lib/krb5/keytab_memory.c

   1 /*
   2  * Copyright (c) 1997 - 2001 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "krb5_locl.h"
  35
  36 /* memory operations -------------------------------------------- */
  37
  38 struct mkt_data {
  39     krb5_keytab_entry *entries;
  40     int num_entries;
  41     char *name;
  42     int refcount;
  43     struct mkt_data *next;
  44 };
  45
  46 /* this mutex protects mkt_head, ->refcount, and ->next
  47  * content is not protected (name is static and need no protection)
  48  */
  49 static HEIMDAL_MUTEX mkt_mutex = HEIMDAL_MUTEX_INITIALIZER;
  50 static struct mkt_data *mkt_head;
  51
  52
  53 static krb5_error_code
  54 mkt_resolve(krb5_context context, const char *name, krb5_keytab id)
  55 {
  56     struct mkt_data *d;
  57
  58     HEIMDAL_MUTEX_lock(&mkt_mutex);
  59
  60     for (d = mkt_head; d != NULL; d = d->next)
  61         if (strcmp(d->name, name) == 0)
  62             break;
  63     if (d) {
  64         if (d->refcount < 1)
  65             krb5_abortx(context, "Double close on memory keytab, "
  66                         "refcount < 1 %d", d->refcount);
  67         d->refcount++;
  68         id->data = d;
  69         HEIMDAL_MUTEX_unlock(&mkt_mutex);
  70         return 0;
  71     }
  72
  73     d = calloc(1, sizeof(*d));
  74     if(d == NULL) {
  75         HEIMDAL_MUTEX_unlock(&mkt_mutex);
  76         krb5_set_error_message(context, ENOMEM,
  77                                N_("malloc: out of memory", ""));
  78         return ENOMEM;
  79     }
  80     d->name = strdup(name);
  81     if (d->name == NULL) {
  82         HEIMDAL_MUTEX_unlock(&mkt_mutex);
  83         free(d);
  84         krb5_set_error_message(context, ENOMEM,
  85                                N_("malloc: out of memory", ""));
  86         return ENOMEM;
  87     }
  88     d->entries = NULL;
  89     d->num_entries = 0;
  90     d->refcount = 1;
  91     d->next = mkt_head;
  92     mkt_head = d;
  93     HEIMDAL_MUTEX_unlock(&mkt_mutex);
  94     id->data = d;
  95     return 0;
  96 }
  97
  98 static krb5_error_code
  99 mkt_close(krb5_context context, krb5_keytab id)
 100 {
 101     struct mkt_data *d = id->data, **dp;
 102     int i;
 103
 104     HEIMDAL_MUTEX_lock(&mkt_mutex);
 105     if (d->refcount < 1)
 106         krb5_abortx(context,
 107                     "krb5 internal error, memory keytab refcount < 1 on close");
 108
 109     if (--d->refcount > 0) {
 110         HEIMDAL_MUTEX_unlock(&mkt_mutex);
 111         return 0;
 112     }
 113     for (dp = &mkt_head; *dp != NULL; dp = &(*dp)->next) {
 114         if (*dp == d) {
 115             *dp = d->next;
 116             break;
 117         }
 118     }
 119     HEIMDAL_MUTEX_unlock(&mkt_mutex);
 120
 121     free(d->name);
 122     for(i = 0; i < d->num_entries; i++)
 123         krb5_kt_free_entry(context, &d->entries[i]);
 124     free(d->entries);
 125     free(d);
 126     return 0;
 127 }
 128
 129 static krb5_error_code
 130 mkt_get_name(krb5_context context,
 131              krb5_keytab id,
 132              char *name,
 133              size_t namesize)
 134 {
 135     struct mkt_data *d = id->data;
 136     strlcpy(name, d->name, namesize);
 137     return 0;
 138 }
 139
 140 static krb5_error_code
 141 mkt_start_seq_get(krb5_context context,
 142                   krb5_keytab id,
 143                   krb5_kt_cursor *c)
 144 {
 145     /* XXX */
 146     c->fd = 0;
 147     return 0;
 148 }
 149
 150 static krb5_error_code
 151 mkt_next_entry(krb5_context context,
 152                krb5_keytab id,
 153                krb5_keytab_entry *entry,
 154                krb5_kt_cursor *c)
 155 {
 156     struct mkt_data *d = id->data;
 157     if(c->fd >= d->num_entries)
 158         return KRB5_KT_END;
 159     return krb5_kt_copy_entry_contents(context, &d->entries[c->fd++], entry);
 160 }
 161
 162 static krb5_error_code
 163 mkt_end_seq_get(krb5_context context,
 164                 krb5_keytab id,
 165                 krb5_kt_cursor *cursor)
 166 {
 167     return 0;
 168 }
 169
 170 static krb5_error_code
 171 mkt_add_entry(krb5_context context,
 172               krb5_keytab id,
 173               krb5_keytab_entry *entry)
 174 {
 175     struct mkt_data *d = id->data;
 176     krb5_keytab_entry *tmp;
 177     tmp = realloc(d->entries, (d->num_entries + 1) * sizeof(*d->entries));
 178     if(tmp == NULL) {
 179         krb5_set_error_message(context, ENOMEM,
 180                                N_("malloc: out of memory", ""));
 181         return ENOMEM;
 182     }
 183     d->entries = tmp;
 184     return krb5_kt_copy_entry_contents(context, entry,
 185                                        &d->entries[d->num_entries++]);
 186 }
 187
 188 static krb5_error_code
 189 mkt_remove_entry(krb5_context context,
 190                  krb5_keytab id,
 191                  krb5_keytab_entry *entry)
 192 {
 193     struct mkt_data *d = id->data;
 194     krb5_keytab_entry *e, *end;
 195     int found = 0;
 196
 197     if (d->num_entries == 0) {
 198         krb5_clear_error_message(context);
 199         return KRB5_KT_NOTFOUND;
 200     }
 201
 202     /* do this backwards to minimize copying */
 203     for(end = d->entries + d->num_entries, e = end - 1; e >= d->entries; e--) {
 204         if(krb5_kt_compare(context, e, entry->principal,
 205                            entry->vno, entry->keyblock.keytype)) {
 206             krb5_kt_free_entry(context, e);
 207             memmove(e, e + 1, (end - e - 1) * sizeof(*e));
 208             memset(end - 1, 0, sizeof(*end));
 209             d->num_entries--;
 210             end--;
 211             found = 1;
 212         }
 213     }
 214     if (!found) {
 215         krb5_clear_error_message (context);
 216         return KRB5_KT_NOTFOUND;
 217     }
 218     e = realloc(d->entries, d->num_entries * sizeof(*d->entries));
 219     if(e != NULL || d->num_entries == 0)
 220         d->entries = e;
 221     return 0;
 222 }
 223
 224 const krb5_kt_ops krb5_mkt_ops = {
 225     "MEMORY",
 226     mkt_resolve,
 227     mkt_get_name,
 228     mkt_close,
 229     NULL, /* destroy */
 230     NULL, /* get */
 231     mkt_start_seq_get,
 232     mkt_next_entry,
 233     mkt_end_seq_get,
 234     mkt_add_entry,
 235     mkt_remove_entry
 236 };