gss_init_sec_context (minor_status,
                      claimant_cred_handle,
                      context_handle,
                      target_name,
                      req_mech_type,
                      req_flags,
                      time_req,
                      input_chan_bindings,
                      input_token,
                      actual_mech_type,
                      output_token,
                      ret_flags,
                      time_rec)

OM_uint32 *		minor_status;
gss_cred_id_t		claimant_cred_handle;
gss_ctx_id_t *		context_handle;
gss_name_t		target_name;
gss_OID			req_mech_type;
OM_uint32		req_flags;
OM_uint32		time_req;
gss_channel_bindings_t	input_chan_bindings;
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		status, temp_minor_status;
    gss_union_name_t	union_name;
    gss_union_cred_t	union_cred;
    gss_name_t		internal_name;
    gss_union_ctx_id_t	union_ctx_id;
    gss_OID		selected_mech;
    gss_mechanism	mech;
    gss_cred_id_t	input_cred_handle;

    status = val_init_sec_ctx_args(minor_status,
				   claimant_cred_handle,
				   context_handle,
				   target_name,
				   req_mech_type,
				   req_flags,
				   time_req,
				   input_chan_bindings,
				   input_token,
				   actual_mech_type,
				   output_token,
				   ret_flags,
				   time_rec);
    if (status != GSS_S_COMPLETE)
	return (status);

    status = gssint_select_mech_type(minor_status, req_mech_type,
				     &selected_mech);
    if (status != GSS_S_COMPLETE)
	return (status);

    union_name = (gss_union_name_t)target_name;

    /*
     * obtain the gss mechanism information for the requested
     * mechanism.  If mech_type is NULL, set it to the resultant
     * mechanism
     */
    mech = gssint_get_mechanism(selected_mech);
    if (mech == NULL)
	return (GSS_S_BAD_MECH);

    if (mech->gss_init_sec_context == NULL)
	return (GSS_S_UNAVAILABLE);

    /*
     * If target_name is mechanism_specific, then it must match the
     * mech_type that we're about to use.  Otherwise, do an import on
     * the external_name form of the target name.
     */
    if (union_name->mech_type &&
	g_OID_equal(union_name->mech_type, selected_mech)) {
	internal_name = union_name->mech_name;
    } else {
	if ((status = gssint_import_internal_name(minor_status, selected_mech,
						 union_name,
						 &internal_name)) != GSS_S_COMPLETE)
	    return (status);
    }

    /*
     * if context_handle is GSS_C_NO_CONTEXT, allocate a union context
     * descriptor to hold the mech type information as well as the
     * underlying mechanism context handle. Otherwise, cast the
     * value of *context_handle to the union context variable.
     */

    if(*context_handle == GSS_C_NO_CONTEXT) {
	status = GSS_S_FAILURE;
	union_ctx_id = (gss_union_ctx_id_t)
	    malloc(sizeof(gss_union_ctx_id_desc));
	if (union_ctx_id == NULL)
	    goto end;

	if (generic_gss_copy_oid(&temp_minor_status, selected_mech,
				 &union_ctx_id->mech_type) != GSS_S_COMPLETE) {
	    free(union_ctx_id);
	    goto end;
	}

	/* copy the supplied context handle */
	union_ctx_id->internal_ctx_id = GSS_C_NO_CONTEXT;
    } else {
	union_ctx_id = (gss_union_ctx_id_t)*context_handle;
	if (union_ctx_id->internal_ctx_id == GSS_C_NO_CONTEXT) {
	    status = GSS_S_NO_CONTEXT;
	    goto end;
	}
    }

    /*
     * get the appropriate cred handle from the union cred struct.
     * defaults to GSS_C_NO_CREDENTIAL if there is no cred, which will
     * use the default credential.
     */
    union_cred = (gss_union_cred_t) claimant_cred_handle;
    input_cred_handle = gssint_get_mechanism_cred(union_cred, selected_mech);

    /*
     * now call the approprate underlying mechanism routine
     */

    status = mech->gss_init_sec_context(
	minor_status,
	input_cred_handle,
	&union_ctx_id->internal_ctx_id,
	internal_name,
	gssint_get_public_oid(selected_mech),
	req_flags,
	time_req,
	input_chan_bindings,
	input_token,
	actual_mech_type,
	output_token,
	ret_flags,
	time_rec);

    if (status != GSS_S_COMPLETE && status != GSS_S_CONTINUE_NEEDED) {
	/*
	 * RFC 2744 5.19 requires that we not create a context on a failed
	 * first call to init, and recommends that on a failed subsequent call
	 * we make the caller responsible for calling gss_delete_sec_context.
	 * Even if the mech deleted its context, keep the union context around
	 * for the caller to delete.
	 */
	map_error(minor_status, mech);
	if (*context_handle == GSS_C_NO_CONTEXT) {
	    free(union_ctx_id->mech_type->elements);
	    free(union_ctx_id->mech_type);
	    free(union_ctx_id);
	}
    } else if (*context_handle == GSS_C_NO_CONTEXT) {
	union_ctx_id->loopback = union_ctx_id;
	*context_handle = (gss_ctx_id_t)union_ctx_id;
    }

end:
    if (union_name->mech_name == NULL ||
	union_name->mech_name != internal_name) {
	(void) gssint_release_internal_name(&temp_minor_status,
					    selected_mech, &internal_name);
    }

    return(status);
}