- add a credential-element to a credential
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);
The parameter descriptions for gss_add_cred() follow:
Mechanism specific status code.
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.
Name of the principal for which a credential should be acquired.
Underlying security mechanism with which the credential can be used. GSS_C_NULL_OID can be used to obtain a default.
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.
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.
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.
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).
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.
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.
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.
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:
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.
The gss_add_cred() function can return the following status codes:
An unavailable mechanism has been requested.
The type contained within the desired_name parameter is not supported.
The value supplied for desired_name parameter is ill formed.
The credential already contains an element for the requested mechanism that has overlapping usage and validity period.
The credentials could not be added because they have expired.
No credentials were found for the specified name.
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.
See attributes(5) for descriptions of the following attributes:
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)