xref: /freebsd/crypto/heimdal/lib/krb5/build_auth.c (revision 4c8945a06b01a5c8122cdeb402af36bb46a06acc)
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 
36 RCSID("$Id: build_auth.c 17033 2006-04-10 08:53:21Z lha $");
37 
38 static krb5_error_code
39 make_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 
102 krb5_error_code KRB5_LIB_FUNCTION
103 krb5_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