1 /* $OpenBSD: tls13_buffer.c,v 1.5 2021/05/16 14:19:04 jsing Exp $ */
2 /*
3 * Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #include "bytestring.h"
19 #include "tls13_internal.h"
20
21 struct tls13_buffer {
22 size_t capacity;
23 uint8_t *data;
24 size_t len;
25 size_t offset;
26 };
27
28 static int tls13_buffer_resize(struct tls13_buffer *buf, size_t capacity);
29
30 struct tls13_buffer *
tls13_buffer_new(size_t init_size)31 tls13_buffer_new(size_t init_size)
32 {
33 struct tls13_buffer *buf = NULL;
34
35 if ((buf = calloc(1, sizeof(struct tls13_buffer))) == NULL)
36 goto err;
37
38 if (!tls13_buffer_resize(buf, init_size))
39 goto err;
40
41 return buf;
42
43 err:
44 tls13_buffer_free(buf);
45
46 return NULL;
47 }
48
49 void
tls13_buffer_free(struct tls13_buffer * buf)50 tls13_buffer_free(struct tls13_buffer *buf)
51 {
52 if (buf == NULL)
53 return;
54
55 freezero(buf->data, buf->capacity);
56 freezero(buf, sizeof(struct tls13_buffer));
57 }
58
59 static int
tls13_buffer_resize(struct tls13_buffer * buf,size_t capacity)60 tls13_buffer_resize(struct tls13_buffer *buf, size_t capacity)
61 {
62 uint8_t *data;
63
64 if (buf->capacity == capacity)
65 return 1;
66
67 if ((data = recallocarray(buf->data, buf->capacity, capacity, 1)) == NULL)
68 return 0;
69
70 buf->data = data;
71 buf->capacity = capacity;
72
73 return 1;
74 }
75
76 int
tls13_buffer_set_data(struct tls13_buffer * buf,CBS * data)77 tls13_buffer_set_data(struct tls13_buffer *buf, CBS *data)
78 {
79 if (!tls13_buffer_resize(buf, CBS_len(data)))
80 return 0;
81 memcpy(buf->data, CBS_data(data), CBS_len(data));
82 return 1;
83 }
84
85 ssize_t
tls13_buffer_extend(struct tls13_buffer * buf,size_t len,tls13_read_cb read_cb,void * cb_arg)86 tls13_buffer_extend(struct tls13_buffer *buf, size_t len,
87 tls13_read_cb read_cb, void *cb_arg)
88 {
89 ssize_t ret;
90
91 if (len == buf->len)
92 return buf->len;
93
94 if (len < buf->len)
95 return TLS13_IO_FAILURE;
96
97 if (!tls13_buffer_resize(buf, len))
98 return TLS13_IO_FAILURE;
99
100 for (;;) {
101 if ((ret = read_cb(&buf->data[buf->len],
102 buf->capacity - buf->len, cb_arg)) <= 0)
103 return ret;
104
105 if (ret > buf->capacity - buf->len)
106 return TLS13_IO_FAILURE;
107
108 buf->len += ret;
109
110 if (buf->len == buf->capacity)
111 return buf->len;
112 }
113 }
114
115 void
tls13_buffer_cbs(struct tls13_buffer * buf,CBS * cbs)116 tls13_buffer_cbs(struct tls13_buffer *buf, CBS *cbs)
117 {
118 CBS_init(cbs, buf->data, buf->len);
119 }
120
121 int
tls13_buffer_finish(struct tls13_buffer * buf,uint8_t ** out,size_t * out_len)122 tls13_buffer_finish(struct tls13_buffer *buf, uint8_t **out, size_t *out_len)
123 {
124 if (out == NULL || out_len == NULL)
125 return 0;
126
127 *out = buf->data;
128 *out_len = buf->len;
129
130 buf->capacity = 0;
131 buf->data = NULL;
132 buf->len = 0;
133
134 return 1;
135 }
136