Introduction
Most encrypted file sharing solutions today use digital certificates, which are designed for applications where there is a large user base not known in advance. However, if someone wants to avoid the cost and the hassle of obtaining and maintaining certificates, there is another possible solution around. In this article, a simple client/server solution is presented for secure private file sharing. The security is provided through symmetric encryption algorithm (AES 128) with shared secret keys. It could be more efficient and practical in many situations, when small groups are established.
Before We Start
Download and install the freeware edition of file sharing SDK, which is free for non-commercial use. The client/server components employ 128-bit AES encryption, without any need for SSL certificates. Instead, it uses a shared secret key, which creates an application-based virtual private network. In addition to standard FTP operations, such as upload, download, rename, delete, etc., the library also offers a number of advanced features, like opening of seekable streams on the server, remote searching for files and text, remote zip compression and decompression.
The Server
Load the sample project FileServer.sln. The server component can be accessed via the control variable c_FileSrv
. Let's review its main properties and methods.
Starting the Server
In order to start accepting connections, we have to go through the following steps:
- Setting the property
ListenningPort
to the number of the listening port. We take the value from the Settings form. The default one in our case is 2345
. - If we want to establish encrypted connections, we have to set the property
SecurityMode
to 2
, and SecretKey
to the value of the crypto key, specified on the settings form. If we don't need encryption, we must set SecurityMode
to 0
. - If we want to use packet compression, we must set
UseCompression
to TRUE
. - Invoke the method
Start()
.
void CbsFileSrvDlg::SetProperties(void)
{
c_FileSrv.put_ListeningPort(dlgSettings.m_Port);
if ((dlgSettings.m_edKey) > "")
{
c_FileSrv.put_SecurityMode(2); c_FileSrv.put_SecretKey(dlgSettings.m_edKey);
}
else
c_FileSrv.put_SecurityMode(0); c_FileSrv.put_UseCompression(dlgSettings.m_chkCompress);
}
void CbsFileSrvDlg::OnBnClickedbtnstart()
{
if (c_FileSrv.Start())
LogMsg("Server started");
else
MessageBox("Cannot start the server!", "Error", MB_OK);
UpdateStatus();
}
Stopping the Server
In order to stop accepting connections, we have to call the method Stop()
. If we have some client currently connected, we should remove them with the method RemoveClient()
.
void CbsFileSrvDlg::OnBnClickedbtnstop()
{
int i;
LVITEM lvi;
c_FileSrv.Stop();
for (i=c_lvClients.GetItemCount()-1; i>= 0; i--)
{
lvi.mask = LVIF_TEXT | LVIF_IMAGE;
lvi.iItem = i;
lvi.iSubItem = 0;
if (c_lvClients.GetItem(&lvi))
c_FileSrv.RemoveClient(int(lvi.iImage));
c_lvClients.DeleteItem(i);
}
UpdateStatus();
LogMsg("Server stopped");
}
Adding a New Connection
When a new client is connected, the event OnNewClient
is fired. At this point, we should take the client information (address/port) and store its handle somewhere for later on use.
void CbsFileSrvDlg::OnNewClientBsfilesrvx(long aHandle)
{
LVITEM lvi;
CString Addr, Port, Tm;
Addr = c_FileSrv.GetClientAddress(aHandle);
Port.Format("%d", c_FileSrv.GetClientPort(aHandle));
int i = c_lvClients.GetItemCount();
lvi.mask = LVIF_TEXT | LVIF_IMAGE | LVIF_PARAM;
lvi.iItem = i;
lvi.iSubItem = 0;
lvi.lParam = aHandle;
lvi.pszText = "Not signed in";
c_lvClients.InsertItem(&lvi);
c_lvClients.SetItemText(i, 1, Addr);
c_lvClients.SetItemText(i, 2, Port);
CTime tm = time(NULL);
Tm = tm.Format("%m/%d/%Y %H:%M:%S");
c_lvClients.SetItemText(i, 3, Tm);
c_lvClients.SetItemText(i, 4, "Connected");
UpdateStatus();
LogMsg("New connection from " + Addr + ":" + Port);
}
Removing Disconnected Clients
When a connected client is disconnected, the event OnClientDisconnected
is fired. At this point, we should release all data associated with this client.
void CbsFileSrvDlg::OnClientDisconnectedBsfilesrvx(long aHandle)
{
int i;
LVITEM lvi;
CString Name, Addr, Port;
i = IndexFromHandle(aHandle);
if (i < 0) return;
lvi.mask = LVIF_TEXT;
lvi.iItem = i;
lvi.iSubItem = 0;
c_lvClients.GetItem(&lvi);
Name = c_lvClients.GetItemText(i, 0);
Addr = c_lvClients.GetItemText(i, 1);
Name = c_lvClients.GetItemText(i, 2);
LogMsg("Disconnected " + Name + " " + Addr + ":" + Port);
c_FileSrv.RemoveClient(int(lvi.iImage));
c_lvClients.DeleteItem(i);
UpdateStatus();
}
Providing the User Password
When a connection is established, the client immediately sends a sign-in request. In our simple implementation, we accept only the default users (Guest
). That's why in the handler of the event OnNeedPassword
, the asked username should be always empty, and we always pass an empty string
for the password value.
void CbsFileSrvDlg::OnNeedPasswordBsfilesrvx(long aHandle,
LPCTSTR aUsername, BOOL* aOkay, BSTR* aPassword)
{
if (aUsername == "")
{
*aOkay = true;
}
else
{
*aOkay = false;
}
}
Signing In
After checking the password, the server component fires the event OnSignin
. Since that moment, the client can perform various file operations.
void CbsFileSrvDlg::OnSigninBsfilesrvx(long aHandle, long aCode)
{
int i;
CString Name, S;
i = IndexFromHandle(aHandle);
if (i < 0) return;
Name = GetUsername(aHandle);
c_lvClients.SetItemText(i, 0, Name);
S.Format("%s %s:%d", Name, c_FileSrv.GetClientAddress(aHandle),
c_FileSrv.GetClientPort(aHandle));
if (aCode == 0)
S = S + " signed in successfully";
else
S = S + " failed sign-in";
LogMsg(S);
}
Listing the Folder Contents
The first thing which the client does after the signing in, is to get the (main) folder content. The handler of the event OnNeedListFolder
is responsible to grant or refuse permission for the operation. There are two input and two output parameters:
aHandle
- Handle of the client object firing the event aPath
- Relative pathname of the folder of interest aOkay
- Set this variable to true
in order to permit the operation aRoot
- If the operation is permitted, write here the root folder assigned to this user
void CbsFileSrvDlg::OnNeedListFolderBsfilesrvx(long aHandle,
LPCTSTR aPath, BOOL* aOkay, BSTR* aRoot)
{
CString Dir = GetAppDir();
*aOkay = true;
*aRoot = Dir.AllocSysString();
LogMsg(GetUsername(aHandle) + ": list folder " + PreSlash(aPath));
}
The end of listing operation is signaled with the event OnListFolderDone
.
Handling of "Create Folder" Requests
When a "create folder" request is received from the client, the event OnNeedNewFolder
is fired. The handler must grant or refuse permission for the operation. The parameters are:
aHandle
- Handle of the client object firing the event aPath
- Relative pathname of the file to be zipped aOkay
- Set this variable to true
in order to permit the operation aRoot
- If the operation is permitted, write here the root folder assigned to this user
void CbsFileSrvDlg::OnNeedZipBsfilesrvx(long aHandle,
LPCTSTR aPath, BOOL* aOkay, BSTR* aRoot)
{
CString Dir = GetAppDir();
*aOkay = true;
*aRoot = Dir.AllocSysString();
LogMsg(GetUsername(aHandle) +
": starting zip operaton" + PreSlash(aPath));
}
The event OnZipDone
informs about the end of the operation.
void CbsFileSrvDlg::OnZipDoneBsfilesrvx(long aHandle, long aCode)
{
LogMsg(GetUsername(aHandle) + ": finishing zip operation");
}
Handling of "Rename File" Requests
When a "rename file" request is received from the client, the event OnNeedRename
is fired. The handler must grant or refuse permission for the operation. The parameters are:
aHandle
- Handle of the client object firing the event aPath
- Relative pathname of the file to be renamed aOkay
- Set this variable to true
in order to permit the operation aRoot
- If the operation is permitted, write here the root folder assigned to this user
void CbsFileSrvDlg::OnNeedRenameFileBsfilesrvx(long aHandle,
LPCTSTR aPath, BOOL* aOkay, BSTR* aRoot)
{
CString Dir = GetAppDir();
*aOkay = true;
*aRoot = Dir.AllocSysString();
LogMsg(GetUsername(aHandle) + ": rename file " + PreSlash(aPath));
}
Handling of "Delete File" Requests
When a "delete file" request is received from the client, the event OnNeedDeleteFile
is fired. The handler must grant or refuse permission for the operation. The parameters are:
aHandle
- Handle of the client object firing the event aPath
- Relative pathname of the file to be deleted aOkay
- Set this variable to true
in order to permit the operation aRoot
- If the operation is permitted, write here the root folder assigned to this user
void CbsFileSrvDlg::OnNeedDeleteFileBsfilesrvx(long aHandle,
LPCTSTR aPath, BOOL* aOkay, BSTR* aRoot)
{
CString Dir = GetAppDir();
*aOkay = true;
*aRoot = Dir.AllocSysString();
LogMsg(GetUsername(aHandle) + ": delete file " + PreSlash(aPath));
}
Handling of Download Requests
When a download request is received from the client, the event OnNeedDownload
is fired. The handler must grant or refuse permission for the operation. The parameters are:
aHandle
- Handle of the client object firing the event aPath
- Relative pathname of the file to be downloaded aOkay
- Set this variable to true
in order to permit the operation aRoot
- If the operation is permitted, write here the root folder assigned to this user
void CbsFileSrvDlg::OnNeedDownloadBsfilesrvx(long aHandle,
LPCTSTR aPath, BOOL* aOkay, BSTR* aRoot)
{
CString Dir = GetAppDir();
*aOkay = true;
*aRoot = Dir.AllocSysString();
LogMsg(GetUsername(aHandle) +
": starting download " + PreSlash(aPath));
}
The event OnDownloadDone
informs about the end of the operation.
void CbsFileSrvDlg::OnDownloadDoneBsfilesrvx(long aHandle,
long aCode)
{
LogMsg(GetUsername(aHandle) + ": finishing download");
}
Handling of Upload Requests
When an upload request is received from the client, the event OnNeedUpload
is fired. The handler must grant or refuse permission for the operation. The parameters are:
aHandle
- Handle of the client object firing the event aPath
- Relative pathname of the file of interest aOkay
- Set this variable to true
in order to permit the operation aRoot
- If the operation is permitted, write here the root folder assigned to this user
void CbsFileSrvDlg::OnNeedUploadBsfilesrvx(long aHandle,
LPCTSTR aPath, BOOL* aOkay, BSTR* aRoot)
{
CString Dir = GetAppDir();
*aOkay = true;
*aRoot = Dir.AllocSysString();
LogMsg(GetUsername(aHandle) + ": starting upload " +
PreSlash(aPath));
}
The event OnUploadDone
informs about the end of the operation.
void CbsFileSrvDlg::OnUploadDoneBsfilesrvx(long aHandle, long aCode)
{
LogMsg(GetUsername(aHandle) + ": finishing upload");
}
Handling of Zipping Requests
When a zipping request is received from the client, the event OnNeedZip
is fired. The handler must grant or refuse permission for the operation. The parameters are:
aHandle
- Handle of the client object firing the event aPath
- Relative pathname of the file to be zipped aOkay
- Set this variable to true
in order to permit the operation aRoot
- If the operation is permitted, write here the root folder assigned to this user
void CbsFileSrvDlg::OnNeedZipBsfilesrvx(long aHandle,
LPCTSTR aPath, BOOL* aOkay, BSTR* aRoot)
{
CString Dir = GetAppDir();
*aOkay = true;
*aRoot = Dir.AllocSysString();
LogMsg(GetUsername(aHandle) + ": starting zip operaton" +
PreSlash(aPath));
}
The event OnZipDone
informs about the end of the operation.
void CbsFileSrvDlg::OnZipDoneBsfilesrvx(long aHandle, long aCode)
{
LogMsg(GetUsername(aHandle) + ": finishing zip operation");
}
Handling of Unzipping Requests
When an unzipping request is received from the client, the event OnNeedUnzip
is fired. The handler must grant or refuse permission for the operation. The parameters are:
aHandle
- Handle of the client object firing the event aPath
- Relative pathname of the file to be unzipped aOkay
- Set this variable to true
in order to permit the operation aRoot
- If the operation is permitted, write here the root folder assigned to this user
void CbsFileSrvDlg::OnNeedUnzipBsfilesrvx(long aHandle,
LPCTSTR aPath, BOOL* aOkay, BSTR* aRoot)
{
CString Dir = GetAppDir();
*aOkay = true;
*aRoot = Dir.AllocSysString();
LogMsg(GetUsername(aHandle) + ": starting unzip operaton" +
PreSlash(aPath));
}
The event OnUnzipDone
informs about the end of the operation
void CbsFileSrvDlg::OnUnzipDoneBsfilesrvx(long aHandle, long aCode)
{
LogMsg(GetUsername(aHandle) + ": finishing unzip operation");
}
The Client
Load the sample project FileClient.sln. The client component can be accessed via the control variable c_FileCln
. Let's review its main properties and methods.
Connecting to the Server
In order to establish a new connection to the server, we have to go through the following steps:
- If we want encrypted connections, we have to set the property
SecurityMode
to 2
, and SecretKey
to the value of the crypto key, specified on the "Connect
" form. If we don't need encryption, we just set SecurityMode
to 0. - If we want to use packet compression, we must set the property
UseCompression
to TRUE
. - Invoking the method
Connect(Addr, Port)
, passing as parameters the IP address/Domain name and the listening port of the server.
void CbsFileClnDlg::OnBnClickedbtnconnect()
{
CString Msg;
if (dlgConnect.DoModal() != IDOK) return;
if (dlgConnect.m_edKey > "")
{
c_FileCln.put_SecurityMode(2); c_FileCln.put_SecretKey(dlgConnect.m_edKey);
}
else
c_FileCln.put_SecurityMode(0);
c_FileCln.put_UseCompression(dlgConnect.m_chkCompress);
if (!c_FileCln.Connect(dlgConnect.m_edHost, dlgConnect.m_edPort))
{
Msg.Format("Error Code: %d", c_FileCln.get_LastError());
AfxMessageBox(Msg);
}
UpdateStatus();
}
Disconnecting from the Server
In order to end a connection to the server, we have to call the method Disconnect()
.
void CbsFileClnDlg::OnBnClickedbtndisconnect()
{
if (!c_FileCln.get_Connected()) return;
c_FileCln.Disconnect();
OnDisconnectedBsfileclnx();
}
Listing Folder Contents
The method ListFolder()
sends a request for folder contents:
void CbsFileClnDlg::ListFolder(void)
{
CString S;
if (m_NowList) return;
c_stFolder.GetWindowText(S);
if (c_FileCln.ListFolder(S))
{
m_NowList = true;
c_lvFiles.DeleteAllItems();
c_btnList.EnableWindow(false);
if (S > "\\")
OnHaveListItemBsfileclnx("..", true, 0, 0, 0, 0);
}
else
CheckError(c_FileCln.get_LastError());
}
The event OnHaveListItem
is fired for each available folder item.
void CbsFileClnDlg::OnHaveListItemBsfileclnx(LPCTSTR aName,
BOOL aFolder, long aSizeLo, long aSizeHi, long aTimeLo, long aTimeHi)
{
LVITEM lvi;
CString Sz, Tm;
FILETIME ft;
int i = c_lvFiles.GetItemCount();
lvi.mask = LVIF_TEXT | LVIF_IMAGE;
lvi.iItem = i;
lvi.iSubItem = 0;
if (aFolder)
{
lvi.iImage = 0;
Sz = "";
}
else
{
lvi.iImage = 1;
Sz.Format("%d", aSizeLo);
}
lvi.pszText = (LPTSTR)(LPCTSTR) aName;
c_lvFiles.InsertItem(&lvi);
if (aName == "..")
Tm = "";
else
{
ft.dwLowDateTime = aTimeLo;
ft.dwHighDateTime = aTimeHi;
CTime tm(ft, -1);
Tm = tm.Format("%m/%d/%Y %H:%M:%S");
}
c_lvFiles.SetItemText(i, 1, Sz);
c_lvFiles.SetItemText(i, 2, Tm);
}
The end of the list is signaled with the event OnListFolderDone()
.
void CbsFileClnDlg::OnListFolderDoneBsfileclnx(long aCode)
{
m_NowList = false;
CheckError (aCode);
UpdateButtons();
}
Creating a New Folder
The method CreateFolder()
sends a request to create a new folder.
void CbsFileClnDlg::OnBnClickedbtnnew()
{
CString Nm, Fol;
if (!GetInputText(Nm, "Create folder", "Folder name:")) return;
c_stFolder.GetWindowText(Fol);
Nm = AddSlash(Fol) + Nm;
if (c_FileCln.CreateFolder(Nm))
m_NowCreateFolder = true;
else
CheckError(c_FileCln.get_LastError());
UpdateButtons();
}
The event OnCreateFolderDone()
is fired when the folder is created.
void CbsFileClnDlg::OnCreateFolderDoneBsfileclnx(long aCode)
{
m_NowCreateFolder = false;
CheckError(aCode);
UpdateButtons();
if (aCode > 0) return;
ListFolder();
}
Renaming a File
The method RenameFile()
sends a request to rename a file on the server.
void CbsFileClnDlg::OnBnClickedbtnrename()
{
CString Nm, Fol;
if (c_lvFiles.GetSelectedCount() == 0) return;
if (GetImageIndex(GetSelectedIndex()) == FolderImgIdx)
{
if (!GetInputText(Nm, "Rename folder", "New name:")) return;
Nm = AddSlash(GetCurFol()) + Nm;
if (c_FileCln.RenameFolder(AddSlash(GetCurFol()) +
c_lvFiles.GetItemText(GetSelectedIndex(), 0), Nm))
m_NowRenameFolder = true;
else
CheckError(c_FileCln.get_LastError());
}
else
{
if (!GetInputText(Nm, "Rename file", "New name:")) return;
Nm = AddSlash(GetCurFol()) + Nm;
if (c_FileCln.RenameFile(AddSlash(GetCurFol()) +
c_lvFiles.GetItemText(GetSelectedIndex(), 0), Nm))
m_NowRenameFile = true;
else
CheckError(c_FileCln.get_LastError());
}
UpdateButtons();
}
The event OnRenameFileDone()
is fired when the confirmation is received.
void CbsFileClnDlg::OnRenameFileDoneBsfileclnx(long aCode)
{
m_NowRenameFile = false;
CheckError(aCode);
UpdateButtons();
if (aCode > 0) return;
ListFolder();
}
Deleting a File
The method DeleteFile()
sends a request to delete a file.
void CbsFileClnDlg::OnBnClickedbtndelete()
{
CString Nm, Fol;
if (c_lvFiles.GetSelectedCount() == 0) return;
if (GetImageIndex(GetSelectedIndex()) == FolderImgIdx)
{
if (c_FileCln.DeleteFolder(AddSlash(GetCurFol()) +
c_lvFiles.GetItemText(GetSelectedIndex(), 0)))
m_NowDeleteFolder = true;
else
CheckError(c_FileCln.get_LastError());
}
else
{
if (c_FileCln.DeleteFile(AddSlash(GetCurFol()) +
c_lvFiles.GetItemText(GetSelectedIndex(), 0)))
m_NowDeleteFile = true;
else
CheckError(c_FileCln.get_LastError());
}
UpdateButtons();
}
The event OnDeleteFileDone()
is fired when the confirmation is received.
void CbsFileClnDlg::OnDeleteFileDoneBsfileclnx(long aCode)
{
m_NowDeleteFile = false;
CheckError(aCode);
UpdateButtons();
if (aCode > 0) return;
ListFolder();
}
Downloading a File
The method Download()
sends a request to download a file.
void CbsFileClnDlg::GoDownload(void)
{
CString Nm, Fol;
if (c_lvFiles.GetSelectedCount() == 0) return;
if (GetImageIndex(GetSelectedIndex()) == FolderImgIdx) return;
Nm = c_lvFiles.GetItemText(GetSelectedIndex(), 0);
CFileDialog FileDlg(FALSE, "", Nm, 0, NULL);
if( FileDlg.DoModal() != IDOK ) return;
m_DnldFile = Nm;
if (c_FileCln.Download(AddSlash(GetCurFol()) + Nm,
ExtractFilePath(FileDlg.GetPathName())))
{
m_NowDownload = true;
c_stDownload.SetWindowText(m_DnldFile + ": handshaking");
}
else
CheckError (c_FileCln.get_LastError());
UpdateStatus();
}
The event OnDownloadProgress()
informs about the download progress.
void CbsFileClnDlg::OnDownloadProgressBsfileclnx(long aCountLo,
long aCountHi, long aSizeLo, long aSizeHi)
{
CString S;
S.Format("%s - %d/%d", m_DnldFile, aCountLo, aSizeLo);
c_stDownload.SetWindowText(S);
}
The event OnDownloadDone()
is fired when the download is completed.
void CbsFileClnDlg::OnDownloadDoneBsfileclnx(long aCode)
{
if (aCode == 0)
c_stDownload.SetWindowText(m_DnldFile + " - Done.");
else
c_stDownload.SetWindowText(m_DnldFile +
" - Aborted: " + ErrorText(aCode));
m_NowDownload = false;
UpdateButtons();
}
Uploading a File
The method Upload()
sends a request to upload a file.
void CbsFileClnDlg::OnBnClickedbtnupload()
{
CFileDialog FileDlg(TRUE, "", NULL, 0, NULL);
if( FileDlg.DoModal() != IDOK ) return;
m_UpldFile = FileDlg.GetFileName();
if (c_FileCln.Upload(FileDlg.GetPathName(), GetCurFol()))
{
m_NowUpload = true;
m_UpldFol = GetCurFol();
c_stUpload.SetWindowText(m_UpldFile + ": handshaking");
}
else
CheckError (c_FileCln.get_LastError());
UpdateStatus();
}
The event OnUploadProgress()
provides information about the upload progress.
void CbsFileClnDlg::OnUploadProgressBsfileclnx(long aCountLo,
long aCountHi, long aSizeLo, long aSizeHi)
{
CString S;
S.Format("%s - %d/%d", m_UpldFile, aCountLo, aSizeLo);
c_stUpload.SetWindowText(S);
}
The event OnUploadDone()
is fired when the upload operation is completed.
void CbsFileClnDlg::OnUploadDoneBsfileclnx(long aCode)
{
if (aCode == 0)
c_stUpload.SetWindowText(m_UpldFile + " - Done.");
else
c_stUpload.SetWindowText(m_UpldFile + " - Aborted: " +
ErrorText(aCode));
m_NowUpload = false;
UpdateButtons();
if (m_UpldFol == GetCurFol())
ListFolder();
}
Zipping
The Zip
method starts a new compression operation.
Private Sub btnZip_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnZip.Click
Dim Nm As String
Nm = InputBox("Zip file name", "Zipping")
If Nm = "" Then Exit Sub
If ExtractFileExt(Nm) = "" Then
Nm = Nm + ".zip"
End If
If FileCln.Zip(AddSlash(txtFolder.Text) + Nm, _
AddSlash(txtFolder.Text) + _
lvFiles.SelectedItems(0).Text) Then
NowZip = True
ZipFile = Nm
ZipFol = txtFolder.Text
txtZip.Text = "Handshaking..."
Else
CheckError(FileCln.LastError)
End If
UpdateStatus()
End Sub
We prompt the user for the zip file name, and if it's not empty, we call the Zip
method with two parameters. The first one is the relative pathname of the zip archive, the second one is the relative pathname of the file to be compressed. If the request is successful, we remember the current folder and the zip file name. Otherwise, we show an error message.
Showing the Progress Information
The event OnZipProgress
event provides progress information about the zip operation.
void CbsFileClnDlg::OnZipProgressBsfileclnx(long aFileCount,
long aFileTotal, long aByteCountLo, long aByteCountHi,
long aByteTotalLo, long aByteTotalHi)
{
CString S;
S.Format("%s - %d/%d", m_ZipFile, aByteCountLo, aByteTotalLo);
c_stZip.SetWindowText(S);
}
We display two counters (low 32 bits only) - the number of bytes compressed so far and the total number of requested bytes.
OnZipDone
The event OnZipDone
reports the result of the zip operation.
void CbsFileClnDlg::OnZipDoneBsfileclnx(long aCode)
{
if (aCode == 0)
{
c_stZip.SetWindowText(m_ZipFile + " - Done."); }
else
c_stZip.SetWindowText(m_ZipFile +
" - Aborted: " + ErrorText(aCode)); m_NowZip = false;
if (m_ZipFol == GetCurFol())
ListFolder();
UpdateButtons();
}
We display the completion status of the zip operation, and if the current folder is affected, we update the file list.
Unzip
The Unzip
method starts a new decompression operation.
void CbsFileClnDlg::OnBnClickedbtnunzip()
{
CString Arc, Nm, Fol;
if (c_lvFiles.GetSelectedCount() == 0) return;
if (GetImageIndex(GetSelectedIndex()) == FolderImgIdx) return;
Arc = c_lvFiles.GetItemText(GetSelectedIndex(), 0);
if (ExtractFileExt(Arc) != ".zip") return;
if (!GetInputText(Fol, "Unzipping",
"Extract to folder (leave blank for current):")) return;
if (c_FileCln.Unzip(AddSlash(GetCurFol()) + Arc, Fol))
{
m_NowUnzip = true; m_UnzipFile = Arc; m_UnzipFol = GetCurFol(); c_stUnzip.SetWindowText(m_UnzipFile + ": handshaking");
}
else
CheckError (c_FileCln.get_LastError());
UpdateStatus();
}
We prompt the user for the destination folder, where the extracted file will be placed. Then we call the Unzip
method with two parameters. The first one is the relative pathname of the zip archive, the second one is the relative pathname of the destination folder. If the request is successful, we remember the current folder and the zip file name. Otherwise, we show an error message.
OnUnzipProgress
OnUnzipProgress
event provides progress information about the unzip operation.
void CbsFileClnDlg::OnUnzipProgressBsfileclnx(long aFileCount,
long aFileTotal, long aByteCountLo, long aByteCountHi,
long aByteTotalLo, long aByteTotalHi)
{
CString S;
S.Format("%s - %d/%d", m_ZipFile, aByteCountLo, aByteTotalLo);
c_stUnzip.SetWindowText(S);
}
We display two counters (low 32 bits only) - the number of bytes decompressed so far, and the total number of bytes in the archive.
OnUnzipDone
OnUnzipDone
event reports the result of the unzip operation.
void CbsFileClnDlg::OnUnzipDoneBsfileclnx(long aCode)
{
if (aCode == 0)
{
c_stUnzip.SetWindowText(m_UnzipFile + " - Done."); }
else
c_stUnzip.SetWindowText(m_UnzipFile + " - Aborted: " +
ErrorText(aCode)); m_NowUnzip = false;
if (m_UnzipFol == GetCurFol())
ListFolder();
UpdateButtons();
}
We display the completion status of the unzip operation, and if the current folder is affected, we update the file list.
The Bottom Line
Nowadays, the Internet is insecure for a variety of reasons. Exchanging sensitive information could be a problem in many situations. In this article, we have presented one simple and affordable solution for secure private file sharing without the need for certificates.
License
This article has no explicit license attached to it, but may contain usage terms in the article text or the download files themselves. If in doubt, please contact the author via the discussion board below.
A list of licenses authors might use can be found here.