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 KRB5_CALLCONV
mkt_resolve(krb5_context context,const char * name,krb5_keytab id)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 KRB5_CALLCONV
mkt_close(krb5_context context,krb5_keytab id)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 KRB5_CALLCONV
mkt_get_name(krb5_context context,krb5_keytab id,char * name,size_t namesize)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 KRB5_CALLCONV
mkt_start_seq_get(krb5_context context,krb5_keytab id,krb5_kt_cursor * c)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 KRB5_CALLCONV
mkt_next_entry(krb5_context context,krb5_keytab id,krb5_keytab_entry * entry,krb5_kt_cursor * c)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 KRB5_CALLCONV
mkt_end_seq_get(krb5_context context,krb5_keytab id,krb5_kt_cursor * cursor)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 KRB5_CALLCONV
mkt_add_entry(krb5_context context,krb5_keytab id,krb5_keytab_entry * entry)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 KRB5_CALLCONV
mkt_remove_entry(krb5_context context,krb5_keytab id,krb5_keytab_entry * entry)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 };
237