libzmq/tests/test_bind_curve_fuzzer.cpp

/* SPDX-License-Identifier: MPL-2.0 */

#ifdef ZMQ_USE_FUZZING_ENGINE
#include <fuzzer/FuzzedDataProvider.h>
#endif

#include <string.h>

#include "testutil.hpp"
#include "testutil_security.hpp"

// Test that the ZMTP engine handles invalid handshake when binding
// https://rfc.zeromq.org/spec/37/
extern "C" int LLVMFuzzerTestOneInput (const uint8_t *data, size_t size)
{
    const char *fixed_client_public =
      "{{k*81)yMWEF{/BxdMd[5RL^qRFxBgoL<8m.D^KD";
    const char *fixed_client_secret =
      "N?Gmik8R[2ACw{b7*[-$S6[4}aO#?DB?#=<OQPc7";
    const char *fixed_server_public =
      "3.9-xXwy{g*w72TP*3iB9IJJRxlBH<ufTAvPd2>C";
    const char *fixed_server_secret =
      "T}t5GLq%&Qm1)y3ywu-}pY3KEA//{^Ut!M1ut+B4";
    void *handler;
    void *zap_thread;
    void *server;
    void *server_mon;
    char my_endpoint[MAX_SOCKET_STRING];

    setup_test_context ();
    memcpy (valid_client_public, fixed_client_public, 41);
    setup_context_and_server_side (
      &handler, &zap_thread, &server, &server_mon, my_endpoint, &zap_handler,
      &socket_config_curve_server, (void *) fixed_server_secret);
    fd_t client = connect_socket (my_endpoint);

    //  If there is not enough data for a full greeting, just send what we can
    //  Otherwise send greeting first, as expected by the protocol
    uint8_t buf[512];
    if (size >= 64) {
        send (client, (void *) data, 64, MSG_NOSIGNAL);
        data += 64;
        size -= 64;
    }
    recv (client, buf, 64, 0);
    // Then send HELLO and expect WELCOME if there's enough data
    if (size >= 202) {
        send (client, (void *) data, 202, MSG_NOSIGNAL);
        data += 202;
        size -= 202;
        recv (client, buf, 170, MSG_DONTWAIT);
    }
    // Then send READY and expect INITIATE if there's enough data
    if (size >= 301) {
        send (client, (void *) data, 301, MSG_NOSIGNAL);
        data += 301;
        size -= 301;
        recv (client, buf, 512, MSG_DONTWAIT);
    }
    msleep (250);
    for (ssize_t sent = 0; size > 0 && (sent != -1 || errno == EINTR);
         size -= sent > 0 ? sent : 0, data += sent > 0 ? sent : 0)
        sent = send (client, (const char *) data, size, MSG_NOSIGNAL);
    msleep (250);

    //  Drain the queue, if any
    zmq_msg_t msg;
    zmq_msg_init (&msg);
    while (-1 != zmq_msg_recv (&msg, server, ZMQ_DONTWAIT)) {
        zmq_msg_close (&msg);
        zmq_msg_init (&msg);
    }

    //  A well-behaved client should work while the malformed data from the other
    //  is being received
    curve_client_data_t curve_client_data = {
      fixed_server_public, fixed_client_public, fixed_client_secret};
    void *client_mon;
    void *client_good = create_and_connect_client (
      my_endpoint, socket_config_curve_client, &curve_client_data, &client_mon);

    bounce (server, client_good);

    close (client);
    test_context_socket_close_zero_linger (client_good);
    test_context_socket_close_zero_linger (client_mon);
    shutdown_context_and_server_side (zap_thread, server, server_mon, handler);
    teardown_test_context ();

    return 0;
}

#ifndef ZMQ_USE_FUZZING_ENGINE
void test_bind_curve_fuzzer ()
{
    uint8_t **data;
    size_t *len, num_cases = 0;
    if (fuzzer_corpus_encode (
          "tests/libzmq-fuzz-corpora/test_bind_curve_fuzzer_seed_corpus", &data,
          &len, &num_cases)
        != 0)
        exit (77);

    while (num_cases-- > 0) {
        TEST_ASSERT_SUCCESS_ERRNO (
          LLVMFuzzerTestOneInput (data[num_cases], len[num_cases]));
        free (data[num_cases]);
    }

    free (data);
    free (len);
}

int main (int argc, char **argv)
{
    setup_test_environment ();

    UNITY_BEGIN ();
    RUN_TEST (test_bind_curve_fuzzer);

    return UNITY_END ();
}
#endif