xref: /freebsd/crypto/heimdal/lib/krb5/convert_creds.c (revision eacee0ff7ec955b32e09515246bd97b6edcd2b0f)
1 /*
2  * Copyright (c) 1997 - 2001 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"
35 RCSID("$Id: convert_creds.c,v 1.24 2001/06/20 02:49:21 joda Exp $");
36 
37 static krb5_error_code
38 check_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 
52 struct 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 
58 struct 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 
81 static 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 
92 static 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 
122 krb5_error_code
123 krb524_convert_creds_kdc(krb5_context context,
124 			 krb5_creds *in_cred,
125 			 struct credentials *v4creds)
126 {
127     krb5_error_code ret;
128     krb5_data reply;
129     krb5_storage *sp;
130     int32_t tmp;
131     krb5_data ticket;
132     char realm[REALM_SZ];
133     krb5_creds *v5_creds = in_cred;
134 
135     ret = check_ticket_flags(v5_creds->flags.b);
136     if(ret)
137 	goto out2;
138 
139     {
140 	krb5_krbhst_handle handle;
141 
142 	ret = krb5_krbhst_init(context,
143 			       *krb5_princ_realm(context,
144 						v5_creds->server),
145 			       KRB5_KRBHST_KRB524,
146 			       &handle);
147 	if (ret)
148 	    goto out2;
149 
150 	ret = krb5_sendto (context,
151 			   &v5_creds->ticket,
152 			   handle,
153 			   &reply);
154 	krb5_krbhst_free(context, handle);
155 	if (ret)
156 	    goto out2;
157     }
158     sp = krb5_storage_from_mem(reply.data, reply.length);
159     if(sp == NULL) {
160 	ret = ENOMEM;
161 	krb5_set_error_string (context, "malloc: out of memory");
162 	goto out2;
163     }
164     krb5_ret_int32(sp, &tmp);
165     ret = tmp;
166     if(ret == 0) {
167 	memset(v4creds, 0, sizeof(*v4creds));
168 	ret = krb5_ret_int32(sp, &tmp);
169 	if(ret)
170 	    goto out;
171 	v4creds->kvno = tmp;
172 	ret = krb5_ret_data(sp, &ticket);
173 	if(ret)
174 	    goto out;
175 	v4creds->ticket_st.length = ticket.length;
176 	memcpy(v4creds->ticket_st.dat, ticket.data, ticket.length);
177 	krb5_data_free(&ticket);
178 	ret = krb5_524_conv_principal(context,
179 				      v5_creds->server,
180 				      v4creds->service,
181 				      v4creds->instance,
182 				      v4creds->realm);
183 	if(ret)
184 	    goto out;
185 	v4creds->issue_date = v5_creds->times.starttime;
186 	v4creds->lifetime = _krb_time_to_life(v4creds->issue_date,
187 					      v5_creds->times.endtime);
188 	ret = krb5_524_conv_principal(context, v5_creds->client,
189 				      v4creds->pname,
190 				      v4creds->pinst,
191 				      realm);
192 	if(ret)
193 	    goto out;
194 	memcpy(v4creds->session, v5_creds->session.keyvalue.data, 8);
195     } else {
196 	krb5_set_error_string(context, "converting credentials: %s",
197 			      krb5_get_err_text(context, ret));
198     }
199 out:
200     krb5_storage_free(sp);
201     krb5_data_free(&reply);
202 out2:
203     if (v5_creds != in_cred)
204 	krb5_free_creds (context, v5_creds);
205     return ret;
206 }
207 
208 krb5_error_code
209 krb524_convert_creds_kdc_ccache(krb5_context context,
210 				krb5_ccache ccache,
211 				krb5_creds *in_cred,
212 				struct credentials *v4creds)
213 {
214     krb5_error_code ret;
215     krb5_creds *v5_creds = in_cred;
216     krb5_keytype keytype;
217 
218     keytype = v5_creds->session.keytype;
219 
220     if (keytype != ENCTYPE_DES_CBC_CRC) {
221 	/* MIT krb524d doesn't like nothing but des-cbc-crc tickets,
222            so go get one */
223 	krb5_creds template;
224 
225 	memset (&template, 0, sizeof(template));
226 	template.session.keytype = ENCTYPE_DES_CBC_CRC;
227 	ret = krb5_copy_principal (context, in_cred->client, &template.client);
228 	if (ret) {
229 	    krb5_free_creds_contents (context, &template);
230 	    return ret;
231 	}
232 	ret = krb5_copy_principal (context, in_cred->server, &template.server);
233 	if (ret) {
234 	    krb5_free_creds_contents (context, &template);
235 	    return ret;
236 	}
237 
238 	ret = krb5_get_credentials (context, 0, ccache,
239 				    &template, &v5_creds);
240 	krb5_free_creds_contents (context, &template);
241 	if (ret)
242 	    return ret;
243     }
244 
245     ret = krb524_convert_creds_kdc(context, v5_creds, v4creds);
246 
247     if (v5_creds != in_cred)
248 	krb5_free_creds (context, v5_creds);
249     return ret;
250 }
251