1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
|
/* $OpenBSD: tls_buffer.c,v 1.3 2022/07/22 19:33:53 jsing Exp $ */
/*
* Copyright (c) 2018, 2019, 2022 Joel Sing <jsing@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <stdlib.h>
#include <string.h>
#include "bytestring.h"
#include "tls_internal.h"
#define TLS_BUFFER_CAPACITY_LIMIT (1024 * 1024)
struct tls_buffer {
size_t capacity;
size_t capacity_limit;
uint8_t *data;
size_t len;
size_t offset;
};
static int tls_buffer_resize(struct tls_buffer *buf, size_t capacity);
struct tls_buffer *
tls_buffer_new(size_t init_size)
{
struct tls_buffer *buf = NULL;
if ((buf = calloc(1, sizeof(struct tls_buffer))) == NULL)
goto err;
buf->capacity_limit = TLS_BUFFER_CAPACITY_LIMIT;
if (!tls_buffer_resize(buf, init_size))
goto err;
return buf;
err:
tls_buffer_free(buf);
return NULL;
}
void
tls_buffer_clear(struct tls_buffer *buf)
{
freezero(buf->data, buf->capacity);
buf->data = NULL;
buf->capacity = 0;
buf->len = 0;
buf->offset = 0;
}
void
tls_buffer_free(struct tls_buffer *buf)
{
if (buf == NULL)
return;
tls_buffer_clear(buf);
freezero(buf, sizeof(struct tls_buffer));
}
static int
tls_buffer_grow(struct tls_buffer *buf, size_t capacity)
{
if (buf->capacity >= capacity)
return 1;
return tls_buffer_resize(buf, capacity);
}
static int
tls_buffer_resize(struct tls_buffer *buf, size_t capacity)
{
uint8_t *data;
/*
* XXX - Consider maintaining a minimum size and growing more
* intelligently (rather than exactly).
*/
if (buf->capacity == capacity)
return 1;
if (capacity > buf->capacity_limit)
return 0;
if ((data = recallocarray(buf->data, buf->capacity, capacity, 1)) == NULL)
return 0;
buf->data = data;
buf->capacity = capacity;
/* Ensure that len and offset are valid if capacity decreased. */
if (buf->len > buf->capacity)
buf->len = buf->capacity;
if (buf->offset > buf->len)
buf->offset = buf->len;
return 1;
}
void
tls_buffer_set_capacity_limit(struct tls_buffer *buf, size_t limit)
{
/*
* XXX - do we want to force a resize if this limit is less than current
* capacity... and what do we do with existing data? Force a clear?
*/
buf->capacity_limit = limit;
}
ssize_t
tls_buffer_extend(struct tls_buffer *buf, size_t len,
tls_read_cb read_cb, void *cb_arg)
{
ssize_t ret;
if (len == buf->len)
return buf->len;
if (len < buf->len)
return TLS_IO_FAILURE;
if (!tls_buffer_resize(buf, len))
return TLS_IO_FAILURE;
for (;;) {
if ((ret = read_cb(&buf->data[buf->len],
buf->capacity - buf->len, cb_arg)) <= 0)
return ret;
if (ret > buf->capacity - buf->len)
return TLS_IO_FAILURE;
buf->len += ret;
if (buf->len == buf->capacity)
return buf->len;
}
}
ssize_t
tls_buffer_read(struct tls_buffer *buf, uint8_t *rbuf, size_t n)
{
if (buf->offset > buf->len)
return TLS_IO_FAILURE;
if (buf->offset == buf->len)
return TLS_IO_WANT_POLLIN;
if (n > buf->len - buf->offset)
n = buf->len - buf->offset;
memcpy(rbuf, &buf->data[buf->offset], n);
buf->offset += n;
return n;
}
ssize_t
tls_buffer_write(struct tls_buffer *buf, const uint8_t *wbuf, size_t n)
{
if (buf->offset > buf->len)
return TLS_IO_FAILURE;
/*
* To avoid continually growing the buffer, pull data up to the
* start of the buffer. If all data has been read then we can simply
* reset, otherwise wait until we're going to save at least 4KB of
* memory to reduce overhead.
*/
if (buf->offset == buf->len) {
buf->len = 0;
buf->offset = 0;
}
if (buf->offset >= 4096) {
memmove(buf->data, &buf->data[buf->offset],
buf->len - buf->offset);
buf->len -= buf->offset;
buf->offset = 0;
}
if (buf->len > SIZE_MAX - n)
return TLS_IO_FAILURE;
if (!tls_buffer_grow(buf, buf->len + n))
return TLS_IO_FAILURE;
memcpy(&buf->data[buf->len], wbuf, n);
buf->len += n;
return n;
}
int
tls_buffer_append(struct tls_buffer *buf, const uint8_t *wbuf, size_t n)
{
return tls_buffer_write(buf, wbuf, n) == n;
}
int
tls_buffer_data(struct tls_buffer *buf, CBS *out_cbs)
{
CBS cbs;
CBS_init(&cbs, buf->data, buf->len);
if (!CBS_skip(&cbs, buf->offset))
return 0;
CBS_dup(&cbs, out_cbs);
return 1;
}
int
tls_buffer_finish(struct tls_buffer *buf, uint8_t **out, size_t *out_len)
{
if (out == NULL || out_len == NULL)
return 0;
*out = buf->data;
*out_len = buf->len;
buf->data = NULL;
buf->capacity = 0;
buf->len = 0;
buf->offset = 0;
return 1;
}
|
