1/*
2 * Copyright (c) 1997 - 2001 Kungliga Tekniska H�gskolan
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
36RCSID("$Id: keytab_memory.c 16352 2005-12-05 18:39:46Z lha $");
37
38/* memory operations -------------------------------------------- */
39
40struct mkt_data {
41    krb5_keytab_entry *entries;
42    int num_entries;
43    char *name;
44    int refcount;
45    struct mkt_data *next;
46};
47
48/* this mutex protects mkt_head, ->refcount, and ->next
49 * content is not protected (name is static and need no protection)
50 */
51static HEIMDAL_MUTEX mkt_mutex = HEIMDAL_MUTEX_INITIALIZER;
52static struct mkt_data *mkt_head;
53
54
55static krb5_error_code
56mkt_resolve(krb5_context context, const char *name, krb5_keytab id)
57{
58    struct mkt_data *d;
59
60    HEIMDAL_MUTEX_lock(&mkt_mutex);
61
62    for (d = mkt_head; d != NULL; d = d->next)
63	if (strcmp(d->name, name) == 0)
64	    break;
65    if (d) {
66	if (d->refcount < 1)
67	    krb5_abortx(context, "Double close on memory keytab, "
68			"refcount < 1 %d", d->refcount);
69	d->refcount++;
70	id->data = d;
71	HEIMDAL_MUTEX_unlock(&mkt_mutex);
72	return 0;
73    }
74
75    d = calloc(1, sizeof(*d));
76    if(d == NULL) {
77	HEIMDAL_MUTEX_unlock(&mkt_mutex);
78	krb5_set_error_string (context, "malloc: out of memory");
79	return ENOMEM;
80    }
81    d->name = strdup(name);
82    if (d->name == NULL) {
83	HEIMDAL_MUTEX_unlock(&mkt_mutex);
84	free(d);
85	krb5_set_error_string (context, "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
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
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
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
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
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
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_string (context, "malloc: out of memory");
180	return ENOMEM;
181    }
182    d->entries = tmp;
183    return krb5_kt_copy_entry_contents(context, entry,
184				       &d->entries[d->num_entries++]);
185}
186
187static krb5_error_code
188mkt_remove_entry(krb5_context context,
189		 krb5_keytab id,
190		 krb5_keytab_entry *entry)
191{
192    struct mkt_data *d = id->data;
193    krb5_keytab_entry *e, *end;
194    int found = 0;
195
196    if (d->num_entries == 0) {
197	krb5_clear_error_string(context);
198        return KRB5_KT_NOTFOUND;
199    }
200
201    /* do this backwards to minimize copying */
202    for(end = d->entries + d->num_entries, e = end - 1; e >= d->entries; e--) {
203	if(krb5_kt_compare(context, e, entry->principal,
204			   entry->vno, entry->keyblock.keytype)) {
205	    krb5_kt_free_entry(context, e);
206	    memmove(e, e + 1, (end - e - 1) * sizeof(*e));
207	    memset(end - 1, 0, sizeof(*end));
208	    d->num_entries--;
209	    end--;
210	    found = 1;
211	}
212    }
213    if (!found) {
214	krb5_clear_error_string (context);
215	return KRB5_KT_NOTFOUND;
216    }
217    e = realloc(d->entries, d->num_entries * sizeof(*d->entries));
218    if(e != NULL || d->num_entries == 0)
219	d->entries = e;
220    return 0;
221}
222
223const krb5_kt_ops krb5_mkt_ops = {
224    "MEMORY",
225    mkt_resolve,
226    mkt_get_name,
227    mkt_close,
228    NULL, /* get */
229    mkt_start_seq_get,
230    mkt_next_entry,
231    mkt_end_seq_get,
232    mkt_add_entry,
233    mkt_remove_entry
234};
235