gss_add_cred

- add a credential-element to a credential

Synopsis

cc [ flag... ] file... -lgss [ library... ]
#include <gssapi/gssapi.h>

OM_uint32 gss_add_cred(OM_uint32 *minor_status,
     const gss_cred_id_t input_cred_handle,
     const gss_name_t desired_name,
     const gss_OID desired_mech,
     gss_cred_usage_t cred_usage,
     OM_uint32 initiator_time_req,
     OM_uint32 acceptor_time_req,
     gss_cred_id_t *output_cred_handle,
     gss_OID_set *actual_mechs,
     OM_uint32 *initiator_time_rec,
     OM_uint32 *acceptor_time_rec);

Parameters

The parameter descriptions for gss_add_cred() follow:

minor_status

Mechanism specific status code.

input_cred_handle

Credential to which the credential-element is added. If GSS_C_NO_CREDENTIAL is specified, the function composes the new credential based on default behavior. While the credential-handle is not modified by gss_add_cred(), the underlying credential is modified if output_credential_handle is NULL.

desired_name

Name of the principal for which a credential should be acquired.

desired_mech

Underlying security mechanism with which the credential can be used. GSS_C_NULL_OID can be used to obtain a default.

cred_usage

Flag that indicates how a credential is used to initiate or accept security credentials. If the flag is GSS_C_ACCEPT, the credentials are used only to accept security credentials. If the flag is GSS_C_INITIATE, the credentials are used only to initiate security credentials. If the flag is GSS_C_BOTH, the credentials can be used to either initiate or accept security contexts.

initiator_time_req

Number of seconds that the credential may remain valid for initiating security contexts. This argument is ignored if the composed credentials are of the GSS_C_ACCEPT type. Specify GSS_C_INDEFINITE to request that the credentials have the maximum permitted initiator lifetime.

acceptor_time_req

Number of seconds that the credential may remain valid for accepting security contexts. This argument is ignored if the composed credentials are of the GSS_C_INITIATE type. Specify GSS_C_INDEFINITE to request that the credentials have the maximum permitted initiator lifetime.

output_cred_handle

Returned credential handle that contains the new credential-element and all the credential-elements from input_cred_handle. If a valid pointer to a gss_cred_id_t is supplied for this parameter, gss_add_cred() creates a new credential handle that contains all credential-elements from input_cred_handle and the newly acquired credential-element. If NULL is specified for this parameter, the newly acquired credential-element is added to the credential identified by input_cred_handle.

The resources associated with any credential handle returned by means of this parameter must be released by the application after use by a call to gss_release_cred(3GSS).

actual_mechs

Complete set of mechanisms for which the new credential is valid. Storage for the returned OID-set must be freed by the application after use by a call to gss_release_oid_set(3GSS). Specify NULL if this parameter is not required.

initiator_time_rec

Actual number of seconds for which the returned credentials remain valid for initiating contexts using the specified mechanism. If a mechanism does not support expiration of credentials, the value GSS_C_INDEFINITE is returned. Specify NULL if this parameter is not required.

acceptor_time_rec

Actual number of seconds for which the returned credentials remain valid for accepting security contexts using the specified mechanism. If a mechanism does not support expiration of credentials, the value GSS_C_INDEFINITE is returned. Specify NULL if this parameter is not required.

Description

The gss_add_cred() function adds a credential-element to a credential. The credential-element is identified by the name of the principal to which it refers. This function is not intended as a function to login to the network. A function for login to the network would involve creating new mechanism-specific authentication data, rather than acquiring a handle to existing data.

If the value of desired_name is GSS_C_NO_NAME, the call is interpreted as a request to add a credential-element to invoke default behavior when passed to gss_init_sec_context(3GSS) if the value of cred_usage is GSS_C_INITIATE or GSS_C_BOTH. The call is also interpreted as a request to add a credential-element to the invoke default behavior when passed to gss_accept_sec_context(3GSS) if the value of cred_usage is GSS_C_ACCEPT or GSS_C_BOTH.

The gss_add_cred() function is expected to be used primarily by context acceptors. The GSS-API provides mechanism-specific ways to obtain GSS-API initiator credentials through the system login process. Consequently, the GSS-API does not support acquiring GSS_C_INITIATE or GSS_C_BOTH credentials by means of gss_acquire_cred(3GSS) for any name other than the following:

• GSS_C_NO_NAME

• Name produced by gss_inquire_cred(3GSS) applied to a valid credential

• Name produced by gss_inquire_context(3GSS) applied to an active context

If credential acquisition is time consuming for a mechanism, the mechanism can choose to delay the actual acquisition until the credential is required by gss_init_sec_context(3GSS), for example, or by gss_accept_sec_context(3GSS). Such mechanism-specific implementation decisions are invisible to the calling application. A call to gss_inquire_cred(3GSS) immediately following the call gss_add_cred() returns valid credential data as well as incurring the overhead of deferred credential acquisition.

The gss_add_cred() function can be used either to compose a new credential that contains all credential-elements of the original in addition to the newly-acquired credential-element. The function can also be used to add the new credential-element to an existing credential. If the value of the output_cred_handle parameter is NULL, the new credential-element is added to the credential identified by input_cred_handle. If a valid pointer is specified for the output_cred_handle parameter, a new credential handle is created.

If the value of input_cred_handle is GSS_C_NO_CREDENTIAL, the gss_add_cred() function composes a credential and sets the output_cred_handle parameter based on the default behavior. The call has the same effect as a call first made by the application to gss_acquire_cred(3GSS) to specify the same usage and to pass GSS_C_NO_NAME as the desired_name parameter. Such an application call obtains an explicit credential handle that incorporates the default behaviors, then passes the credential handle to gss_add_cred(), and finally calls gss_release_cred(3GSS) on the first credential handle.

If the value of the input_cred_handle parameter is GSS_C_NO_CREDENTIAL, a non-NULL value must be supplied for the output_cred_handle parameter.

Return Values

The gss_add_cred() function can return the following status codes:

GSS_S_COMPLETE

Successful completion.

GSS_S_BAD_MECH

An unavailable mechanism has been requested.

GSS_S_BAD_NAMETYPE

The type contained within the desired_name parameter is not supported.

GSS_S_BAD_NAME

The value supplied for desired_name parameter is ill formed.

GSS_S_DUPLICATE_ELEMENT

The credential already contains an element for the requested mechanism that has overlapping usage and validity period.

GSS_S_CREDENTIALS_EXPIRED

The credentials could not be added because they have expired.

GSS_S_NO_CRED

No credentials were found for the specified name.

GSS_S_FAILURE

The underlying mechanism detected an error for which no specific GSS status code is defined. The mechanism-specific status code reported by means of the minor_status parameter details the error condition.

Attributes

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

See Also

gss_accept_sec_context(3GSS), gss_acquire_cred(3GSS), gss_init_sec_context(3GSS), gss_inquire_context(3GSS), gss_inquire_cred(3GSS), gss_release_cred(3GSS), gss_release_oid_set(3GSS), libgss(3LIB), attributes(5)

Developer’s Guide to Oracle Solaris 11 Security