xref: /illumos-gate/usr/src/lib/smbsrv/libsmbns/common/smbns_ksetpwd.c (revision 7800901e60d340b6af88e94a2149805dcfcaaf56)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <strings.h>
33 #include <unistd.h>
34 #include <ctype.h>
35 #include <errno.h>
36 #include <syslog.h>
37 #include <fcntl.h>
38 #include <sys/types.h>
39 #include <sys/stat.h>
40 #include <kerberosv5/krb5.h>
41 
42 static int smb_krb5_ktadd(krb5_context ctx, krb5_keytab kt,
43     const krb5_principal princ, krb5_enctype enctype, krb5_kvno kvno,
44     const char *pw);
45 
46 /*
47  * smb_krb5_ctx_init
48  *
49  * Initialize the kerberos context.
50  * Return 0 on success. Otherwise, return -1.
51  */
52 int
53 smb_krb5_ctx_init(krb5_context *ctx)
54 {
55 	if (krb5_init_context(ctx) != 0)
56 		return (-1);
57 
58 	return (0);
59 }
60 
61 /*
62  * smb_krb5_get_principal
63  *
64  * Setup the krb5_principal given the host principal in string format.
65  * Return 0 on success. Otherwise, return -1.
66  */
67 int
68 smb_krb5_get_principal(krb5_context ctx, char *princ_str, krb5_principal *princ)
69 {
70 	if (krb5_parse_name(ctx, princ_str, princ) != 0)
71 		return (-1);
72 
73 	return (0);
74 }
75 
76 /*
77  * smb_krb5_ctx_fini
78  *
79  * Free the kerberos context.
80  */
81 void
82 smb_krb5_ctx_fini(krb5_context ctx)
83 {
84 	krb5_free_context(ctx);
85 }
86 
87 /*
88  * smb_ksetpw
89  *
90  * Set the workstation trust account password.
91  * Returns 0 on success.  Otherwise, returns non-zero value.
92  */
93 int
94 smb_krb5_setpwd(krb5_context ctx, krb5_principal princ, char *passwd)
95 {
96 	krb5_error_code code;
97 	krb5_ccache cc = NULL;
98 	int result_code;
99 	krb5_data result_code_string, result_string;
100 
101 	(void) memset(&result_code_string, 0, sizeof (result_code_string));
102 	(void) memset(&result_string, 0, sizeof (result_string));
103 
104 	if ((code = krb5_cc_default(ctx, &cc)) != 0) {
105 		syslog(LOG_ERR, "smb_krb5_setpwd: failed to find a ccache\n");
106 		return (-1);
107 	}
108 
109 	code = krb5_set_password_using_ccache(ctx, cc, passwd, princ,
110 	    &result_code, &result_code_string, &result_string);
111 
112 	krb5_cc_close(ctx, cc);
113 
114 	if (code != 0)
115 		(void) syslog(LOG_ERR,
116 		    "smb_krb5_setpwd: Result: %.*s (%d) %.*s\n",
117 		    result_code == 0 ?
118 		    strlen("success") : result_code_string.length,
119 		    result_code == 0 ? "success" : result_code_string.data,
120 		    result_code, result_string.length, result_string.data);
121 	return (code);
122 }
123 
124 /*
125  * smb_krb5_write_keytab
126  *
127  * Write all the Kerberos keys to the keytab file.
128  * Returns 0 on success.  Otherwise, returns -1.
129  */
130 int
131 smb_krb5_write_keytab(krb5_context ctx, krb5_principal princ, char *fname,
132     krb5_kvno kvno, char *passwd, krb5_enctype *enctypes, int enctype_count)
133 {
134 	krb5_keytab kt = NULL;
135 	char *ktname;
136 	int i, len;
137 	int rc = 0;
138 	struct stat fstat;
139 
140 	if (stat(fname, &fstat) == 0) {
141 		if (remove(fname) != 0) {
142 			syslog(LOG_ERR, "smb_krb5_write_keytab: cannot remove"
143 			    " existing keytab");
144 			return (-1);
145 		}
146 	}
147 
148 	len = snprintf(NULL, 0, "WRFILE:%s", fname) + 1;
149 	if ((ktname = malloc(len)) == NULL) {
150 		syslog(LOG_ERR, "smb_krb5_write_keytab: resource shortage");
151 		return (-1);
152 	}
153 
154 	(void) snprintf(ktname, len, "WRFILE:%s", fname);
155 
156 	if (krb5_kt_resolve(ctx, ktname, &kt) != 0) {
157 		syslog(LOG_ERR, "smb_krb5_write_keytab: failed to open/create "
158 		    "keytab %s\n", fname);
159 		free(ktname);
160 		return (-1);
161 	}
162 
163 	free(ktname);
164 
165 	for (i = 0; i < enctype_count; i++) {
166 		if (smb_krb5_ktadd(ctx, kt, princ, enctypes[i], kvno, passwd)
167 		    != 0) {
168 			rc = -1;
169 			break;
170 		}
171 
172 	}
173 
174 	if (kt != NULL)
175 		krb5_kt_close(ctx, kt);
176 
177 	return (rc);
178 }
179 
180 /*
181  * smb_krb5_ktadd
182  *
183  * Add a Keberos key to the keytab file.
184  * Returns 0 on success. Otherwise, returns -1.
185  */
186 static int
187 smb_krb5_ktadd(krb5_context ctx, krb5_keytab kt, const krb5_principal princ,
188 	krb5_enctype enctype, krb5_kvno kvno, const char *pw)
189 {
190 	krb5_keytab_entry *entry;
191 	krb5_data password, salt;
192 	krb5_keyblock key;
193 	krb5_error_code code;
194 	char buf[100];
195 	int rc = 0;
196 
197 	if ((code = krb5_enctype_to_string(enctype, buf, sizeof (buf)))) {
198 		syslog(LOG_ERR, "smb_krb5_ktadd[%d]: unknown enctype",
199 		    enctype);
200 		return (-1);
201 	}
202 
203 	if ((entry = (krb5_keytab_entry *) malloc(sizeof (*entry))) == NULL) {
204 		syslog(LOG_ERR, "smb_krb5_ktadd[%d]: resource shortage",
205 		    enctype);
206 		return (-1);
207 	}
208 
209 	(void) memset((char *)entry, 0, sizeof (*entry));
210 
211 	password.length = strlen(pw);
212 	password.data = (char *)pw;
213 
214 	if ((code = krb5_principal2salt(ctx, princ, &salt)) != 0) {
215 		syslog(LOG_ERR, "smb_krb5_ktadd[%d]: failed to compute salt",
216 		    enctype);
217 		free(entry);
218 		return (-1);
219 	}
220 
221 	code = krb5_c_string_to_key(ctx, enctype, &password, &salt, &key);
222 	krb5_xfree(salt.data);
223 	if (code != 0) {
224 		syslog(LOG_ERR, "smb_krb5_ktadd[%d]: failed to generate key",
225 		    enctype);
226 		free(entry);
227 		return (-1);
228 	}
229 
230 	(void) memcpy(&entry->key, &key, sizeof (krb5_keyblock));
231 	entry->vno = kvno;
232 	entry->principal = princ;
233 
234 	if ((code = krb5_kt_add_entry(ctx, kt, entry)) != 0) {
235 		syslog(LOG_ERR, "smb_krb5_ktadd[%d] failed to add entry to "
236 		    "keytab (%d)", enctype, code);
237 		rc = -1;
238 	}
239 
240 	free(entry);
241 	return (rc);
242 }
243