GSS_ACQUIRE_CRED(3) | Library Functions Manual | GSS_ACQUIRE_CRED(3)

# 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/gssapi.h>`

OM_uint32
`gss_accept_sec_context`(OM_uint32 * minor_status, gss_ctx_id_t * context_handle, gss_const_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, gss_const_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, gss_const_cred_id_t input_cred_handle, gss_const_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, gss_const_name_t input_name, const gss_OID mech_type, gss_name_t * output_name);

OM_uint32
`gss_compare_name`(OM_uint32 * minor_status, gss_const_name_t name1, gss_const_name_t name2, int * name_equal);

OM_uint32
`gss_context_time`(OM_uint32 * minor_status, gss_const_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, gss_const_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, gss_const_name_t src_name, gss_name_t * dest_name);

OM_uint32
`gss_export_name`(OM_uint32 * minor_status, gss_const_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, gss_const_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, gss_const_cred_id_t initiator_cred_handle, gss_ctx_id_t * context_handle, gss_const_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, gss_const_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, gss_const_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, gss_const_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, gss_const_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, gss_const_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, gss_const_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, gss_const_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, gss_const_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, gss_const_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_KRB5_MECHANISM`
- `GSS_SPNEGO_MECHANISM`

GSS-API have generic name types that all mechanism are supposed to implement (if possible):

- `GSS_C_NT_USER_NAME`
- `GSS_C_NT_MACHINE_UID_NAME`
- `GSS_C_NT_STRING_UID_NAME`
- `GSS_C_NT_HOSTBASED_SERVICE`
- `GSS_C_NT_ANONYMOUS`
- `GSS_C_NT_EXPORT_NAME`

GSS-API implementations that supports Kerberos 5 have some additional name types:

- `GSS_KRB5_NT_PRINCIPAL_NAME`
- `GSS_KRB5_NT_USER_NAME`
- `GSS_KRB5_NT_MACHINE_UID_NAME`
- `GSS_KRB5_NT_STRING_UID_NAME`

In GSS-API, names have two forms, internal names and contiguous string names.

- `Internal name and mechanism name`

  Internal names are implementation specific representation of a GSS-API name. `Mechanism names` special 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 name`

  Contiguous string names are gssapi names stored in a `OCTET STRING` that 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 nametype `GSS_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 several 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` (don't 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.

# SEE ALSO

gssapi(3), krb5(3), krb5_ccache(3), kerberos(8)

October 26, 2005 | NetBSD 9.5