/* $OpenBSD: tls13_record.c,v 1.10 2022/07/22 19:33:53 jsing 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 "tls13_internal.h"
#include "tls13_record.h"

struct tls13_record {
        uint16_t version;
        uint8_t content_type;
        size_t rec_len;
        uint8_t *data;
        size_t data_len;
        CBS cbs;

        struct tls_buffer *buf;
};

struct tls13_record *
tls13_record_new(void)
{
        struct tls13_record *rec = NULL;

        if ((rec = calloc(1, sizeof(struct tls13_record))) == NULL)
                goto err;
        if ((rec->buf = tls_buffer_new(TLS13_RECORD_MAX_LEN)) == NULL)
                goto err;

        return rec;

 err:
        tls13_record_free(rec);

        return NULL;
}

void
tls13_record_free(struct tls13_record *rec)
{
        if (rec == NULL)
                return;

        tls_buffer_free(rec->buf);

        freezero(rec->data, rec->data_len);
        freezero(rec, sizeof(struct tls13_record));
}

uint16_t
tls13_record_version(struct tls13_record *rec)
{
        return rec->version;
}

uint8_t
tls13_record_content_type(struct tls13_record *rec)
{
        return rec->content_type;
}

int
tls13_record_header(struct tls13_record *rec, CBS *cbs)
{
        if (rec->data_len < TLS13_RECORD_HEADER_LEN)
                return 0;

        CBS_init(cbs, rec->data, TLS13_RECORD_HEADER_LEN);

        return 1;
}

int
tls13_record_content(struct tls13_record *rec, CBS *cbs)
{
        CBS content;

        tls13_record_data(rec, &content);

        if (!CBS_skip(&content, TLS13_RECORD_HEADER_LEN))
                return 0;

        CBS_dup(&content, cbs);

        return 1;
}

void
tls13_record_data(struct tls13_record *rec, CBS *cbs)
{
        CBS_init(cbs, rec->data, rec->data_len);
}

int
tls13_record_set_data(struct tls13_record *rec, uint8_t *data, size_t data_len)
{
        if (data_len > TLS13_RECORD_MAX_LEN)
                return 0;

        freezero(rec->data, rec->data_len);
        rec->data = data;
        rec->data_len = data_len;
        CBS_init(&rec->cbs, rec->data, rec->data_len);

        return 1;
}

ssize_t
tls13_record_recv(struct tls13_record *rec, tls_read_cb wire_read,
    void *wire_arg)
{
        uint16_t rec_len, rec_version;
        uint8_t content_type;
        ssize_t ret;
        CBS cbs;

        if (rec->data != NULL)
                return TLS13_IO_FAILURE;

        if (rec->content_type == 0) {
                if ((ret = tls_buffer_extend(rec->buf,
                    TLS13_RECORD_HEADER_LEN, wire_read, wire_arg)) <= 0)
                        return ret;

                if (!tls_buffer_data(rec->buf, &cbs))
                        return TLS13_IO_FAILURE;

                if (!CBS_get_u8(&cbs, &content_type))
                        return TLS13_IO_FAILURE;
                if (!CBS_get_u16(&cbs, &rec_version))
                        return TLS13_IO_FAILURE;
                if (!CBS_get_u16(&cbs, &rec_len))
                        return TLS13_IO_FAILURE;

                if ((rec_version >> 8) != SSL3_VERSION_MAJOR)
                        return TLS13_IO_RECORD_VERSION;
                if (rec_len > TLS13_RECORD_MAX_CIPHERTEXT_LEN)
                        return TLS13_IO_RECORD_OVERFLOW;

                rec->content_type = content_type;
                rec->version = rec_version;
                rec->rec_len = rec_len;
        }

        if ((ret = tls_buffer_extend(rec->buf,
            TLS13_RECORD_HEADER_LEN + rec->rec_len, wire_read, wire_arg)) <= 0)
                return ret;

        if (!tls_buffer_finish(rec->buf, &rec->data, &rec->data_len))
                return TLS13_IO_FAILURE;

        return rec->data_len;
}

ssize_t
tls13_record_send(struct tls13_record *rec, tls_write_cb wire_write,
    void *wire_arg)
{
        ssize_t ret;

        if (rec->data == NULL)
                return TLS13_IO_FAILURE;

        while (CBS_len(&rec->cbs) > 0) {
                if ((ret = wire_write(CBS_data(&rec->cbs),
                    CBS_len(&rec->cbs), wire_arg)) <= 0)
                        return ret;

                if (!CBS_skip(&rec->cbs, ret))
                        return TLS13_IO_FAILURE;
        }

        return rec->data_len;
}