1 /* $OpenBSD: tls13_handshake_msg.c,v 1.1 2019/01/20 12:27:34 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 "ssl_locl.h" 20 #include "tls13_internal.h" 21 22 #define TLS13_HANDSHAKE_MSG_HEADER_LEN 4 23 #define TLS13_HANDSHAKE_MSG_INITIAL_LEN 256 24 #define TLS13_HANDSHAKE_MSG_MAX_LEN (256 * 1024) 25 26 struct tls13_handshake_msg { 27 uint8_t msg_type; 28 uint32_t msg_len; 29 uint8_t *data; 30 size_t data_len; 31 32 struct tls13_buffer *buf; 33 CBS cbs; 34 CBB cbb; 35 }; 36 37 struct tls13_handshake_msg * 38 tls13_handshake_msg_new() 39 { 40 struct tls13_handshake_msg *msg = NULL; 41 42 if ((msg = calloc(1, sizeof(struct tls13_handshake_msg))) == NULL) 43 goto err; 44 if ((msg->buf = tls13_buffer_new(0)) == NULL) 45 goto err; 46 47 return msg; 48 49 err: 50 tls13_handshake_msg_free(msg); 51 52 return NULL; 53 } 54 55 void 56 tls13_handshake_msg_free(struct tls13_handshake_msg *msg) 57 { 58 if (msg == NULL) 59 return; 60 61 tls13_buffer_free(msg->buf); 62 63 CBB_cleanup(&msg->cbb); 64 65 freezero(msg->data, msg->data_len); 66 freezero(msg, sizeof(struct tls13_handshake_msg)); 67 } 68 69 void 70 tls13_handshake_msg_data(struct tls13_handshake_msg *msg, CBS *cbs) 71 { 72 CBS_init(cbs, msg->data, msg->data_len); 73 } 74 75 uint8_t 76 tls13_handshake_msg_type(struct tls13_handshake_msg *msg) 77 { 78 return msg->msg_type; 79 } 80 81 int 82 tls13_handshake_msg_content(struct tls13_handshake_msg *msg, CBS *cbs) 83 { 84 tls13_handshake_msg_data(msg, cbs); 85 86 return CBS_skip(cbs, TLS13_HANDSHAKE_MSG_HEADER_LEN); 87 } 88 89 int 90 tls13_handshake_msg_start(struct tls13_handshake_msg *msg, CBB *body, 91 uint8_t msg_type) 92 { 93 if (!CBB_init(&msg->cbb, TLS13_HANDSHAKE_MSG_INITIAL_LEN)) 94 return 0; 95 if (!CBB_add_u8(&msg->cbb, msg_type)) 96 return 0; 97 if (!CBB_add_u24_length_prefixed(&msg->cbb, body)) 98 return 0; 99 100 return 1; 101 } 102 103 int 104 tls13_handshake_msg_finish(struct tls13_handshake_msg *msg) 105 { 106 if (!CBB_finish(&msg->cbb, &msg->data, &msg->data_len)) 107 return 0; 108 109 CBS_init(&msg->cbs, msg->data, msg->data_len); 110 111 return 1; 112 } 113 114 static ssize_t 115 tls13_handshake_msg_read_cb(void *buf, size_t n, void *cb_arg) 116 { 117 struct tls13_record_layer *rl = cb_arg; 118 119 return tls13_read_handshake_data(rl, buf, n); 120 } 121 122 int 123 tls13_handshake_msg_recv(struct tls13_handshake_msg *msg, 124 struct tls13_record_layer *rl) 125 { 126 uint8_t msg_type; 127 uint32_t msg_len; 128 CBS cbs; 129 int ret; 130 131 if (msg->data != NULL) 132 return TLS13_IO_FAILURE; 133 134 if (msg->msg_type == 0) { 135 if ((ret = tls13_buffer_extend(msg->buf, 136 TLS13_HANDSHAKE_MSG_HEADER_LEN, 137 tls13_handshake_msg_read_cb, rl)) <= 0) 138 return ret; 139 140 tls13_buffer_cbs(msg->buf, &cbs); 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 = tls13_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 (!tls13_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