc_gss_error_t`

Structure used by rpc_gss_get_error() to fetch an error code when a RPCSEC_GSS routine fails.

typedef struct {
   int rpc_gss_error;
   int system_error;		same as errno
} rpc_gss_error_t;

Index to Routines

The following lists RPCSEC_GSS routines and the manual reference pages on which they are described. An (S) indicates it is a server-side function:

Routine (Manual Page): Description
rpc_gss_seccreate(3N): Create a secure RPCSEC_GSS context
rpc_gss_set_defaults(3N): Switch service, QOP for a session
rpc_gss_max_data_length(3N): Get maximum data length allowed by transport
rpc_gss_set_svc_name(3N): Set server's principal name (S)
rpc_gss_getcred(3N): Get credentials of caller (S)
rpc_gss_set_callback(3N): Specify callback to see context use (S)
rpc_gss_get_principal_name(3N): Get client principal name (S)
rpc_gss_svc_max_data_length(3N): Get maximum data length allowed by transport (S)
rpc_gss_get_error(3N): Get error number
rpc_gss_get_mechanisms(3N): Get valid mechanism strings
rpc_gss_get_mech_info(3N): Get valid QOP strings, current service
rpc_gss_get_versions(3N): Get supported RPCSEC_GSS versions
rpc_gss_is_installed(3N): Checks if a mechanism is installed
rpc_gss_mech_to_oid(3N): Maps ASCII mechanism to OID representation
rpc_gss_qop_to_num(3N): Maps ASCII QOP, mechansim to u_int number

Utilities

The gsscred utility manages the gsscred table, which contains mappings of principal names between network and local credentials. See gsscred(1M).

FILES

/etc/gss/mech: List of installed mechanisms
/etc/gss/qop: List of valid QOPs

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
MT-Level	MT-Safe
Packages	SUNWrsg, SUNWrsgx

rpcsec_gss(3N)

NAME

SYNOPSIS

DESCRIPTION

Data Structures

rpc_gss_service_t

rpc_gss_options_req_t

rpc_gss_OID

rpc_gss_options_ret_t

rpc_gss_principal_t

rpc_gss_rawcred_t

rpc_gss_ucred_t

rpc_gss_callback_t

rpc_gss_lock_t

rpc_gss_error_t