1/*	$NetBSD: build_auth.c,v 1.3 2019/12/15 22:50:50 christos Exp $	*/
2
3/*
4 * Copyright (c) 1997 - 2003 Kungliga Tekniska H��gskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include "krb5_locl.h"
37
38static krb5_error_code
39make_etypelist(krb5_context context,
40	       krb5_authdata **auth_data)
41{
42    EtypeList etypes;
43    krb5_error_code ret;
44    krb5_authdata ad;
45    u_char *buf;
46    size_t len = 0;
47    size_t buf_size;
48
49    ret = _krb5_init_etype(context, KRB5_PDU_NONE,
50			   &etypes.len, &etypes.val,
51			   NULL);
52    if (ret)
53	return ret;
54
55    ASN1_MALLOC_ENCODE(EtypeList, buf, buf_size, &etypes, &len, ret);
56    if (ret) {
57	free_EtypeList(&etypes);
58	return ret;
59    }
60    if(buf_size != len)
61	krb5_abortx(context, "internal error in ASN.1 encoder");
62    free_EtypeList(&etypes);
63
64    ALLOC_SEQ(&ad, 1);
65    if (ad.val == NULL) {
66	free(buf);
67	return krb5_enomem(context);
68    }
69
70    ad.val[0].ad_type = KRB5_AUTHDATA_GSS_API_ETYPE_NEGOTIATION;
71    ad.val[0].ad_data.length = len;
72    ad.val[0].ad_data.data = buf;
73
74    ASN1_MALLOC_ENCODE(AD_IF_RELEVANT, buf, buf_size, &ad, &len, ret);
75    if (ret) {
76	free_AuthorizationData(&ad);
77	return ret;
78    }
79    if(buf_size != len)
80	krb5_abortx(context, "internal error in ASN.1 encoder");
81    free_AuthorizationData(&ad);
82
83    ALLOC(*auth_data, 1);
84    if (*auth_data == NULL) {
85        free(buf);
86	return krb5_enomem(context);
87    }
88
89    ALLOC_SEQ(*auth_data, 1);
90    if ((*auth_data)->val == NULL) {
91        free(*auth_data);
92	free(buf);
93	return krb5_enomem(context);
94    }
95
96    (*auth_data)->val[0].ad_type = KRB5_AUTHDATA_IF_RELEVANT;
97    (*auth_data)->val[0].ad_data.length = len;
98    (*auth_data)->val[0].ad_data.data = buf;
99
100    return 0;
101}
102
103KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
104_krb5_build_authenticator (krb5_context context,
105			   krb5_auth_context auth_context,
106			   krb5_enctype enctype,
107			   krb5_creds *cred,
108			   Checksum *cksum,
109			   krb5_data *result,
110			   krb5_key_usage usage)
111{
112    Authenticator auth;
113    u_char *buf = NULL;
114    size_t buf_size;
115    size_t len = 0;
116    krb5_error_code ret;
117    krb5_crypto crypto;
118
119    memset(&auth, 0, sizeof(auth));
120
121    auth.authenticator_vno = 5;
122    ret = copy_Realm(&cred->client->realm, &auth.crealm);
123    if (ret)
124	goto fail;
125    ret = copy_PrincipalName(&cred->client->name, &auth.cname);
126    if (ret)
127	goto fail;
128
129    krb5_us_timeofday (context, &auth.ctime, &auth.cusec);
130
131    ret = krb5_auth_con_getlocalsubkey(context, auth_context, &auth.subkey);
132    if(ret)
133	goto fail;
134
135    if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
136	if(auth_context->local_seqnumber == 0)
137	    krb5_generate_seq_number (context,
138				      &cred->session,
139				      &auth_context->local_seqnumber);
140	ALLOC(auth.seq_number, 1);
141	if(auth.seq_number == NULL) {
142	    ret = krb5_enomem(context);
143	    goto fail;
144	}
145	*auth.seq_number = auth_context->local_seqnumber;
146    } else
147	auth.seq_number = NULL;
148    auth.authorization_data = NULL;
149
150    if (cksum) {
151	ALLOC(auth.cksum, 1);
152	if (auth.cksum == NULL) {
153	    ret = krb5_enomem(context);
154	    goto fail;
155	}
156	ret = copy_Checksum(cksum, auth.cksum);
157	if (ret)
158	    goto fail;
159
160	if (auth.cksum->cksumtype == CKSUMTYPE_GSSAPI) {
161	    /*
162	     * This is not GSS-API specific, we only enable it for
163	     * GSS for now
164	     */
165	    ret = make_etypelist(context, &auth.authorization_data);
166	    if (ret)
167		goto fail;
168	}
169    }
170
171    /* XXX - Copy more to auth_context? */
172
173    auth_context->authenticator->ctime = auth.ctime;
174    auth_context->authenticator->cusec = auth.cusec;
175
176    ASN1_MALLOC_ENCODE(Authenticator, buf, buf_size, &auth, &len, ret);
177    if (ret)
178	goto fail;
179    if(buf_size != len)
180	krb5_abortx(context, "internal error in ASN.1 encoder");
181
182    ret = krb5_crypto_init(context, &cred->session, enctype, &crypto);
183    if (ret)
184	goto fail;
185    ret = krb5_encrypt (context,
186			crypto,
187			usage /* KRB5_KU_AP_REQ_AUTH */,
188			buf,
189			len,
190			result);
191    krb5_crypto_destroy(context, crypto);
192
193    if (ret)
194	goto fail;
195
196 fail:
197    free_Authenticator (&auth);
198    free (buf);
199
200    return ret;
201}
202