convert_creds.c revision 55682 
1/*
2 * Copyright (c) 1997, 1999 Kungliga Tekniska H�gskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include "krb5_locl.h"
35RCSID("$Id: convert_creds.c,v 1.13 1999/12/02 17:05:08 joda Exp $");
36
37static krb5_error_code
38check_ticket_flags(TicketFlags f)
39{
40    return 0; /* maybe add some more tests here? */
41}
42
43/* include this here, to avoid dependencies on libkrb */
44
45#define		MAX_KTXT_LEN	1250
46
47#define 	ANAME_SZ	40
48#define		REALM_SZ	40
49#define		SNAME_SZ	40
50#define		INST_SZ		40
51
52struct ktext {
53    unsigned int length;		/* Length of the text */
54    unsigned char dat[MAX_KTXT_LEN];	/* The data itself */
55    u_int32_t mbz;		/* zero to catch runaway strings */
56};
57
58struct credentials {
59    char    service[ANAME_SZ];	/* Service name */
60    char    instance[INST_SZ];	/* Instance */
61    char    realm[REALM_SZ];	/* Auth domain */
62    des_cblock session;		/* Session key */
63    int     lifetime;		/* Lifetime */
64    int     kvno;		/* Key version number */
65    struct ktext ticket_st;	/* The ticket itself */
66    int32_t    issue_date;	/* The issue time */
67    char    pname[ANAME_SZ];	/* Principal's name */
68    char    pinst[INST_SZ];	/* Principal's instance */
69};
70
71
72#define TKTLIFENUMFIXED 64
73#define TKTLIFEMINFIXED 0x80
74#define TKTLIFEMAXFIXED 0xBF
75#define TKTLIFENOEXPIRE 0xFF
76#define MAXTKTLIFETIME	(30*24*3600)	/* 30 days */
77#ifndef NEVERDATE
78#define NEVERDATE ((time_t)0x7fffffffL)
79#endif
80
81static const int _tkt_lifetimes[TKTLIFENUMFIXED] = {
82   38400,   41055,   43894,   46929,   50174,   53643,   57352,   61318,
83   65558,   70091,   74937,   80119,   85658,   91581,   97914,  104684,
84  111922,  119661,  127935,  136781,  146239,  156350,  167161,  178720,
85  191077,  204289,  218415,  233517,  249664,  266926,  285383,  305116,
86  326213,  348769,  372885,  398668,  426234,  455705,  487215,  520904,
87  556921,  595430,  636601,  680618,  727680,  777995,  831789,  889303,
88  950794, 1016537, 1086825, 1161973, 1242318, 1328218, 1420057, 1518247,
89 1623226, 1735464, 1855462, 1983758, 2120925, 2267576, 2424367, 2592000
90};
91
92static int
93_krb_time_to_life(time_t start, time_t end)
94{
95    int i;
96    time_t life = end - start;
97
98    if (life > MAXTKTLIFETIME || life <= 0)
99	return 0;
100#if 0
101    if (krb_no_long_lifetimes)
102	return (life + 5*60 - 1)/(5*60);
103#endif
104
105    if (end >= NEVERDATE)
106	return TKTLIFENOEXPIRE;
107    if (life < _tkt_lifetimes[0])
108	return (life + 5*60 - 1)/(5*60);
109    for (i=0; i<TKTLIFENUMFIXED; i++)
110	if (life <= _tkt_lifetimes[i])
111	    return i + TKTLIFEMINFIXED;
112    return 0;
113
114}
115
116/* Convert the v5 credentials in `in_cred' to v4-dito in `v4creds'.
117 * This is done by sending them to the 524 function in the KDC.  If
118 * `in_cred' doesn't contain a DES session key, then a new one is
119 * gotten from the KDC and stored in the cred cache `ccache'.
120 */
121
122krb5_error_code
123krb524_convert_creds_kdc(krb5_context context,
124			 krb5_ccache ccache,
125			 krb5_creds *in_cred,
126			 struct credentials *v4creds)
127{
128    krb5_error_code ret;
129    krb5_data reply;
130    krb5_storage *sp;
131    int32_t tmp;
132    krb5_data ticket;
133    char realm[REALM_SZ];
134    krb5_creds *v5_creds = in_cred;
135    krb5_keytype keytype;
136
137    ret = krb5_enctype_to_keytype (context, v5_creds->session.keytype,
138				   &keytype);
139    if (ret)
140	return ret;
141
142    if (keytype != KEYTYPE_DES) {
143	krb5_creds template;
144
145	memset (&template, 0, sizeof(template));
146	template.session.keytype = KEYTYPE_DES;
147	ret = krb5_copy_principal (context, in_cred->client, &template.client);
148	if (ret) {
149	    krb5_free_creds_contents (context, &template);
150	    return ret;
151	}
152	ret = krb5_copy_principal (context, in_cred->server, &template.server);
153	if (ret) {
154	    krb5_free_creds_contents (context, &template);
155	    return ret;
156	}
157
158	ret = krb5_get_credentials (context, 0, ccache,
159				    &template, &v5_creds);
160	krb5_free_creds_contents (context, &template);
161	if (ret)
162	    return ret;
163    }
164
165    ret = check_ticket_flags(v5_creds->flags.b);
166    if(ret)
167	goto out2;
168
169    ret = krb5_sendto_kdc (context,
170			   &v5_creds->ticket,
171			   krb5_princ_realm(context, v5_creds->server),
172			   &reply);
173    if (ret)
174	goto out2;
175    sp = krb5_storage_from_mem(reply.data, reply.length);
176    if(sp == NULL) {
177	ret = ENOMEM;
178	goto out2;
179    }
180    krb5_ret_int32(sp, &tmp);
181    ret = tmp;
182    if(ret == 0) {
183	memset(v4creds, 0, sizeof(*v4creds));
184	ret = krb5_ret_int32(sp, &tmp);
185	if(ret) goto out;
186	v4creds->kvno = tmp;
187	ret = krb5_ret_data(sp, &ticket);
188	if(ret) goto out;
189	v4creds->ticket_st.length = ticket.length;
190	memcpy(v4creds->ticket_st.dat, ticket.data, ticket.length);
191	krb5_data_free(&ticket);
192	ret = krb5_524_conv_principal(context,
193				      v5_creds->server,
194				      v4creds->service,
195				      v4creds->instance,
196				      v4creds->realm);
197	if(ret) goto out;
198	v4creds->issue_date = v5_creds->times.authtime;
199	v4creds->lifetime = _krb_time_to_life(v4creds->issue_date,
200					      v5_creds->times.endtime);
201	ret = krb5_524_conv_principal(context, v5_creds->client,
202				      v4creds->pname,
203				      v4creds->pinst,
204				      realm);
205	if(ret) goto out;
206	memcpy(v4creds->session, v5_creds->session.keyvalue.data, 8);
207    }
208out:
209    krb5_storage_free(sp);
210    krb5_data_free(&reply);
211out2:
212    if (v5_creds != in_cred)
213	krb5_free_creds (context, v5_creds);
214    return ret;
215}
216