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
38struct 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 */
49static HEIMDAL_MUTEX mkt_mutex = HEIMDAL_MUTEX_INITIALIZER;
50static struct mkt_data *mkt_head;
51
52
53static krb5_error_code KRB5_CALLCONV
54mkt_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
98static krb5_error_code KRB5_CALLCONV
99mkt_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
129static krb5_error_code KRB5_CALLCONV
130mkt_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
140static krb5_error_code KRB5_CALLCONV
141mkt_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
150static krb5_error_code KRB5_CALLCONV
151mkt_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
162static krb5_error_code KRB5_CALLCONV
163mkt_end_seq_get(krb5_context context,
164		krb5_keytab id,
165		krb5_kt_cursor *cursor)
166{
167    return 0;
168}
169
170static krb5_error_code KRB5_CALLCONV
171mkt_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
188static krb5_error_code KRB5_CALLCONV
189mkt_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
224const 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};
237