588 lines
15 KiB
C
588 lines
15 KiB
C
/*
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* Copyright (c) 1997 - 2000 Kungliga Tekniska Högskolan
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* (Royal Institute of Technology, Stockholm, Sweden).
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* 3. Neither the name of the Institute nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include "kdc_locl.h"
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RCSID("$Id: kerberos4.c,v 1.27 2000/02/13 19:27:36 assar Exp $");
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#ifdef KRB4
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#include "kerberos4.h"
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#ifndef swap32
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static u_int32_t
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swap32(u_int32_t x)
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{
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return ((x << 24) & 0xff000000) |
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((x << 8) & 0xff0000) |
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((x >> 8) & 0xff00) |
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((x >> 24) & 0xff);
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}
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#endif /* swap32 */
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int
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maybe_version4(unsigned char *buf, int len)
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{
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return len > 0 && *buf == 4;
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}
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static void
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make_err_reply(krb5_data *reply, int code, const char *msg)
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{
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KTEXT_ST er;
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/* name, instance and realm is not checked in most (all?) version
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implementations; msg is also never used, but we send it anyway
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(for debugging purposes) */
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if(msg == NULL)
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msg = krb_get_err_text(code);
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cr_err_reply(&er, "", "", "", kdc_time, code, (char*)msg);
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krb5_data_copy(reply, er.dat, er.length);
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}
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static krb5_boolean
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valid_princ(krb5_context context, krb5_principal princ)
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{
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char *s;
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hdb_entry *ent;
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krb5_unparse_name(context, princ, &s);
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ent = db_fetch(princ);
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if(ent == NULL){
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kdc_log(7, "Lookup %s failed", s);
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free(s);
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return 0;
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}
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kdc_log(7, "Lookup %s succeeded", s);
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free(s);
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hdb_free_entry(context, ent);
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free(ent);
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return 1;
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}
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hdb_entry*
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db_fetch4(const char *name, const char *instance, const char *realm)
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{
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krb5_principal p;
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hdb_entry *ent;
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krb5_error_code ret;
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ret = krb5_425_conv_principal_ext(context, name, instance, realm,
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valid_princ, 0, &p);
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if(ret)
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return NULL;
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ent = db_fetch(p);
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krb5_free_principal(context, p);
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return ent;
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}
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krb5_error_code
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get_des_key(hdb_entry *principal, Key **key)
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{
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krb5_error_code ret;
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ret = hdb_enctype2key(context, principal, ETYPE_DES_CBC_MD5, key);
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if(ret)
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ret = hdb_enctype2key(context, principal, ETYPE_DES_CBC_MD4, key);
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if(ret)
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ret = hdb_enctype2key(context, principal, ETYPE_DES_CBC_CRC, key);
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if(ret)
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return ret;
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if ((*key)->key.keyvalue.length == 0)
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return KERB_ERR_NULL_KEY;
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return 0;
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}
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#define RCHECK(X, L) if(X){make_err_reply(reply, KFAILURE, "Packet too short"); goto L;}
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/*
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* Process the v4 request in `buf, len' (received from `addr'
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* (with string `from').
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* Return an error code and a reply in `reply'.
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*/
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krb5_error_code
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do_version4(unsigned char *buf,
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size_t len,
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krb5_data *reply,
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const char *from,
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struct sockaddr_in *addr)
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{
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krb5_storage *sp;
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krb5_error_code ret;
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hdb_entry *client = NULL, *server = NULL;
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Key *ckey, *skey;
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int8_t pvno;
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int8_t msg_type;
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int lsb;
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char *name = NULL, *inst = NULL, *realm = NULL;
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char *sname = NULL, *sinst = NULL;
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int32_t req_time;
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time_t max_life;
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u_int8_t life;
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sp = krb5_storage_from_mem(buf, len);
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RCHECK(krb5_ret_int8(sp, &pvno), out);
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if(pvno != 4){
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kdc_log(0, "Protocol version mismatch (%d)", pvno);
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make_err_reply(reply, KDC_PKT_VER, NULL);
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goto out;
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}
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RCHECK(krb5_ret_int8(sp, &msg_type), out);
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lsb = msg_type & 1;
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msg_type &= ~1;
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switch(msg_type){
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case AUTH_MSG_KDC_REQUEST:
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RCHECK(krb5_ret_stringz(sp, &name), out1);
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RCHECK(krb5_ret_stringz(sp, &inst), out1);
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RCHECK(krb5_ret_stringz(sp, &realm), out1);
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RCHECK(krb5_ret_int32(sp, &req_time), out1);
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if(lsb)
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req_time = swap32(req_time);
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RCHECK(krb5_ret_int8(sp, &life), out1);
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RCHECK(krb5_ret_stringz(sp, &sname), out1);
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RCHECK(krb5_ret_stringz(sp, &sinst), out1);
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kdc_log(0, "AS-REQ %s.%s@%s from %s for %s.%s",
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name, inst, realm, from, sname, sinst);
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client = db_fetch4(name, inst, realm);
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if(client == NULL){
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kdc_log(0, "Client not found in database: %s.%s@%s",
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name, inst, realm);
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make_err_reply(reply, KERB_ERR_PRINCIPAL_UNKNOWN, NULL);
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goto out1;
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}
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server = db_fetch4(sname, sinst, v4_realm);
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if(server == NULL){
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kdc_log(0, "Server not found in database: %s.%s@%s",
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sname, sinst, v4_realm);
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make_err_reply(reply, KERB_ERR_PRINCIPAL_UNKNOWN, NULL);
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goto out1;
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}
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/*
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* There's no way to do pre-authentication in v4 and thus no
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* good error code to return if preauthentication is required.
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*/
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if (require_preauth
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|| client->flags.require_preauth
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|| server->flags.require_preauth) {
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kdc_log(0,
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"Pre-authentication required for v4-request: "
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"%s.%s@%s for %s.%s@%s",
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name, inst, realm,
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sname, sinst, v4_realm);
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make_err_reply(reply, KERB_ERR_NULL_KEY, NULL);
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goto out1;
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}
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ret = get_des_key(client, &ckey);
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if(ret){
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kdc_log(0, "%s", krb5_get_err_text(context, ret));
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/* XXX */
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make_err_reply(reply, KDC_NULL_KEY,
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"No DES key in database (client)");
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goto out1;
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}
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#if 0
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/* this is not necessary with the new code in libkrb */
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/* find a properly salted key */
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while(ckey->salt == NULL || ckey->salt->salt.length != 0)
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ret = hdb_next_keytype2key(context, client, KEYTYPE_DES, &ckey);
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if(ret){
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kdc_log(0, "No version-4 salted key in database -- %s.%s@%s",
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name, inst, realm);
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make_err_reply(reply, KDC_NULL_KEY,
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"No version-4 salted key in database");
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goto out1;
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}
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#endif
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ret = get_des_key(server, &skey);
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if(ret){
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kdc_log(0, "%s", krb5_get_err_text(context, ret));
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/* XXX */
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make_err_reply(reply, KDC_NULL_KEY,
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"No DES key in database (server)");
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goto out1;
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}
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max_life = krb_life_to_time(0, life);
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if(client->max_life)
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max_life = min(max_life, *client->max_life);
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if(server->max_life)
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max_life = min(max_life, *server->max_life);
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life = krb_time_to_life(kdc_time, kdc_time + max_life);
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{
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KTEXT_ST cipher, ticket;
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KTEXT r;
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des_cblock session;
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des_new_random_key(&session);
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krb_create_ticket(&ticket, 0, name, inst, v4_realm,
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addr->sin_addr.s_addr, session, life, kdc_time,
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sname, sinst, skey->key.keyvalue.data);
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create_ciph(&cipher, session, sname, sinst, v4_realm,
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life, server->kvno, &ticket, kdc_time,
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ckey->key.keyvalue.data);
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memset(&session, 0, sizeof(session));
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r = create_auth_reply(name, inst, realm, req_time, 0,
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client->pw_end ? *client->pw_end : 0,
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client->kvno, &cipher);
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krb5_data_copy(reply, r->dat, r->length);
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memset(&cipher, 0, sizeof(cipher));
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memset(&ticket, 0, sizeof(ticket));
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}
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out1:
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break;
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case AUTH_MSG_APPL_REQUEST: {
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int8_t kvno;
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int8_t ticket_len;
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int8_t req_len;
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KTEXT_ST auth;
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AUTH_DAT ad;
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size_t pos;
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krb5_principal tgt_princ = NULL;
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hdb_entry *tgt = NULL;
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Key *tkey;
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RCHECK(krb5_ret_int8(sp, &kvno), out2);
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RCHECK(krb5_ret_stringz(sp, &realm), out2);
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ret = krb5_425_conv_principal(context, "krbtgt", realm, v4_realm,
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&tgt_princ);
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if(ret){
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kdc_log(0, "Converting krbtgt principal: %s",
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krb5_get_err_text(context, ret));
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make_err_reply(reply, KFAILURE,
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"Failed to convert v4 principal (krbtgt)");
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goto out2;
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}
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tgt = db_fetch(tgt_princ);
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if(tgt == NULL){
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char *s;
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s = kdc_log_msg(0, "Ticket-granting ticket not "
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"found in database: krbtgt.%s@%s",
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realm, v4_realm);
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make_err_reply(reply, KFAILURE, s);
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free(s);
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goto out2;
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}
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if(tgt->kvno != kvno){
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kdc_log(0, "tgs-req with old kvno %d (current %d) for "
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"krbtgt.%s@%s", kvno, tgt->kvno, realm, v4_realm);
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make_err_reply(reply, KDC_AUTH_EXP,
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"old krbtgt kvno used");
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goto out2;
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}
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ret = get_des_key(tgt, &tkey);
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if(ret){
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kdc_log(0, "%s", krb5_get_err_text(context, ret));
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/* XXX */
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make_err_reply(reply, KDC_NULL_KEY,
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"No DES key in database (krbtgt)");
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goto out2;
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}
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RCHECK(krb5_ret_int8(sp, &ticket_len), out2);
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RCHECK(krb5_ret_int8(sp, &req_len), out2);
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pos = sp->seek(sp, ticket_len + req_len, SEEK_CUR);
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memset(&auth, 0, sizeof(auth));
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memcpy(&auth.dat, buf, pos);
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auth.length = pos;
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krb_set_key(tkey->key.keyvalue.data, 0);
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krb_ignore_ip_address = !check_ticket_addresses;
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ret = krb_rd_req(&auth, "krbtgt", realm,
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addr->sin_addr.s_addr, &ad, 0);
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if(ret){
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kdc_log(0, "krb_rd_req: %s", krb_get_err_text(ret));
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make_err_reply(reply, ret, NULL);
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goto out2;
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}
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RCHECK(krb5_ret_int32(sp, &req_time), out2);
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if(lsb)
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req_time = swap32(req_time);
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RCHECK(krb5_ret_int8(sp, &life), out2);
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RCHECK(krb5_ret_stringz(sp, &sname), out2);
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RCHECK(krb5_ret_stringz(sp, &sinst), out2);
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kdc_log(0, "TGS-REQ %s.%s@%s from %s for %s.%s",
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ad.pname, ad.pinst, ad.prealm, from, sname, sinst);
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if(strcmp(ad.prealm, realm)){
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kdc_log(0, "Can't hop realms %s -> %s", realm, ad.prealm);
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make_err_reply(reply, KERB_ERR_PRINCIPAL_UNKNOWN,
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"Can't hop realms");
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goto out2;
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}
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if(strcmp(sname, "changepw") == 0){
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kdc_log(0, "Bad request for changepw ticket");
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make_err_reply(reply, KERB_ERR_PRINCIPAL_UNKNOWN,
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"Can't authorize password change based on TGT");
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goto out2;
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}
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#if 0
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client = db_fetch4(ad.pname, ad.pinst, ad.prealm);
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if(client == NULL){
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char *s;
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s = kdc_log_msg(0, "Client not found in database: %s.%s@%s",
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ad.pname, ad.pinst, ad.prealm);
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make_err_reply(reply, KERB_ERR_PRINCIPAL_UNKNOWN, s);
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free(s);
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goto out2;
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}
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#endif
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server = db_fetch4(sname, sinst, v4_realm);
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if(server == NULL){
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char *s;
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s = kdc_log_msg(0, "Server not found in database: %s.%s@%s",
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sname, sinst, v4_realm);
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make_err_reply(reply, KERB_ERR_PRINCIPAL_UNKNOWN, s);
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free(s);
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goto out2;
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}
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ret = get_des_key(server, &skey);
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if(ret){
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kdc_log(0, "%s", krb5_get_err_text(context, ret));
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/* XXX */
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make_err_reply(reply, KDC_NULL_KEY,
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"No DES key in database (server)");
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goto out2;
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}
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max_life = krb_life_to_time(ad.time_sec, ad.life);
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max_life = min(max_life, krb_life_to_time(kdc_time, life));
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life = min(life, krb_time_to_life(kdc_time, max_life));
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max_life = krb_life_to_time(0, life);
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#if 0
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if(client->max_life)
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max_life = min(max_life, *client->max_life);
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#endif
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if(server->max_life)
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max_life = min(max_life, *server->max_life);
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{
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KTEXT_ST cipher, ticket;
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KTEXT r;
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des_cblock session;
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des_new_random_key(&session);
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krb_create_ticket(&ticket, 0, ad.pname, ad.pinst, ad.prealm,
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addr->sin_addr.s_addr, &session, life, kdc_time,
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sname, sinst, skey->key.keyvalue.data);
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create_ciph(&cipher, session, sname, sinst, v4_realm,
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life, server->kvno, &ticket,
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kdc_time, &ad.session);
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memset(&session, 0, sizeof(session));
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memset(ad.session, 0, sizeof(ad.session));
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r = create_auth_reply(ad.pname, ad.pinst, ad.prealm,
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req_time, 0, 0, 0, &cipher);
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krb5_data_copy(reply, r->dat, r->length);
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memset(&cipher, 0, sizeof(cipher));
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memset(&ticket, 0, sizeof(ticket));
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}
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out2:
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if(tgt_princ)
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krb5_free_principal(context, tgt_princ);
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if(tgt){
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hdb_free_entry(context, tgt);
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free(tgt);
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}
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break;
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}
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case AUTH_MSG_ERR_REPLY:
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break;
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default:
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kdc_log(0, "Unknown message type: %d from %s",
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msg_type, from);
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make_err_reply(reply, KFAILURE, "Unknown message type");
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}
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out:
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if(name)
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free(name);
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if(inst)
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free(inst);
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if(realm)
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free(realm);
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if(sname)
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free(sname);
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if(sinst)
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free(sinst);
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if(client){
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hdb_free_entry(context, client);
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free(client);
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}
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if(server){
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hdb_free_entry(context, server);
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free(server);
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}
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krb5_storage_free(sp);
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return 0;
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}
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#define ETYPE_DES_PCBC 17 /* XXX */
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krb5_error_code
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encrypt_v4_ticket(void *buf, size_t len, des_cblock *key, EncryptedData *reply)
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{
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des_key_schedule schedule;
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|
|
reply->etype = ETYPE_DES_PCBC;
|
|
reply->kvno = NULL;
|
|
reply->cipher.length = len;
|
|
reply->cipher.data = malloc(len);
|
|
if(len != 0 && reply->cipher.data == NULL)
|
|
return ENOMEM;
|
|
des_set_key(key, schedule);
|
|
des_pcbc_encrypt(buf,
|
|
reply->cipher.data,
|
|
len,
|
|
schedule,
|
|
key,
|
|
DES_ENCRYPT);
|
|
memset(schedule, 0, sizeof(schedule));
|
|
return 0;
|
|
}
|
|
|
|
krb5_error_code
|
|
encode_v4_ticket(void *buf, size_t len, EncTicketPart *et,
|
|
PrincipalName *service, size_t *size)
|
|
{
|
|
krb5_storage *sp;
|
|
krb5_error_code ret;
|
|
char name[40], inst[40], realm[40];
|
|
char sname[40], sinst[40];
|
|
|
|
{
|
|
krb5_principal princ;
|
|
principalname2krb5_principal(&princ,
|
|
*service,
|
|
et->crealm);
|
|
ret = krb5_524_conv_principal(context,
|
|
princ,
|
|
sname,
|
|
sinst,
|
|
realm);
|
|
krb5_free_principal(context, princ);
|
|
if(ret)
|
|
return ret;
|
|
|
|
principalname2krb5_principal(&princ,
|
|
et->cname,
|
|
et->crealm);
|
|
|
|
ret = krb5_524_conv_principal(context,
|
|
princ,
|
|
name,
|
|
inst,
|
|
realm);
|
|
krb5_free_principal(context, princ);
|
|
}
|
|
if(ret)
|
|
return ret;
|
|
|
|
sp = krb5_storage_emem();
|
|
|
|
krb5_store_int8(sp, 0); /* flags */
|
|
krb5_store_stringz(sp, name);
|
|
krb5_store_stringz(sp, inst);
|
|
krb5_store_stringz(sp, realm);
|
|
{
|
|
unsigned char tmp[4] = { 0, 0, 0, 0 };
|
|
int i;
|
|
if(et->caddr){
|
|
for(i = 0; i < et->caddr->len; i++)
|
|
if(et->caddr->val[i].addr_type == AF_INET &&
|
|
et->caddr->val[i].address.length == 4){
|
|
memcpy(tmp, et->caddr->val[i].address.data, 4);
|
|
break;
|
|
}
|
|
}
|
|
sp->store(sp, tmp, sizeof(tmp));
|
|
}
|
|
|
|
if((et->key.keytype != ETYPE_DES_CBC_MD5 &&
|
|
et->key.keytype != ETYPE_DES_CBC_MD4 &&
|
|
et->key.keytype != ETYPE_DES_CBC_CRC) ||
|
|
et->key.keyvalue.length != 8)
|
|
return -1;
|
|
sp->store(sp, et->key.keyvalue.data, 8);
|
|
|
|
{
|
|
time_t start = et->starttime ? *et->starttime : et->authtime;
|
|
krb5_store_int8(sp, krb_time_to_life(start, et->endtime));
|
|
krb5_store_int32(sp, start);
|
|
}
|
|
|
|
krb5_store_stringz(sp, sname);
|
|
krb5_store_stringz(sp, sinst);
|
|
|
|
{
|
|
krb5_data data;
|
|
krb5_storage_to_data(sp, &data);
|
|
krb5_storage_free(sp);
|
|
*size = (data.length + 7) & ~7; /* pad to 8 bytes */
|
|
if(*size > len)
|
|
return -1;
|
|
memset((unsigned char*)buf - *size + 1, 0, *size);
|
|
memcpy((unsigned char*)buf - *size + 1, data.data, data.length);
|
|
krb5_data_free(&data);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#endif /* KRB4 */
|