1/*
2 * Copyright (c) 1997 - 2003 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
36RCSID("$Id: build_auth.c 17033 2006-04-10 08:53:21Z lha $");
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;
47    size_t buf_size;
48
49    ret = krb5_init_etype(context, &etypes.len, &etypes.val, NULL);
50    if (ret)
51	return ret;
52
53    ASN1_MALLOC_ENCODE(EtypeList, buf, buf_size, &etypes, &len, ret);
54    if (ret) {
55	free_EtypeList(&etypes);
56	return ret;
57    }
58    if(buf_size != len)
59	krb5_abortx(context, "internal error in ASN.1 encoder");
60    free_EtypeList(&etypes);
61
62    ALLOC_SEQ(&ad, 1);
63    if (ad.val == NULL) {
64	free(buf);
65	krb5_set_error_string(context, "malloc: out of memory");
66	return ENOMEM;
67    }
68
69    ad.val[0].ad_type = KRB5_AUTHDATA_GSS_API_ETYPE_NEGOTIATION;
70    ad.val[0].ad_data.length = len;
71    ad.val[0].ad_data.data = buf;
72
73    ASN1_MALLOC_ENCODE(AD_IF_RELEVANT, buf, buf_size, &ad, &len, ret);
74    if (ret) {
75	free_AuthorizationData(&ad);
76	return ret;
77    }
78    if(buf_size != len)
79	krb5_abortx(context, "internal error in ASN.1 encoder");
80    free_AuthorizationData(&ad);
81
82    ALLOC(*auth_data, 1);
83    if (*auth_data == NULL) {
84	krb5_set_error_string(context, "malloc: out of memory");
85	return ENOMEM;
86    }
87
88    ALLOC_SEQ(*auth_data, 1);
89    if ((*auth_data)->val == NULL) {
90	free(buf);
91	krb5_set_error_string(context, "malloc: out of memory");
92	return ENOMEM;
93    }
94
95    (*auth_data)->val[0].ad_type = KRB5_AUTHDATA_IF_RELEVANT;
96    (*auth_data)->val[0].ad_data.length = len;
97    (*auth_data)->val[0].ad_data.data = buf;
98
99    return 0;
100}
101
102krb5_error_code KRB5_LIB_FUNCTION
103krb5_build_authenticator (krb5_context context,
104			  krb5_auth_context auth_context,
105			  krb5_enctype enctype,
106			  krb5_creds *cred,
107			  Checksum *cksum,
108			  Authenticator **auth_result,
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;
116    krb5_error_code ret;
117    krb5_crypto crypto;
118
119    auth = calloc(1, sizeof(*auth));
120    if (auth == NULL) {
121	krb5_set_error_string(context, "malloc: out of memory");
122	return ENOMEM;
123    }
124
125    auth->authenticator_vno = 5;
126    copy_Realm(&cred->client->realm, &auth->crealm);
127    copy_PrincipalName(&cred->client->name, &auth->cname);
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 = ENOMEM;
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    auth->cksum = cksum;
150
151    if (cksum != NULL && cksum->cksumtype == CKSUMTYPE_GSSAPI) {
152	/*
153	 * This is not GSS-API specific, we only enable it for
154	 * GSS for now
155	 */
156	ret = make_etypelist(context, &auth->authorization_data);
157	if (ret)
158	    goto fail;
159    }
160
161    /* XXX - Copy more to auth_context? */
162
163    auth_context->authenticator->ctime = auth->ctime;
164    auth_context->authenticator->cusec = auth->cusec;
165
166    ASN1_MALLOC_ENCODE(Authenticator, buf, buf_size, auth, &len, ret);
167    if (ret)
168	goto fail;
169    if(buf_size != len)
170	krb5_abortx(context, "internal error in ASN.1 encoder");
171
172    ret = krb5_crypto_init(context, &cred->session, enctype, &crypto);
173    if (ret)
174	goto fail;
175    ret = krb5_encrypt (context,
176			crypto,
177			usage /* KRB5_KU_AP_REQ_AUTH */,
178			buf + buf_size - len,
179			len,
180			result);
181    krb5_crypto_destroy(context, crypto);
182
183    if (ret)
184	goto fail;
185
186    free (buf);
187
188    if (auth_result)
189	*auth_result = auth;
190    else {
191	/* Don't free the `cksum', it's allocated by the caller */
192	auth->cksum = NULL;
193	free_Authenticator (auth);
194	free (auth);
195    }
196    return ret;
197  fail:
198    free_Authenticator (auth);
199    free (auth);
200    free (buf);
201    return ret;
202}
203