xref: /freebsd/crypto/heimdal/lib/krb5/store_mem.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 /*
2  * Copyright (c) 1997 - 2000, 2002 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 #include "store-int.h"
36 
37 typedef struct mem_storage{
38     unsigned char *base;
39     size_t size;
40     unsigned char *ptr;
41 }mem_storage;
42 
43 static ssize_t
44 mem_fetch(krb5_storage *sp, void *data, size_t size)
45 {
46     mem_storage *s = (mem_storage*)sp->data;
47     if(size > (size_t)(s->base + s->size - s->ptr))
48 	size = s->base + s->size - s->ptr;
49     memmove(data, s->ptr, size);
50     sp->seek(sp, size, SEEK_CUR);
51     return size;
52 }
53 
54 static ssize_t
55 mem_store(krb5_storage *sp, const void *data, size_t size)
56 {
57     mem_storage *s = (mem_storage*)sp->data;
58     if(size > (size_t)(s->base + s->size - s->ptr))
59 	size = s->base + s->size - s->ptr;
60     memmove(s->ptr, data, size);
61     sp->seek(sp, size, SEEK_CUR);
62     return size;
63 }
64 
65 static ssize_t
66 mem_no_store(krb5_storage *sp, const void *data, size_t size)
67 {
68     return -1;
69 }
70 
71 static off_t
72 mem_seek(krb5_storage *sp, off_t offset, int whence)
73 {
74     mem_storage *s = (mem_storage*)sp->data;
75     switch(whence){
76     case SEEK_SET:
77 	if((size_t)offset > s->size)
78 	    offset = s->size;
79 	if(offset < 0)
80 	    offset = 0;
81 	s->ptr = s->base + offset;
82 	break;
83     case SEEK_CUR:
84 	return sp->seek(sp, s->ptr - s->base + offset, SEEK_SET);
85     case SEEK_END:
86 	return sp->seek(sp, s->size + offset, SEEK_SET);
87     default:
88 	errno = EINVAL;
89 	return -1;
90     }
91     return s->ptr - s->base;
92 }
93 
94 static int
95 mem_trunc(krb5_storage *sp, off_t offset)
96 {
97     mem_storage *s = (mem_storage*)sp->data;
98     if((size_t)offset > s->size)
99 	return ERANGE;
100     s->size = offset;
101     if ((s->ptr - s->base) > offset)
102 	s->ptr = s->base + offset;
103     return 0;
104 }
105 
106 static int
107 mem_no_trunc(krb5_storage *sp, off_t offset)
108 {
109     return EINVAL;
110 }
111 
112 /**
113  * Create a fixed size memory storage block
114  *
115  * @return A krb5_storage on success, or NULL on out of memory error.
116  *
117  * @ingroup krb5_storage
118  *
119  * @sa krb5_storage_mem()
120  * @sa krb5_storage_from_readonly_mem()
121  * @sa krb5_storage_from_data()
122  * @sa krb5_storage_from_fd()
123  */
124 
125 KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
126 krb5_storage_from_mem(void *buf, size_t len)
127 {
128     krb5_storage *sp = malloc(sizeof(krb5_storage));
129     mem_storage *s;
130     if(sp == NULL)
131 	return NULL;
132     s = malloc(sizeof(*s));
133     if(s == NULL) {
134 	free(sp);
135 	return NULL;
136     }
137     sp->data = s;
138     sp->flags = 0;
139     sp->eof_code = HEIM_ERR_EOF;
140     s->base = buf;
141     s->size = len;
142     s->ptr = buf;
143     sp->fetch = mem_fetch;
144     sp->store = mem_store;
145     sp->seek = mem_seek;
146     sp->trunc = mem_trunc;
147     sp->free = NULL;
148     sp->max_alloc = UINT_MAX/8;
149     return sp;
150 }
151 
152 /**
153  * Create a fixed size memory storage block
154  *
155  * @return A krb5_storage on success, or NULL on out of memory error.
156  *
157  * @ingroup krb5_storage
158  *
159  * @sa krb5_storage_mem()
160  * @sa krb5_storage_from_mem()
161  * @sa krb5_storage_from_readonly_mem()
162  * @sa krb5_storage_from_fd()
163  */
164 
165 KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
166 krb5_storage_from_data(krb5_data *data)
167 {
168     return krb5_storage_from_mem(data->data, data->length);
169 }
170 
171 /**
172  * Create a fixed size memory storage block that is read only
173  *
174  * @return A krb5_storage on success, or NULL on out of memory error.
175  *
176  * @ingroup krb5_storage
177  *
178  * @sa krb5_storage_mem()
179  * @sa krb5_storage_from_mem()
180  * @sa krb5_storage_from_data()
181  * @sa krb5_storage_from_fd()
182  */
183 
184 KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
185 krb5_storage_from_readonly_mem(const void *buf, size_t len)
186 {
187     krb5_storage *sp = malloc(sizeof(krb5_storage));
188     mem_storage *s;
189     if(sp == NULL)
190 	return NULL;
191     s = malloc(sizeof(*s));
192     if(s == NULL) {
193 	free(sp);
194 	return NULL;
195     }
196     sp->data = s;
197     sp->flags = 0;
198     sp->eof_code = HEIM_ERR_EOF;
199     s->base = rk_UNCONST(buf);
200     s->size = len;
201     s->ptr = rk_UNCONST(buf);
202     sp->fetch = mem_fetch;
203     sp->store = mem_no_store;
204     sp->seek = mem_seek;
205     sp->trunc = mem_no_trunc;
206     sp->free = NULL;
207     sp->max_alloc = UINT_MAX/8;
208     return sp;
209 }
210