/src/FreeRDP/libfreerdp/core/rdstls.c

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/**
 * FreeRDP: A Remote Desktop Protocol Implementation
 * RDSTLS Security protocol
 *
 * Copyright 2023 Joan Torres <joan.torres@suse.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <freerdp/config.h>

#include "settings.h"

#include <freerdp/log.h>
#include <freerdp/error.h>
#include <freerdp/settings.h>

#include <winpr/assert.h>
#include <winpr/stream.h>
#include <winpr/wlog.h>

#include "rdstls.h"
#include "transport.h"
#include "utils.h"

#define RDSTLS_VERSION_1 0x01

#define RDSTLS_TYPE_CAPABILITIES 0x01
#define RDSTLS_TYPE_AUTHREQ 0x02
#define RDSTLS_TYPE_AUTHRSP 0x04

#define RDSTLS_DATA_CAPABILITIES 0x01
#define RDSTLS_DATA_PASSWORD_CREDS 0x01
#define RDSTLS_DATA_AUTORECONNECT_COOKIE 0x02
#define RDSTLS_DATA_RESULT_CODE 0x01

typedef enum
{
  RDSTLS_STATE_INITIAL,
  RDSTLS_STATE_CAPABILITIES,
  RDSTLS_STATE_AUTH_REQ,
  RDSTLS_STATE_AUTH_RSP,
  RDSTLS_STATE_FINAL,
} RDSTLS_STATE;

struct rdp_rdstls
{
  BOOL server;
  RDSTLS_STATE state;
  rdpContext* context;
  rdpTransport* transport;

  UINT32 resultCode;
  wLog* log;
};

/**
 * Create new RDSTLS state machine.
 *
 * @param context A pointer to the rdp context to use
 *
 * @return new RDSTLS state machine.
 */

rdpRdstls* rdstls_new(rdpContext* context, rdpTransport* transport)
{
  WINPR_ASSERT(context);
  WINPR_ASSERT(transport);

  rdpSettings* settings = context->settings;
  WINPR_ASSERT(settings);

  rdpRdstls* rdstls = (rdpRdstls*)calloc(1, sizeof(rdpRdstls));

  if (!rdstls)
    return NULL;
  rdstls->log = WLog_Get(FREERDP_TAG("core.rdstls"));
  rdstls->context = context;
  rdstls->transport = transport;
  rdstls->server = settings->ServerMode;

  rdstls->state = RDSTLS_STATE_INITIAL;

  return rdstls;
}

/**
 * Free RDSTLS state machine.
 * @param rdstls The RDSTLS instance to free
 */

void rdstls_free(rdpRdstls* rdstls)
{
  free(rdstls);
}

static const char* rdstls_get_state_str(RDSTLS_STATE state)
{
  switch (state)
  {
    case RDSTLS_STATE_INITIAL:
      return "RDSTLS_STATE_INITIAL";
    case RDSTLS_STATE_CAPABILITIES:
      return "RDSTLS_STATE_CAPABILITIES";
    case RDSTLS_STATE_AUTH_REQ:
      return "RDSTLS_STATE_AUTH_REQ";
    case RDSTLS_STATE_AUTH_RSP:
      return "RDSTLS_STATE_AUTH_RSP";
    case RDSTLS_STATE_FINAL:
      return "RDSTLS_STATE_FINAL";
    default:
      return "UNKNOWN";
  }
}

static RDSTLS_STATE rdstls_get_state(rdpRdstls* rdstls)
{
  WINPR_ASSERT(rdstls);
  return rdstls->state;
}

static BOOL check_transition(wLog* log, RDSTLS_STATE current, RDSTLS_STATE expected,
                             RDSTLS_STATE requested)
{
  if (requested != expected)
  {
    WLog_Print(log, WLOG_ERROR,
               "Unexpected rdstls state transition from %s [%d] to %s [%d], expected %s [%d]",
               rdstls_get_state_str(current), current, rdstls_get_state_str(requested),
               requested, rdstls_get_state_str(expected), expected);
    return FALSE;
  }
  return TRUE;
}

static BOOL rdstls_set_state(rdpRdstls* rdstls, RDSTLS_STATE state)
{
  BOOL rc = FALSE;
  WINPR_ASSERT(rdstls);

  WLog_Print(rdstls->log, WLOG_DEBUG, "-- %s\t--> %s", rdstls_get_state_str(rdstls->state),
             rdstls_get_state_str(state));

  switch (rdstls->state)
  {
    case RDSTLS_STATE_INITIAL:
      rc = check_transition(rdstls->log, rdstls->state, RDSTLS_STATE_CAPABILITIES, state);
      break;
    case RDSTLS_STATE_CAPABILITIES:
      rc = check_transition(rdstls->log, rdstls->state, RDSTLS_STATE_AUTH_REQ, state);
      break;
    case RDSTLS_STATE_AUTH_REQ:
      rc = check_transition(rdstls->log, rdstls->state, RDSTLS_STATE_AUTH_RSP, state);
      break;
    case RDSTLS_STATE_AUTH_RSP:
      rc = check_transition(rdstls->log, rdstls->state, RDSTLS_STATE_FINAL, state);
      break;
    case RDSTLS_STATE_FINAL:
      rc = check_transition(rdstls->log, rdstls->state, RDSTLS_STATE_CAPABILITIES, state);
      break;
    default:
      WLog_Print(rdstls->log, WLOG_ERROR,
                 "Invalid rdstls state %s [%d], requested transition to %s [%d]",
                 rdstls_get_state_str(rdstls->state), rdstls->state,
                 rdstls_get_state_str(state), state);
      break;
  }
  if (rc)
    rdstls->state = state;

  return rc;
}

static BOOL rdstls_write_capabilities(rdpRdstls* rdstls, wStream* s)
{
  if (!Stream_EnsureRemainingCapacity(s, 6))
    return FALSE;

  Stream_Write_UINT16(s, RDSTLS_TYPE_CAPABILITIES);
  Stream_Write_UINT16(s, RDSTLS_DATA_CAPABILITIES);
  Stream_Write_UINT16(s, RDSTLS_VERSION_1);

  return TRUE;
}

static SSIZE_T rdstls_write_string(wStream* s, const char* str)
{
  const size_t pos = Stream_GetPosition(s);

  if (!Stream_EnsureRemainingCapacity(s, 2))
    return -1;

  if (!str)
  {
    /* Write unicode null */
    Stream_Write_UINT16(s, 2);
    if (!Stream_EnsureRemainingCapacity(s, 2))
      return -1;

    Stream_Write_UINT16(s, 0);
    return (SSIZE_T)(Stream_GetPosition(s) - pos);
  }

  const size_t length = (strlen(str) + 1);

  Stream_Write_UINT16(s, (UINT16)length * sizeof(WCHAR));

  if (!Stream_EnsureRemainingCapacity(s, length * sizeof(WCHAR)))
    return -1;

  if (Stream_Write_UTF16_String_From_UTF8(s, length, str, length, TRUE) < 0)
    return -1;

  return (SSIZE_T)(Stream_GetPosition(s) - pos);
}

static BOOL rdstls_write_data(wStream* s, UINT32 length, const BYTE* data)
{
  WINPR_ASSERT(data || (length == 0));

  if (!Stream_EnsureRemainingCapacity(s, 2))
    return FALSE;

  Stream_Write_UINT16(s, length);

  if (!Stream_EnsureRemainingCapacity(s, length))
    return FALSE;

  Stream_Write(s, data, length);

  return TRUE;
}

static BOOL rdstls_write_authentication_request_with_password(rdpRdstls* rdstls, wStream* s)
{
  rdpSettings* settings = rdstls->context->settings;
  WINPR_ASSERT(settings);

  if (!Stream_EnsureRemainingCapacity(s, 4))
    return FALSE;

  Stream_Write_UINT16(s, RDSTLS_TYPE_AUTHREQ);
  Stream_Write_UINT16(s, RDSTLS_DATA_PASSWORD_CREDS);

  if (!rdstls_write_data(s, settings->RedirectionGuidLength, settings->RedirectionGuid))
    return FALSE;

  if (rdstls_write_string(s, settings->Username) < 0)
    return FALSE;

  if (rdstls_write_string(s, settings->Domain) < 0)
    return FALSE;

  if (!rdstls_write_data(s, settings->RedirectionPasswordLength, settings->RedirectionPassword))
    return FALSE;

  return TRUE;
}

static BOOL rdstls_write_authentication_request_with_cookie(rdpRdstls* rdstls, wStream* s)
{
  // TODO
  return FALSE;
}

static BOOL rdstls_write_authentication_response(rdpRdstls* rdstls, wStream* s)
{
  if (!Stream_EnsureRemainingCapacity(s, 8))
    return FALSE;

  Stream_Write_UINT16(s, RDSTLS_TYPE_AUTHRSP);
  Stream_Write_UINT16(s, RDSTLS_DATA_RESULT_CODE);
  Stream_Write_UINT32(s, rdstls->resultCode);

  return TRUE;
}

static BOOL rdstls_process_capabilities(rdpRdstls* rdstls, wStream* s)
{
  UINT16 dataType = 0;
  UINT16 supportedVersions = 0;

  if (!Stream_CheckAndLogRequiredLengthWLog(rdstls->log, s, 4))
    return FALSE;

  Stream_Read_UINT16(s, dataType);
  if (dataType != RDSTLS_DATA_CAPABILITIES)
  {
    WLog_Print(rdstls->log, WLOG_ERROR,
               "received invalid DataType=0x%04" PRIX16 ", expected 0x%04" PRIX16, dataType,
               RDSTLS_DATA_CAPABILITIES);
    return FALSE;
  }

  Stream_Read_UINT16(s, supportedVersions);
  if ((supportedVersions & RDSTLS_VERSION_1) == 0)
  {
    WLog_Print(rdstls->log, WLOG_ERROR,
               "received invalid supportedVersions=0x%04" PRIX16 ", expected 0x%04" PRIX16,
               supportedVersions, RDSTLS_VERSION_1);
    return FALSE;
  }

  return TRUE;
}

static BOOL rdstls_read_unicode_string(wLog* log, wStream* s, char** str)
{
  UINT16 length = 0;

  WINPR_ASSERT(str);

  if (!Stream_CheckAndLogRequiredLengthWLog(log, s, 2))
    return FALSE;

  Stream_Read_UINT16(s, length);

  if (!Stream_CheckAndLogRequiredLengthWLog(log, s, length))
    return FALSE;

  if (length <= 2)
  {
    Stream_Seek(s, length);
    return TRUE;
  }

  *str = Stream_Read_UTF16_String_As_UTF8(s, length / sizeof(WCHAR), NULL);
  if (!*str)
    return FALSE;

  return TRUE;
}

static BOOL rdstls_read_data(wLog* log, wStream* s, UINT16* pLength, const BYTE** pData)
{
  UINT16 length = 0;

  WINPR_ASSERT(pLength);
  WINPR_ASSERT(pData);

  *pData = NULL;
  *pLength = 0;
  if (!Stream_CheckAndLogRequiredLengthWLog(log, s, 2))
    return FALSE;

  Stream_Read_UINT16(s, length);

  if (!Stream_CheckAndLogRequiredLengthWLog(log, s, length))
    return FALSE;

  if (length <= 2)
  {
    Stream_Seek(s, length);
    return TRUE;
  }

  *pData = Stream_ConstPointer(s);
  *pLength = length;
  return Stream_SafeSeek(s, length);
}

static BOOL rdstls_cmp_data(wLog* log, const char* field, const BYTE* serverData,
                            const UINT32 serverDataLength, const BYTE* clientData,
                            const UINT16 clientDataLength)
{
  if (serverDataLength > 0)
  {
    if (clientDataLength == 0)
    {
      WLog_Print(log, WLOG_ERROR, "expected %s", field);
      return FALSE;
    }

    if (serverDataLength > UINT16_MAX || serverDataLength != clientDataLength ||
        memcmp(serverData, clientData, serverDataLength) != 0)
    {
      WLog_Print(log, WLOG_ERROR, "%s verification failed", field);
      return FALSE;
    }
  }

  return TRUE;
}

static BOOL rdstls_cmp_str(wLog* log, const char* field, const char* serverStr,
                           const char* clientStr)
{
  if (!utils_str_is_empty(serverStr))
  {
    if (utils_str_is_empty(clientStr))
    {
      WLog_Print(log, WLOG_ERROR, "expected %s", field);
      return FALSE;
    }

    if (strcmp(serverStr, clientStr) != 0)
    {
      WLog_Print(log, WLOG_ERROR, "%s verification failed", field);
      return FALSE;
    }
  }

  return TRUE;
}

static BOOL rdstls_process_authentication_request_with_password(rdpRdstls* rdstls, wStream* s)
{
  BOOL rc = FALSE;

  const BYTE* clientRedirectionGuid = NULL;
  UINT16 clientRedirectionGuidLength = 0;
  char* clientPassword = NULL;
  char* clientUsername = NULL;
  char* clientDomain = NULL;

  const BYTE* serverRedirectionGuid = NULL;
  UINT16 serverRedirectionGuidLength = 0;
  const char* serverPassword = NULL;
  const char* serverUsername = NULL;
  const char* serverDomain = NULL;

  rdpSettings* settings = rdstls->context->settings;
  WINPR_ASSERT(settings);

  if (!rdstls_read_data(rdstls->log, s, &clientRedirectionGuidLength, &clientRedirectionGuid))
    goto fail;

  if (!rdstls_read_unicode_string(rdstls->log, s, &clientUsername))
    goto fail;

  if (!rdstls_read_unicode_string(rdstls->log, s, &clientDomain))
    goto fail;

  if (!rdstls_read_unicode_string(rdstls->log, s, &clientPassword))
    goto fail;

  serverRedirectionGuid = freerdp_settings_get_pointer(settings, FreeRDP_RedirectionGuid);
  serverRedirectionGuidLength =
      freerdp_settings_get_uint32(settings, FreeRDP_RedirectionGuidLength);
  serverUsername = freerdp_settings_get_string(settings, FreeRDP_Username);
  serverDomain = freerdp_settings_get_string(settings, FreeRDP_Domain);
  serverPassword = freerdp_settings_get_string(settings, FreeRDP_Password);

  rdstls->resultCode = ERROR_SUCCESS;

  if (!rdstls_cmp_data(rdstls->log, "RedirectionGuid", serverRedirectionGuid,
                       serverRedirectionGuidLength, clientRedirectionGuid,
                       clientRedirectionGuidLength))
    rdstls->resultCode = ERROR_LOGON_FAILURE;

  if (!rdstls_cmp_str(rdstls->log, "UserName", serverUsername, clientUsername))
    rdstls->resultCode = ERROR_LOGON_FAILURE;

  if (!rdstls_cmp_str(rdstls->log, "Domain", serverDomain, clientDomain))
    rdstls->resultCode = ERROR_LOGON_FAILURE;

  if (!rdstls_cmp_str(rdstls->log, "Password", serverPassword, clientPassword))
    rdstls->resultCode = ERROR_LOGON_FAILURE;

  rc = TRUE;
fail:
  return rc;
}

static BOOL rdstls_process_authentication_request_with_cookie(rdpRdstls* rdstls, wStream* s)
{
  // TODO
  return FALSE;
}

static BOOL rdstls_process_authentication_request(rdpRdstls* rdstls, wStream* s)
{
  UINT16 dataType = 0;

  if (!Stream_CheckAndLogRequiredLengthWLog(rdstls->log, s, 2))
    return FALSE;

  Stream_Read_UINT16(s, dataType);
  switch (dataType)
  {
    case RDSTLS_DATA_PASSWORD_CREDS:
      if (!rdstls_process_authentication_request_with_password(rdstls, s))
        return FALSE;
      break;
    case RDSTLS_DATA_AUTORECONNECT_COOKIE:
      if (!rdstls_process_authentication_request_with_cookie(rdstls, s))
        return FALSE;
      break;
    default:
      WLog_Print(rdstls->log, WLOG_ERROR,
                 "received invalid DataType=0x%04" PRIX16 ", expected 0x%04" PRIX16
                 " or 0x%04" PRIX16,
                 dataType, RDSTLS_DATA_PASSWORD_CREDS, RDSTLS_DATA_AUTORECONNECT_COOKIE);
      return FALSE;
  }

  return TRUE;
}

static BOOL rdstls_process_authentication_response(rdpRdstls* rdstls, wStream* s)
{
  UINT16 dataType = 0;
  UINT32 resultCode = 0;

  if (!Stream_CheckAndLogRequiredLengthWLog(rdstls->log, s, 6))
    return FALSE;

  Stream_Read_UINT16(s, dataType);
  if (dataType != RDSTLS_DATA_RESULT_CODE)
  {
    WLog_Print(rdstls->log, WLOG_ERROR,
               "received invalid DataType=0x%04" PRIX16 ", expected 0x%04" PRIX16, dataType,
               RDSTLS_DATA_RESULT_CODE);
    return FALSE;
  }

  Stream_Read_UINT32(s, resultCode);
  if (resultCode != ERROR_SUCCESS)
  {
    WLog_Print(rdstls->log, WLOG_ERROR, "resultCode: %s [0x%08" PRIX32 "] %s",
               freerdp_get_last_error_name(resultCode), resultCode,
               freerdp_get_last_error_string(resultCode));
    return FALSE;
  }

  return TRUE;
}

static BOOL rdstls_send(rdpTransport* transport, wStream* s, void* extra)
{
  rdpRdstls* rdstls = (rdpRdstls*)extra;
  rdpSettings* settings = NULL;

  WINPR_ASSERT(transport);
  WINPR_ASSERT(s);
  WINPR_ASSERT(rdstls);

  settings = rdstls->context->settings;
  WINPR_ASSERT(settings);

  if (!Stream_EnsureRemainingCapacity(s, 2))
    return FALSE;

  Stream_Write_UINT16(s, RDSTLS_VERSION_1);

  const RDSTLS_STATE state = rdstls_get_state(rdstls);
  switch (state)
  {
    case RDSTLS_STATE_CAPABILITIES:
      if (!rdstls_write_capabilities(rdstls, s))
        return FALSE;
      break;
    case RDSTLS_STATE_AUTH_REQ:
      if (settings->RedirectionFlags & LB_PASSWORD_IS_PK_ENCRYPTED)
      {
        if (!rdstls_write_authentication_request_with_password(rdstls, s))
          return FALSE;
      }
      else if (settings->ServerAutoReconnectCookie != NULL)
      {
        if (!rdstls_write_authentication_request_with_cookie(rdstls, s))
          return FALSE;
      }
      else
      {
        WLog_Print(rdstls->log, WLOG_ERROR,
                   "cannot authenticate with password or auto-reconnect cookie");
        return FALSE;
      }
      break;
    case RDSTLS_STATE_AUTH_RSP:
      if (!rdstls_write_authentication_response(rdstls, s))
        return FALSE;
      break;
    default:
      WLog_Print(rdstls->log, WLOG_ERROR, "Invalid rdstls state %s [%d]",
                 rdstls_get_state_str(state), state);
      return FALSE;
  }

  if (transport_write(rdstls->transport, s) < 0)
    return FALSE;

  return TRUE;
}

static int rdstls_recv(rdpTransport* transport, wStream* s, void* extra)
{
  UINT16 version = 0;
  UINT16 pduType = 0;
  rdpRdstls* rdstls = (rdpRdstls*)extra;

  WINPR_ASSERT(transport);
  WINPR_ASSERT(s);
  WINPR_ASSERT(rdstls);

  if (!Stream_CheckAndLogRequiredLengthWLog(rdstls->log, s, 4))
    return FALSE;

  Stream_Read_UINT16(s, version);
  if (version != RDSTLS_VERSION_1)
  {
    WLog_Print(rdstls->log, WLOG_ERROR,
               "received invalid RDSTLS Version=0x%04" PRIX16 ", expected 0x%04" PRIX16,
               version, RDSTLS_VERSION_1);
    return -1;
  }

  Stream_Read_UINT16(s, pduType);
  switch (pduType)
  {
    case RDSTLS_TYPE_CAPABILITIES:
      if (!rdstls_process_capabilities(rdstls, s))
        return -1;
      break;
    case RDSTLS_TYPE_AUTHREQ:
      if (!rdstls_process_authentication_request(rdstls, s))
        return -1;
      break;
    case RDSTLS_TYPE_AUTHRSP:
      if (!rdstls_process_authentication_response(rdstls, s))
        return -1;
      break;
    default:
      WLog_Print(rdstls->log, WLOG_ERROR, "unknown RDSTLS PDU type [0x%04" PRIx16 "]",
                 pduType);
      return -1;
  }

  return 1;
}

#define rdstls_check_state_requirements(rdstls, expected) \
  rdstls_check_state_requirements_((rdstls), (expected), __FILE__, __func__, __LINE__)
static BOOL rdstls_check_state_requirements_(rdpRdstls* rdstls, RDSTLS_STATE expected,
                                             const char* file, const char* fkt, size_t line)
{
  const RDSTLS_STATE current = rdstls_get_state(rdstls);
  if (current == expected)
    return TRUE;

  const DWORD log_level = WLOG_ERROR;
  if (WLog_IsLevelActive(rdstls->log, log_level))
    WLog_PrintMessage(rdstls->log, WLOG_MESSAGE_TEXT, log_level, line, file, fkt,
                      "Unexpected rdstls state %s [%d], expected %s [%d]",
                      rdstls_get_state_str(current), current, rdstls_get_state_str(expected),
                      expected);

  return FALSE;
}

static BOOL rdstls_send_capabilities(rdpRdstls* rdstls)
{
  BOOL rc = FALSE;
  wStream* s = NULL;

  if (!rdstls_check_state_requirements(rdstls, RDSTLS_STATE_CAPABILITIES))
    goto fail;

  s = Stream_New(NULL, 512);
  if (!s)
    goto fail;

  if (!rdstls_send(rdstls->transport, s, rdstls))
    goto fail;

  rc = rdstls_set_state(rdstls, RDSTLS_STATE_AUTH_REQ);
fail:
  Stream_Free(s, TRUE);
  return rc;
}

static BOOL rdstls_recv_authentication_request(rdpRdstls* rdstls)
{
  BOOL rc = FALSE;
  int status = 0;
  wStream* s = NULL;

  if (!rdstls_check_state_requirements(rdstls, RDSTLS_STATE_AUTH_REQ))
    goto fail;

  s = Stream_New(NULL, 4096);
  if (!s)
    goto fail;

  status = transport_read_pdu(rdstls->transport, s);

  if (status < 0)
    goto fail;

  status = rdstls_recv(rdstls->transport, s, rdstls);

  if (status < 0)
    goto fail;

  rc = rdstls_set_state(rdstls, RDSTLS_STATE_AUTH_RSP);
fail:
  Stream_Free(s, TRUE);
  return rc;
}

static BOOL rdstls_send_authentication_response(rdpRdstls* rdstls)
{
  BOOL rc = FALSE;
  wStream* s = NULL;

  if (!rdstls_check_state_requirements(rdstls, RDSTLS_STATE_AUTH_RSP))
    goto fail;

  s = Stream_New(NULL, 512);
  if (!s)
    goto fail;

  if (!rdstls_send(rdstls->transport, s, rdstls))
    goto fail;

  rc = rdstls_set_state(rdstls, RDSTLS_STATE_FINAL);
fail:
  Stream_Free(s, TRUE);
  return rc;
}

static BOOL rdstls_recv_capabilities(rdpRdstls* rdstls)
{
  BOOL rc = FALSE;
  int status = 0;
  wStream* s = NULL;

  if (!rdstls_check_state_requirements(rdstls, RDSTLS_STATE_CAPABILITIES))
    goto fail;

  s = Stream_New(NULL, 512);
  if (!s)
    goto fail;

  status = transport_read_pdu(rdstls->transport, s);

  if (status < 0)
    goto fail;

  status = rdstls_recv(rdstls->transport, s, rdstls);

  if (status < 0)
    goto fail;

  rc = rdstls_set_state(rdstls, RDSTLS_STATE_AUTH_REQ);
fail:
  Stream_Free(s, TRUE);
  return rc;
}

static BOOL rdstls_send_authentication_request(rdpRdstls* rdstls)
{
  BOOL rc = FALSE;
  wStream* s = NULL;

  if (!rdstls_check_state_requirements(rdstls, RDSTLS_STATE_AUTH_REQ))
    goto fail;

  s = Stream_New(NULL, 4096);
  if (!s)
    goto fail;

  if (!rdstls_send(rdstls->transport, s, rdstls))
    goto fail;

  rc = rdstls_set_state(rdstls, RDSTLS_STATE_AUTH_RSP);
fail:
  Stream_Free(s, TRUE);
  return rc;
}

static BOOL rdstls_recv_authentication_response(rdpRdstls* rdstls)
{
  BOOL rc = FALSE;
  int status = 0;
  wStream* s = NULL;

  WINPR_ASSERT(rdstls);

  if (!rdstls_check_state_requirements(rdstls, RDSTLS_STATE_AUTH_RSP))
    goto fail;

  s = Stream_New(NULL, 512);
  if (!s)
    goto fail;

  status = transport_read_pdu(rdstls->transport, s);

  if (status < 0)
    goto fail;

  status = rdstls_recv(rdstls->transport, s, rdstls);

  if (status < 0)
    goto fail;

  rc = rdstls_set_state(rdstls, RDSTLS_STATE_FINAL);
fail:
  Stream_Free(s, TRUE);
  return rc;
}

static int rdstls_server_authenticate(rdpRdstls* rdstls)
{
  if (!rdstls_set_state(rdstls, RDSTLS_STATE_CAPABILITIES))
    return -1;

  if (!rdstls_send_capabilities(rdstls))
    return -1;

  if (!rdstls_recv_authentication_request(rdstls))
    return -1;

  if (!rdstls_send_authentication_response(rdstls))
    return -1;

  if (rdstls->resultCode != 0)
    return -1;

  return 1;
}

static int rdstls_client_authenticate(rdpRdstls* rdstls)
{
  if (!rdstls_set_state(rdstls, RDSTLS_STATE_CAPABILITIES))
    return -1;

  if (!rdstls_recv_capabilities(rdstls))
    return -1;

  if (!rdstls_send_authentication_request(rdstls))
    return -1;

  if (!rdstls_recv_authentication_response(rdstls))
    return -1;

  return 1;
}

/**
 * Authenticate using RDSTLS.
 * @param rdstls The RDSTLS instance to use
 *
 * @return 1 if authentication is successful
 */

int rdstls_authenticate(rdpRdstls* rdstls)
{
  WINPR_ASSERT(rdstls);

  if (rdstls->server)
    return rdstls_server_authenticate(rdstls);
  else
    return rdstls_client_authenticate(rdstls);
}

static SSIZE_T rdstls_parse_pdu_data_type(wLog* log, UINT16 dataType, wStream* s)
{
  switch (dataType)
  {
    case RDSTLS_DATA_PASSWORD_CREDS:
    {
      UINT16 redirGuidLength = 0;
      if (Stream_GetRemainingLength(s) < 2)
        return 0;
      Stream_Read_UINT16(s, redirGuidLength);

      if (Stream_GetRemainingLength(s) < redirGuidLength)
        return 0;
      Stream_Seek(s, redirGuidLength);

      UINT16 usernameLength = 0;
      if (Stream_GetRemainingLength(s) < 2)
        return 0;
      Stream_Read_UINT16(s, usernameLength);

      if (Stream_GetRemainingLength(s) < usernameLength)
        return 0;
      Stream_Seek(s, usernameLength);

      UINT16 domainLength = 0;
      if (Stream_GetRemainingLength(s) < 2)
        return 0;
      Stream_Read_UINT16(s, domainLength);

      if (Stream_GetRemainingLength(s) < domainLength)
        return 0;
      Stream_Seek(s, domainLength);

      UINT16 passwordLength = 0;
      if (Stream_GetRemainingLength(s) < 2)
        return 0;
      Stream_Read_UINT16(s, passwordLength);

      return Stream_GetPosition(s) + passwordLength;
    }
    case RDSTLS_DATA_AUTORECONNECT_COOKIE:
    {
      if (Stream_GetRemainingLength(s) < 4)
        return 0;
      Stream_Seek(s, 4);

      UINT16 cookieLength = 0;
      if (Stream_GetRemainingLength(s) < 2)
        return 0;
      Stream_Read_UINT16(s, cookieLength);

      return 12u + cookieLength;
    }
    default:
      WLog_Print(log, WLOG_ERROR, "invalid RDSLTS dataType");
      return -1;
  }
}

SSIZE_T rdstls_parse_pdu(wLog* log, wStream* stream)
{
  SSIZE_T pduLength = -1;
  wStream sbuffer = { 0 };
  wStream* s = Stream_StaticConstInit(&sbuffer, Stream_Buffer(stream), Stream_Length(stream));

  UINT16 version = 0;
  if (Stream_GetRemainingLength(s) < 2)
    return 0;
  Stream_Read_UINT16(s, version);
  if (version != RDSTLS_VERSION_1)
  {
    WLog_Print(log, WLOG_ERROR, "invalid RDSTLS version");
    return -1;
  }

  UINT16 pduType = 0;
  if (Stream_GetRemainingLength(s) < 2)
    return 0;
  Stream_Read_UINT16(s, pduType);
  switch (pduType)
  {
    case RDSTLS_TYPE_CAPABILITIES:
      pduLength = 8;
      break;
    case RDSTLS_TYPE_AUTHREQ:
      if (Stream_GetRemainingLength(s) < 2)
        return 0;
      UINT16 dataType = 0;
      Stream_Read_UINT16(s, dataType);
      pduLength = rdstls_parse_pdu_data_type(log, dataType, s);

      break;
    case RDSTLS_TYPE_AUTHRSP:
      pduLength = 10;
      break;
    default:
      WLog_Print(log, WLOG_ERROR, "invalid RDSTLS PDU type");
      return -1;
  }

  return pduLength;
}

Coverage Report

Created: 2024-05-20 06:11