kcm/client.c

   1 /*
   2  * Copyright (c) 2005, PADL Software Pty Ltd.
   3  * All rights reserved.
   4  *
   5  * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  *
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * 3. Neither the name of PADL Software nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY PADL SOFTWARE AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL PADL SOFTWARE OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include "kcm_locl.h"
  36 #include <pwd.h>
  37
  38 krb5_error_code
  39 kcm_ccache_resolve_client(krb5_context context,
  40                           kcm_client *client,
  41                           kcm_operation opcode,
  42                           const char *name,
  43                           kcm_ccache *ccache)
  44 {
  45     krb5_error_code ret;
  46
  47     ret = kcm_ccache_resolve(context, name, ccache);
  48     if (ret) {
  49         kcm_log(1, "Failed to resolve cache %s: %s",
  50                 name, krb5_get_err_text(context, ret));
  51         return ret;
  52     }
  53
  54     ret = kcm_access(context, client, opcode, *ccache);
  55     if (ret) {
  56         ret = KRB5_FCC_NOFILE; /* don't disclose */
  57         kcm_release_ccache(context, *ccache);
  58     }
  59
  60     return ret;
  61 }
  62
  63 krb5_error_code
  64 kcm_ccache_destroy_client(krb5_context context,
  65                           kcm_client *client,
  66                           const char *name)
  67 {
  68     krb5_error_code ret;
  69     kcm_ccache ccache;
  70
  71     ret = kcm_ccache_resolve(context, name, &ccache);
  72     if (ret) {
  73         kcm_log(1, "Failed to resolve cache %s: %s",
  74                 name, krb5_get_err_text(context, ret));
  75         return ret;
  76     }
  77
  78     ret = kcm_access(context, client, KCM_OP_DESTROY, ccache);
  79     kcm_cleanup_events(context, ccache);
  80     kcm_release_ccache(context, ccache);
  81     if (ret)
  82         return ret;
  83
  84     return kcm_ccache_destroy(context, name);
  85 }
  86
  87 krb5_error_code
  88 kcm_ccache_new_client(krb5_context context,
  89                       kcm_client *client,
  90                       const char *name,
  91                       kcm_ccache *ccache_p)
  92 {
  93     krb5_error_code ret;
  94     kcm_ccache ccache;
  95
  96     /* We insist the ccache name starts with UID or UID: */
  97     if (name_constraints != 0) {
  98         char prefix[64];
  99         size_t prefix_len;
 100         int bad = 1;
 101
 102         snprintf(prefix, sizeof(prefix), "%ld:", (long)client->uid);
 103         prefix_len = strlen(prefix);
 104
 105         if (strncmp(name, prefix, prefix_len) == 0)
 106             bad = 0;
 107         else {
 108             prefix[prefix_len - 1] = '\0';
 109             if (strcmp(name, prefix) == 0)
 110                 bad = 0;
 111         }
 112
 113         /* Allow root to create badly-named ccaches */
 114         if (bad && !CLIENT_IS_ROOT(client))
 115             return KRB5_CC_BADNAME;
 116     }
 117
 118     ret = kcm_ccache_resolve(context, name, &ccache);
 119     if (ret == 0) {
 120         if ((ccache->uid != client->uid ||
 121              ccache->gid != client->gid) && !CLIENT_IS_ROOT(client))
 122             return KRB5_FCC_PERM;
 123     } else if (ret != KRB5_FCC_NOFILE && !(CLIENT_IS_ROOT(client) && ret == KRB5_FCC_PERM)) {
 124                 return ret;
 125     }
 126
 127     if (ret == KRB5_FCC_NOFILE) {
 128         ret = kcm_ccache_new(context, name, &ccache);
 129         if (ret) {
 130             kcm_log(1, "Failed to initialize cache %s: %s",
 131                     name, krb5_get_err_text(context, ret));
 132             return ret;
 133         }
 134
 135         /* bind to current client */
 136         ccache->uid = client->uid;
 137         ccache->gid = client->gid;
 138         ccache->session = client->session;
 139     } else {
 140         ret = kcm_zero_ccache_data(context, ccache);
 141         if (ret) {
 142             kcm_log(1, "Failed to empty cache %s: %s",
 143                     name, krb5_get_err_text(context, ret));
 144             kcm_release_ccache(context, ccache);
 145             return ret;
 146         }
 147         kcm_cleanup_events(context, ccache);
 148     }
 149
 150     ret = kcm_access(context, client, KCM_OP_INITIALIZE, ccache);
 151     if (ret) {
 152         kcm_release_ccache(context, ccache);
 153         kcm_ccache_destroy(context, name);
 154         return ret;
 155     }
 156
 157     /*
 158      * Finally, if the user is root and the cache was created under
 159      * another user's name, chown the cache to that user and their
 160      * default gid.
 161      */
 162     if (CLIENT_IS_ROOT(client)) {
 163         unsigned long uid;
 164         int matches = sscanf(name,"%ld:",&uid);
 165         if (matches == 0)
 166             matches = sscanf(name,"%ld",&uid);
 167         if (matches == 1) {
 168             struct passwd *pwd = getpwuid(uid);
 169             if (pwd != NULL) {
 170                 gid_t gid = pwd->pw_gid;
 171                 kcm_chown(context, client, ccache, uid, gid);
 172             }
 173         }
 174     }
 175
 176     *ccache_p = ccache;
 177     return 0;
 178 }
 179