xref: /netbsd-src/crypto/external/bsd/heimdal/dist/lib/krb5/build_auth.c (revision 241bea01a19bbb306af27777a870b86d41cb3fda)
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 Högskolan
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 
38 static krb5_error_code
make_etypelist(krb5_context context,krb5_authdata ** auth_data)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 = 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 
103 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_build_authenticator(krb5_context context,krb5_auth_context auth_context,krb5_enctype enctype,krb5_creds * cred,Checksum * cksum,krb5_data * result,krb5_key_usage usage)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