/*
 * Copyright (c) 1997 - 2001 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden). 
 * All rights reserved. 
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions 
 * are met: 
 *
 * 1. Redistributions of source code must retain the above copyright 
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright 
 *    notice, this list of conditions and the following disclaimer in the 
 *    documentation and/or other materials provided with the distribution. 
 *
 * 3. Neither the name of the Institute nor the names of its contributors 
 *    may be used to endorse or promote products derived from this software 
 *    without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
 * SUCH DAMAGE. 
 */

#include "gssapi_locl.h"

RCSID("$Id: encapsulate.c,v 1.6.6.1 2003/09/18 21:47:44 lha Exp $");

void
gssapi_krb5_encap_length (size_t data_len,
			  size_t *len,
			  size_t *total_len)
{
    size_t len_len;

    *len = 1 + 1 + GSS_KRB5_MECHANISM->length + 2 + data_len;

    len_len = length_len(*len);

    *total_len = 1 + len_len + *len;
}

u_char *
gssapi_krb5_make_header (u_char *p,
			 size_t len,
			 u_char *type)
{
    int e;
    size_t len_len, foo;

    *p++ = 0x60;
    len_len = length_len(len);
    e = der_put_length (p + len_len - 1, len_len, len, &foo);
    if(e || foo != len_len)
	abort ();
    p += len_len;
    *p++ = 0x06;
    *p++ = GSS_KRB5_MECHANISM->length;
    memcpy (p, GSS_KRB5_MECHANISM->elements, GSS_KRB5_MECHANISM->length);
    p += GSS_KRB5_MECHANISM->length;
    memcpy (p, type, 2);
    p += 2;
    return p;
}

u_char *
_gssapi_make_mech_header(u_char *p,
			 size_t len)
{
    int e;
    size_t len_len, foo;

    *p++ = 0x60;
    len_len = length_len(len);
    e = der_put_length (p + len_len - 1, len_len, len, &foo);
    if(e || foo != len_len)
	abort ();
    p += len_len;
    *p++ = 0x06;
    *p++ = GSS_KRB5_MECHANISM->length;
    memcpy (p, GSS_KRB5_MECHANISM->elements, GSS_KRB5_MECHANISM->length);
    p += GSS_KRB5_MECHANISM->length;
    return p;
}

/*
 * Give it a krb5_data and it will encapsulate with extra GSS-API wrappings.
 */

OM_uint32
gssapi_krb5_encapsulate(
			OM_uint32 *minor_status,    
			const krb5_data *in_data,
			gss_buffer_t output_token,
			u_char *type
)
{
    size_t len, outer_len;
    u_char *p;

    gssapi_krb5_encap_length (in_data->length, &len, &outer_len);
    
    output_token->length = outer_len;
    output_token->value  = malloc (outer_len);
    if (output_token->value == NULL) {
	*minor_status = ENOMEM;
	return GSS_S_FAILURE;
    }	

    p = gssapi_krb5_make_header (output_token->value, len, type);
    memcpy (p, in_data->data, in_data->length);
    return GSS_S_COMPLETE;
}