xref: /illumos-gate/usr/src/uts/common/fs/smbsrv/smb_cred.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
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  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright 2020 Nexenta by DDN, Inc. All rights reserved.
24  * Copyright 2023 RackTop Systems, Inc.
25  */
26 
27 /*
28  * Authentication helpers for building credentials
29  */
30 
31 #include <sys/types.h>
32 #include <sys/cred.h>
33 #include <sys/cred_impl.h>
34 #include <sys/sid.h>
35 #include <sys/priv_names.h>
36 #include <sys/socket.h>
37 #include <sys/un.h>
38 #include <netinet/in.h>
39 #include <smbsrv/smb_idmap.h>
40 #include <smbsrv/smb_kproto.h>
41 #include <smbsrv/smb_token.h>
42 
43 static void smb_cred_set_sid(smb_id_t *id, ksid_t *ksid);
44 static ksidlist_t *smb_cred_set_sidlist(smb_ids_t *token_grps);
45 
46 /*
47  * Allocate a Solaris cred and initialize it based on the access token.
48  *
49  * If the user can be mapped to a non-ephemeral ID, the cred gid is set
50  * to the Solaris user's primary group.
51  *
52  * If the mapped UID is ephemeral, or the primary group could not be
53  * obtained, the cred gid is set to whatever Solaris group is mapped
54  * to the token's primary group.
55  *
56  * Also add any privileges that should always be in effect for this user.
57  * Note that an SMB user object also gets a u_privcred which is used
58  * when the client opens an object with "backup/restore intent".
59  * That cred is setup later, in smb_user_setcred().
60  */
61 cred_t *
62 smb_cred_create(smb_token_t *token)
63 {
64 	ksid_t			ksid;
65 	ksidlist_t		*ksidlist = NULL;
66 	smb_posix_grps_t	*posix_grps;
67 	cred_t			*cr;
68 	gid_t			gid;
69 
70 	ASSERT(token);
71 	ASSERT(token->tkn_posix_grps);
72 	posix_grps = token->tkn_posix_grps;
73 
74 	cr = crget();
75 	ASSERT(cr != NULL);
76 
77 	/*
78 	 * Add (preserve) PRIV_SYS_SMB in the permitted set.
79 	 * See the privilege check in smbd:pipe_has_priv
80 	 */
81 	priv_addset(&CR_PPRIV(cr), PRIV_SYS_SMB);
82 
83 	if (!IDMAP_ID_IS_EPHEMERAL(token->tkn_user.i_id) &&
84 	    (posix_grps->pg_ngrps != 0)) {
85 		gid = posix_grps->pg_grps[0];
86 	} else {
87 		gid = token->tkn_primary_grp.i_id;
88 	}
89 
90 	if (crsetugid(cr, token->tkn_user.i_id, gid) != 0) {
91 		crfree(cr);
92 		return (NULL);
93 	}
94 
95 	if (crsetgroups(cr, posix_grps->pg_ngrps, posix_grps->pg_grps) != 0) {
96 		crfree(cr);
97 		return (NULL);
98 	}
99 
100 	smb_cred_set_sid(&token->tkn_user, &ksid);
101 	crsetsid(cr, &ksid, KSID_USER);
102 	smb_cred_set_sid(&token->tkn_primary_grp, &ksid);
103 	crsetsid(cr, &ksid, KSID_GROUP);
104 	smb_cred_set_sid(&token->tkn_owner, &ksid);
105 	crsetsid(cr, &ksid, KSID_OWNER);
106 	ksidlist = smb_cred_set_sidlist(&token->tkn_win_grps);
107 	crsetsidlist(cr, ksidlist);
108 
109 	return (cr);
110 }
111 
112 /*
113  * Initialize the ksid based on the given smb_id_t.
114  */
115 static void
116 smb_cred_set_sid(smb_id_t *id, ksid_t *ksid)
117 {
118 	char sidstr[SMB_SID_STRSZ];
119 	int rc;
120 
121 	ASSERT(id);
122 	ASSERT(id->i_sid);
123 
124 	ksid->ks_id = id->i_id;
125 	smb_sid_tostr(id->i_sid, sidstr);
126 	rc = smb_sid_splitstr(sidstr, &ksid->ks_rid);
127 	ASSERT(rc == 0);
128 
129 	ksid->ks_attr = id->i_attrs;
130 	ksid->ks_domain = ksid_lookupdomain(sidstr);
131 }
132 
133 /*
134  * Allocate and initialize the ksidlist based on the access token group list.
135  */
136 static ksidlist_t *
137 smb_cred_set_sidlist(smb_ids_t *token_grps)
138 {
139 	int i;
140 	ksidlist_t *lp;
141 
142 	lp = kmem_zalloc(KSIDLIST_MEM(token_grps->i_cnt), KM_SLEEP);
143 	lp->ksl_ref = 1;
144 	lp->ksl_nsid = token_grps->i_cnt;
145 	lp->ksl_neid = 0;
146 
147 	for (i = 0; i < lp->ksl_nsid; i++) {
148 		smb_cred_set_sid(&token_grps->i_ids[i], &lp->ksl_sids[i]);
149 		if (lp->ksl_sids[i].ks_id > IDMAP_WK__MAX_GID)
150 			lp->ksl_neid++;
151 	}
152 
153 	return (lp);
154 }
155 
156 /*
157  * Special variant of smb_cred_create() used when we need an
158  * SMB kcred (e.g. DH import).  The returned cred must be
159  * from crget() so it can be passed to smb_user_setcred().
160  */
161 cred_t *
162 smb_kcred_create(void)
163 {
164 	cred_t	*cr;
165 
166 	cr = crget();
167 	ASSERT(cr != NULL);
168 
169 	return (cr);
170 }
171