TestFuzzServerSeedGen.c

 
#include <freerdp/peer.h>
#include <freerdp/freerdp.h>
#include <freerdp/settings.h>
#include <freerdp/constants.h>
#include <freerdp/crypto/certificate.h>
#include <freerdp/crypto/privatekey.h>
#include <freerdp/channels/wtsvc.h>
#include <freerdp/channels/channels.h>
#include <freerdp/client.h>
#include <freerdp/client/cmdline.h>
#include <freerdp/input.h>
#include <winpr/tools/makecert.h>
 
#include "../multitransport.h"
 
#include "TestFuzzServerCerts.h"
 
#include <winpr/ssl.h>
#include <winpr/synch.h>
#include <winpr/thread.h>
#include <winpr/crt.h>
#include <winpr/path.h>
 
#include <arpa/inet.h>
#include <errno.h>
#include <netinet/in.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
 
struct test_peer_context
{
  rdpContext _p;
 
  HANDLE vcm;
};
typedef struct test_peer_context testPeerContext;
 
typedef struct
{
  BYTE* data;
  size_t len;
  size_t cap;
} capture_t;
 
typedef struct
{
  freerdp_peer* client;
} peer_arg_t;
 
typedef struct
{
  int client_sock;
  int peer_sock;
  capture_t* capture;
} relay_arg_t;
 
static void capture_add(capture_t* c, const void* data, size_t size)
{
  WINPR_ASSERT(c);
  WINPR_ASSERT(data || (size == 0));
 
  if (c->len + size > c->cap)
  {
    size_t ncap = c->cap ? c->cap * 2 : 65536;
    while (ncap < c->len + size)
      ncap *= 2;
    BYTE* nd = realloc(c->data, ncap);
    if (!nd)
    {
      (void)fprintf(stderr, "capture realloc failed\n");
      return;
    }
    c->data = nd;
    c->cap = ncap;
  }
  memcpy(c->data + c->len, data, size);
  c->len += size;
}
 
static void test_peer_context_free(freerdp_peer* client, rdpContext* ctx)
{
  testPeerContext* context = (testPeerContext*)ctx;
  WINPR_UNUSED(client);
  if (context && context->vcm)
  {
    WTSCloseServer(context->vcm);
    context->vcm = nullptr;
  }
}
 
static BOOL test_peer_context_new(freerdp_peer* client, rdpContext* ctx)
{
  testPeerContext* context = (testPeerContext*)ctx;
  WINPR_ASSERT(client);
  WINPR_ASSERT(context);
  context->vcm = WTSOpenServerA((LPSTR)client->context);
  if (!context->vcm || context->vcm == INVALID_HANDLE_VALUE)
    goto fail;
  return TRUE;
fail:
  test_peer_context_free(client, ctx);
  return FALSE;
}
 
static BOOL test_peer_post_connect(freerdp_peer* peer)
{
  WINPR_ASSERT(peer);
  return TRUE;
}
 
static BOOL test_peer_activate(freerdp_peer* peer)
{
  WINPR_ASSERT(peer);
  return TRUE;
}
 
static int test_peer_virtual_channel_read(freerdp_peer* peer, HANDLE hChannel, BYTE* buffer,
                                          UINT32 length)
{
  WINPR_UNUSED(peer);
  WINPR_UNUSED(hChannel);
  WINPR_UNUSED(buffer);
  WINPR_UNUSED(length);
  return 0;
}
 
/*
 * Configure the server peer exactly like TestFuzzServer.c does so the
 * captured client stream replays against the fuzzer.
 */
static BOOL configure_server(freerdp_peer* client)
{
  WINPR_ASSERT(client);
  BOOL rc = FALSE;
 
  char* path = getTestCredentialsFilePath();
  char* fcert = getTestCredentialsFileNameFor("crt");
  char* fkey = getTestCredentialsFileNameFor("key");
  if (!path || !fcert || !fkey)
    goto fail;
 
  client->ContextSize = sizeof(testPeerContext);
  client->ContextNew = test_peer_context_new;
  client->ContextFree = test_peer_context_free;
  if (!freerdp_peer_context_new(client))
    goto fail;
 
  WINPR_ASSERT(client->context);
  rdpSettings* settings = client->context->settings;
  WINPR_ASSERT(settings);
 
  rdpCertificate* cert = freerdp_certificate_new_from_file(fcert);
  if (!cert)
    goto fail;
  if (!freerdp_settings_set_pointer_len(settings, FreeRDP_RdpServerCertificate, cert, 1))
    goto fail;
 
  rdpPrivateKey* key = freerdp_key_new_from_file(fkey);
  if (!key)
    goto fail;
  if (!freerdp_settings_set_pointer_len(settings, FreeRDP_RdpServerRsaKey, key, 1))
    goto fail;
 
  /*
   * Plain RDP security. Together with the local peer flag below this
   * results in the plaintext local peer path (no RDP encryption), which
   * allows the byte stream fuzzer to reach all the way into the post
   * activation parsing code.
   */
  if (!freerdp_settings_set_bool(settings, FreeRDP_RdpSecurity, TRUE))
    goto fail;
  if (!freerdp_settings_set_bool(settings, FreeRDP_UseRdpSecurityLayer, TRUE))
    goto fail;
  if (!freerdp_settings_set_bool(settings, FreeRDP_TlsSecurity, FALSE))
    goto fail;
  if (!freerdp_settings_set_bool(settings, FreeRDP_NlaSecurity, FALSE))
    goto fail;
  if (!freerdp_settings_set_bool(settings, FreeRDP_ExtSecurity, FALSE))
    goto fail;
  if (!freerdp_settings_set_uint32(settings, FreeRDP_EncryptionLevel, ENCRYPTION_LEVEL_NONE))
    goto fail;
 
  if (!freerdp_settings_set_bool(settings, FreeRDP_RemoteFxCodec, TRUE))
    goto fail;
  if (!freerdp_settings_set_bool(settings, FreeRDP_NSCodec, TRUE))
    goto fail;
  if (!freerdp_settings_set_bool(settings, FreeRDP_SupportMultitransport, TRUE))
    goto fail;
  if (!freerdp_settings_set_uint32(settings, FreeRDP_MultitransportFlags,
                                   INITIATE_REQUEST_PROTOCOL_UDPFECR))
    goto fail;
  if (!freerdp_settings_set_bool(settings, FreeRDP_SupportSkipChannelJoin, FALSE))
    goto fail;
 
  client->PostConnect = test_peer_post_connect;
  client->Activate = test_peer_activate;
  client->VirtualChannelRead = test_peer_virtual_channel_read;
 
  /* local connection => the server uses the plaintext local peer path */
  client->local = TRUE;
  if (!client->Initialize(client))
    goto fail;
 
  rc = TRUE;
fail:
 
  free(path);
  return rc;
}
 
static DWORD WINAPI peer_thread(LPVOID arg)
{
  freerdp_peer* client = ((peer_arg_t*)arg)->client;
  DWORD error = CHANNEL_RC_OK;
 
  if (!configure_server(client))
  {
    freerdp_peer_context_free(client);
    freerdp_peer_free(client);
    return 1;
  }
 
  testPeerContext* context = (testPeerContext*)client->context;
  WINPR_ASSERT(context);
 
  while (error == CHANNEL_RC_OK)
  {
    HANDLE handles[32] = WINPR_C_ARRAY_INIT;
    DWORD count = 0;
    DWORD tmp = client->GetEventHandles(client, &handles[count], ARRAYSIZE(handles) - count);
    if (tmp == 0)
      break;
    count += tmp;
    handles[count++] = WTSVirtualChannelManagerGetEventHandle(context->vcm);
    DWORD status = WaitForMultipleObjects(count, handles, FALSE, 5000);
    if (status == WAIT_FAILED || status == WAIT_TIMEOUT)
      break;
    if (client->CheckFileDescriptor(client) != TRUE)
      break;
    if (WTSVirtualChannelManagerCheckFileDescriptor(context->vcm) != TRUE)
      break;
  }
 
  client->Disconnect(client);
  freerdp_peer_context_free(client);
  freerdp_peer_free(client);
  return 0;
}
 
static void* relay_c2s(void* arg)
{
  relay_arg_t* a = (relay_arg_t*)arg;
  BYTE buf[65536] = WINPR_C_ARRAY_INIT;
  for (;;)
  {
    ssize_t rc = read(a->client_sock, buf, sizeof(buf));
    if (rc <= 0)
      break;
    capture_add(a->capture, buf, (size_t)rc);
    ssize_t w = write(a->peer_sock, buf, (size_t)rc);
    if (w != rc)
      break;
  }
  shutdown(a->peer_sock, SHUT_WR);
  return nullptr;
}
 
static void* relay_s2c(void* arg)
{
  relay_arg_t* a = (relay_arg_t*)arg;
  BYTE buf[65536] = WINPR_C_ARRAY_INIT;
  for (;;)
  {
    ssize_t rc = read(a->peer_sock, buf, sizeof(buf));
    if (rc <= 0)
      break;
    ssize_t w = write(a->client_sock, buf, (size_t)rc);
    if (w != rc)
      break;
  }
  shutdown(a->client_sock, SHUT_WR);
  return nullptr;
}
 
typedef struct
{
  int port;
  int send_input;
} client_arg_t;
 
static DWORD WINAPI client_thread(LPVOID arg)
{
  client_arg_t* a = (client_arg_t*)arg;
  char arg1[64] = WINPR_C_ARRAY_INIT;
  (void)snprintf(arg1, sizeof(arg1), "/v:127.0.0.1:%d", a->port);
  char* argv[] = { "seedgen", arg1, "/sec:rdp", "/cert:ignore", "/rfx", nullptr };
  int argc = 5;
 
  RDP_CLIENT_ENTRY_POINTS entry = WINPR_C_ARRAY_INIT;
  entry.Size = sizeof(RDP_CLIENT_ENTRY_POINTS);
  entry.Version = RDP_CLIENT_INTERFACE_VERSION;
  entry.ContextSize = sizeof(rdpContext);
 
  rdpContext* context = freerdp_client_context_new(&entry);
  if (!context)
    return 1;
 
  if (!freerdp_settings_set_bool(context->settings, FreeRDP_DeactivateClientDecoding, TRUE))
    goto fail;
  if (!freerdp_settings_set_string(context->settings, FreeRDP_Username, "test"))
    goto fail;
  if (!freerdp_settings_set_string(context->settings, FreeRDP_Password, "test"))
    goto fail;
  /* Enable network autodetect so the client announces the MCS message
   * channel; the server needs it to send the licensing and demand active
   * PDUs on the correct channel. */
  if (!freerdp_settings_set_bool(context->settings, FreeRDP_NetworkAutoDetect, TRUE))
    goto fail;
  if (!freerdp_settings_set_bool(context->settings, FreeRDP_SupportMultitransport, TRUE))
    goto fail;
 
  if (freerdp_client_settings_parse_command_line(context->settings, argc, argv, FALSE) < 0)
    goto fail;
 
  if (!freerdp_connect(context->instance))
  {
    (void)fprintf(stderr, "client connect failed\n");
    return 1;
  }
 
  if (a->send_input)
  {
    rdpInput* input = context->input;
    WINPR_ASSERT(input);
    for (int i = 0; i < 3; i++)
    {
      freerdp_input_send_synchronize_event(input, 0);
      freerdp_input_send_keyboard_event(input, KBD_FLAGS_DOWN, 0x1e); /* 'a' */
      freerdp_input_send_keyboard_event(input, KBD_FLAGS_RELEASE, 0x1e);
      freerdp_input_send_mouse_event(input, PTR_FLAGS_MOVE, 100 + i * 10, 100);
      freerdp_input_send_mouse_event(input, PTR_FLAGS_BUTTON1, 100 + i * 10, 100);
      Sleep(50);
    }
    Sleep(500);
  }
 
  freerdp_disconnect(context->instance);
  freerdp_client_context_free(context);
  return 0;
fail:
  return 1;
}
 
static int write_seed(const char* dir, const char* name, const capture_t* c)
{
  char path[512] = WINPR_C_ARRAY_INIT;
  (void)snprintf(path, sizeof(path), "%s/%s", dir, name);
  FILE* f = fopen(path, "wb");
  if (!f)
    return -1;
  size_t w = fwrite(c->data, 1, c->len, f);
  (void)fclose(f);
  return (w == c->len) ? 0 : -1;
}
 
int main(int argc, char** argv)
{
  const char* outdir = argc > 1 ? argv[1] : ".";
  int do_input = 1;
  if (argc > 2)
  {
    errno = 0;
    const unsigned long val = strtoul(argv[2], nullptr, 0);
    if ((errno != 0) || (val > INT_MAX))
      return -1;
    do_input = (int)val;
  }
 
  WTSRegisterWtsApiFunctionTable(FreeRDP_InitWtsApi());
  (void)winpr_InitializeSSL(WINPR_SSL_INIT_DEFAULT);
 
  int lfd = socket(AF_INET, SOCK_STREAM, 0);
  if (lfd < 0)
    return 1;
  int one = 1;
  setsockopt(lfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
  struct sockaddr_in sa = { 0 };
  sa.sin_family = AF_INET;
  sa.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  sa.sin_port = 0;
  if (bind(lfd, (struct sockaddr*)&sa, sizeof(sa)) != 0)
    return 1;
  if (listen(lfd, 4) != 0)
    return 1;
  socklen_t slen = sizeof(sa);
  getsockname(lfd, (struct sockaddr*)&sa, &slen);
  int port = ntohs(sa.sin_port);
  printf("listening on 127.0.0.1:%d\n", port);
 
  client_arg_t carg = { port, do_input };
  HANDLE hclient = CreateThread(nullptr, 0, client_thread, &carg, 0, nullptr);
 
  int cfd = accept(lfd, nullptr, nullptr);
  if (cfd < 0)
    return 1;
  printf("client connected\n");
 
  int sv[2];
  if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) != 0)
    return 1;
 
  freerdp_peer* client = freerdp_peer_new(sv[0]);
  if (!client)
    return 1;
 
  capture_t capture = WINPR_C_ARRAY_INIT;
  relay_arg_t ra = { cfd, sv[1], &capture };
 
  pthread_t t1 = WINPR_C_ARRAY_INIT;
  pthread_create(&t1, nullptr, relay_c2s, &ra);
  pthread_t t2 = WINPR_C_ARRAY_INIT;
  pthread_create(&t2, nullptr, relay_s2c, &ra);
 
  peer_arg_t pa = { client };
  HANDLE hpeer = CreateThread(nullptr, 0, peer_thread, &pa, 0, nullptr);
 
  WaitForSingleObject(hclient, 30000);
  /* give the peer a moment to drain */
  Sleep(200);
  close(cfd);
  close(sv[1]);
  WaitForSingleObject(hpeer, 10000);
 
  CloseHandle(hclient);
  CloseHandle(hpeer);
  close(sv[0]);
  close(lfd);
 
  printf("captured %zu bytes\n", capture.len);
 
  if (capture.len == 0)
    return 1;
 
  /* write full capture as the primary seed */
  write_seed(outdir, "handshake", &capture);
 
  /* write truncated seeds at phase boundaries to give the fuzzer
   * incremental starting points */
  static const size_t cuts[] = { 64, 128, 256, 512, 1024 };
  for (size_t i = 0; i < sizeof(cuts) / sizeof(cuts[0]); i++)
  {
    if (capture.len > cuts[i])
    {
      char name[64] = WINPR_C_ARRAY_INIT;
      capture_t t = WINPR_C_ARRAY_INIT;
      t.data = capture.data;
      t.len = cuts[i];
      (void)snprintf(name, sizeof(name), "handshake_cut%zu", cuts[i]);
      write_seed(outdir, name, &t);
    }
  }
 
  free(capture.data);
  return 0;
}