1 /* $OpenBSD: tls13_handshake_msg.c,v 1.6 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 "bytestring.h" 19 #include "tls13_internal.h" 20 21 #define TLS13_HANDSHAKE_MSG_HEADER_LEN 4 22 #define TLS13_HANDSHAKE_MSG_INITIAL_LEN 256 23 #define TLS13_HANDSHAKE_MSG_MAX_LEN (256 * 1024) 24 25 struct tls13_handshake_msg { 26 uint8_t msg_type; 27 uint32_t msg_len; 28 uint8_t *data; 29 size_t data_len; 30 31 struct tls_buffer *buf; 32 CBS cbs; 33 CBB cbb; 34 }; 35 36 struct tls13_handshake_msg * 37 tls13_handshake_msg_new() 38 { 39 struct tls13_handshake_msg *msg = NULL; 40 41 if ((msg = calloc(1, sizeof(struct tls13_handshake_msg))) == NULL) 42 goto err; 43 if ((msg->buf = tls_buffer_new(0)) == NULL) 44 goto err; 45 46 return msg; 47 48 err: 49 tls13_handshake_msg_free(msg); 50 51 return NULL; 52 } 53 54 void 55 tls13_handshake_msg_free(struct tls13_handshake_msg *msg) 56 { 57 if (msg == NULL) 58 return; 59 60 tls_buffer_free(msg->buf); 61 62 CBB_cleanup(&msg->cbb); 63 64 freezero(msg->data, msg->data_len); 65 freezero(msg, sizeof(struct tls13_handshake_msg)); 66 } 67 68 void 69 tls13_handshake_msg_data(struct tls13_handshake_msg *msg, CBS *cbs) 70 { 71 CBS_init(cbs, msg->data, msg->data_len); 72 } 73 74 uint8_t 75 tls13_handshake_msg_type(struct tls13_handshake_msg *msg) 76 { 77 return msg->msg_type; 78 } 79 80 int 81 tls13_handshake_msg_content(struct tls13_handshake_msg *msg, CBS *cbs) 82 { 83 tls13_handshake_msg_data(msg, cbs); 84 85 return CBS_skip(cbs, TLS13_HANDSHAKE_MSG_HEADER_LEN); 86 } 87 88 int 89 tls13_handshake_msg_start(struct tls13_handshake_msg *msg, CBB *body, 90 uint8_t msg_type) 91 { 92 if (!CBB_init(&msg->cbb, TLS13_HANDSHAKE_MSG_INITIAL_LEN)) 93 return 0; 94 if (!CBB_add_u8(&msg->cbb, msg_type)) 95 return 0; 96 if (!CBB_add_u24_length_prefixed(&msg->cbb, body)) 97 return 0; 98 99 return 1; 100 } 101 102 int 103 tls13_handshake_msg_finish(struct tls13_handshake_msg *msg) 104 { 105 if (!CBB_finish(&msg->cbb, &msg->data, &msg->data_len)) 106 return 0; 107 108 CBS_init(&msg->cbs, msg->data, msg->data_len); 109 110 return 1; 111 } 112 113 static ssize_t 114 tls13_handshake_msg_read_cb(void *buf, size_t n, void *cb_arg) 115 { 116 struct tls13_record_layer *rl = cb_arg; 117 118 return tls13_read_handshake_data(rl, buf, n); 119 } 120 121 int 122 tls13_handshake_msg_recv(struct tls13_handshake_msg *msg, 123 struct tls13_record_layer *rl) 124 { 125 uint8_t msg_type; 126 uint32_t msg_len; 127 CBS cbs; 128 int ret; 129 130 if (msg->data != NULL) 131 return TLS13_IO_FAILURE; 132 133 if (msg->msg_type == 0) { 134 if ((ret = tls_buffer_extend(msg->buf, 135 TLS13_HANDSHAKE_MSG_HEADER_LEN, 136 tls13_handshake_msg_read_cb, rl)) <= 0) 137 return ret; 138 139 if (!tls_buffer_data(msg->buf, &cbs)) 140 return TLS13_IO_FAILURE; 141 142 if (!CBS_get_u8(&cbs, &msg_type)) 143 return TLS13_IO_FAILURE; 144 if (!CBS_get_u24(&cbs, &msg_len)) 145 return TLS13_IO_FAILURE; 146 147 /* XXX - do we want to make this variable on message type? */ 148 if (msg_len > TLS13_HANDSHAKE_MSG_MAX_LEN) 149 return TLS13_IO_FAILURE; 150 151 msg->msg_type = msg_type; 152 msg->msg_len = msg_len; 153 } 154 155 if ((ret = tls_buffer_extend(msg->buf, 156 TLS13_HANDSHAKE_MSG_HEADER_LEN + msg->msg_len, 157 tls13_handshake_msg_read_cb, rl)) <= 0) 158 return ret; 159 160 if (!tls_buffer_finish(msg->buf, &msg->data, &msg->data_len)) 161 return TLS13_IO_FAILURE; 162 163 return TLS13_IO_SUCCESS; 164 } 165 166 int 167 tls13_handshake_msg_send(struct tls13_handshake_msg *msg, 168 struct tls13_record_layer *rl) 169 { 170 ssize_t ret; 171 172 if (msg->data == NULL) 173 return TLS13_IO_FAILURE; 174 175 if (CBS_len(&msg->cbs) == 0) 176 return TLS13_IO_FAILURE; 177 178 while (CBS_len(&msg->cbs) > 0) { 179 if ((ret = tls13_write_handshake_data(rl, CBS_data(&msg->cbs), 180 CBS_len(&msg->cbs))) <= 0) 181 return ret; 182 183 if (!CBS_skip(&msg->cbs, ret)) 184 return TLS13_IO_FAILURE; 185 } 186 187 return TLS13_IO_SUCCESS; 188 } 189