/*
 * Copyright 2016-2022 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 can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

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

#include "helpers/ssltestlib.h"
#include "testutil.h"

static char *cert = NULL;
static char *privkey = NULL;
static unsigned int timer_cb_count;

#define NUM_TESTS   2


#define DUMMY_CERT_STATUS_LEN  12

static unsigned char certstatus[] = {
    SSL3_RT_HANDSHAKE, /* Content type */
    0xfe, 0xfd, /* Record version */
    0, 1, /* Epoch */
    0, 0, 0, 0, 0, 0x0f, /* Record sequence number */
    0, DTLS1_HM_HEADER_LENGTH + DUMMY_CERT_STATUS_LEN - 2,
    SSL3_MT_CERTIFICATE_STATUS, /* Cert Status handshake message type */
    0, 0, DUMMY_CERT_STATUS_LEN, /* Message len */
    0, 5, /* Message sequence */
    0, 0, 0, /* Fragment offset */
    0, 0, DUMMY_CERT_STATUS_LEN - 2, /* Fragment len */
    0x80, 0x80, 0x80, 0x80, 0x80,
    0x80, 0x80, 0x80, 0x80, 0x80 /* Dummy data */
};

#define RECORD_SEQUENCE 10

static const char dummy_cookie[] = "0123456";

static int generate_cookie_cb(SSL *ssl, unsigned char *cookie,
                              unsigned int *cookie_len)
{
    memcpy(cookie, dummy_cookie, sizeof(dummy_cookie));
    *cookie_len = sizeof(dummy_cookie);
    return 1;
}

static int verify_cookie_cb(SSL *ssl, const unsigned char *cookie,
                            unsigned int cookie_len)
{
    return TEST_mem_eq(cookie, cookie_len, dummy_cookie, sizeof(dummy_cookie));
}

static unsigned int timer_cb(SSL *s, unsigned int timer_us)
{
    ++timer_cb_count;

    if (timer_us == 0)
        return 50000;
    else
        return 2 * timer_us;
}

static int test_dtls_unprocessed(int testidx)
{
    SSL_CTX *sctx = NULL, *cctx = NULL;
    SSL *serverssl1 = NULL, *clientssl1 = NULL;
    BIO *c_to_s_fbio, *c_to_s_mempacket;
    int testresult = 0;

    timer_cb_count = 0;

    if (!TEST_true(create_ssl_ctx_pair(NULL, DTLS_server_method(),
                                       DTLS_client_method(),
                                       DTLS1_VERSION, 0,
                                       &sctx, &cctx, cert, privkey)))
        return 0;

#ifndef OPENSSL_NO_DTLS1_2
    if (!TEST_true(SSL_CTX_set_cipher_list(cctx, "AES128-SHA")))
        goto end;
#else
    /* Default sigalgs are SHA1 based in <DTLS1.2 which is in security level 0 */
    if (!TEST_true(SSL_CTX_set_cipher_list(sctx, "AES128-SHA:@SECLEVEL=0"))
            || !TEST_true(SSL_CTX_set_cipher_list(cctx,
                                                  "AES128-SHA:@SECLEVEL=0")))
        goto end;
#endif

    c_to_s_fbio = BIO_new(bio_f_tls_dump_filter());
    if (!TEST_ptr(c_to_s_fbio))
        goto end;

    /* BIO is freed by create_ssl_connection on error */
    if (!TEST_true(create_ssl_objects(sctx, cctx, &serverssl1, &clientssl1,
                                      NULL, c_to_s_fbio)))
        goto end;

    DTLS_set_timer_cb(clientssl1, timer_cb);

    if (testidx == 1)
        certstatus[RECORD_SEQUENCE] = 0xff;

    /*
     * Inject a dummy record from the next epoch. In test 0, this should never
     * get used because the message sequence number is too big. In test 1 we set
     * the record sequence number to be way off in the future.
     */
    c_to_s_mempacket = SSL_get_wbio(clientssl1);
    c_to_s_mempacket = BIO_next(c_to_s_mempacket);
    mempacket_test_inject(c_to_s_mempacket, (char *)certstatus,
                          sizeof(certstatus), 1, INJECT_PACKET_IGNORE_REC_SEQ);

    /*
     * Create the connection. We use "create_bare_ssl_connection" here so that
     * we can force the connection to not do "SSL_read" once partly connected.
     * We don't want to accidentally read the dummy records we injected because
     * they will fail to decrypt.
     */
    if (!TEST_true(create_bare_ssl_connection(serverssl1, clientssl1,
                                              SSL_ERROR_NONE, 0)))
        goto end;

    if (timer_cb_count == 0) {
        printf("timer_callback was not called.\n");
        goto end;
    }

    testresult = 1;
 end:
    SSL_free(serverssl1);
    SSL_free(clientssl1);
    SSL_CTX_free(sctx);
    SSL_CTX_free(cctx);

    return testresult;
}

/* One record for the cookieless initial ClientHello */
#define CLI_TO_SRV_COOKIE_EXCH 1

/*
 * In a resumption handshake we use 2 records for the initial ClientHello in
 * this test because we are using a very small MTU and the ClientHello is
 * bigger than in the non resumption case.
 */
#define CLI_TO_SRV_RESUME_COOKIE_EXCH 2
#define SRV_TO_CLI_COOKIE_EXCH 1

#define CLI_TO_SRV_EPOCH_0_RECS 3
#define CLI_TO_SRV_EPOCH_1_RECS 1
#if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)
# define SRV_TO_CLI_EPOCH_0_RECS 10
#else
/*
 * In this case we have no ServerKeyExchange message, because we don't have
 * ECDHE or DHE. When it is present it gets fragmented into 3 records in this
 * test.
 */
# define SRV_TO_CLI_EPOCH_0_RECS 9
#endif
#define SRV_TO_CLI_EPOCH_1_RECS 1
#define TOTAL_FULL_HAND_RECORDS \
            (CLI_TO_SRV_COOKIE_EXCH + SRV_TO_CLI_COOKIE_EXCH + \
             CLI_TO_SRV_EPOCH_0_RECS + CLI_TO_SRV_EPOCH_1_RECS + \
             SRV_TO_CLI_EPOCH_0_RECS + SRV_TO_CLI_EPOCH_1_RECS)

#define CLI_TO_SRV_RESUME_EPOCH_0_RECS 3
#define CLI_TO_SRV_RESUME_EPOCH_1_RECS 1
#define SRV_TO_CLI_RESUME_EPOCH_0_RECS 2
#define SRV_TO_CLI_RESUME_EPOCH_1_RECS 1
#define TOTAL_RESUME_HAND_RECORDS \
            (CLI_TO_SRV_RESUME_COOKIE_EXCH + SRV_TO_CLI_COOKIE_EXCH + \
             CLI_TO_SRV_RESUME_EPOCH_0_RECS + CLI_TO_SRV_RESUME_EPOCH_1_RECS + \
             SRV_TO_CLI_RESUME_EPOCH_0_RECS + SRV_TO_CLI_RESUME_EPOCH_1_RECS)

#define TOTAL_RECORDS (TOTAL_FULL_HAND_RECORDS + TOTAL_RESUME_HAND_RECORDS)

/*
 * We are assuming a ServerKeyExchange message is sent in this test. If we don't
 * have either DH or EC, then it won't be
 */
#if !defined(OPENSSL_NO_DH) || !defined(OPENSSL_NO_EC)
static int test_dtls_drop_records(int idx)
{
    SSL_CTX *sctx = NULL, *cctx = NULL;
    SSL *serverssl = NULL, *clientssl = NULL;
    BIO *c_to_s_fbio, *mempackbio;
    int testresult = 0;
    int epoch = 0;
    SSL_SESSION *sess = NULL;
    int cli_to_srv_cookie, cli_to_srv_epoch0, cli_to_srv_epoch1;
    int srv_to_cli_epoch0;

    if (!TEST_true(create_ssl_ctx_pair(NULL, DTLS_server_method(),
                                       DTLS_client_method(),
                                       DTLS1_VERSION, 0,
                                       &sctx, &cctx, cert, privkey)))
        return 0;

#ifdef OPENSSL_NO_DTLS1_2
    /* Default sigalgs are SHA1 based in <DTLS1.2 which is in security level 0 */
    if (!TEST_true(SSL_CTX_set_cipher_list(sctx, "DEFAULT:@SECLEVEL=0"))
            || !TEST_true(SSL_CTX_set_cipher_list(cctx,
                                                  "DEFAULT:@SECLEVEL=0")))
        goto end;
#endif

    if (!TEST_true(SSL_CTX_set_dh_auto(sctx, 1)))
        goto end;

    SSL_CTX_set_options(sctx, SSL_OP_COOKIE_EXCHANGE);
    SSL_CTX_set_cookie_generate_cb(sctx, generate_cookie_cb);
    SSL_CTX_set_cookie_verify_cb(sctx, verify_cookie_cb);

    if (idx >= TOTAL_FULL_HAND_RECORDS) {
        /* We're going to do a resumption handshake. Get a session first. */
        if (!TEST_true(create_ssl_objects(sctx, cctx, &serverssl, &clientssl,
                                          NULL, NULL))
                || !TEST_true(create_ssl_connection(serverssl, clientssl,
                              SSL_ERROR_NONE))
                || !TEST_ptr(sess = SSL_get1_session(clientssl)))
            goto end;

        SSL_shutdown(clientssl);
        SSL_shutdown(serverssl);
        SSL_free(serverssl);
        SSL_free(clientssl);
        serverssl = clientssl = NULL;

        cli_to_srv_epoch0 = CLI_TO_SRV_RESUME_EPOCH_0_RECS;
        cli_to_srv_epoch1 = CLI_TO_SRV_RESUME_EPOCH_1_RECS;
        srv_to_cli_epoch0 = SRV_TO_CLI_RESUME_EPOCH_0_RECS;
        cli_to_srv_cookie = CLI_TO_SRV_RESUME_COOKIE_EXCH;
        idx -= TOTAL_FULL_HAND_RECORDS;
    } else {
        cli_to_srv_epoch0 = CLI_TO_SRV_EPOCH_0_RECS;
        cli_to_srv_epoch1 = CLI_TO_SRV_EPOCH_1_RECS;
        srv_to_cli_epoch0 = SRV_TO_CLI_EPOCH_0_RECS;
        cli_to_srv_cookie = CLI_TO_SRV_COOKIE_EXCH;
    }

    c_to_s_fbio = BIO_new(bio_f_tls_dump_filter());
    if (!TEST_ptr(c_to_s_fbio))
        goto end;

    /* BIO is freed by create_ssl_connection on error */
    if (!TEST_true(create_ssl_objects(sctx, cctx, &serverssl, &clientssl,
                                      NULL, c_to_s_fbio)))
        goto end;

    if (sess != NULL) {
        if (!TEST_true(SSL_set_session(clientssl, sess)))
            goto end;
    }

    DTLS_set_timer_cb(clientssl, timer_cb);
    DTLS_set_timer_cb(serverssl, timer_cb);

    /* Work out which record to drop based on the test number */
    if (idx >= cli_to_srv_cookie + cli_to_srv_epoch0 + cli_to_srv_epoch1) {
        mempackbio = SSL_get_wbio(serverssl);
        idx -= cli_to_srv_cookie + cli_to_srv_epoch0 + cli_to_srv_epoch1;
        if (idx >= SRV_TO_CLI_COOKIE_EXCH + srv_to_cli_epoch0) {
            epoch = 1;
            idx -= SRV_TO_CLI_COOKIE_EXCH + srv_to_cli_epoch0;
        }
    } else {
        mempackbio = SSL_get_wbio(clientssl);
        if (idx >= cli_to_srv_cookie + cli_to_srv_epoch0) {
            epoch = 1;
            idx -= cli_to_srv_cookie + cli_to_srv_epoch0;
        }
         mempackbio = BIO_next(mempackbio);
    }
    BIO_ctrl(mempackbio, MEMPACKET_CTRL_SET_DROP_EPOCH, epoch, NULL);
    BIO_ctrl(mempackbio, MEMPACKET_CTRL_SET_DROP_REC, idx, NULL);

    if (!TEST_true(create_ssl_connection(serverssl, clientssl, SSL_ERROR_NONE)))
        goto end;

    if (sess != NULL && !TEST_true(SSL_session_reused(clientssl)))
        goto end;

    /* If the test did what we planned then it should have dropped a record */
    if (!TEST_int_eq((int)BIO_ctrl(mempackbio, MEMPACKET_CTRL_GET_DROP_REC, 0,
                                   NULL), -1))
        goto end;

    testresult = 1;
 end:
    SSL_SESSION_free(sess);
    SSL_free(serverssl);
    SSL_free(clientssl);
    SSL_CTX_free(sctx);
    SSL_CTX_free(cctx);

    return testresult;
}
#endif /* !defined(OPENSSL_NO_DH) || !defined(OPENSSL_NO_EC) */

static int test_cookie(void)
{
    SSL_CTX *sctx = NULL, *cctx = NULL;
    SSL *serverssl = NULL, *clientssl = NULL;
    int testresult = 0;

    if (!TEST_true(create_ssl_ctx_pair(NULL, DTLS_server_method(),
                                       DTLS_client_method(),
                                       DTLS1_VERSION, 0,
                                       &sctx, &cctx, cert, privkey)))
        return 0;

    SSL_CTX_set_options(sctx, SSL_OP_COOKIE_EXCHANGE);
    SSL_CTX_set_cookie_generate_cb(sctx, generate_cookie_cb);
    SSL_CTX_set_cookie_verify_cb(sctx, verify_cookie_cb);

#ifdef OPENSSL_NO_DTLS1_2
    /* Default sigalgs are SHA1 based in <DTLS1.2 which is in security level 0 */
    if (!TEST_true(SSL_CTX_set_cipher_list(sctx, "DEFAULT:@SECLEVEL=0"))
            || !TEST_true(SSL_CTX_set_cipher_list(cctx,
                                                  "DEFAULT:@SECLEVEL=0")))
        goto end;
#endif

    if (!TEST_true(create_ssl_objects(sctx, cctx, &serverssl, &clientssl,
                                      NULL, NULL))
            || !TEST_true(create_ssl_connection(serverssl, clientssl,
                                                SSL_ERROR_NONE)))
        goto end;

    testresult = 1;
 end:
    SSL_free(serverssl);
    SSL_free(clientssl);
    SSL_CTX_free(sctx);
    SSL_CTX_free(cctx);

    return testresult;
}

static int test_dtls_duplicate_records(void)
{
    SSL_CTX *sctx = NULL, *cctx = NULL;
    SSL *serverssl = NULL, *clientssl = NULL;
    int testresult = 0;

    if (!TEST_true(create_ssl_ctx_pair(NULL, DTLS_server_method(),
                                       DTLS_client_method(),
                                       DTLS1_VERSION, 0,
                                       &sctx, &cctx, cert, privkey)))
        return 0;

#ifdef OPENSSL_NO_DTLS1_2
    /* Default sigalgs are SHA1 based in <DTLS1.2 which is in security level 0 */
    if (!TEST_true(SSL_CTX_set_cipher_list(sctx, "DEFAULT:@SECLEVEL=0"))
            || !TEST_true(SSL_CTX_set_cipher_list(cctx,
                                                  "DEFAULT:@SECLEVEL=0")))
        goto end;
#endif

    if (!TEST_true(create_ssl_objects(sctx, cctx, &serverssl, &clientssl,
                                      NULL, NULL)))
        goto end;

    DTLS_set_timer_cb(clientssl, timer_cb);
    DTLS_set_timer_cb(serverssl, timer_cb);

    BIO_ctrl(SSL_get_wbio(clientssl), MEMPACKET_CTRL_SET_DUPLICATE_REC, 1, NULL);
    BIO_ctrl(SSL_get_wbio(serverssl), MEMPACKET_CTRL_SET_DUPLICATE_REC, 1, NULL);

    if (!TEST_true(create_ssl_connection(serverssl, clientssl, SSL_ERROR_NONE)))
        goto end;

    testresult = 1;
 end:
    SSL_free(serverssl);
    SSL_free(clientssl);
    SSL_CTX_free(sctx);
    SSL_CTX_free(cctx);

    return testresult;
}

/*
 * Test just sending a Finished message as the first message. Should fail due
 * to an unexpected message.
 */
static int test_just_finished(void)
{
    int testresult = 0, ret;
    SSL_CTX *sctx = NULL;
    SSL *serverssl = NULL;
    BIO *rbio = NULL, *wbio = NULL, *sbio = NULL;
    unsigned char buf[] = {
        /* Record header */
        SSL3_RT_HANDSHAKE, /* content type */
        (DTLS1_2_VERSION >> 8) & 0xff, /* protocol version hi byte */
        DTLS1_2_VERSION & 0xff, /* protocol version lo byte */
        0, 0, /* epoch */
        0, 0, 0, 0, 0, 0, /* record sequence */
        0, DTLS1_HM_HEADER_LENGTH + SHA_DIGEST_LENGTH, /* record length */

        /* Message header */
        SSL3_MT_FINISHED, /* message type */
        0, 0, SHA_DIGEST_LENGTH, /* message length */
        0, 0, /* message sequence */
        0, 0, 0, /* fragment offset */
        0, 0, SHA_DIGEST_LENGTH, /* fragment length */

        /* Message body */
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
    };


    if (!TEST_true(create_ssl_ctx_pair(NULL, DTLS_server_method(),
                                       NULL, 0, 0,
                                       &sctx, NULL, cert, privkey)))
        return 0;

    serverssl = SSL_new(sctx);
    rbio = BIO_new(BIO_s_mem());
    wbio = BIO_new(BIO_s_mem());

    if (!TEST_ptr(serverssl) || !TEST_ptr(rbio) || !TEST_ptr(wbio))
        goto end;

    sbio = rbio;
    SSL_set0_rbio(serverssl, rbio);
    SSL_set0_wbio(serverssl, wbio);
    rbio = wbio = NULL;
    DTLS_set_timer_cb(serverssl, timer_cb);

    if (!TEST_int_eq(BIO_write(sbio, buf, sizeof(buf)), sizeof(buf)))
        goto end;

    /* We expect the attempt to process the message to fail */
    if (!TEST_int_le(ret = SSL_accept(serverssl), 0))
        goto end;

    /* Check that we got the error we were expecting */
    if (!TEST_int_eq(SSL_get_error(serverssl, ret), SSL_ERROR_SSL))
        goto end;

    if (!TEST_int_eq(ERR_GET_REASON(ERR_get_error()), SSL_R_UNEXPECTED_MESSAGE))
        goto end;

    testresult = 1;
 end:
    BIO_free(rbio);
    BIO_free(wbio);
    SSL_free(serverssl);
    SSL_CTX_free(sctx);

    return testresult;
}

/*
 * Test that swapping an app data record so that it is received before the
 * Finished message still works.
 */
static int test_swap_app_data(void)
{
    SSL_CTX *sctx = NULL, *cctx = NULL;
    SSL *sssl = NULL, *cssl = NULL;
    int testresult = 0;
    BIO *bio;
    char msg[] = { 0x00, 0x01, 0x02, 0x03 };
    char buf[10];

    if (!TEST_true(create_ssl_ctx_pair(NULL, DTLS_server_method(),
                                       DTLS_client_method(),
                                       DTLS1_VERSION, 0,
                                       &sctx, &cctx, cert, privkey)))
        return 0;

#ifndef OPENSSL_NO_DTLS1_2
    if (!TEST_true(SSL_CTX_set_cipher_list(cctx, "AES128-SHA")))
        goto end;
#else
    /* Default sigalgs are SHA1 based in <DTLS1.2 which is in security level 0 */
    if (!TEST_true(SSL_CTX_set_cipher_list(sctx, "AES128-SHA:@SECLEVEL=0"))
            || !TEST_true(SSL_CTX_set_cipher_list(cctx,
                                                  "AES128-SHA:@SECLEVEL=0")))
        goto end;
#endif

    if (!TEST_true(create_ssl_objects(sctx, cctx, &sssl, &cssl,
                                      NULL, NULL)))
        goto end;

    /* Send flight 1: ClientHello */
    if (!TEST_int_le(SSL_connect(cssl), 0))
        goto end;

    /* Recv flight 1, send flight 2: ServerHello, Certificate, ServerHelloDone */
    if (!TEST_int_le(SSL_accept(sssl), 0))
        goto end;

    /* Recv flight 2, send flight 3: ClientKeyExchange, CCS, Finished */
    if (!TEST_int_le(SSL_connect(cssl), 0))
        goto end;

    /* Recv flight 3, send flight 4: datagram 1(NST, CCS) datagram 2(Finished) */
    if (!TEST_int_gt(SSL_accept(sssl), 0))
        goto end;

    /* Send flight 5: app data */
    if (!TEST_int_eq(SSL_write(sssl, msg, sizeof(msg)), (int)sizeof(msg)))
        goto end;

    bio = SSL_get_wbio(sssl);
    if (!TEST_ptr(bio)
            || !TEST_true(mempacket_swap_recent(bio)))
        goto end;

    /*
     * Recv flight 4 (datagram 1): NST, CCS, + flight 5: app data
     *      + flight 4 (datagram 2): Finished
     */
    if (!TEST_int_gt(SSL_connect(cssl), 0))
        goto end;

    /* The app data should be buffered already */
    if (!TEST_int_eq(SSL_pending(cssl), (int)sizeof(msg))
            || !TEST_true(SSL_has_pending(cssl)))
        goto end;

    /*
     * Recv flight 5 (app data)
     * We already buffered this so it should be available.
     */
    if (!TEST_int_eq(SSL_read(cssl, buf, sizeof(buf)), (int)sizeof(msg)))
        goto end;

    testresult = 1;
 end:
    SSL_free(cssl);
    SSL_free(sssl);
    SSL_CTX_free(cctx);
    SSL_CTX_free(sctx);
    return testresult;
}

OPT_TEST_DECLARE_USAGE("certfile privkeyfile\n")

int setup_tests(void)
{
    if (!test_skip_common_options()) {
        TEST_error("Error parsing test options\n");
        return 0;
    }

    if (!TEST_ptr(cert = test_get_argument(0))
            || !TEST_ptr(privkey = test_get_argument(1)))
        return 0;

    ADD_ALL_TESTS(test_dtls_unprocessed, NUM_TESTS);
#if !defined(OPENSSL_NO_DH) || !defined(OPENSSL_NO_EC)
    ADD_ALL_TESTS(test_dtls_drop_records, TOTAL_RECORDS);
#endif
    ADD_TEST(test_cookie);
    ADD_TEST(test_dtls_duplicate_records);
    ADD_TEST(test_just_finished);
    ADD_TEST(test_swap_app_data);

    return 1;
}

void cleanup_tests(void)
{
    bio_f_tls_dump_filter_free();
    bio_s_mempacket_test_free();
}
