cliprdr_common.c

 
#include <winpr/crt.h>
#include <winpr/stream.h>
#include <freerdp/channels/log.h>
 
#define TAG CHANNELS_TAG("cliprdr.common")
 
#include "cliprdr_common.h"
 
static const char* CB_MSG_TYPE_STR(UINT32 type)
{
  switch (type)
  {
    case CB_TYPE_NONE:
      return "CB_TYPE_NONE";
    case CB_MONITOR_READY:
      return "CB_MONITOR_READY";
    case CB_FORMAT_LIST:
      return "CB_FORMAT_LIST";
    case CB_FORMAT_LIST_RESPONSE:
      return "CB_FORMAT_LIST_RESPONSE";
    case CB_FORMAT_DATA_REQUEST:
      return "CB_FORMAT_DATA_REQUEST";
    case CB_FORMAT_DATA_RESPONSE:
      return "CB_FORMAT_DATA_RESPONSE";
    case CB_TEMP_DIRECTORY:
      return "CB_TEMP_DIRECTORY";
    case CB_CLIP_CAPS:
      return "CB_CLIP_CAPS";
    case CB_FILECONTENTS_REQUEST:
      return "CB_FILECONTENTS_REQUEST";
    case CB_FILECONTENTS_RESPONSE:
      return "CB_FILECONTENTS_RESPONSE";
    case CB_LOCK_CLIPDATA:
      return "CB_LOCK_CLIPDATA";
    case CB_UNLOCK_CLIPDATA:
      return "CB_UNLOCK_CLIPDATA";
    default:
      return "UNKNOWN";
  }
}
 
const char* CB_MSG_TYPE_STRING(UINT16 type, char* buffer, size_t size)
{
  (void)_snprintf(buffer, size, "%s [0x%04" PRIx16 "]", CB_MSG_TYPE_STR(type), type);
  return buffer;
}
 
const char* CB_MSG_FLAGS_STRING(UINT16 msgFlags, char* buffer, size_t size)
{
  if ((msgFlags & CB_RESPONSE_OK) != 0)
    winpr_str_append("CB_RESPONSE_OK", buffer, size, "|");
  if ((msgFlags & CB_RESPONSE_FAIL) != 0)
    winpr_str_append("CB_RESPONSE_FAIL", buffer, size, "|");
  if ((msgFlags & CB_ASCII_NAMES) != 0)
    winpr_str_append("CB_ASCII_NAMES", buffer, size, "|");
 
  const size_t len = strnlen(buffer, size);
  if (!len)
    winpr_str_append("NONE", buffer, size, "");
 
  char val[32] = WINPR_C_ARRAY_INIT;
  (void)_snprintf(val, sizeof(val), "[0x%04" PRIx16 "]", msgFlags);
  winpr_str_append(val, buffer, size, "|");
  return buffer;
}
 
static BOOL cliprdr_validate_file_contents_request(const CLIPRDR_FILE_CONTENTS_REQUEST* request)
{
  /*
   * [MS-RDPECLIP] 2.2.5.3 File Contents Request PDU (CLIPRDR_FILECONTENTS_REQUEST).
   *
   * A request for the size of the file identified by the lindex field. The size MUST be
   * returned as a 64-bit, unsigned integer. The cbRequested field MUST be set to
   * 0x00000008 and both the nPositionLow and nPositionHigh fields MUST be
   * set to 0x00000000.
   */
 
  if (request->dwFlags & FILECONTENTS_SIZE)
  {
    if (request->cbRequested != sizeof(UINT64))
    {
      WLog_ERR(TAG, "cbRequested must be %" PRIuz ", got %" PRIu32 "", sizeof(UINT64),
               request->cbRequested);
      return FALSE;
    }
 
    if (request->nPositionHigh != 0 || request->nPositionLow != 0)
    {
      WLog_ERR(TAG, "nPositionHigh and nPositionLow must be set to 0");
      return FALSE;
    }
  }
 
  return TRUE;
}
 
wStream* cliprdr_packet_new(UINT16 msgType, UINT16 msgFlags, size_t dataLen)
{
  WINPR_ASSERT(dataLen < UINT32_MAX);
  wStream* s = Stream_New(nullptr, dataLen + 8ULL);
 
  if (!s)
  {
    WLog_ERR(TAG, "Stream_New failed!");
    return nullptr;
  }
 
  Stream_Write_UINT16(s, msgType);
  Stream_Write_UINT16(s, msgFlags);
  /* Write actual length after the entire packet has been constructed. */
  Stream_Write_UINT32(s, 0);
  return s;
}
 
static void cliprdr_write_file_contents_request(wStream* s,
                                                const CLIPRDR_FILE_CONTENTS_REQUEST* request)
{
  Stream_Write_UINT32(s, request->streamId);      /* streamId (4 bytes) */
  Stream_Write_UINT32(s, request->listIndex);     /* listIndex (4 bytes) */
  Stream_Write_UINT32(s, request->dwFlags);       /* dwFlags (4 bytes) */
  Stream_Write_UINT32(s, request->nPositionLow);  /* nPositionLow (4 bytes) */
  Stream_Write_UINT32(s, request->nPositionHigh); /* nPositionHigh (4 bytes) */
  Stream_Write_UINT32(s, request->cbRequested);   /* cbRequested (4 bytes) */
 
  if (request->haveClipDataId)
    Stream_Write_UINT32(s, request->clipDataId); /* clipDataId (4 bytes) */
}
 
static inline void cliprdr_write_lock_unlock_clipdata(wStream* s, UINT32 clipDataId)
{
  Stream_Write_UINT32(s, clipDataId);
}
 
static void cliprdr_write_lock_clipdata(wStream* s,
                                        const CLIPRDR_LOCK_CLIPBOARD_DATA* lockClipboardData)
{
  cliprdr_write_lock_unlock_clipdata(s, lockClipboardData->clipDataId);
}
 
static void cliprdr_write_unlock_clipdata(wStream* s,
                                          const CLIPRDR_UNLOCK_CLIPBOARD_DATA* unlockClipboardData)
{
  cliprdr_write_lock_unlock_clipdata(s, unlockClipboardData->clipDataId);
}
 
static void cliprdr_write_file_contents_response(wStream* s,
                                                 const CLIPRDR_FILE_CONTENTS_RESPONSE* response)
{
  Stream_Write_UINT32(s, response->streamId); /* streamId (4 bytes) */
  Stream_Write(s, response->requestedData, response->cbRequested);
}
 
wStream* cliprdr_packet_lock_clipdata_new(const CLIPRDR_LOCK_CLIPBOARD_DATA* lockClipboardData)
{
  wStream* s = nullptr;
 
  if (!lockClipboardData)
    return nullptr;
 
  s = cliprdr_packet_new(CB_LOCK_CLIPDATA, 0, 4);
 
  if (!s)
    return nullptr;
 
  cliprdr_write_lock_clipdata(s, lockClipboardData);
  return s;
}
 
wStream*
cliprdr_packet_unlock_clipdata_new(const CLIPRDR_UNLOCK_CLIPBOARD_DATA* unlockClipboardData)
{
  wStream* s = nullptr;
 
  if (!unlockClipboardData)
    return nullptr;
 
  s = cliprdr_packet_new(CB_UNLOCK_CLIPDATA, 0, 4);
 
  if (!s)
    return nullptr;
 
  cliprdr_write_unlock_clipdata(s, unlockClipboardData);
  return s;
}
 
wStream* cliprdr_packet_file_contents_request_new(const CLIPRDR_FILE_CONTENTS_REQUEST* request)
{
  wStream* s = nullptr;
 
  if (!request)
    return nullptr;
 
  s = cliprdr_packet_new(CB_FILECONTENTS_REQUEST, 0, 28);
 
  if (!s)
    return nullptr;
 
  cliprdr_write_file_contents_request(s, request);
  return s;
}
 
wStream* cliprdr_packet_file_contents_response_new(const CLIPRDR_FILE_CONTENTS_RESPONSE* response)
{
  wStream* s = nullptr;
 
  if (!response)
    return nullptr;
 
  s = cliprdr_packet_new(CB_FILECONTENTS_RESPONSE, response->common.msgFlags,
                         4 + response->cbRequested);
 
  if (!s)
    return nullptr;
 
  cliprdr_write_file_contents_response(s, response);
  return s;
}
 
wStream* cliprdr_packet_format_list_new(const CLIPRDR_FORMAT_LIST* formatList,
                                        BOOL useLongFormatNames, BOOL useAsciiNames)
{
  WINPR_ASSERT(formatList);
 
  if (formatList->common.msgType != CB_FORMAT_LIST)
    WLog_WARN(TAG, "called with invalid type %08" PRIx32, formatList->common.msgType);
 
  if (useLongFormatNames && useAsciiNames)
    WLog_WARN(TAG, "called with invalid arguments useLongFormatNames=true && "
                   "useAsciiNames=true. useAsciiNames requires "
                   "useLongFormatNames=false, ignoring argument.");
 
  const UINT32 length = formatList->numFormats * 36;
  const size_t formatNameCharSize =
      (useLongFormatNames || !useAsciiNames) ? sizeof(WCHAR) : sizeof(CHAR);
 
  wStream* s = cliprdr_packet_new(CB_FORMAT_LIST, 0, length);
  if (!s)
  {
    WLog_ERR(TAG, "cliprdr_packet_new failed!");
    return nullptr;
  }
 
  for (UINT32 index = 0; index < formatList->numFormats; index++)
  {
    const CLIPRDR_FORMAT* format = &(formatList->formats[index]);
 
    const char* szFormatName = format->formatName;
    size_t formatNameLength = 0;
    size_t formatNameStrLength = 0;
    if (szFormatName)
    {
      formatNameStrLength = strlen(szFormatName);
      const SSIZE_T wlen = ConvertUtf8ToWChar(szFormatName, nullptr, 0);
      if (wlen < 0)
        goto fail;
      formatNameLength = WINPR_ASSERTING_INT_CAST(size_t, wlen);
    }
 
    size_t formatNameMaxLength = formatNameLength + 1; /* Ensure '\0' termination in output */
    if (!Stream_EnsureRemainingCapacity(s,
                                        4 + MAX(32, formatNameMaxLength * formatNameCharSize)))
      goto fail;
 
    Stream_Write_UINT32(s, format->formatId); /* formatId (4 bytes) */
 
    if (!useLongFormatNames)
    {
      formatNameMaxLength = useAsciiNames ? 32 : 16;
      formatNameLength = MIN(formatNameMaxLength - 1, formatNameLength);
    }
 
    if (szFormatName && (formatNameLength > 0))
    {
      if (useAsciiNames)
      {
        Stream_Write(s, szFormatName, formatNameLength);
        Stream_Zero(s, formatNameMaxLength - formatNameLength);
      }
      else
      {
        const size_t formatNameWriteLength =
            MIN(formatNameStrLength, formatNameMaxLength - 1);
        if (Stream_Write_UTF16_String_From_UTF8(s, formatNameMaxLength - 1, szFormatName,
                                                formatNameWriteLength, TRUE) < 0)
          goto fail;
        Stream_Write_UINT16(s, 0);
      }
    }
    else
      Stream_Zero(s, formatNameMaxLength * formatNameCharSize);
  }
 
  return s;
 
fail:
  Stream_Free(s, TRUE);
  return nullptr;
}
 
UINT cliprdr_read_unlock_clipdata(wStream* s, CLIPRDR_UNLOCK_CLIPBOARD_DATA* unlockClipboardData)
{
  if (!Stream_CheckAndLogRequiredLength(TAG, s, 4))
    return ERROR_INVALID_DATA;
 
  Stream_Read_UINT32(s, unlockClipboardData->clipDataId); /* clipDataId (4 bytes) */
  return CHANNEL_RC_OK;
}
 
UINT cliprdr_read_format_data_request(wStream* s, CLIPRDR_FORMAT_DATA_REQUEST* request)
{
  if (!Stream_CheckAndLogRequiredLength(TAG, s, 4))
    return ERROR_INVALID_DATA;
 
  Stream_Read_UINT32(s, request->requestedFormatId); /* requestedFormatId (4 bytes) */
  return CHANNEL_RC_OK;
}
 
UINT cliprdr_read_format_data_response(wStream* s, CLIPRDR_FORMAT_DATA_RESPONSE* response)
{
  response->requestedFormatData = nullptr;
 
  if (!Stream_CheckAndLogRequiredLength(TAG, s, response->common.dataLen))
    return ERROR_INVALID_DATA;
 
  if (response->common.dataLen > 0)
  {
    response->requestedFormatData = Stream_ConstPointer(s);
    if (!Stream_SafeSeek(s, response->common.dataLen))
      return ERROR_INVALID_DATA;
  }
  return CHANNEL_RC_OK;
}
 
UINT cliprdr_read_file_contents_request(wStream* s, CLIPRDR_FILE_CONTENTS_REQUEST* request)
{
  if (!Stream_CheckAndLogRequiredLength(TAG, s, 24))
    return ERROR_INVALID_DATA;
 
  request->haveClipDataId = FALSE;
  Stream_Read_UINT32(s, request->streamId);      /* streamId (4 bytes) */
  Stream_Read_UINT32(s, request->listIndex);     /* listIndex (4 bytes) */
  Stream_Read_UINT32(s, request->dwFlags);       /* dwFlags (4 bytes) */
  Stream_Read_UINT32(s, request->nPositionLow);  /* nPositionLow (4 bytes) */
  Stream_Read_UINT32(s, request->nPositionHigh); /* nPositionHigh (4 bytes) */
  Stream_Read_UINT32(s, request->cbRequested);   /* cbRequested (4 bytes) */
 
  if (Stream_GetRemainingLength(s) >= 4)
  {
    Stream_Read_UINT32(s, request->clipDataId); /* clipDataId (4 bytes) */
    request->haveClipDataId = TRUE;
  }
 
  if (!cliprdr_validate_file_contents_request(request))
    return ERROR_BAD_ARGUMENTS;
 
  return CHANNEL_RC_OK;
}
 
UINT cliprdr_read_file_contents_response(wStream* s, CLIPRDR_FILE_CONTENTS_RESPONSE* response)
{
  if (!Stream_CheckAndLogRequiredLength(TAG, s, 4))
    return ERROR_INVALID_DATA;
 
  Stream_Read_UINT32(s, response->streamId);   /* streamId (4 bytes) */
  response->requestedData = Stream_ConstPointer(s); /* requestedFileContentsData */
 
  if (response->common.dataLen < 4)
  {
    WLog_WARN(TAG, "dataLen=%" PRIu32 " but expected >= 4", response->common.dataLen);
    return ERROR_INVALID_DATA;
  }
 
  response->cbRequested = response->common.dataLen - 4;
  if (!Stream_CheckAndLogRequiredLength(TAG, s, response->cbRequested))
    return ERROR_INVALID_DATA;
  Stream_Seek(s, response->cbRequested);
  return CHANNEL_RC_OK;
}
 
UINT cliprdr_read_format_list(wLog* log, wStream* s, CLIPRDR_FORMAT_LIST* formatList,
                              BOOL useLongFormatNames)
{
  UINT32 index = 0;
  size_t formatNameLength = 0;
  const char* szFormatName = nullptr;
  const WCHAR* wszFormatName = nullptr;
  wStream sub1buffer = WINPR_C_ARRAY_INIT;
  CLIPRDR_FORMAT* formats = nullptr;
  UINT error = ERROR_INTERNAL_ERROR;
 
  const BOOL asciiNames = (formatList->common.msgFlags & CB_ASCII_NAMES) != 0;
 
  index = 0;
  /* empty format list */
  formatList->formats = nullptr;
  formatList->numFormats = 0;
 
  wStream* sub1 =
      Stream_StaticConstInit(&sub1buffer, Stream_ConstPointer(s), formatList->common.dataLen);
  if (!Stream_SafeSeek(s, formatList->common.dataLen))
    return ERROR_INVALID_DATA;
 
  if (!formatList->common.dataLen)
  {
  }
  else if (!useLongFormatNames)
  {
    const size_t cap = Stream_Capacity(sub1) / 36ULL;
    if (cap > UINT32_MAX)
    {
      WLog_Print(log, WLOG_ERROR, "Invalid short format list length: %" PRIuz "", cap);
      return ERROR_INTERNAL_ERROR;
    }
    formatList->numFormats = (UINT32)cap;
 
    if (formatList->numFormats)
      formats = (CLIPRDR_FORMAT*)calloc(formatList->numFormats, sizeof(CLIPRDR_FORMAT));
 
    if (!formats)
    {
      WLog_Print(log, WLOG_ERROR, "calloc failed!");
      return CHANNEL_RC_NO_MEMORY;
    }
 
    formatList->formats = formats;
 
    while (Stream_GetRemainingLength(sub1) >= 4)
    {
      if (index >= formatList->numFormats)
        goto error_out;
 
      CLIPRDR_FORMAT* format = &formats[index];
 
      Stream_Read_UINT32(sub1, format->formatId); /* formatId (4 bytes) */
 
      /* According to MS-RDPECLIP 2.2.3.1.1.1 formatName is "a 32-byte block containing
       * the *null-terminated* name assigned to the Clipboard Format: (32 ASCII 8 characters
       * or 16 Unicode characters)"
       * However, both Windows RDSH and mstsc violate this specs as seen in the following
       * example of a transferred short format name string: [R.i.c.h. .T.e.x.t. .F.o.r.m.a.t.]
       * These are 16 unicode characters - *without* terminating null !
       */
 
      szFormatName = Stream_ConstPointer(sub1);
      wszFormatName = Stream_ConstPointer(sub1);
      if (!Stream_SafeSeek(sub1, 32))
        goto error_out;
 
      free(format->formatName);
      format->formatName = nullptr;
 
      if (asciiNames)
      {
        if (szFormatName[0])
        {
          /* ensure null termination */
          format->formatName = strndup(szFormatName, 31);
          if (!format->formatName)
          {
            WLog_Print(log, WLOG_ERROR, "malloc failed!");
            error = CHANNEL_RC_NO_MEMORY;
            goto error_out;
          }
        }
      }
      else
      {
        if (wszFormatName[0])
        {
          format->formatName = ConvertWCharNToUtf8Alloc(wszFormatName, 16, nullptr);
          if (!format->formatName)
            goto error_out;
        }
      }
 
      index++;
    }
  }
  else
  {
    wStream sub2buffer = sub1buffer;
    wStream* sub2 = &sub2buffer;
 
    /* Bound must match the read pass below: some clients pad the format list with
     * trailing bytes that do not start another entry. */
    while (Stream_GetRemainingLength(sub1) >= 4)
    {
      size_t rest = 0;
      if (!Stream_SafeSeek(sub1, 4)) /* formatId (4 bytes) */
        goto error_out;
 
      wszFormatName = Stream_ConstPointer(sub1);
      rest = Stream_GetRemainingLength(sub1);
      formatNameLength = _wcsnlen(wszFormatName, rest / sizeof(WCHAR));
 
      if (!Stream_SafeSeek(sub1, (formatNameLength + 1) * sizeof(WCHAR)))
        goto error_out;
      formatList->numFormats++;
    }
 
    if (formatList->numFormats)
      formats = (CLIPRDR_FORMAT*)calloc(formatList->numFormats, sizeof(CLIPRDR_FORMAT));
 
    if (!formats)
    {
      WLog_Print(log, WLOG_ERROR, "calloc failed!");
      return CHANNEL_RC_NO_MEMORY;
    }
 
    formatList->formats = formats;
 
    while (Stream_GetRemainingLength(sub2) >= 4)
    {
      if (index >= formatList->numFormats)
        goto error_out;
 
      size_t rest = 0;
      CLIPRDR_FORMAT* format = &formats[index];
 
      Stream_Read_UINT32(sub2, format->formatId); /* formatId (4 bytes) */
 
      free(format->formatName);
      format->formatName = nullptr;
 
      wszFormatName = Stream_ConstPointer(sub2);
      rest = Stream_GetRemainingLength(sub2);
      formatNameLength = _wcsnlen(wszFormatName, rest / sizeof(WCHAR));
      if (!Stream_SafeSeek(sub2, (formatNameLength + 1) * sizeof(WCHAR)))
        goto error_out;
 
      if (formatNameLength)
      {
        format->formatName =
            ConvertWCharNToUtf8Alloc(wszFormatName, formatNameLength, nullptr);
        if (!format->formatName)
          goto error_out;
      }
 
      index++;
    }
  }
 
  return CHANNEL_RC_OK;
 
error_out:
  cliprdr_free_format_list(formatList);
  return error;
}
 
void cliprdr_free_format_list(CLIPRDR_FORMAT_LIST* formatList)
{
  if (formatList == nullptr)
    return;
 
  if (formatList->formats)
  {
    for (UINT32 index = 0; index < formatList->numFormats; index++)
    {
      free(formatList->formats[index].formatName);
    }
 
    free(formatList->formats);
    formatList->formats = nullptr;
    formatList->numFormats = 0;
  }
}