/*
 * Copyright (c) 1997, 1999 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 "kadm5_locl.h"

RCSID("$Id: acl.c,v 1.10 1999/12/02 17:05:05 joda Exp $");

static struct units acl_units[] = {
    { "all",		KADM5_PRIV_ALL },
    { "change-password",KADM5_PRIV_CPW },
    { "cpw",		KADM5_PRIV_CPW },
    { "list",		KADM5_PRIV_LIST },
    { "delete",		KADM5_PRIV_DELETE },
    { "modify",		KADM5_PRIV_MODIFY },
    { "add",		KADM5_PRIV_ADD },
    { "get", 		KADM5_PRIV_GET },
    { NULL }
};

kadm5_ret_t
_kadm5_string_to_privs(const char *s, u_int32_t* privs)
{
    int flags;
    flags = parse_flags(s, acl_units, 0);
    if(flags < 0)
	return KADM5_FAILURE;
    *privs = flags;
    return 0;
}

kadm5_ret_t
_kadm5_privs_to_string(u_int32_t privs, char *string, size_t len)
{
    if(privs == 0)
	strlcpy(string, "none", len);
    else
	unparse_flags(privs, acl_units + 1, string, len);
    return 0;
}

kadm5_ret_t
_kadm5_acl_init(kadm5_server_context *context)
{
    FILE *f;
    char buf[128];
    krb5_principal princ;
    int flags;
    krb5_error_code ret;
    
    krb5_parse_name(context->context, KADM5_ADMIN_SERVICE, &princ);
    ret = krb5_principal_compare(context->context, context->caller, princ);
    krb5_free_principal(context->context, princ);
    if(ret != 0){
	context->acl_flags = KADM5_PRIV_ALL;
	return 0;
    }

    flags = -1;
    f = fopen(context->config.acl_file, "r");
    if(f){
	while(fgets(buf, sizeof(buf), f)){
	    char *foo = NULL, *p;
	    p = strtok_r(buf, " \t\n", &foo);
	    if(p == NULL)
		continue;
	    ret = krb5_parse_name(context->context, p, &princ);
	    if(ret)
		continue;
	    if(!krb5_principal_compare(context->context, 
				       context->caller,  princ)){
		krb5_free_principal(context->context, princ);
		continue;
	    }
	    krb5_free_principal(context->context, princ);
	    p = strtok_r(NULL, "\n", &foo);
	    if(p == NULL)
		continue;
	    ret = _kadm5_string_to_privs(p, &flags);
	    break;
	}
	fclose(f);
    }
    if(flags == -1)
	flags = 0;
    context->acl_flags = flags;
    return 0;
}

kadm5_ret_t
_kadm5_acl_check_permission(kadm5_server_context *context, unsigned op)
{
    unsigned res = ~context->acl_flags & op;
    if(res & KADM5_PRIV_GET)
	return KADM5_AUTH_GET;
    if(res & KADM5_PRIV_ADD)
	return KADM5_AUTH_ADD;
    if(res & KADM5_PRIV_MODIFY)
	return KADM5_AUTH_MODIFY;
    if(res & KADM5_PRIV_DELETE)
	return KADM5_AUTH_DELETE;
    if(res & KADM5_PRIV_CPW)
	return KADM5_AUTH_CHANGEPW;
    if(res & KADM5_PRIV_LIST)
	return KADM5_AUTH_LIST;
    if(res)
	return KADM5_AUTH_INSUFFICIENT;
    return 0;
}