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     const char *estr;
  47
  48     ret = kcm_ccache_resolve(context, name, ccache);
  49     if (ret) {
  50         estr = krb5_get_error_message(context, ret);
  51         kcm_log(1, "Failed to resolve cache %s: %s", name, estr);
  52         krb5_free_error_message(context, estr);
  53         return ret;
  54     }
  55
  56     ret = kcm_access(context, client, opcode, *ccache);
  57     if (ret) {
  58         ret = KRB5_FCC_NOFILE; /* don't disclose */
  59         kcm_release_ccache(context, *ccache);
  60     }
  61
  62     return ret;
  63 }
  64
  65 krb5_error_code
  66 kcm_ccache_destroy_client(krb5_context context,
  67                           kcm_client *client,
  68                           const char *name)
  69 {
  70     krb5_error_code ret;
  71     kcm_ccache ccache;
  72     const char *estr;
  73
  74     ret = kcm_ccache_resolve(context, name, &ccache);
  75     if (ret) {
  76         estr = krb5_get_error_message(context, ret);
  77         kcm_log(1, "Failed to resolve cache %s: %s", name, estr);
  78         krb5_free_error_message(context, estr);
  79         return ret;
  80     }
  81
  82     ret = kcm_access(context, client, KCM_OP_DESTROY, ccache);
  83     kcm_cleanup_events(context, ccache);
  84     kcm_release_ccache(context, ccache);
  85     if (ret)
  86         return ret;
  87
  88     return kcm_ccache_destroy(context, name);
  89 }
  90
  91 krb5_error_code
  92 kcm_ccache_new_client(krb5_context context,
  93                       kcm_client *client,
  94                       const char *name,
  95                       kcm_ccache *ccache_p)
  96 {
  97     krb5_error_code ret;
  98     kcm_ccache ccache;
  99     const char *estr;
 100
 101     /* We insist the ccache name starts with UID or UID: */
 102     if (name_constraints != 0) {
 103         char prefix[64];
 104         size_t prefix_len;
 105         int bad = 1;
 106
 107         snprintf(prefix, sizeof(prefix), "%ld:", (long)client->uid);
 108         prefix_len = strlen(prefix);
 109
 110         if (strncmp(name, prefix, prefix_len) == 0)
 111             bad = 0;
 112         else {
 113             prefix[prefix_len - 1] = '\0';
 114             if (strcmp(name, prefix) == 0)
 115                 bad = 0;
 116         }
 117
 118         /* Allow root to create badly-named ccaches */
 119         if (bad && !CLIENT_IS_ROOT(client))
 120             return KRB5_CC_BADNAME;
 121     }
 122
 123     ret = kcm_ccache_resolve(context, name, &ccache);
 124     if (ret == 0) {
 125         if ((ccache->uid != client->uid ||
 126              ccache->gid != client->gid) && !CLIENT_IS_ROOT(client))
 127             return KRB5_FCC_PERM;
 128     } else if (ret != KRB5_FCC_NOFILE && !(CLIENT_IS_ROOT(client) && ret == KRB5_FCC_PERM)) {
 129                 return ret;
 130     }
 131
 132     if (ret == KRB5_FCC_NOFILE) {
 133         ret = kcm_ccache_new(context, name, &ccache);
 134         if (ret) {
 135             estr = krb5_get_error_message(context, ret);
 136             kcm_log(1, "Failed to initialize cache %s: %s", name, estr);
 137             krb5_free_error_message(context, estr);
 138             return ret;
 139         }
 140
 141         /* bind to current client */
 142         ccache->uid = client->uid;
 143         ccache->gid = client->gid;
 144         ccache->session = client->session;
 145     } else {
 146         ret = kcm_zero_ccache_data(context, ccache);
 147         if (ret) {
 148             estr = krb5_get_error_message(context, ret);
 149             kcm_log(1, "Failed to empty cache %s: %s", name, estr);
 150             krb5_free_error_message(context, estr);
 151             kcm_release_ccache(context, ccache);
 152             return ret;
 153         }
 154         kcm_cleanup_events(context, ccache);
 155     }
 156
 157     ret = kcm_access(context, client, KCM_OP_INITIALIZE, ccache);
 158     if (ret) {
 159         kcm_release_ccache(context, ccache);
 160         kcm_ccache_destroy(context, name);
 161         return ret;
 162     }
 163
 164     /*
 165      * Finally, if the user is root and the cache was created under
 166      * another user's name, chown the cache to that user and their
 167      * default gid.
 168      */
 169     if (CLIENT_IS_ROOT(client)) {
 170         unsigned long uid;
 171         int matches = sscanf(name,"%ld:",&uid);
 172         if (matches == 0)
 173             matches = sscanf(name,"%ld",&uid);
 174         if (matches == 1) {
 175             struct passwd *pwd = getpwuid(uid);
 176             if (pwd != NULL) {
 177                 gid_t gid = pwd->pw_gid;
 178                 kcm_chown(context, client, ccache, uid, gid);
 179             }
 180         }
 181     }
 182
 183     *ccache_p = ccache;
 184     return 0;
 185 }
 186