1/* $OpenBSD: tls13_record.c,v 1.10 2022/07/22 19:33:53 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 "tls13_internal.h"
19#include "tls13_record.h"
20
21struct tls13_record {
22	uint16_t version;
23	uint8_t content_type;
24	size_t rec_len;
25	uint8_t *data;
26	size_t data_len;
27	CBS cbs;
28
29	struct tls_buffer *buf;
30};
31
32struct tls13_record *
33tls13_record_new(void)
34{
35	struct tls13_record *rec = NULL;
36
37	if ((rec = calloc(1, sizeof(struct tls13_record))) == NULL)
38		goto err;
39	if ((rec->buf = tls_buffer_new(TLS13_RECORD_MAX_LEN)) == NULL)
40		goto err;
41
42	return rec;
43
44 err:
45	tls13_record_free(rec);
46
47	return NULL;
48}
49
50void
51tls13_record_free(struct tls13_record *rec)
52{
53	if (rec == NULL)
54		return;
55
56	tls_buffer_free(rec->buf);
57
58	freezero(rec->data, rec->data_len);
59	freezero(rec, sizeof(struct tls13_record));
60}
61
62uint16_t
63tls13_record_version(struct tls13_record *rec)
64{
65	return rec->version;
66}
67
68uint8_t
69tls13_record_content_type(struct tls13_record *rec)
70{
71	return rec->content_type;
72}
73
74int
75tls13_record_header(struct tls13_record *rec, CBS *cbs)
76{
77	if (rec->data_len < TLS13_RECORD_HEADER_LEN)
78		return 0;
79
80	CBS_init(cbs, rec->data, TLS13_RECORD_HEADER_LEN);
81
82	return 1;
83}
84
85int
86tls13_record_content(struct tls13_record *rec, CBS *cbs)
87{
88	CBS content;
89
90	tls13_record_data(rec, &content);
91
92	if (!CBS_skip(&content, TLS13_RECORD_HEADER_LEN))
93		return 0;
94
95	CBS_dup(&content, cbs);
96
97	return 1;
98}
99
100void
101tls13_record_data(struct tls13_record *rec, CBS *cbs)
102{
103	CBS_init(cbs, rec->data, rec->data_len);
104}
105
106int
107tls13_record_set_data(struct tls13_record *rec, uint8_t *data, size_t data_len)
108{
109	if (data_len > TLS13_RECORD_MAX_LEN)
110		return 0;
111
112	freezero(rec->data, rec->data_len);
113	rec->data = data;
114	rec->data_len = data_len;
115	CBS_init(&rec->cbs, rec->data, rec->data_len);
116
117	return 1;
118}
119
120ssize_t
121tls13_record_recv(struct tls13_record *rec, tls_read_cb wire_read,
122    void *wire_arg)
123{
124	uint16_t rec_len, rec_version;
125	uint8_t content_type;
126	ssize_t ret;
127	CBS cbs;
128
129	if (rec->data != NULL)
130		return TLS13_IO_FAILURE;
131
132	if (rec->content_type == 0) {
133		if ((ret = tls_buffer_extend(rec->buf,
134		    TLS13_RECORD_HEADER_LEN, wire_read, wire_arg)) <= 0)
135			return ret;
136
137		if (!tls_buffer_data(rec->buf, &cbs))
138			return TLS13_IO_FAILURE;
139
140		if (!CBS_get_u8(&cbs, &content_type))
141			return TLS13_IO_FAILURE;
142		if (!CBS_get_u16(&cbs, &rec_version))
143			return TLS13_IO_FAILURE;
144		if (!CBS_get_u16(&cbs, &rec_len))
145			return TLS13_IO_FAILURE;
146
147		if ((rec_version >> 8) != SSL3_VERSION_MAJOR)
148			return TLS13_IO_RECORD_VERSION;
149		if (rec_len > TLS13_RECORD_MAX_CIPHERTEXT_LEN)
150			return TLS13_IO_RECORD_OVERFLOW;
151
152		rec->content_type = content_type;
153		rec->version = rec_version;
154		rec->rec_len = rec_len;
155	}
156
157	if ((ret = tls_buffer_extend(rec->buf,
158	    TLS13_RECORD_HEADER_LEN + rec->rec_len, wire_read, wire_arg)) <= 0)
159		return ret;
160
161	if (!tls_buffer_finish(rec->buf, &rec->data, &rec->data_len))
162		return TLS13_IO_FAILURE;
163
164	return rec->data_len;
165}
166
167ssize_t
168tls13_record_send(struct tls13_record *rec, tls_write_cb wire_write,
169    void *wire_arg)
170{
171	ssize_t ret;
172
173	if (rec->data == NULL)
174		return TLS13_IO_FAILURE;
175
176	while (CBS_len(&rec->cbs) > 0) {
177		if ((ret = wire_write(CBS_data(&rec->cbs),
178		    CBS_len(&rec->cbs), wire_arg)) <= 0)
179			return ret;
180
181		if (!CBS_skip(&rec->cbs, ret))
182			return TLS13_IO_FAILURE;
183	}
184
185	return rec->data_len;
186}
187