1/*	$NetBSD: keytab_memory.c,v 1.2 2017/01/28 21:31:49 christos Exp $	*/
2
3/*
4 * Copyright (c) 1997 - 2001 Kungliga Tekniska H��gskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include "krb5_locl.h"
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 KRB5_CALLCONV
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	return krb5_enomem(context);
79    }
80    d->name = strdup(name);
81    if (d->name == NULL) {
82	HEIMDAL_MUTEX_unlock(&mkt_mutex);
83	free(d);
84	return krb5_enomem(context);
85    }
86    d->entries = NULL;
87    d->num_entries = 0;
88    d->refcount = 1;
89    d->next = mkt_head;
90    mkt_head = d;
91    HEIMDAL_MUTEX_unlock(&mkt_mutex);
92    id->data = d;
93    return 0;
94}
95
96static krb5_error_code KRB5_CALLCONV
97mkt_close(krb5_context context, krb5_keytab id)
98{
99    struct mkt_data *d = id->data, **dp;
100    int i;
101
102    HEIMDAL_MUTEX_lock(&mkt_mutex);
103    if (d->refcount < 1)
104	krb5_abortx(context,
105		    "krb5 internal error, memory keytab refcount < 1 on close");
106
107    if (--d->refcount > 0) {
108	HEIMDAL_MUTEX_unlock(&mkt_mutex);
109	return 0;
110    }
111    for (dp = &mkt_head; *dp != NULL; dp = &(*dp)->next) {
112	if (*dp == d) {
113	    *dp = d->next;
114	    break;
115	}
116    }
117    HEIMDAL_MUTEX_unlock(&mkt_mutex);
118
119    free(d->name);
120    for(i = 0; i < d->num_entries; i++)
121	krb5_kt_free_entry(context, &d->entries[i]);
122    free(d->entries);
123    free(d);
124    return 0;
125}
126
127static krb5_error_code KRB5_CALLCONV
128mkt_get_name(krb5_context context,
129	     krb5_keytab id,
130	     char *name,
131	     size_t namesize)
132{
133    struct mkt_data *d = id->data;
134    strlcpy(name, d->name, namesize);
135    return 0;
136}
137
138static krb5_error_code KRB5_CALLCONV
139mkt_start_seq_get(krb5_context context,
140		  krb5_keytab id,
141		  krb5_kt_cursor *c)
142{
143    /* XXX */
144    c->fd = 0;
145    return 0;
146}
147
148static krb5_error_code KRB5_CALLCONV
149mkt_next_entry(krb5_context context,
150	       krb5_keytab id,
151	       krb5_keytab_entry *entry,
152	       krb5_kt_cursor *c)
153{
154    struct mkt_data *d = id->data;
155    if(c->fd >= d->num_entries)
156	return KRB5_KT_END;
157    return krb5_kt_copy_entry_contents(context, &d->entries[c->fd++], entry);
158}
159
160static krb5_error_code KRB5_CALLCONV
161mkt_end_seq_get(krb5_context context,
162		krb5_keytab id,
163		krb5_kt_cursor *cursor)
164{
165    return 0;
166}
167
168static krb5_error_code KRB5_CALLCONV
169mkt_add_entry(krb5_context context,
170	      krb5_keytab id,
171	      krb5_keytab_entry *entry)
172{
173    struct mkt_data *d = id->data;
174    krb5_keytab_entry *tmp;
175    tmp = realloc(d->entries, (d->num_entries + 1) * sizeof(*d->entries));
176    if (tmp == NULL)
177	return krb5_enomem(context);
178    d->entries = tmp;
179    return krb5_kt_copy_entry_contents(context, entry,
180				       &d->entries[d->num_entries++]);
181}
182
183static krb5_error_code KRB5_CALLCONV
184mkt_remove_entry(krb5_context context,
185		 krb5_keytab id,
186		 krb5_keytab_entry *entry)
187{
188    struct mkt_data *d = id->data;
189    krb5_keytab_entry *e, *end;
190    int found = 0;
191
192    if (d->num_entries == 0) {
193	krb5_clear_error_message(context);
194        return KRB5_KT_NOTFOUND;
195    }
196
197    /* do this backwards to minimize copying */
198    for(end = d->entries + d->num_entries, e = end - 1; e >= d->entries; e--) {
199	if(krb5_kt_compare(context, e, entry->principal,
200			   entry->vno, entry->keyblock.keytype)) {
201	    krb5_kt_free_entry(context, e);
202	    memmove(e, e + 1, (end - e - 1) * sizeof(*e));
203	    memset(end - 1, 0, sizeof(*end));
204	    d->num_entries--;
205	    end--;
206	    found = 1;
207	}
208    }
209    if (!found) {
210	krb5_clear_error_message (context);
211	return KRB5_KT_NOTFOUND;
212    }
213    e = realloc(d->entries, d->num_entries * sizeof(*d->entries));
214    if(e != NULL || d->num_entries == 0)
215	d->entries = e;
216    return 0;
217}
218
219const krb5_kt_ops krb5_mkt_ops = {
220    "MEMORY",
221    mkt_resolve,
222    mkt_get_name,
223    mkt_close,
224    NULL, /* destroy */
225    NULL, /* get */
226    mkt_start_seq_get,
227    mkt_next_entry,
228    mkt_end_seq_get,
229    mkt_add_entry,
230    mkt_remove_entry,
231    NULL,
232    0
233};
234