gss_add_cred(3)

NAME
gss_add_cred - API function

SYNOPSIS
#include <gss.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);

ARGUMENTS

OM_uint32 * minor_status
    (integer, modify) Mechanism specific status code.

const gss_cred_id_t input_cred_handle
    (gss_cred_id_t, read, optional) The credential
      to which a credential-element will be added. If
      GSS_C_NO_CREDENTIAL is specified, the routine will compose the
      new credential based on default behavior (see text).
      Note that, while the credential-handle is not modified by
      gss_add_cred(), the underlying credential will be modified if
      output_credential_handle is NULL.

const gss_name_t desired_name
    (gss_name_t, read.) Name of principal whose
      credential should be acquired.

const gss_OID desired_mech
    (Object ID, read) Underlying security mechanism with
      which the credential may be used.

gss_cred_usage_t cred_usage
    (gss_cred_usage_t, read) GSS_C_BOTH - Credential may
      be used either to initiate or accept security contexts.
      GSS_C_INITIATE - Credential will only be used to initiate
      security contexts. GSS_C_ACCEPT - Credential will only be used
      to accept security contexts.

OM_uint32 initiator_time_req
    (Integer, read, optional) number of seconds
      that the credential should remain valid for initiating security
      contexts. This argument is ignored if the composed credentials
      are of type GSS_C_ACCEPT. Specify GSS_C_INDEFINITE to request
      that the credentials have the maximum permitted initiator
      lifetime.

OM_uint32 acceptor_time_req
    (Integer, read, optional) number of seconds
      that the credential should remain valid for accepting security
      contexts. This argument is ignored if the composed credentials
      are of type GSS_C_INITIATE. Specify GSS_C_INDEFINITE to request
      that the credentials have the maximum permitted initiator
      lifetime.

gss_cred_id_t * output_cred_handle
    (gss_cred_id_t, modify, optional) The returned
      credential handle, containing 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 containing all
      credential-elements from the input_cred_handle and the newly
      acquired credential-element; if NULL is specified for this
      parameter, the newly acquired credential-element will be added to
      the credential identified by input_cred_handle. The resources
      associated with any credential handle returned via this parameter
      must be released by the application after use with a call to
      gss_release_cred().

gss_OID_set * actual_mechs
    (Set of Object IDs, modify, optional) The 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 with a call to gss_release_oid_set(). Specify NULL if not
      required.

OM_uint32 * initiator_time_rec
    (Integer, modify, optional) Actual number of
      seconds for which the returned credentials will remain valid for
      initiating contexts using the specified mechanism. If the
      implementation or mechanism does not support expiration of
      credentials, the value GSS_C_INDEFINITE will be returned. Specify
      NULL if not required

OM_uint32 * acceptor_time_rec
    (Integer, modify, optional) Actual number of
      seconds for which the returned credentials will remain valid for
      accepting security contexts using the specified mechanism. If
      the implementation or mechanism does not support expiration of
      credentials, the value GSS_C_INDEFINITE will be returned. Specify
      NULL if not required

DESCRIPTION
Adds a credential-element to a credential. The credential-element is identified by the name of the principal to which it refers. GSS-API implementations must impose a local access-control policy on callers of this routine to prevent unauthorized callers from acquiring credential-elements to which they are not entitled. This routine is not intended to provide a "login to the network" function, as such a function would involve the creation of new mechanism-specific authentication data, rather than merely acquiring a GSS-API handle to existing data. Such functions, if required, should be defined in implementation-specific extensions to the API.

If desired_name is GSS_C_NO_NAME, the call is interpreted as a request to add a credential element that will invoke default behavior when passed to gss_init_sec_context() (if cred_usage is GSS_C_INITIATE or GSS_C_BOTH) or gss_accept_sec_context() (if cred_usage is GSS_C_ACCEPT or GSS_C_BOTH).

This routine is expected to be used primarily by context acceptors, since implementations are likely to provide mechanism-specific ways of obtaining GSS-API initiator credentials from the system login process. Some implementations may therefore not support the acquisition of GSS_C_INITIATE or GSS_C_BOTH credentials via gss_acquire_cred for any name other than GSS_C_NO_NAME, or a name produced by applying either gss_inquire_cred to a valid credential, or gss_inquire_context to an active context.

If credential acquisition is time-consuming for a mechanism, the mechanism may choose to delay the actual acquisition until the credential is required (e.g. by gss_init_sec_context or gss_accept_sec_context). Such mechanism-specific implementation decisions should be invisible to the calling application; thus a call of gss_inquire_cred immediately following the call of gss_add_cred must return valid credential data, and may therefore incur the overhead of a deferred credential acquisition.

This routine can be used to either compose a new credential containing all credential-elements of the original in addition to the newly-acquire credential-element, or to add the new credential- element to an existing credential. If NULL is specified for the output_cred_handle parameter argument, the new credential-element will be 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 will be created.

If GSS_C_NO_CREDENTIAL is specified as the input_cred_handle, gss_add_cred will compose a credential (and set the output_cred_handle parameter accordingly) based on default behavior. That is, the call will have the same effect as if the application had first made a call to gss_acquire_cred(), specifying the same usage and passing GSS_C_NO_NAME as the desired_name parameter to obtain an explicit credential handle embodying default behavior, passed this credential handle to gss_add_cred(), and finally called gss_release_cred() on the first credential handle.

If GSS_C_NO_CREDENTIAL is specified as the input_cred_handle parameter, a non-NULL output_cred_handle must be supplied.

RETURN VALUE

`GSS_S_COMPLETE`: Successful completion.

`GSS_S_BAD_MECH`: Unavailable mechanism requested.

`GSS_S_BAD_NAMETYPE`: Type contained within desired_name parameter is not supported.

`GSS_S_BAD_NAME`: Value supplied for desired_name parameter is ill-formed.

`GSS_S_DUPLICATE_ELEMENT`: The credential already contains an element for the requested mechanism with overlapping usage and validity period.

`GSS_S_CREDENTIALS_EXPIRED`: The required credentials could not be added because they have expired.

`GSS_S_NO_CRED`: No credentials were found for the specified name.

REPORTING BUGS
Report bugs to <bug-gss@gnu.org>. GNU Generic Security Service home page: http://www.gnu.org/software/gss/ General help using GNU software: http://www.gnu.org/gethelp/

COPYRIGHT
Copyright © 2003-2022 Simon Josefsson.
Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved.

SEE ALSO
The full documentation for gss is maintained as a Texinfo manual. If the info and gss programs are properly installed at your site, the command

    info gss

should give you access to the complete manual.