/* $OpenBSD: tls13_handshake_msg.c,v 1.7 2024/02/04 20:50:23 tb Exp $ */

/*

 * Copyright (c) 2018, 2019 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 "bytestring.h"

#include "tls13_internal.h"

#define TLS13_HANDSHAKE_MSG_HEADER_LEN  4

#define TLS13_HANDSHAKE_MSG_INITIAL_LEN 256

#define TLS13_HANDSHAKE_MSG_MAX_LEN (256 * 1024)

struct tls13_handshake_msg {

  uint8_t msg_type;

  uint32_t msg_len;

  uint8_t *data;

  size_t data_len;

  struct tls_buffer *buf;

  CBS cbs;

  CBB cbb;

};

struct tls13_handshake_msg *

tls13_handshake_msg_new(void)

{

  struct tls13_handshake_msg *msg = NULL;

  if ((msg = calloc(1, sizeof(struct tls13_handshake_msg))) == NULL)

    goto err;

  if ((msg->buf = tls_buffer_new(0)) == NULL)

    goto err;

  return msg;

 err:

  tls13_handshake_msg_free(msg);

  return NULL;

}

void

tls13_handshake_msg_free(struct tls13_handshake_msg *msg)

{

  if (msg == NULL)

    return;

  tls_buffer_free(msg->buf);

  CBB_cleanup(&msg->cbb);

  freezero(msg->data, msg->data_len);

  freezero(msg, sizeof(struct tls13_handshake_msg));

}

void

tls13_handshake_msg_data(struct tls13_handshake_msg *msg, CBS *cbs)

{

  CBS_init(cbs, msg->data, msg->data_len);

}

uint8_t

tls13_handshake_msg_type(struct tls13_handshake_msg *msg)

{

  return msg->msg_type;

}

int

tls13_handshake_msg_content(struct tls13_handshake_msg *msg, CBS *cbs)

{

  tls13_handshake_msg_data(msg, cbs);

  return CBS_skip(cbs, TLS13_HANDSHAKE_MSG_HEADER_LEN);

}

int

tls13_handshake_msg_start(struct tls13_handshake_msg *msg, CBB *body,

    uint8_t msg_type)

{

  if (!CBB_init(&msg->cbb, TLS13_HANDSHAKE_MSG_INITIAL_LEN))

    return 0;

  if (!CBB_add_u8(&msg->cbb, msg_type))

    return 0;

  if (!CBB_add_u24_length_prefixed(&msg->cbb, body))

    return 0;

  return 1;

}

int

tls13_handshake_msg_finish(struct tls13_handshake_msg *msg)

{

  if (!CBB_finish(&msg->cbb, &msg->data, &msg->data_len))

    return 0;

  CBS_init(&msg->cbs, msg->data, msg->data_len);

  return 1;

}

static ssize_t

tls13_handshake_msg_read_cb(void *buf, size_t n, void *cb_arg)

{

  struct tls13_record_layer *rl = cb_arg;

  return tls13_read_handshake_data(rl, buf, n);

}

int

tls13_handshake_msg_recv(struct tls13_handshake_msg *msg,

    struct tls13_record_layer *rl)

{

  uint8_t msg_type;

  uint32_t msg_len;

  CBS cbs;

  int ret;

  if (msg->data != NULL)

    return TLS13_IO_FAILURE;

  if (msg->msg_type == 0) {

    if ((ret = tls_buffer_extend(msg->buf,

        TLS13_HANDSHAKE_MSG_HEADER_LEN,

        tls13_handshake_msg_read_cb, rl)) <= 0)

      return ret;

    if (!tls_buffer_data(msg->buf, &cbs))

      return TLS13_IO_FAILURE;

    if (!CBS_get_u8(&cbs, &msg_type))

      return TLS13_IO_FAILURE;

    if (!CBS_get_u24(&cbs, &msg_len))

      return TLS13_IO_FAILURE;

    /* XXX - do we want to make this variable on message type? */

    if (msg_len > TLS13_HANDSHAKE_MSG_MAX_LEN)

      return TLS13_IO_FAILURE;

    msg->msg_type = msg_type;

    msg->msg_len = msg_len;

  }

  if ((ret = tls_buffer_extend(msg->buf,

      TLS13_HANDSHAKE_MSG_HEADER_LEN + msg->msg_len,

      tls13_handshake_msg_read_cb, rl)) <= 0)

    return ret;

  if (!tls_buffer_finish(msg->buf, &msg->data, &msg->data_len))

    return TLS13_IO_FAILURE;

  return TLS13_IO_SUCCESS;

}

int

tls13_handshake_msg_send(struct tls13_handshake_msg *msg,

    struct tls13_record_layer *rl)

{

  ssize_t ret;

  if (msg->data == NULL)

    return TLS13_IO_FAILURE;

  if (CBS_len(&msg->cbs) == 0)

    return TLS13_IO_FAILURE;

  while (CBS_len(&msg->cbs) > 0) {

    if ((ret = tls13_write_handshake_data(rl, CBS_data(&msg->cbs),

        CBS_len(&msg->cbs))) <= 0)

      return ret;

    if (!CBS_skip(&msg->cbs, ret))

      return TLS13_IO_FAILURE;

  }

  return TLS13_IO_SUCCESS;

}