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

Source
/**
 * 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;

typedef enum
{

  RDSTLS_RESULT_SUCCESS = 0x00000000,
  RDSTLS_RESULT_ACCESS_DENIED = 0x00000005,
  RDSTLS_RESULT_LOGON_FAILURE = 0x0000052e,
  RDSTLS_RESULT_INVALID_LOGON_HOURS = 0x00000530,
  RDSTLS_RESULT_PASSWORD_EXPIRED = 0x00000532,
  RDSTLS_RESULT_ACCOUNT_DISABLED = 0x00000533,
  RDSTLS_RESULT_PASSWORD_MUST_CHANGE = 0x00000773,
  RDSTLS_RESULT_ACCOUNT_LOCKED_OUT = 0x00000775
} RDSTLS_RESULT_CODE;

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

  RDSTLS_RESULT_CODE resultCode;
  wLog* log;
};

static const char* rdstls_result_code_str(UINT32 resultCode)
{
  switch (resultCode)
  {
    case RDSTLS_RESULT_SUCCESS:
      return "RDSTLS_RESULT_SUCCESS";
    case RDSTLS_RESULT_ACCESS_DENIED:
      return "RDSTLS_RESULT_ACCESS_DENIED";
    case RDSTLS_RESULT_LOGON_FAILURE:
      return "RDSTLS_RESULT_LOGON_FAILURE";
    case RDSTLS_RESULT_INVALID_LOGON_HOURS:
      return "RDSTLS_RESULT_INVALID_LOGON_HOURS";
    case RDSTLS_RESULT_PASSWORD_EXPIRED:
      return "RDSTLS_RESULT_PASSWORD_EXPIRED";
    case RDSTLS_RESULT_ACCOUNT_DISABLED:
      return "RDSTLS_RESULT_ACCOUNT_DISABLED";
    case RDSTLS_RESULT_PASSWORD_MUST_CHANGE:
      return "RDSTLS_RESULT_PASSWORD_MUST_CHANGE";
    case RDSTLS_RESULT_ACCOUNT_LOCKED_OUT:
      return "RDSTLS_RESULT_ACCOUNT_LOCKED_OUT";
    default:
      return "RDSTLS_RESULT_UNKNOWN";
  }
}
/**
 * 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 nullptr;
  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 [%u] to %s [%u], expected %s [%u]",
               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 [%u], requested transition to %s [%u]",
                 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(WINPR_ATTR_UNUSED 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) || (length > UINT16_MAX))
    return FALSE;

  Stream_Write_UINT16(s, (UINT16)length);

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

  Stream_Write(s, data, length);

  return TRUE;
}

static BOOL rdstls_write_cookie(wStream* s, const ARC_SC_PRIVATE_PACKET* cookie)
{
  WINPR_ASSERT(cookie);
  const uint16_t length = 28;

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

  Stream_Write_UINT16(s, length);

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

  Stream_Write_UINT32(s, cookie->cbLen);
  Stream_Write_UINT32(s, cookie->version);
  Stream_Write_UINT32(s, cookie->logonId);
  Stream_Write(s, cookie->arcRandomBits, sizeof(cookie->arcRandomBits));
  return TRUE;
}

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

  WLog_Print(rdstls->log, WLOG_DEBUG, "Writing RDSTLS password authentication message");

  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(WINPR_ATTR_UNUSED rdpRdstls* rdstls,
                                                            WINPR_ATTR_UNUSED wStream* s)
{
  WINPR_ASSERT(rdstls);
  WINPR_ASSERT(rdstls->context);

  WLog_Print(rdstls->log, WLOG_DEBUG, "Writing RDSTLS cookie authentication message");

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

  if (!Stream_EnsureRemainingCapacity(s, 8))
    return FALSE;

  Stream_Write_UINT16(s, RDSTLS_TYPE_AUTHREQ);
  Stream_Write_UINT16(s, RDSTLS_DATA_AUTORECONNECT_COOKIE);
  Stream_Write_UINT32(s, settings->RedirectedSessionId);

  return (rdstls_write_cookie(s, settings->ServerAutoReconnectCookie));
}

static BOOL rdstls_write_authentication_response(rdpRdstls* rdstls, wStream* s)
{
  WINPR_ASSERT(rdstls);
  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)
{
  WINPR_ASSERT(rdstls);
  if (!Stream_CheckAndLogRequiredLengthWLog(rdstls->log, s, 4))
    return FALSE;

  const UINT16 dataType = Stream_Get_UINT16(s);
  if (dataType != RDSTLS_DATA_CAPABILITIES)
  {
    WLog_Print(rdstls->log, WLOG_ERROR,
               "received invalid DataType=0x%04" PRIX16 ", expected 0x%04" PRIX32, dataType,
               WINPR_CXX_COMPAT_CAST(UINT32, RDSTLS_DATA_CAPABILITIES));
    return FALSE;
  }

  const UINT16 supportedVersions = Stream_Get_UINT16(s);
  if ((supportedVersions & RDSTLS_VERSION_1) == 0)
  {
    WLog_Print(rdstls->log, WLOG_ERROR,
               "received invalid supportedVersions=0x%04" PRIX16 ", expected 0x%04" PRIX32,
               supportedVersions, WINPR_CXX_COMPAT_CAST(UINT32, RDSTLS_VERSION_1));
    return FALSE;
  }

  return TRUE;
}

static BOOL rdstls_read_unicode_string(WINPR_ATTR_UNUSED wLog* log, wStream* s, char** str)
{
  WINPR_ASSERT(str);

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

  const UINT16 length = Stream_Get_UINT16(s);

  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), nullptr);
  return (*str) != nullptr;
}

static BOOL rdstls_read_data(WINPR_ATTR_UNUSED wLog* log, wStream* s, UINT16* pLength,
                             const BYTE** pData)
{
  WINPR_ASSERT(pLength);
  WINPR_ASSERT(pData);

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

  const UINT16 length = Stream_Get_UINT16(s);

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

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

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

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;
    }

    WINPR_ASSERT(serverStr);
    WINPR_ASSERT(clientStr);
    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)
{
  WINPR_ASSERT(rdstls);
  WINPR_ASSERT(rdstls->context);

  BOOL rc = FALSE;

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

  const 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;

  {
    const BYTE* serverRedirectionGuid =
        freerdp_settings_get_pointer(settings, FreeRDP_RedirectionGuid);
    const UINT32 serverRedirectionGuidLength =
        freerdp_settings_get_uint32(settings, FreeRDP_RedirectionGuidLength);
    const char* serverUsername = freerdp_settings_get_string(settings, FreeRDP_Username);
    const char* serverDomain = freerdp_settings_get_string(settings, FreeRDP_Domain);
    const char* serverPassword = freerdp_settings_get_string(settings, FreeRDP_Password);

    rdstls->resultCode = RDSTLS_RESULT_SUCCESS;

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

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

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

    if (!rdstls_cmp_str(rdstls->log, "Password", serverPassword, clientPassword))
      rdstls->resultCode = RDSTLS_RESULT_LOGON_FAILURE;
  }
  rc = TRUE;
fail:
  return rc;
}

static BOOL rdstls_process_authentication_request_with_cookie(WINPR_ATTR_UNUSED rdpRdstls* rdstls,
                                                              WINPR_ATTR_UNUSED wStream* s)
{
  // TODO
  WLog_Print(rdstls->log, WLOG_ERROR, "TODO: RDSTLS Cookie authentication not implemented");
  return FALSE;
}

static BOOL rdstls_process_authentication_request(rdpRdstls* rdstls, wStream* s)
{
  if (!Stream_CheckAndLogRequiredLengthWLog(rdstls->log, s, 2))
    return FALSE;

  const UINT16 dataType = Stream_Get_UINT16(s);
  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" PRIX32
                 " or 0x%04" PRIX32,
                 dataType, WINPR_CXX_COMPAT_CAST(UINT32, RDSTLS_DATA_PASSWORD_CREDS),
                 WINPR_CXX_COMPAT_CAST(UINT32, RDSTLS_DATA_AUTORECONNECT_COOKIE));
      return FALSE;
  }

  return TRUE;
}

static BOOL rdstls_process_authentication_response(rdpRdstls* rdstls, wStream* s)
{
  if (!Stream_CheckAndLogRequiredLengthWLog(rdstls->log, s, 6))
    return FALSE;

  const UINT16 dataType = Stream_Get_UINT16(s);
  if (dataType != RDSTLS_DATA_RESULT_CODE)
  {
    WLog_Print(rdstls->log, WLOG_ERROR,
               "received invalid DataType=0x%04" PRIX16 ", expected 0x%04" PRIX32, dataType,
               WINPR_CXX_COMPAT_CAST(UINT32, RDSTLS_DATA_RESULT_CODE));
    return FALSE;
  }

  const UINT32 resultCode = Stream_Get_UINT32(s);
  if (resultCode != RDSTLS_RESULT_SUCCESS)
  {
    WLog_Print(rdstls->log, WLOG_ERROR, "resultCode: %s [0x%08" PRIX32 "]",
               rdstls_result_code_str(resultCode), resultCode);

    UINT32 error = FREERDP_ERROR_CONNECT_UNDEFINED;
    switch (resultCode)
    {
      case RDSTLS_RESULT_ACCESS_DENIED:
        error = FREERDP_ERROR_CONNECT_ACCESS_DENIED;
        break;
      case RDSTLS_RESULT_ACCOUNT_DISABLED:
        error = FREERDP_ERROR_CONNECT_ACCOUNT_DISABLED;
        break;
      case RDSTLS_RESULT_ACCOUNT_LOCKED_OUT:
        error = FREERDP_ERROR_CONNECT_ACCOUNT_LOCKED_OUT;
        break;
      case RDSTLS_RESULT_LOGON_FAILURE:
        error = FREERDP_ERROR_CONNECT_LOGON_FAILURE;
        break;
      case RDSTLS_RESULT_INVALID_LOGON_HOURS:
        error = FREERDP_ERROR_CONNECT_ACCOUNT_RESTRICTION;
        break;
      case RDSTLS_RESULT_PASSWORD_EXPIRED:
        error = FREERDP_ERROR_CONNECT_PASSWORD_EXPIRED;
        break;
      case RDSTLS_RESULT_PASSWORD_MUST_CHANGE:
        error = FREERDP_ERROR_CONNECT_PASSWORD_MUST_CHANGE;
        break;
      default:
        WLog_Print(rdstls->log, WLOG_ERROR,
                   "Unexpected resultCode: [0x%08" PRIX32 "], NTSTATUS=%s, Win32Error=%s",
                   resultCode, GetSecurityStatusString((SECURITY_STATUS)resultCode),
                   Win32ErrorCode2Tag(resultCode & 0xFFFF));
        error = FREERDP_ERROR_CONNECT_UNDEFINED;
        break;
    }

    freerdp_set_last_error_if_not(rdstls->context, error);
    return FALSE;
  }

  return TRUE;
}

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

  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 != nullptr)
      {
        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 [%" PRIu32 "]",
                 rdstls_get_state_str(state), state);
      return FALSE;
  }

  return (transport_write(rdstls->transport, s) >= 0);
}

static int rdstls_recv(WINPR_ATTR_UNUSED rdpTransport* transport, wStream* s, void* extra)
{
  rdpRdstls* rdstls = (rdpRdstls*)extra;

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

  if (!Stream_CheckAndLogRequiredLengthWLog(rdstls->log, s, 4))
    return -1;

  const UINT16 version = Stream_Get_UINT16(s);
  if (version != RDSTLS_VERSION_1)
  {
    WLog_Print(rdstls->log, WLOG_ERROR,
               "received invalid RDSTLS Version=0x%04" PRIX16 ", expected 0x%04" PRIX16,
               version, WINPR_CXX_COMPAT_CAST(UINT32, RDSTLS_VERSION_1));
    return -1;
  }

  const UINT16 pduType = Stream_Get_UINT16(s);
  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;

  WINPR_ASSERT(rdstls);

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

  return FALSE;
}

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

  if (!rdstls_check_state_requirements(rdstls, RDSTLS_STATE_CAPABILITIES))
    return FALSE;

  wStream* s = Stream_New(nullptr, 512);
  if (!s)
    goto fail;

  WINPR_ASSERT(rdstls);
  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;

  if (!rdstls_check_state_requirements(rdstls, RDSTLS_STATE_AUTH_REQ))
    return FALSE;

  wStream* s = Stream_New(nullptr, 4096);
  if (!s)
    goto fail;

  WINPR_ASSERT(rdstls);

  {
    const int res = transport_read_pdu(rdstls->transport, s);
    if (res < 0)
      goto fail;
  }

  {
    const int 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;

  if (!rdstls_check_state_requirements(rdstls, RDSTLS_STATE_AUTH_RSP))
    return FALSE;

  wStream* s = Stream_New(nullptr, 512);
  if (!s)
    goto fail;

  WINPR_ASSERT(rdstls);
  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;

  if (!rdstls_check_state_requirements(rdstls, RDSTLS_STATE_CAPABILITIES))
    return FALSE;

  wStream* s = Stream_New(nullptr, 512);
  if (!s)
    goto fail;

  WINPR_ASSERT(rdstls);

  {
    const int res = transport_read_pdu(rdstls->transport, s);
    if (res < 0)
      goto fail;
  }

  {
    const int 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;

  if (!rdstls_check_state_requirements(rdstls, RDSTLS_STATE_AUTH_REQ))
    return FALSE;

  wStream* s = Stream_New(nullptr, 4096);
  if (!s)
    goto fail;

  WINPR_ASSERT(rdstls);
  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;

  WINPR_ASSERT(rdstls);

  if (!rdstls_check_state_requirements(rdstls, RDSTLS_STATE_AUTH_RSP))
    return FALSE;

  wStream* s = Stream_New(nullptr, 512);
  if (!s)
    goto fail;

  {
    const int res = transport_read_pdu(rdstls->transport, s);
    if (res < 0)
      goto fail;
  }

  {
    const int 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)
{
  WINPR_ASSERT(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 != RDSTLS_RESULT_SUCCESS)
    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)
{
  size_t pduLength = 0;

  switch (dataType)
  {
    case RDSTLS_DATA_PASSWORD_CREDS:
    {
      if (Stream_GetRemainingLength(s) < 2)
        return 0;

      const UINT16 redirGuidLength = Stream_Get_UINT16(s);

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

      if (Stream_GetRemainingLength(s) < 2)
        return 0;

      const UINT16 usernameLength = Stream_Get_UINT16(s);

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

      if (Stream_GetRemainingLength(s) < 2)
        return 0;
      const UINT16 domainLength = Stream_Get_UINT16(s);

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

      if (Stream_GetRemainingLength(s) < 2)
        return 0;
      const UINT16 passwordLength = Stream_Get_UINT16(s);

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

      if (Stream_GetRemainingLength(s) < 2)
        return 0;
      const UINT16 cookieLength = Stream_Get_UINT16(s);

      pduLength = Stream_GetPosition(s) + cookieLength;
    }
    break;
    default:
      WLog_Print(log, WLOG_ERROR, "invalid RDSLTS dataType");
      return -1;
  }

  if (pduLength > SSIZE_MAX)
    return 0;
  return (SSIZE_T)pduLength;
}

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

  if (Stream_GetRemainingLength(s) < 2)
    return 0;

  const UINT16 version = Stream_Get_UINT16(s);
  if (version != RDSTLS_VERSION_1)
  {
    WLog_Print(log, WLOG_ERROR, "invalid RDSTLS version");
    return -1;
  }

  if (Stream_GetRemainingLength(s) < 2)
    return 0;

  const UINT16 pduType = Stream_Get_UINT16(s);
  switch (pduType)
  {
    case RDSTLS_TYPE_CAPABILITIES:
      pduLength = 8;
      break;
    case RDSTLS_TYPE_AUTHREQ:
    {
      if (Stream_GetRemainingLength(s) < 2)
        return 0;

      const UINT16 dataType = Stream_Get_UINT16(s);
      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: 2026-03-04 06:17