xref: /freebsd/crypto/heimdal/lib/krb5/build_auth.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*
2  * Copyright (c) 1997 - 2003 Kungliga Tekniska Högskolan
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 static krb5_error_code
37 make_etypelist(krb5_context context,
38 	       krb5_authdata **auth_data)
39 {
40     EtypeList etypes;
41     krb5_error_code ret;
42     krb5_authdata ad;
43     u_char *buf;
44     size_t len = 0;
45     size_t buf_size;
46 
47     ret = _krb5_init_etype(context, KRB5_PDU_NONE,
48 			   &etypes.len, &etypes.val,
49 			   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_message(context, ENOMEM, N_("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         free(buf);
85 	krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
86 	return ENOMEM;
87     }
88 
89     ALLOC_SEQ(*auth_data, 1);
90     if ((*auth_data)->val == NULL) {
91         free(*auth_data);
92 	free(buf);
93 	krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
94 	return ENOMEM;
95     }
96 
97     (*auth_data)->val[0].ad_type = KRB5_AUTHDATA_IF_RELEVANT;
98     (*auth_data)->val[0].ad_data.length = len;
99     (*auth_data)->val[0].ad_data.data = buf;
100 
101     return 0;
102 }
103 
104 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
105 _krb5_build_authenticator (krb5_context context,
106 			   krb5_auth_context auth_context,
107 			   krb5_enctype enctype,
108 			   krb5_creds *cred,
109 			   Checksum *cksum,
110 			   krb5_data *result,
111 			   krb5_key_usage usage)
112 {
113     Authenticator auth;
114     u_char *buf = NULL;
115     size_t buf_size;
116     size_t len = 0;
117     krb5_error_code ret;
118     krb5_crypto crypto;
119 
120     memset(&auth, 0, sizeof(auth));
121 
122     auth.authenticator_vno = 5;
123     copy_Realm(&cred->client->realm, &auth.crealm);
124     copy_PrincipalName(&cred->client->name, &auth.cname);
125 
126     krb5_us_timeofday (context, &auth.ctime, &auth.cusec);
127 
128     ret = krb5_auth_con_getlocalsubkey(context, auth_context, &auth.subkey);
129     if(ret)
130 	goto fail;
131 
132     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
133 	if(auth_context->local_seqnumber == 0)
134 	    krb5_generate_seq_number (context,
135 				      &cred->session,
136 				      &auth_context->local_seqnumber);
137 	ALLOC(auth.seq_number, 1);
138 	if(auth.seq_number == NULL) {
139 	    ret = ENOMEM;
140 	    goto fail;
141 	}
142 	*auth.seq_number = auth_context->local_seqnumber;
143     } else
144 	auth.seq_number = NULL;
145     auth.authorization_data = NULL;
146 
147     if (cksum) {
148 	ALLOC(auth.cksum, 1);
149 	if (auth.cksum == NULL) {
150 	    ret = ENOMEM;
151 	    goto fail;
152 	}
153 	ret = copy_Checksum(cksum, auth.cksum);
154 	if (ret)
155 	    goto fail;
156 
157 	if (auth.cksum->cksumtype == CKSUMTYPE_GSSAPI) {
158 	    /*
159 	     * This is not GSS-API specific, we only enable it for
160 	     * GSS for now
161 	     */
162 	    ret = make_etypelist(context, &auth.authorization_data);
163 	    if (ret)
164 		goto fail;
165 	}
166     }
167 
168     /* XXX - Copy more to auth_context? */
169 
170     auth_context->authenticator->ctime = auth.ctime;
171     auth_context->authenticator->cusec = auth.cusec;
172 
173     ASN1_MALLOC_ENCODE(Authenticator, buf, buf_size, &auth, &len, ret);
174     if (ret)
175 	goto fail;
176     if(buf_size != len)
177 	krb5_abortx(context, "internal error in ASN.1 encoder");
178 
179     ret = krb5_crypto_init(context, &cred->session, enctype, &crypto);
180     if (ret)
181 	goto fail;
182     ret = krb5_encrypt (context,
183 			crypto,
184 			usage /* KRB5_KU_AP_REQ_AUTH */,
185 			buf,
186 			len,
187 			result);
188     krb5_crypto_destroy(context, crypto);
189 
190     if (ret)
191 	goto fail;
192 
193  fail:
194     free_Authenticator (&auth);
195     free (buf);
196 
197     return ret;
198 }
199