cliprdr_utils.c

 
#include <winpr/stream.h>
#include <freerdp/utils/cliprdr_utils.h>
#include <freerdp/channels/cliprdr.h>
 
#include <freerdp/log.h>
#define TAG FREERDP_TAG("utils." CLIPRDR_SVC_CHANNEL_NAME)
 
#define CLIPRDR_FILEDESCRIPTOR_SIZE (4 + 32 + 4 + 16 + 8 + 8 + 520)
#define CLIPRDR_MAX_FILE_SIZE (2U * 1024 * 1024 * 1024)
 
static UINT64 filetime_to_uint64(FILETIME value)
{
  UINT64 converted = 0;
  converted |= (UINT32)value.dwHighDateTime;
  converted <<= 32;
  converted |= (UINT32)value.dwLowDateTime;
  return converted;
}
 
static FILETIME uint64_to_filetime(UINT64 value)
{
  FILETIME converted;
  converted.dwLowDateTime = (UINT32)(value >> 0);
  converted.dwHighDateTime = (UINT32)(value >> 32);
  return converted;
}
 
UINT cliprdr_parse_file_list(const BYTE* format_data, UINT32 format_data_length,
                             FILEDESCRIPTORW** file_descriptor_array, UINT32* file_descriptor_count)
{
  UINT result = NO_ERROR;
  UINT32 count = 0;
  wStream sbuffer;
  wStream* s = nullptr;
 
  if (!format_data || !file_descriptor_array || !file_descriptor_count)
    return ERROR_BAD_ARGUMENTS;
 
  s = Stream_StaticConstInit(&sbuffer, format_data, format_data_length);
  if (!s)
    return ERROR_NOT_ENOUGH_MEMORY;
 
  if (!Stream_CheckAndLogRequiredLength(TAG, s, 4))
  {
    result = ERROR_INCORRECT_SIZE;
    goto out;
  }
 
  Stream_Read_UINT32(s, count); /* cItems (4 bytes) */
 
  if (!Stream_CheckAndLogRequiredLengthOfSize(TAG, s, count, CLIPRDR_FILEDESCRIPTOR_SIZE))
  {
    result = ERROR_INCORRECT_SIZE;
    goto out;
  }
 
  *file_descriptor_count = count;
  *file_descriptor_array = calloc(count, sizeof(FILEDESCRIPTORW));
  if (!*file_descriptor_array)
  {
    result = ERROR_NOT_ENOUGH_MEMORY;
    goto out;
  }
 
  for (UINT32 i = 0; i < count; i++)
  {
    FILEDESCRIPTORW* file = &((*file_descriptor_array)[i]);
 
    if (!cliprdr_read_filedescriptor(s, file))
      goto out;
  }
 
  if (Stream_GetRemainingLength(s) > 0)
    WLog_WARN(TAG, "packed file list has %" PRIuz " excess bytes",
              Stream_GetRemainingLength(s));
out:
 
  return result;
}
 
BOOL cliprdr_read_filedescriptor(wStream* s, FILEDESCRIPTORW* descriptor)
{
  UINT64 tmp = 0;
  WINPR_ASSERT(descriptor);
 
  if (!Stream_CheckAndLogRequiredLength(TAG, s, sizeof(FILEDESCRIPTORW)))
    return FALSE;
 
  Stream_Read_UINT32(s, descriptor->dwFlags); /* flags (4 bytes) */
  Stream_Read_UINT32(s, descriptor->clsid.Data1);
  Stream_Read_UINT16(s, descriptor->clsid.Data2);
  Stream_Read_UINT16(s, descriptor->clsid.Data3);
  Stream_Read(s, &descriptor->clsid.Data4, sizeof(descriptor->clsid.Data4));
  Stream_Read_INT32(s, descriptor->sizel.cx);
  Stream_Read_INT32(s, descriptor->sizel.cy);
  Stream_Read_INT32(s, descriptor->pointl.x);
  Stream_Read_INT32(s, descriptor->pointl.y);
  Stream_Read_UINT32(s, descriptor->dwFileAttributes); /* fileAttributes (4 bytes) */
  Stream_Read_UINT64(s, tmp);                    /* ftCreationTime (8 bytes) */
  descriptor->ftCreationTime = uint64_to_filetime(tmp);
  Stream_Read_UINT64(s, tmp); /* ftLastAccessTime (8 bytes) */
  descriptor->ftLastAccessTime = uint64_to_filetime(tmp);
  Stream_Read_UINT64(s, tmp); /* lastWriteTime (8 bytes) */
  descriptor->ftLastWriteTime = uint64_to_filetime(tmp);
  Stream_Read_UINT32(s, descriptor->nFileSizeHigh); /* fileSizeHigh (4 bytes) */
  Stream_Read_UINT32(s, descriptor->nFileSizeLow);  /* fileSizeLow (4 bytes) */
  return Stream_Read_UTF16_String(s, descriptor->cFileName,
                                  ARRAYSIZE(descriptor->cFileName)); /* cFileName (520 bytes) */
}
 
BOOL cliprdr_write_filedescriptor(wStream* s, const FILEDESCRIPTORW* descriptor)
{
  WINPR_ASSERT(descriptor);
 
  if (!Stream_EnsureRemainingCapacity(s, sizeof(FILEDESCRIPTORW)))
    return FALSE;
 
  Stream_Write_UINT32(s, descriptor->dwFlags); /* flags (4 bytes) */
 
  Stream_Write_UINT32(s, descriptor->clsid.Data1);
  Stream_Write_UINT16(s, descriptor->clsid.Data2);
  Stream_Write_UINT16(s, descriptor->clsid.Data3);
  Stream_Write(s, &descriptor->clsid.Data4, sizeof(descriptor->clsid.Data4));
  Stream_Write_INT32(s, descriptor->sizel.cx);
  Stream_Write_INT32(s, descriptor->sizel.cy);
  Stream_Write_INT32(s, descriptor->pointl.x);
  Stream_Write_INT32(s, descriptor->pointl.y);
  Stream_Write_UINT32(s, descriptor->dwFileAttributes); /* fileAttributes (4 bytes) */
  Stream_Write_UINT64(s, filetime_to_uint64(descriptor->ftCreationTime));
  Stream_Write_UINT64(s, filetime_to_uint64(descriptor->ftLastAccessTime));
  Stream_Write_UINT64(
      s, filetime_to_uint64(descriptor->ftLastWriteTime)); /* lastWriteTime (8 bytes) */
  Stream_Write_UINT32(s, descriptor->nFileSizeHigh);       /* fileSizeHigh (4 bytes) */
  Stream_Write_UINT32(s, descriptor->nFileSizeLow);        /* fileSizeLow (4 bytes) */
  return Stream_Write_UTF16_String(s, descriptor->cFileName,
                                   ARRAYSIZE(descriptor->cFileName)); /* cFileName (520 bytes) */
}
 
UINT cliprdr_serialize_file_list(const FILEDESCRIPTORW* file_descriptor_array,
                                 UINT32 file_descriptor_count, BYTE** format_data,
                                 UINT32* format_data_length)
{
  return cliprdr_serialize_file_list_ex(CB_STREAM_FILECLIP_ENABLED, file_descriptor_array,
                                        file_descriptor_count, format_data, format_data_length);
}
 
UINT cliprdr_serialize_file_list_ex(UINT32 flags, const FILEDESCRIPTORW* file_descriptor_array,
                                    UINT32 file_descriptor_count, BYTE** format_data,
                                    UINT32* format_data_length)
{
  UINT result = NO_ERROR;
  size_t len = 0;
  wStream* s = nullptr;
 
  if (!file_descriptor_array || !format_data || !format_data_length)
    return ERROR_BAD_ARGUMENTS;
 
  if ((flags & CB_STREAM_FILECLIP_ENABLED) == 0)
  {
    WLog_WARN(TAG, "No file clipboard support annouonced!");
    return ERROR_BAD_ARGUMENTS;
  }
 
  s = Stream_New(nullptr, 4 + file_descriptor_count * CLIPRDR_FILEDESCRIPTOR_SIZE);
  if (!s)
    return ERROR_NOT_ENOUGH_MEMORY;
 
  Stream_Write_UINT32(s, file_descriptor_count); /* cItems (4 bytes) */
 
  for (UINT32 i = 0; i < file_descriptor_count; i++)
  {
    const FILEDESCRIPTORW* file = &file_descriptor_array[i];
 
    /*
     * There is a known issue with Windows server getting stuck in
     * an infinite loop when downloading files that are larger than
     * 2 gigabytes. Do not allow clients to send such file lists.
     *
     * https://support.microsoft.com/en-us/help/2258090
     */
    if ((flags & CB_HUGE_FILE_SUPPORT_ENABLED) == 0)
    {
      if ((file->nFileSizeHigh > 0) || (file->nFileSizeLow >= CLIPRDR_MAX_FILE_SIZE))
      {
        WLog_ERR(TAG, "cliprdr does not support files over 2 GB");
        result = ERROR_FILE_TOO_LARGE;
        goto error;
      }
    }
 
    if (!cliprdr_write_filedescriptor(s, file))
      goto error;
  }
 
  Stream_SealLength(s);
 
  Stream_GetBuffer(s, *format_data);
  Stream_GetLength(s, len);
  if (len > UINT32_MAX)
    goto error;
 
  *format_data_length = (UINT32)len;
 
  Stream_Free(s, FALSE);
 
  return result;
 
error:
  Stream_Free(s, TRUE);
 
  return result;
}