/*
 * Copyright 1993 by OpenVision Technologies, Inc.
 * 
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appears in all copies and
 * that both that copyright notice and this permission notice appear in
 * supporting documentation, and that the name of OpenVision not be used
 * in advertising or publicity pertaining to distribution of the software
 * without specific, written prior permission. OpenVision makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 * 
 * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

#include "gssapiP_krb5.h"

/*
 * $Id: wrap_size_limit.c,v 1.2 1996/07/22 20:34:47 marc Exp $
 */

/* V2 interface */
OM_uint32
krb5_gss_wrap_size_limit(minor_status, context_handle, conf_req_flag,
			 qop_req, req_output_size, max_input_size)
    OM_uint32		*minor_status;
    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;
{
    krb5_context	context;
    krb5_gss_ctx_id_rec	*ctx;
    OM_uint32		cfsize;
    OM_uint32		ohlen;

    if (GSS_ERROR(kg_get_context(minor_status, &context)))
       return(GSS_S_FAILURE);

    /* only default qop is allowed */
    if (qop_req != GSS_C_QOP_DEFAULT) {
	*minor_status = (OM_uint32) G_UNKNOWN_QOP;
	return(GSS_S_FAILURE);
    }
    
    /* validate the context handle */
    if (! kg_validate_ctx_id(context_handle)) {
	*minor_status = (OM_uint32) G_VALIDATE_FAILED;
	return(GSS_S_NO_CONTEXT);
    }
    
    ctx = (krb5_gss_ctx_id_rec *) context_handle;
    if (! ctx->established) {
	*minor_status = KG_CTX_INCOMPLETE;
	return(GSS_S_NO_CONTEXT);
    }

    /* Calculate the token size and subtract that from the output size */
    cfsize = (conf_req_flag) ? kg_confounder_size(&ctx->enc) : 0;
    ohlen = g_token_size((gss_OID) ctx->mech_used,
			 (unsigned int) cfsize + ctx->cksum_size + 14);

    /* Cannot have trailer length that will cause us to pad over our length */
    *max_input_size = (req_output_size - ohlen) & (~7);
    *minor_status = 0;
    return(GSS_S_COMPLETE);
}
