GSS_ACQUIRE_CRED(3) Programmer's Manual GSS_ACQUIRE_CRED(3)NAMEgss_acquire_cred — Obtain a GSS-API credential handle for pre-existing
credentials
SYNOPSIS
#include <gssapi/gssapi.h>
OM_uint32
gss_acquire_cred(OM_uint32 *minor_status, const gss_name_t desired_name,
OM_uint32 time_req, const gss_OID_set desired_mechs,
gss_cred_usage_t cred_usage, gss_cred_id_t *output_cred_handle,
gss_OID_set *actual_mechs, OM_uint32 *time_rec);
DESCRIPTION
Allows an application to acquire a handle for a pre-existing credential
by name. GSS-API implementations must impose a local access-control pol‐
icy on callers of this routine to prevent unauthorized callers from
acquiring credentials 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 credentials rather than merely
acquiring a handle to existing credentials. 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
for a credential handle 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 ).
Mechanisms should honor the desired_mechs parameter, and return a creden‐
tial that is suitable to use only with the requested mechanisms. An
exception to this is the case where one underlying credential element can
be shared by multiple mechanisms; in this case it is permissible for an
implementation to indicate all mechanisms with which the credential ele‐
ment may be used. If desired_mechs is an empty set, behavior is unde‐
fined.
This routine is expected to be used primarily by context acceptors, since
implementations are likely to provide mechanism-specific ways of obtain‐
ing 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 mecha‐
nism 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_acquire_cred() must return valid credential
data, and may therefore incur the overhead of a deferred credential
acquisition.
PARAMETERS
desired_name Name of principal whose credential should be acquired.
time_req Number of seconds that credentials should remain valid.
Specify GSS_C_INDEFINITE to request that the credentials
have the maximum permitted lifetime.
desired_mechs
Set of underlying security mechanisms that may be used.
GSS_C_NO_OID_SET may be used to obtain an implementation-
specific default.
cred_usage
GSS_C_BOTH Credentials may be used either to initiate
or accept security contexts.
GSS_C_INITIATE Credentials will only be used to initiate
security contexts.
GSS_C_ACCEPT Credentials will only be used to accept
security contexts.
output_cred_handle
The returned credential handle. Resources associated with
this credential handle must be released by the application
after use with a call to gss_release_cred().
actual_mechs The set of mechanisms for which the credential is valid.
Storage associated with the returned OID-set must be
released by the application after use with a call to
gss_release_oid_set(). Specify NULL if not required.
time_rec Actual number of seconds for which the returned credentials
will remain valid. If the implementation does not support
expiration of credentials, the value GSS_C_INDEFINITE will
be returned. Specify NULL if not required.
minor_status Mechanism specific status code.
RETURN VALUES
GSS_S_COMPLETE
Successful completion.
GSS_S_BAD_MECH
Unavailable mechanism requested.
GSS_S_BAD_NAMETYPE
Type contained within desired_name parameter is not sup‐
ported.
GSS_S_BAD_NAME
Value supplied for desired_name parameter is ill formed.
GSS_S_CREDENTIALS_EXPIRED
The credentials could not be acquired Because they have
expired.
GSS_S_NO_CRED
No credentials were found for the specified name.
SEE ALSOgss_init_sec_context(3), gss_accept_sec_context(3), gss_inquire_cred(3),
gss_inquire_context(3), gss_release_cred(3), gss_release_oid_set(3)STANDARDS
RFC 2743 Generic Security Service Application Program Interface Ver‐
sion 2, Update 1
RFC 2744 Generic Security Service API Version 2 : C-bindings
HISTORY
The gss_acquire_cred function first appeared in FreeBSD 7.0.
AUTHORS
John Wray, Iris Associates
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BSD January 26, 2010 BSD