/*

 * Copyright 2023-2024 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 * https://www.openssl.org/source/license.html

 * or in the file LICENSE in the source distribution.

 */

#include <openssl/ssl.h>

#include <openssl/err.h>

#include <openssl/bio.h>

#include "fuzzer.h"

#include "internal/quic_rcidm.h"

#include "internal/packet.h"

int FuzzerInitialize(int *argc, char ***argv)

{

    FuzzerSetRand();

    OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CRYPTO_STRINGS | OPENSSL_INIT_ASYNC, NULL);

    OPENSSL_init_ssl(OPENSSL_INIT_LOAD_SSL_STRINGS, NULL);

    ERR_clear_error();

    return 1;

}

/*

 * Fuzzer input "protocol":

 *   Big endian

 *   Zero or more of:

 *     RESET_WITH_ODCID                 u8(0x00) u8(cidl):cid

 *     RESET_WITHOUT_ODCID              u8(0x01)

 *       (free and reallocate)

 *     ADD_FROM_INITIAL                 u8(0x02) u8(cidl):cid

 *     ADD_FROM_SERVER_RETRY            u8(0x03) u8(cidl):cid

 *     ADD_FROM_NCID                    u8(0x04) u64(seq_num)

 *                                        u64(retire_prior_to) u8(cidl):cid

 *     ON_HANDSHAKE_COMPLETE            u8(0x05)

 *     ON_PACKET_SENT                   u8(0x06) u64(num_pkt)

 *     REQUEST_ROLL                     u8(0x07)

 *     POP_RETIRE_SEQ_NUM               u8(0x08)

 *     PEEK_RETIRE_SEQ_NUM              u8(0x09)

 *     GET_PREFERRED_TX_DCID            u8(0x0A)

 *     GET_PREFERRED_TX_DCID_CHANGED    u8(0x0B) u8(clear)

 */

enum {

    CMD_RESET_WITH_ODCID,

    CMD_RESET_WITHOUT_ODCID,

    CMD_ADD_FROM_INITIAL,

    CMD_ADD_FROM_SERVER_RETRY,

    CMD_ADD_FROM_NCID,

    CMD_ON_HANDSHAKE_COMPLETE,

    CMD_ON_PACKET_SENT,

    CMD_REQUEST_ROLL,

    CMD_POP_RETIRE_SEQ_NUM,

    CMD_PEEK_RETIRE_SEQ_NUM,

    CMD_GET_PREFERRED_TX_DCID,

    CMD_GET_PREFERRED_TX_DCID_CHANGED

};

static int get_cid(PACKET *pkt, QUIC_CONN_ID *cid)

{

    unsigned int cidl;

    if (!PACKET_get_1(pkt, &cidl)

        || cidl > QUIC_MAX_CONN_ID_LEN

        || !PACKET_copy_bytes(pkt, cid->id, cidl))

        return 0;

    cid->id_len = (unsigned char)cidl;

    return 1;

}

int FuzzerTestOneInput(const uint8_t *buf, size_t len)

{

    int rc = 0;

    QUIC_RCIDM *rcidm = NULL;

    PACKET pkt;

    uint64_t seq_num_out, arg_num_pkt;

    unsigned int cmd, arg_clear;

    QUIC_CONN_ID arg_cid, cid_out;

    OSSL_QUIC_FRAME_NEW_CONN_ID ncid_frame;

    if (!PACKET_buf_init(&pkt, buf, len))

        goto err;

    if ((rcidm = ossl_quic_rcidm_new(NULL)) == NULL)

        goto err;

    while (PACKET_remaining(&pkt) > 0) {

        if (!PACKET_get_1(&pkt, &cmd))

            goto err;

        switch (cmd) {

        case CMD_RESET_WITH_ODCID:

            if (!get_cid(&pkt, &arg_cid)) {

                rc = -1;

                goto err;

            }

            ossl_quic_rcidm_free(rcidm);

            if ((rcidm = ossl_quic_rcidm_new(&arg_cid)) == NULL)

                goto err;

            break;

        case CMD_RESET_WITHOUT_ODCID:

            ossl_quic_rcidm_free(rcidm);

            if ((rcidm = ossl_quic_rcidm_new(NULL)) == NULL)

                goto err;

            break;

        case CMD_ADD_FROM_INITIAL:

            if (!get_cid(&pkt, &arg_cid)) {

                rc = -1;

                goto err;

            }

            ossl_quic_rcidm_add_from_initial(rcidm, &arg_cid);

            break;

        case CMD_ADD_FROM_SERVER_RETRY:

            if (!get_cid(&pkt, &arg_cid)) {

                rc = -1;

                goto err;

            }

            ossl_quic_rcidm_add_from_server_retry(rcidm, &arg_cid);

            break;

        case CMD_ADD_FROM_NCID:

            if (!PACKET_get_net_8(&pkt, &ncid_frame.seq_num)

                || !PACKET_get_net_8(&pkt, &ncid_frame.retire_prior_to)

                || !get_cid(&pkt, &ncid_frame.conn_id)) {

                rc = -1;

                goto err;

            }

            ossl_quic_rcidm_add_from_ncid(rcidm, &ncid_frame);

            break;

        case CMD_ON_HANDSHAKE_COMPLETE:

            ossl_quic_rcidm_on_handshake_complete(rcidm);

            break;

        case CMD_ON_PACKET_SENT:

            if (!PACKET_get_net_8(&pkt, &arg_num_pkt)) {

                rc = -1;

                goto err;

            }

            ossl_quic_rcidm_on_packet_sent(rcidm, arg_num_pkt);

            break;

        case CMD_REQUEST_ROLL:

            ossl_quic_rcidm_request_roll(rcidm);

            break;

        case CMD_POP_RETIRE_SEQ_NUM:

            ossl_quic_rcidm_pop_retire_seq_num(rcidm, &seq_num_out);

            break;

        case CMD_PEEK_RETIRE_SEQ_NUM:

            ossl_quic_rcidm_peek_retire_seq_num(rcidm, &seq_num_out);

            break;

        case CMD_GET_PREFERRED_TX_DCID:

            ossl_quic_rcidm_get_preferred_tx_dcid(rcidm, &cid_out);

            break;

        case CMD_GET_PREFERRED_TX_DCID_CHANGED:

            if (!PACKET_get_1(&pkt, &arg_clear)) {

                rc = -1;

                goto err;

            }

            ossl_quic_rcidm_get_preferred_tx_dcid_changed(rcidm, arg_clear);

            break;

        default:

            rc = -1;

            goto err;

        }

    }

err:

    ossl_quic_rcidm_free(rcidm);

    return rc;

}

void FuzzerCleanup(void)

{

    FuzzerClearRand();

}