/* $OpenBSD: renegotiation_test.c,v 1.3 2025/03/12 14:07:35 jsing Exp $ */
/*
 * Copyright (c) 2020,2025 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;

int tls_client_alert;
int tls_server_alert;

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");
}

static SSL *
tls_client(BIO *rbio, BIO *wbio)
{
        SSL_CTX *ssl_ctx = NULL;
        SSL *ssl = NULL;

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

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

        BIO_up_ref(rbio);
        BIO_up_ref(wbio);

        SSL_set_bio(ssl, rbio, wbio);

        SSL_CTX_free(ssl_ctx);

        return ssl;
}

static SSL *
tls_server(BIO *rbio, BIO *wbio)
{
        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");
                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");
                goto failure;
        }

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

        BIO_up_ref(rbio);
        BIO_up_ref(wbio);

        SSL_set_bio(ssl, rbio, wbio);

 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) {
                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 {
                if (tls_client_alert >> 8 == SSL3_AL_FATAL ||
                    tls_server_alert >> 8 == SSL3_AL_FATAL) {
                        ERR_clear_error();
                        return 0;
                }
                if (tls_client_alert >> 8 == SSL3_AL_WARNING ||
                    tls_server_alert >> 8 == SSL3_AL_WARNING) {
                        ERR_clear_error();
                        return 1;
                }
                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_connect(SSL *ssl, const char *name, int *done)
{
        int ssl_ret;

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

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

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

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

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

static int
do_read(SSL *ssl, const char *name, int *done)
{
        uint8_t buf[512];
        int ssl_ret;

        if ((ssl_ret = SSL_read(ssl, buf, sizeof(buf))) > 0) {
                fprintf(stderr, "INFO: %s read done\n", name);
                if (debug > 1)
                        hexdump(buf, ssl_ret);
                *done = 1;
                return 1;
        }

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

static int
do_write(SSL *ssl, const char *name, int *done)
{
        const uint8_t buf[] = "Hello, World!\n";
        int ssl_ret;

        if ((ssl_ret = SSL_write(ssl, buf, sizeof(buf))) > 0) {
                fprintf(stderr, "INFO: %s write done\n", name);
                *done = 1;
                return 1;
        }

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

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

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

struct tls_reneg_test {
        const unsigned char *desc;
        int ssl_max_proto_version;
        long ssl_client_options;
        long ssl_server_options;
        int renegotiate_client;
        int renegotiate_server;
        int client_ignored;
        int want_client_alert;
        int want_server_alert;
        int want_failure;
};

static const struct tls_reneg_test tls_reneg_tests[] = {
        {
                .desc = "TLSv1.2 - Renegotiation permitted, no renegotiation",
                .ssl_max_proto_version = TLS1_2_VERSION,
        },
        {
                .desc = "TLSv1.2 - Renegotiation permitted, server initiated "
                    "renegotiation",
                .ssl_max_proto_version = TLS1_2_VERSION,
                .renegotiate_server = 1,
        },
        {
                .desc = "TLSv1.2 - Renegotiation permitted, client initiated "
                    "renegotiation",
                .ssl_max_proto_version = TLS1_2_VERSION,
                .renegotiate_client = 1,
        },
        {
                .desc = "TLSv1.2 - Renegotiation permitted, server and client "
                    "initiated renegotiation",
                .ssl_max_proto_version = TLS1_2_VERSION,
                .renegotiate_client = 1,
                .renegotiate_server = 1,
        },
        {
                .desc = "TLSv1.2 - Client renegotiation not permitted, server "
                    "initiated renegotiation",
                .ssl_max_proto_version = TLS1_2_VERSION,
                .ssl_server_options = SSL_OP_NO_CLIENT_RENEGOTIATION,
                .renegotiate_server = 1,
                .want_client_alert = SSL3_AL_FATAL << 8 | SSL_AD_NO_RENEGOTIATION,
        },
        {
                .desc = "TLSv1.2 - Client renegotiation not permitted, client "
                    "initiated renegotiation",
                .ssl_max_proto_version = TLS1_2_VERSION,
                .ssl_server_options = SSL_OP_NO_CLIENT_RENEGOTIATION,
                .renegotiate_client = 1,
                .want_client_alert = SSL3_AL_FATAL << 8 | SSL_AD_NO_RENEGOTIATION,
        },
        {
                .desc = "TLSv1.2 - Client renegotiation not permitted, client "
                    "initiated renegotiation",
                .ssl_max_proto_version = TLS1_2_VERSION,
                .ssl_server_options = SSL_OP_NO_RENEGOTIATION,
                .renegotiate_client = 1,
                .want_client_alert = SSL3_AL_FATAL << 8 | SSL_AD_NO_RENEGOTIATION,
        },
        {
                .desc = "TLSv1.2 - Server renegotiation not permitted, server "
                    "initiated renegotiation",
                .ssl_max_proto_version = TLS1_2_VERSION,
                .ssl_client_options = SSL_OP_NO_RENEGOTIATION,
                .renegotiate_server = 1,
                .client_ignored = 1,
                .want_server_alert = SSL3_AL_WARNING << 8 | SSL_AD_NO_RENEGOTIATION,
        },
        {
                .desc = "TLSv1.2 - Client renegotiation permitted, client "
                    "initiated renegotiation",
                .ssl_max_proto_version = TLS1_2_VERSION,
                .ssl_server_options = SSL_OP_NO_RENEGOTIATION |
                    SSL_OP_ALLOW_CLIENT_RENEGOTIATION,
                .renegotiate_client = 1,
        },
        {
                .desc = "TLSv1.2 - Client renegotiation permitted, server "
                    "initiated renegotiation",
                .ssl_max_proto_version = TLS1_2_VERSION,
                .ssl_server_options = SSL_OP_ALLOW_CLIENT_RENEGOTIATION,
                .renegotiate_server = 1,
        },
        {
                .desc = "TLSv1.2 - Client renegotiation permitted, client "
                    "initiated renegotiation",
                .ssl_max_proto_version = TLS1_2_VERSION,
                .ssl_server_options = SSL_OP_ALLOW_CLIENT_RENEGOTIATION,
                .renegotiate_client = 1,
        },
        {
                .desc = "TLSv1.2 - Client renegotiation disabled, client "
                    "initiated renegotiation",
                .ssl_max_proto_version = TLS1_2_VERSION,
                .ssl_client_options = SSL_OP_NO_RENEGOTIATION,
                .renegotiate_client = 1,
                .want_failure = 1,
        },
        {
                .desc = "TLSv1.2 - Server renegotiation disabled, server "
                    "initiated renegotiation",
                .ssl_max_proto_version = TLS1_2_VERSION,
                .ssl_server_options = SSL_OP_NO_RENEGOTIATION,
                .renegotiate_server = 1,
                .want_failure = 1,
        },
        {
                .desc = "TLSv1.3 - No renegotiation supported, no renegotiation",
                .ssl_max_proto_version = TLS1_3_VERSION,
        },
        {
                .desc = "TLSv1.3 - No renegotiation supported, server "
                    "initiated renegotiation",
                .ssl_max_proto_version = TLS1_3_VERSION,
                .renegotiate_server = 1,
                .want_failure = 1,
        },
        {
                .desc = "TLSv1.3 - No renegotiation supported, client "
                    "initiated renegotiation",
                .ssl_max_proto_version = TLS1_3_VERSION,
                .renegotiate_client = 1,
                .want_failure = 1,
        },
};

#define N_TLS_RENEG_TESTS (sizeof(tls_reneg_tests) / sizeof(*tls_reneg_tests))

static void
tls_client_info_callback(const SSL *ssl, int where, int value)
{
        if (where == SSL_CB_READ_ALERT) {
                fprintf(stderr, "INFO: client read %s alert - %s\n",
                    SSL_alert_type_string_long(value),
                    SSL_alert_desc_string_long(value));
                tls_client_alert = value;
        }
}

static void
tls_server_info_callback(const SSL *ssl, int where, int value)
{
        if (where == SSL_CB_READ_ALERT) {
                fprintf(stderr, "INFO: server read %s alert - %s\n",
                    SSL_alert_type_string_long(value),
                    SSL_alert_desc_string_long(value));
                tls_server_alert = value;
        }
}

static int
tls_check_reneg(SSL *client, SSL *server, int client_pending,
    int server_pending, long client_num_reneg, long server_num_reneg)
{
        if (debug) {
                fprintf(stderr, "DEBUG: client - pending = %d, num reneg = %ld\n",
                    SSL_renegotiate_pending(client), SSL_num_renegotiations(client));
                fprintf(stderr, "DEBUG: server - pending = %d, num reneg = %ld\n",
                    SSL_renegotiate_pending(server), SSL_num_renegotiations(server));
        }

        if (SSL_renegotiate_pending(client) != client_pending) {
                fprintf(stderr, "FAIL: client SSL_renegotiate_pending() = %d, want %d\n",
                    SSL_renegotiate_pending(client), client_pending);
                return 0;
        }
        if (SSL_renegotiate_pending(server) != server_pending) {
                fprintf(stderr, "FAIL: server SSL_renegotiate_pending() = %d, want %d\n",
                    SSL_renegotiate_pending(server), server_pending);
                return 0;
        }
        if (SSL_num_renegotiations(client) != client_num_reneg) {
                fprintf(stderr, "FAIL: client SSL_num_renegotiations() = %ld, want %ld\n",
                    SSL_num_renegotiations(client), client_num_reneg);
                return 0;
        }
        if (SSL_num_renegotiations(server) != server_num_reneg) {
                fprintf(stderr, "FAIL: server SSL_num_renegotiations() = %ld, want %ld\n",
                    SSL_num_renegotiations(server), server_num_reneg);
                return 0;
        }
        return 1;
}

static int
tls_reneg_test(const struct tls_reneg_test *trt)
{
        BIO *client_wbio = NULL, *server_wbio = NULL;
        SSL *client = NULL, *server = NULL;
        int failed = 1;

        fprintf(stderr, "\n== Testing %s... ==\n", trt->desc);

        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 = tls_client(server_wbio, client_wbio)) == NULL)
                goto failure;

        SSL_set_options(client, trt->ssl_client_options);
        SSL_set_info_callback(client, tls_client_info_callback);

        if ((server = tls_server(client_wbio, server_wbio)) == NULL)
                goto failure;

        SSL_set_options(server, trt->ssl_server_options);
        SSL_set_info_callback(server, tls_server_info_callback);

        if (!SSL_set_max_proto_version(server, trt->ssl_max_proto_version))
                goto failure;

        tls_client_alert = 0;
        tls_server_alert = 0;

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

        if (!do_client_server_loop(client, do_write, server, do_read)) {
                fprintf(stderr, "FAIL: client write and server read failed\n");
                goto failure;
        }

        if (!do_client_server_loop(client, do_read, server, do_write)) {
                fprintf(stderr, "FAIL: client read and server write failed\n");
                goto failure;
        }

        if (!tls_check_reneg(client, server, 0, 0, 0, 0))
                goto failure;

        if (trt->renegotiate_server) {
                /*
                 * Trigger renegotiation from the server - this results in the
                 * server sending a HelloRequest, then waiting for the client to
                 * respond with a ClientHello.
                 */
                if (!SSL_renegotiate(server)) {
                        if (!trt->want_failure) {
                                fprintf(stderr, "FAIL: server renegotiation failed\n");
                                goto failure;
                        }
                        goto done;
                }
                if (trt->want_failure) {
                        fprintf(stderr, "FAIL: server renegotiation should have failed\n");
                        goto failure;
                }

                if (!tls_check_reneg(client, server, 0, 1, 0, 0))
                        goto failure;

                if (!do_client_server_loop(client, do_read, server, do_write)) {
                        fprintf(stderr, "FAIL: client read and server write failed\n");
                        goto failure;
                }

                if (!tls_check_reneg(client, server, (trt->client_ignored == 0), 1,
                    (trt->client_ignored == 0), 1))
                        goto failure;

                if (!do_client_server_loop(client, do_write, server, do_read)) {
                        if (!trt->want_client_alert && !trt->want_server_alert) {
                                fprintf(stderr, "FAIL: client write and server read failed\n");
                                goto failure;
                        }
                        if (tls_client_alert != trt->want_client_alert) {
                                fprintf(stderr, "FAIL: client alert = %x, want %x\n",
                                    tls_client_alert, trt->want_client_alert);
                                goto failure;
                        }
                        if (tls_server_alert != trt->want_server_alert) {
                                fprintf(stderr, "FAIL: server alert = %x, want %x\n",
                                    tls_server_alert, trt->want_server_alert);
                                goto failure;
                        }
                        goto done;
                }
                if (tls_client_alert != trt->want_client_alert) {
                        fprintf(stderr, "FAIL: client alert = %x, want %x\n",
                            tls_client_alert, trt->want_client_alert);
                        goto failure;
                }
                if (tls_server_alert != trt->want_server_alert) {
                        fprintf(stderr, "FAIL: server alert = %x, want %x\n",
                            tls_server_alert, trt->want_server_alert);
                        goto failure;
                }

                if (!tls_check_reneg(client, server, 0, (trt->client_ignored != 0),
                    (trt->client_ignored == 0), 1))
                        goto failure;
        }

        SSL_clear_num_renegotiations(client);
        SSL_clear_num_renegotiations(server);

        tls_client_alert = 0;
        tls_server_alert = 0;

        if (trt->renegotiate_client) {
                /*
                 * Trigger renegotiation from the client - this results in the
                 * client sending a ClientHello.
                 */
                if (!SSL_renegotiate(client)) {
                        if (!trt->want_failure) {
                                fprintf(stderr, "FAIL: client renegotiation failed\n");
                                goto failure;
                        }
                        goto done;
                }
                if (trt->want_failure) {
                        fprintf(stderr, "FAIL: client renegotiation should have failed\n");
                        goto failure;
                }

                if (!tls_check_reneg(client, server, 1, 0, 0, 0))
                        goto failure;

                if (!do_client_server_loop(client, do_read, server, do_write)) {
                        fprintf(stderr, "FAIL: client read and server write failed\n");
                        goto failure;
                }

                if (!tls_check_reneg(client, server, 1, 0, 1, 0))
                        goto failure;

                if (!do_client_server_loop(client, do_write, server, do_read)) {
                        if (!trt->want_client_alert && !trt->want_server_alert) {
                                fprintf(stderr, "FAIL: client write and server read failed\n");
                                goto failure;
                        }
                        if (tls_client_alert != trt->want_client_alert) {
                                fprintf(stderr, "FAIL: client alert = %x, want %x\n",
                                    tls_client_alert, trt->want_client_alert);
                                goto failure;
                        }
                        if (tls_server_alert != trt->want_server_alert) {
                                fprintf(stderr, "FAIL: server alert = %x, want %x\n",
                                    tls_server_alert, trt->want_server_alert);
                                goto failure;
                        }
                        goto done;
                }
                if (tls_client_alert != trt->want_client_alert) {
                        fprintf(stderr, "FAIL: client alert = %x, want %x\n",
                            tls_client_alert, trt->want_client_alert);
                        goto failure;
                }
                if (tls_server_alert != trt->want_server_alert) {
                        fprintf(stderr, "FAIL: server alert = %x, want %x\n",
                            tls_server_alert, trt->want_server_alert);
                        goto failure;
                }

                if (!tls_check_reneg(client, server, 0, 0, 1, 0))
                        goto failure;
        }

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

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

        failed = 0;

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

        SSL_free(client);
        SSL_free(server);

        return failed;
}

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

        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];

        for (i = 0; i < N_TLS_RENEG_TESTS; i++)
                failed |= tls_reneg_test(&tls_reneg_tests[i]);

        return failed;
}