NAME
gss_accept_sec_context,
gss_acquire_cred,
gss_add_cred,
gss_add_oid_set_member,
gss_canonicalize_name,
gss_compare_name,
gss_context_time,
gss_create_empty_oid_set,
gss_delete_sec_context,
gss_display_name,
gss_display_status,
gss_duplicate_name,
gss_export_name,
gss_export_sec_context,
gss_get_mic,
gss_import_name,
gss_import_sec_context,
gss_indicate_mechs,
gss_init_sec_context,
gss_inquire_context,
gss_inquire_cred,
gss_inquire_cred_by_mech,
gss_inquire_mechs_for_name,
gss_inquire_names_for_mech,
gss_krb5_ccache_name,
gss_krb5_compat_des3_mic,
gss_krb5_copy_ccache,
gss_krb5_import_cred
gsskrb5_extract_authz_data_from_sec_context,
gsskrb5_register_acceptor_identity,
gss_krb5_import_ccache,
gss_krb5_get_tkt_flags,
gss_process_context_token,
gss_release_buffer,
gss_release_cred,
gss_release_name,
gss_release_oid_set,
gss_seal, gss_sign,
gss_test_oid_set_member,
gss_unseal, gss_unwrap,
gss_verify, gss_verify_mic,
gss_wrap,
gss_wrap_size_limit —
Generic Security Service Application
Program Interface library
LIBRARY
GSS-API library (libgssapi, -lgssapi)
SYNOPSIS
#include
<gssapi.h>
OM_uint32
gss_accept_sec_context(OM_uint32 *
minor_status, gss_ctx_id_t * context_handle,
const gss_cred_id_t acceptor_cred_handle,
const gss_buffer_t input_token_buffer,
const gss_channel_bindings_t input_chan_bindings,
gss_name_t * src_name, gss_OID *
mech_type, gss_buffer_t output_token,
OM_uint32 * ret_flags, OM_uint32 *
time_rec, gss_cred_id_t *
delegated_cred_handle);
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);
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);
OM_uint32
gss_add_oid_set_member(OM_uint32 *
minor_status, const gss_OID member_oid,
gss_OID_set * oid_set);
OM_uint32
gss_canonicalize_name(OM_uint32 *
minor_status, const gss_name_t input_name,
const gss_OID mech_type, gss_name_t *
output_name);
OM_uint32
gss_compare_name(OM_uint32 *
minor_status, const gss_name_t name1,
const gss_name_t name2, int *
name_equal);
OM_uint32
gss_context_time(OM_uint32 *
minor_status, const gss_ctx_id_t context_handle,
OM_uint32 * time_rec);
OM_uint32
gss_create_empty_oid_set(OM_uint32 *
minor_status, gss_OID_set * oid_set);
OM_uint32
gss_delete_sec_context(OM_uint32 *
minor_status, gss_ctx_id_t * context_handle,
gss_buffer_t output_token);
OM_uint32
gss_display_name(OM_uint32 *
minor_status, const gss_name_t input_name,
gss_buffer_t output_name_buffer,
gss_OID * output_name_type);
OM_uint32
gss_display_status(OM_uint32
*minor_status, OM_uint32 status_value,
int status_type, const gss_OID
mech_type, OM_uint32 *message_context,
gss_buffer_t status_string);
OM_uint32
gss_duplicate_name(OM_uint32 *
minor_status, const gss_name_t src_name,
gss_name_t * dest_name);
OM_uint32
gss_export_name(OM_uint32 *
minor_status, const gss_name_t input_name,
gss_buffer_t exported_name);
OM_uint32
gss_export_sec_context(OM_uint32 *
minor_status, gss_ctx_id_t * context_handle,
gss_buffer_t interprocess_token);
OM_uint32
gss_get_mic(OM_uint32 *
minor_status, const gss_ctx_id_t context_handle,
gss_qop_t qop_req, const gss_buffer_t
message_buffer, gss_buffer_t message_token);
OM_uint32
gss_import_name(OM_uint32 *
minor_status, const gss_buffer_t
input_name_buffer, const gss_OID
input_name_type, gss_name_t * output_name);
OM_uint32
gss_import_sec_context(OM_uint32 *
minor_status, const gss_buffer_t
interprocess_token, gss_ctx_id_t *
context_handle);
OM_uint32
gss_indicate_mechs(OM_uint32 *
minor_status, gss_OID_set * mech_set);
OM_uint32
gss_init_sec_context(OM_uint32 *
minor_status, const gss_cred_id_t
initiator_cred_handle, gss_ctx_id_t *
context_handle, const gss_name_t target_name,
const gss_OID mech_type, OM_uint32
req_flags, OM_uint32 time_req,
const gss_channel_bindings_t input_chan_bindings,
const gss_buffer_t input_token,
gss_OID * actual_mech_type,
gss_buffer_t output_token, OM_uint32 *
ret_flags, OM_uint32 * time_rec);
OM_uint32
gss_inquire_context(OM_uint32 *
minor_status, const gss_ctx_id_t context_handle,
gss_name_t * src_name, gss_name_t *
targ_name, OM_uint32 * lifetime_rec,
gss_OID * mech_type, OM_uint32 *
ctx_flags, int * locally_initiated,
int * open_context);
OM_uint32
gss_inquire_cred(OM_uint32 *
minor_status, const gss_cred_id_t cred_handle,
gss_name_t * name, OM_uint32 *
lifetime, gss_cred_usage_t * cred_usage,
gss_OID_set * mechanisms);
OM_uint32
gss_inquire_cred_by_mech(OM_uint32 *
minor_status, const gss_cred_id_t cred_handle,
const gss_OID mech_type, gss_name_t *
name, OM_uint32 * initiator_lifetime,
OM_uint32 * acceptor_lifetime,
gss_cred_usage_t * cred_usage);
OM_uint32
gss_inquire_mechs_for_name(OM_uint32 *
minor_status, const gss_name_t input_name,
gss_OID_set * mech_types);
OM_uint32
gss_inquire_names_for_mech(OM_uint32 *
minor_status, const gss_OID mechanism,
gss_OID_set * name_types);
OM_uint32
gss_krb5_ccache_name(OM_uint32
*minor, const char *name, const
char **old_name);
OM_uint32
gss_krb5_copy_ccache(OM_uint32
*minor, gss_cred_id_t cred,
krb5_ccache out);
OM_uint32
gss_krb5_import_cred(OM_uint32
*minor_status, krb5_ccache id,
krb5_principal keytab_principal,
krb5_keytab keytab, gss_cred_id_t
*cred);
OM_uint32
gss_krb5_compat_des3_mic(OM_uint32 *
minor_status, gss_ctx_id_t context_handle,
int onoff);
OM_uint32
gsskrb5_extract_authz_data_from_sec_context(OM_uint32
*minor_status, gss_ctx_id_t context_handle,
int ad_type, gss_buffer_t
ad_data);
OM_uint32
gsskrb5_register_acceptor_identity(const
char *identity);
OM_uint32
gss_krb5_import_cache(OM_uint32
*minor, krb5_ccache id,
krb5_keytab keytab, gss_cred_id_t
*cred);
OM_uint32
gss_krb5_get_tkt_flags(OM_uint32
*minor_status, gss_ctx_id_t context_handle,
OM_uint32 *tkt_flags);
OM_uint32
gss_process_context_token(OM_uint32 *
minor_status, const gss_ctx_id_t context_handle,
const gss_buffer_t token_buffer);
OM_uint32
gss_release_buffer(OM_uint32 *
minor_status, gss_buffer_t buffer);
OM_uint32
gss_release_cred(OM_uint32 *
minor_status, gss_cred_id_t * cred_handle);
OM_uint32
gss_release_name(OM_uint32 *
minor_status, gss_name_t * input_name);
OM_uint32
gss_release_oid_set(OM_uint32 *
minor_status, gss_OID_set * set);
OM_uint32
gss_seal(OM_uint32 *
minor_status, gss_ctx_id_t context_handle,
int conf_req_flag, int qop_req,
gss_buffer_t input_message_buffer, int
* conf_state, gss_buffer_t
output_message_buffer);
OM_uint32
gss_sign(OM_uint32 *
minor_status, gss_ctx_id_t context_handle,
int qop_req, gss_buffer_t
message_buffer, gss_buffer_t message_token);
OM_uint32
gss_test_oid_set_member(OM_uint32 *
minor_status, const gss_OID member,
const gss_OID_set set, int *
present);
OM_uint32
gss_unseal(OM_uint32 *
minor_status, gss_ctx_id_t context_handle,
gss_buffer_t input_message_buffer,
gss_buffer_t output_message_buffer,
int * conf_state, int *
qop_state);
OM_uint32
gss_unwrap(OM_uint32 *
minor_status, const gss_ctx_id_t context_handle,
const gss_buffer_t input_message_buffer,
gss_buffer_t output_message_buffer,
int * conf_state, gss_qop_t *
qop_state);
OM_uint32
gss_verify(OM_uint32 *
minor_status, gss_ctx_id_t context_handle,
gss_buffer_t message_buffer,
gss_buffer_t token_buffer, int *
qop_state);
OM_uint32
gss_verify_mic(OM_uint32 *
minor_status, const gss_ctx_id_t context_handle,
const gss_buffer_t message_buffer,
const gss_buffer_t token_buffer,
gss_qop_t * qop_state);
OM_uint32
gss_wrap(OM_uint32 *
minor_status, const gss_ctx_id_t context_handle,
int conf_req_flag, gss_qop_t
qop_req, const gss_buffer_t
input_message_buffer, int * conf_state,
gss_buffer_t output_message_buffer);
OM_uint32
gss_wrap_size_limit(OM_uint32 *
minor_status, const gss_ctx_id_t context_handle,
int conf_req_flag, gss_qop_t
qop_req, OM_uint32 req_output_size,
OM_uint32 * max_input_size);
DESCRIPTION
Generic Security Service API (GSS-API) version 2, and its C
binding, is described in RFC2743 and
RFC2744. Version 1 (deprecated) of the C binding is
described in RFC1509.
Heimdals GSS-API implementation supports the following mechanisms
GSS-API have generic name types that all mechanism are supposed to implement (if possible):
GSS_C_NT_USER_NAMEGSS_C_NT_MACHINE_UID_NAMEGSS_C_NT_STRING_UID_NAMEGSS_C_NT_HOSTBASED_SERVICEGSS_C_NT_ANONYMOUSGSS_C_NT_EXPORT_NAME
GSS-API implementations that supports Kerberos 5 have some additional name types:
GSS_KRB5_NT_PRINCIPAL_NAMEGSS_KRB5_NT_USER_NAMEGSS_KRB5_NT_MACHINE_UID_NAMEGSS_KRB5_NT_STRING_UID_NAME
In GSS-API, names have two forms, internal names and contiguous string names.
Internal name and mechanism nameInternal names are implementation specific representation of a GSS-API name.
Mechanism namesspecial form of internal names corresponds to one and only one mechanism.In GSS-API an internal name is stored in a
gss_name_t.Contiguous string name and exported nameContiguous string names are gssapi names stored in a
OCTET STRINGthat together with a name type identifier (OID) uniquely specifies a gss-name. A special form of the contiguous string name is the exported name that have a OID embedded in the string to make it unique. Exported name have the nametypeGSS_C_NT_EXPORT_NAME.In GSS-API an contiguous string name is stored in a
gss_buffer_t.Exported names also have the property that they are specified by the mechanism itself and compatible between different GSS-API implementations.
ACCESS CONTROL
There are two ways of comparing GSS-API names, either comparing two internal names with each other or two contiguous string names with either other.
To compare two internal names with each
other, import (if needed) the names with
gss_import_name()
into the GSS-API implementation and the compare the imported name with
gss_compare_name().
Importing names can be slow, so when its possible to store exported names in the access control list, comparing contiguous string name might be better.
when comparing contiguous string name, first
export them into a GSS_C_NT_EXPORT_NAME name with
gss_export_name()
and then compare with
memcmp(3).
Note that there are might be a difference
between the two methods of comparing names. The first (using
gss_compare_name())
will compare to (unauthenticated) names are the same. The second will
compare if a mechanism will authenticate them as the same principal.
For example, if
gss_import_name()
name was used with GSS_C_NO_OID the default syntax
is used for all mechanism the GSS-API implementation supports. When compare
the imported name of GSS_C_NO_OID it may match
serveral mechanism names (MN).
The resulting name from
gss_display_name()
must not be used for acccess control.
FUNCTIONS
gss_display_name() takes the gss name in
input_name and puts a printable form in
output_name_buffer.
output_name_buffer should be freed when done using
gss_release_buffer().
output_name_type can either be
NULL or a pointer to a
gss_OID and will in the latter case contain the OID
type of the name. The name must only be used for printing. If access control
is needed, see section ACCESS
CONTROL.
gss_inquire_context()
returns information about the context. Information is available even after
the context have expired. lifetime_rec argument is set
to GSS_C_INDEFINITE (dont expire) or the number of
seconds that the context is still valid. A value of 0 means that the context
is expired. mech_type argument should be considered
readonly and must not be released. src_name and
dest_name()
are both mechanims names and must be released with
gss_release_name()
when no longer used.
gss_context_time will return the amount of
time (in seconds) of the context is still valid. If its expired
time_rec will be set to 0 and
GSS_S_CONTEXT_EXPIRED returned.
gss_sign(),
gss_verify(),
gss_seal(),
and
gss_unseal()
are part of the GSS-API V1 interface and are obsolete. The functions should
not be used for new applications. They are provided so that version 1
applications can link against the library.
EXTENSIONS
gss_krb5_ccache_name()
sets the internal kerberos 5 credential cache name to
name. The old name is returned in
old_name, and must not be freed. The data allocated
for old_name is free upon next call to
gss_krb5_ccache_name(). This function is not
threadsafe if old_name argument is used.
gss_krb5_copy_ccache()
will extract the krb5 credentials that are transferred from the initiator to
the acceptor when using token delegation in the Kerberos mechanism. The
acceptor receives the delegated token in the last argument to
gss_accept_sec_context().
gss_krb5_import_cred()
will import the krb5 credentials (both keytab and/or credential cache) into
gss credential so it can be used withing GSS-API. The
ccache is copied by reference and thus shared, so if
the credential is destroyed with krb5_cc_destroy, all
users of thep gss_cred_id_t returned by
gss_krb5_import_ccache()
will fail.
gsskrb5_register_acceptor_identity()
sets the Kerberos 5 filebased keytab that the acceptor will use. The
identifier is the file name.
gsskrb5_extract_authz_data_from_sec_context()
extracts the Kerberos authorizationdata that may be stored within the
context. Tha caller must free the returned buffer
ad_data with
gss_release_buffer()
upon success.
gss_krb5_get_tkt_flags()
return the ticket flags for the kerberos ticket receive when authenticating
the initiator. Only valid on the acceptor context.
gss_krb5_compat_des3_mic()
turns on or off the compatibility with older version of Heimdal using des3
get and verify mic, this is way to programmatically set the
[gssapi]broken_des3_mic and [gssapi]correct_des3_mic flags (see
COMPATIBILITY section in
gssapi(3)). If the CPP symbol
GSS_C_KRB5_COMPAT_DES3_MIC is present,
gss_krb5_compat_des3_mic() exists.
gss_krb5_compat_des3_mic() will be removed in a
later version of the GSS-API library.