crypto/dist/heimdal/kcm/acl.c

   1 /*
   2  * Copyright (c) 2005, PADL Software Pty Ltd.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * 3. Neither the name of PADL Software nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY PADL SOFTWARE AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL PADL SOFTWARE OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include "kcm_locl.h"
  34
  35 __RCSID("$Heimdal: acl.c 20472 2007-04-20 10:43:25Z lha $"
  36         "$NetBSD$");
  37
  38 krb5_error_code
  39 kcm_access(krb5_context context,
  40            kcm_client *client,
  41            kcm_operation opcode,
  42            kcm_ccache ccache)
  43 {
  44     int read_p = 0;
  45     int write_p = 0;
  46     uint16_t mask;
  47     krb5_error_code ret;
  48
  49     KCM_ASSERT_VALID(ccache);
  50
  51     switch (opcode) {
  52     case KCM_OP_INITIALIZE:
  53     case KCM_OP_DESTROY:
  54     case KCM_OP_STORE:
  55     case KCM_OP_REMOVE_CRED:
  56     case KCM_OP_SET_FLAGS:
  57     case KCM_OP_CHOWN:
  58     case KCM_OP_CHMOD:
  59     case KCM_OP_GET_INITIAL_TICKET:
  60     case KCM_OP_GET_TICKET:
  61         write_p = 1;
  62         read_p = 0;
  63         break;
  64     case KCM_OP_NOOP:
  65     case KCM_OP_GET_NAME:
  66     case KCM_OP_RESOLVE:
  67     case KCM_OP_GEN_NEW:
  68     case KCM_OP_RETRIEVE:
  69     case KCM_OP_GET_PRINCIPAL:
  70     case KCM_OP_GET_FIRST:
  71     case KCM_OP_GET_NEXT:
  72     case KCM_OP_END_GET:
  73     case KCM_OP_MAX:
  74         write_p = 0;
  75         read_p = 1;
  76         break;
  77     }
  78
  79     if (ccache->flags & KCM_FLAGS_OWNER_IS_SYSTEM) {
  80         /* System caches cannot be reinitialized or destroyed by users */
  81         if (opcode == KCM_OP_INITIALIZE ||
  82             opcode == KCM_OP_DESTROY ||
  83             opcode == KCM_OP_REMOVE_CRED) {
  84             ret = KRB5_FCC_PERM;
  85             goto out;
  86         }
  87
  88         /* Let root always read system caches */
  89         if (client->uid == 0) {
  90             ret = 0;
  91             goto out;
  92         }
  93     }
  94
  95     mask = 0;
  96
  97     /* Root may do whatever they like */
  98     if (client->uid == ccache->uid || CLIENT_IS_ROOT(client)) {
  99         if (read_p)
 100             mask |= S_IRUSR;
 101         if (write_p)
 102             mask |= S_IWUSR;
 103     } else if (client->gid == ccache->gid || CLIENT_IS_ROOT(client)) {
 104         if (read_p)
 105             mask |= S_IRGRP;
 106         if (write_p)
 107             mask |= S_IWGRP;
 108     } else {
 109         if (read_p)
 110             mask |= S_IROTH;
 111         if (write_p)
 112             mask |= S_IWOTH;
 113     }
 114
 115     ret = ((ccache->mode & mask) == mask) ? 0 : KRB5_FCC_PERM;
 116
 117 out:
 118     if (ret) {
 119         kcm_log(2, "Process %d is not permitted to call %s on cache %s",
 120                 client->pid, kcm_op2string(opcode), ccache->name);
 121     }
 122
 123     return ret;
 124 }
 125
 126 krb5_error_code
 127 kcm_chmod(krb5_context context,
 128           kcm_client *client,
 129           kcm_ccache ccache,
 130           uint16_t mode)
 131 {
 132     KCM_ASSERT_VALID(ccache);
 133
 134     /* System cache mode can only be set at startup */
 135     if (ccache->flags & KCM_FLAGS_OWNER_IS_SYSTEM)
 136         return KRB5_FCC_PERM;
 137
 138     if (ccache->uid != client->uid)
 139         return KRB5_FCC_PERM;
 140
 141     if (ccache->gid != client->gid)
 142         return KRB5_FCC_PERM;
 143
 144     HEIMDAL_MUTEX_lock(&ccache->mutex);
 145
 146     ccache->mode = mode;
 147
 148     HEIMDAL_MUTEX_unlock(&ccache->mutex);
 149
 150     return 0;
 151 }
 152
 153 krb5_error_code
 154 kcm_chown(krb5_context context,
 155           kcm_client *client,
 156           kcm_ccache ccache,
 157           uid_t uid,
 158           gid_t gid)
 159 {
 160     KCM_ASSERT_VALID(ccache);
 161
 162     /* System cache owner can only be set at startup */
 163     if (ccache->flags & KCM_FLAGS_OWNER_IS_SYSTEM)
 164         return KRB5_FCC_PERM;
 165
 166     if (ccache->uid != client->uid)
 167         return KRB5_FCC_PERM;
 168
 169     if (ccache->gid != client->gid)
 170         return KRB5_FCC_PERM;
 171
 172     HEIMDAL_MUTEX_lock(&ccache->mutex);
 173
 174     ccache->uid = uid;
 175     ccache->gid = gid;
 176
 177     HEIMDAL_MUTEX_unlock(&ccache->mutex);
 178
 179     return 0;
 180 }
 181