/* $OpenBSD: quictest.c,v 1.1 2022/08/27 09:16:29 jsing Exp $ */
/*
 * Copyright (c) 2020, 2021, 2022 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 <err.h>

#include <openssl/bio.h>
#include <openssl/err.h>
#include <openssl/ssl.h>

const char *server_ca_file;
const char *server_cert_file;
const char *server_key_file;

int debug = 0;

static void
hexdump(const unsigned char *buf, size_t len)
{
        size_t i;

        for (i = 1; i <= len; i++)
                fprintf(stderr, " 0x%02hhx,%s", buf[i - 1], i % 8 ? "" : "\n");

        if (len % 8)
                fprintf(stderr, "\n");
}

struct quic_data {
        enum ssl_encryption_level_t rlevel;
        enum ssl_encryption_level_t wlevel;
        BIO *rbio;
        BIO *wbio;
};

static int
quic_set_read_secret(SSL *ssl, enum ssl_encryption_level_t level,
    const SSL_CIPHER *cipher, const uint8_t *secret, size_t secret_len)
{
        struct quic_data *qd = SSL_get_app_data(ssl);

        qd->rlevel = level;

        return 1;
}

static int
quic_set_write_secret(SSL *ssl, enum ssl_encryption_level_t level,
    const SSL_CIPHER *cipher, const uint8_t *secret, size_t secret_len)
{
        struct quic_data *qd = SSL_get_app_data(ssl);

        qd->wlevel = level;

        return 1;
}

static int
quic_read_handshake_data(SSL *ssl)
{
        struct quic_data *qd = SSL_get_app_data(ssl);
        uint8_t buf[2048];
        int ret;

        if ((ret = BIO_read(qd->rbio, buf, sizeof(buf))) > 0) {
                if (debug > 1) {
                        fprintf(stderr, "== quic_read_handshake_data ==\n");
                        hexdump(buf, ret);
                }
                if (!SSL_provide_quic_data(ssl, qd->rlevel, buf, ret))
                        return -1;
        }

        return 1;
}

static int
quic_add_handshake_data(SSL *ssl, enum ssl_encryption_level_t level,
    const uint8_t *data, size_t len)
{
        struct quic_data *qd = SSL_get_app_data(ssl);
        int ret;

        if (debug > 1) {
                fprintf(stderr, "== quic_add_handshake_data\n");
                hexdump(data, len);
        }

        if ((ret = BIO_write(qd->wbio, data, len)) <= 0)
                return 0;

        return (size_t)ret == len;
}

static int
quic_flush_flight(SSL *ssl)
{
        return 1;
}

static int
quic_send_alert(SSL *ssl, enum ssl_encryption_level_t level, uint8_t alert)
{
        return 1;
}

const SSL_QUIC_METHOD quic_method = {
        .set_read_secret = quic_set_read_secret,
        .set_write_secret = quic_set_write_secret,
        .add_handshake_data = quic_add_handshake_data,
        .flush_flight = quic_flush_flight,
        .send_alert = quic_send_alert,
};

static SSL *
quic_client(struct quic_data *data)
{
        SSL_CTX *ssl_ctx = NULL;
        SSL *ssl = NULL;

        if ((ssl_ctx = SSL_CTX_new(TLS_method())) == NULL)
                errx(1, "client context");

        if (!SSL_CTX_set_quic_method(ssl_ctx, &quic_method)) {
                fprintf(stderr, "FAIL: Failed to set QUIC method\n");
                goto failure;
        }

        if ((ssl = SSL_new(ssl_ctx)) == NULL)
                errx(1, "client ssl");

        SSL_set_connect_state(ssl);
        SSL_set_app_data(ssl, data);

 failure:
        SSL_CTX_free(ssl_ctx);

        return ssl;
}

static SSL *
quic_server(struct quic_data *data)
{
        SSL_CTX *ssl_ctx = NULL;
        SSL *ssl = NULL;

        if ((ssl_ctx = SSL_CTX_new(TLS_method())) == NULL)
                errx(1, "server context");

        SSL_CTX_set_dh_auto(ssl_ctx, 2);

        if (SSL_CTX_use_certificate_file(ssl_ctx, server_cert_file,
            SSL_FILETYPE_PEM) != 1) {
                fprintf(stderr, "FAIL: Failed to load server certificate\n");
                goto failure;
        }
        if (SSL_CTX_use_PrivateKey_file(ssl_ctx, server_key_file,
            SSL_FILETYPE_PEM) != 1) {
                fprintf(stderr, "FAIL: Failed to load server private key\n");
                goto failure;
        }

        if (!SSL_CTX_set_quic_method(ssl_ctx, &quic_method)) {
                fprintf(stderr, "FAIL: Failed to set QUIC method\n");
                goto failure;
        }

        if ((ssl = SSL_new(ssl_ctx)) == NULL)
                errx(1, "server ssl");

        SSL_set_accept_state(ssl);
        SSL_set_app_data(ssl, data);

 failure:
        SSL_CTX_free(ssl_ctx);

        return ssl;
}

static int
ssl_error(SSL *ssl, const char *name, const char *desc, int ssl_ret)
{
        int ssl_err;

        ssl_err = SSL_get_error(ssl, ssl_ret);

        if (ssl_err == SSL_ERROR_WANT_READ) {
                if (quic_read_handshake_data(ssl) < 0)
                        return 0;
                return 1;
        } else if (ssl_err == SSL_ERROR_WANT_WRITE) {
                return 1;
        } else if (ssl_err == SSL_ERROR_SYSCALL && errno == 0) {
                /* Yup, this is apparently a thing... */
        } else {
                fprintf(stderr, "FAIL: %s %s failed - ssl err = %d, errno = %d\n",
                    name, desc, ssl_err, errno);
                ERR_print_errors_fp(stderr);
                return 0;
        }

        return 1;
}

static int
do_handshake(SSL *ssl, const char *name, int *done)
{
        int ssl_ret;

        if ((ssl_ret = SSL_do_handshake(ssl)) == 1) {
                fprintf(stderr, "INFO: %s handshake done\n", name);
                *done = 1;
                return 1;
        }

        return ssl_error(ssl, name, "handshake", ssl_ret);
}

typedef int (*ssl_func)(SSL *ssl, const char *name, int *done);

static int
do_client_server_loop(SSL *client, ssl_func client_func, SSL *server,
    ssl_func server_func)
{
        int client_done = 0, server_done = 0;
        int i = 0;

        do {
                if (!client_done) {
                        if (debug)
                                fprintf(stderr, "DEBUG: client loop\n");
                        if (!client_func(client, "client", &client_done))
                                return 0;
                }
                if (!server_done) {
                        if (debug)
                                fprintf(stderr, "DEBUG: server loop\n");
                        if (!server_func(server, "server", &server_done))
                                return 0;
                }
        } while (i++ < 100 && (!client_done || !server_done));

        if (!client_done || !server_done)
                fprintf(stderr, "FAIL: gave up\n");

        return client_done && server_done;
}

static int
quictest(void)
{
        struct quic_data *client_data = NULL, *server_data = NULL;
        BIO *client_wbio = NULL, *server_wbio = NULL;
        SSL *client = NULL, *server = NULL;
        int failed = 1;

        if ((client_wbio = BIO_new(BIO_s_mem())) == NULL)
                goto failure;
        if (BIO_set_mem_eof_return(client_wbio, -1) <= 0)
                goto failure;

        if ((server_wbio = BIO_new(BIO_s_mem())) == NULL)
                goto failure;
        if (BIO_set_mem_eof_return(server_wbio, -1) <= 0)
                goto failure;

        if ((client_data = calloc(1, sizeof(*client_data))) == NULL)
                goto failure;

        client_data->rbio = server_wbio;
        client_data->wbio = client_wbio;

        if ((client = quic_client(client_data)) == NULL)
                goto failure;

        if ((server_data = calloc(1, sizeof(*server_data))) == NULL)
                goto failure;

        server_data->rbio = client_wbio;
        server_data->wbio = server_wbio;

        if ((server = quic_server(server_data)) == NULL)
                goto failure;

        if (!do_client_server_loop(client, do_handshake, server, do_handshake)) {
                fprintf(stderr, "FAIL: client and server handshake failed\n");
                ERR_print_errors_fp(stderr);
                goto failure;
        }

        fprintf(stderr, "INFO: Done!\n");

        failed = 0;

 failure:
        BIO_free(client_wbio);
        BIO_free(server_wbio);

        free(client_data);
        free(server_data);

        SSL_free(client);
        SSL_free(server);

        return failed;
}

int
main(int argc, char **argv)
{
        int failed = 0;

        if (argc != 4) {
                fprintf(stderr, "usage: %s keyfile certfile cafile\n",
                    argv[0]);
                exit(1);
        }

        server_key_file = argv[1];
        server_cert_file = argv[2];
        server_ca_file = argv[3];

        failed |= quictest();

        return failed;
}