I'm in the process of creating a utility to backup user's media files. The media isn't being shared etc its only a backup utility.
I'm trying to think of the best way to protect users from ISPs accusing them of downloading illegal media files by using some sort of secure connection.
The utility is written in C++ using the Qt lib and so far I've only been able to find the QtSslSocket component for secure connections. The domain already has a valid SSL certificate for the next few years.
Can anyone suggest the best way to go about implementing this from both the server and client side. i.e what does the server need to have in place and is there anything in particular the backup utility needs to implement from the client side to ensure secure transactions?
Are there any known, stable sftp or ftps servers available etc?
As far as I know, Qt doesn't have support for secure FTP transfers.
Not sure what other info. would be useful to make the question any clearer but any advice or help pointing me in the right direction will be most welcomed.
EDIT I'm also Java competent so a Java solution will work just as well...
As Martin wrote, you can wrap client. But if you don't want to do that, you can use libssh.
I searched for some sort of solution to this for a couple days and then forgot about the problem. Then today I stumbled across this little gem in the Qt-Creator source Utils::ssh, includes support for SFTP, plain-old SSH, and all sorts of goodies.
Disentangling stuff from Qt-Creator can be a pain, but having gone through this process it amounts to grabbing Botan (one of the other libs in QT-Creator) + Utils.
When it rains, it pours, I find two solutions to this problem in an hour - http://nullget.sourceforge.net/ (Requires Chinese translation), but from their summary:
NullGet is written with Qt, runs on
multiple platforms, the GUI interface
of the multi-threaded multi-protocol
HTTP download software. Use NullGet
can easily download a variety of
network protocol data stream, faster
download speeds, support for HTTP, the
protocol currently supported are:
HTTP, HTTPS, FTP, MMS, RTSP. And it
can run on most current popular
operating systems including Windows,
Linux, FreeBSD and so on.
Easiest way would be to just wrap a commandline sftp client with a Qt front end.
On the server any ftp server should do sftp pretty much out of the box.
As Synthesizerpatel says Qt Creator implements SFTP. So I have isolated the library that contains SSH and SFTP and I have created a new project named QSsh in Github (https://github.com/lvklabs/QSsh). The aim of the project is to provide SSH and SFTP support for any Qt Application.
I have written an example on how to upload a file using SFTP in examples/SecureUploader/
I hope it might be helpful
Related
How can I upload a file in FTP in segmented way ? Is there any open source tool/library so that I can use it?.
Is there any server side change needed to combine the uploads? Currently I am using vsftpd.
The first thing to consider is that segmented transfers are not considered to be good net citizen behaviour. (i.e. you are gaming the system by setting up multi downloads on a shared link, gaining more than your fair share of bandwidth) As such, the protocol definitions do not support specifically segmented upload. (Or download for that matter) Resume yes.
Segmented DOWNLOAD is a hack by some tools that use the RESUME function of the protocol to transfer different parts of the same file at the same time.. this behaviour has a "NON-STANDARD" and not the intention of the protocol specifications.
Segmented UPLOAD is possible but the client AND ftpd server (or whatever protocol server your using) would need to support this NO-STANDARD and frowned upon implementation.
Again, this is not supported specifically in any standards as such poor behaviour is not encouraged by an open standard.
HOWEVER, you will find tools like lftp that support segmented ftp downloads. But currently, I have not seen any implementation of segmented upload that uses common open protocols like ftp.
I did find a java (Custom open source) based udp tool that did this, but udp needs tcp fallback if you want reliability in the internet. (udp is dropped by some internet gateways)
In FTP protocol, you can implement a transfer by parts using REST command.
The REST command defines offset in a file, where transfer starts. You then transfer as many bytes as you want. And then you can restart the transfer again from a further offset.
vsftpd server supports REST command.
I have a C++ program which I want to use on my clients machines. However, some of my clients are behind proxies. Therefore, I want my program to automatically detect these proxies.
I have tried many solutions, such as reading the registry for the proxy settings, trying the Windows API's, etc.
However none of them have worked out well. E.g. the registry sometimes holds the url for the PAC-file and sometimes the actual proxy-address itself. Besides that, I haven't been able to find any username and password related to the proxy if it is set on the client machine (which some users say they have).
So, basically my question is:
How can I automatically determine the proxy settings of my clients in C++ so I can use the proxy-settings in my LibCurl requests later on regarding:
Proxy-address
Proxy-port
Proxy-User
Proxy-Password
I can't get it to work and I have been trying it for two weeks now without any improvement...
You can not read proxy setting in a generic way, since every application is free to store it in any way it wants. You should be able to read Internet Explorer proxy by using WinHttpGetIEProxyConfigForCurrentUser function, and it would also work for users browsers which use this setting, like Google Chrome.
How can I automatically determine the proxy settings of my clients in C++ so I can use the proxy-settings in my LibCurl requests?
libproxy is the answer!
Libproxy home page on GitHub
Libproxy repo on GitHub
It has these features according to the home page:
support for all major platforms: Windows, Mac and Linux/UNIX (see upcoming 0.4 release)
extremely small core footprint
no external dependencies within libproxy core (libproxy plugins may have dependencies)
only 3 functions in the stable-ish external API (1.0 will offer full stability)
dynamic adjustment to changing network topology
a standard way of dealing with proxy settings across all scenarios
a sublime sense of joy and accomplishment
So, I have a desktop application and I want it to be able to check a website for new versions of itself. I am completely new to sockets (Windsocks and Berkeley), so before I invest time learning network programming I want some guidance to point me in the right direction.
The application is going to pretty much download an installation file from its website. The connection will not be secure as it doesn't matter if users can see it or not. Also the application's website will most likely be hosted # godaddy (in case somebody wants to be specific).
So my questions are; What technology should I be looking into, FTP, TCP or UDP? What are some things I should keep in mind as far as the client/server communication when it comes to file transfer with a remote server? Does anybody knows if godaddy allows this type of thing?
PS. If you think this might be a little too much to accomplish without enough theoretical/technical background, then please don't hesitate to recommend a book.
Use HTTP, and use a library to download a URL to a file. This should take 1-5 lines of code.
Why build a file transfer protocol yourself using sockets? Everything you need is built-in with HTTP. There are pre-made clients and servers available.
We are developing win-mac file sync installer which is quite similar to Dropbox. The installer is built with c++ and QT. We had a use case, where if the internet is disconnected(plugged out network cable (or) not connected to any wifi) so basically no access to web, During this case we need to make the installer into offline.
I tried few approaches like polling continuously to our web servers. If we are not able to reach then we detect as internet dis-connectivity. Due to some reasons we wanted to have clean native implementation which will look for machines network connectivity.
I even tried http://msdn.microsoft.com/en-us/library/aa965303%28VS.85%29.aspx for windows but this is failing in wifi cases even though we don't connect to wifi this example is saying "Network connected".
Can anyone suggest other alternatives. Platform specific solutions also invited.
You probably want to look at INetworkManager::GetConnectivity, and check for NLM_CONNECTIVITY_IPV4_INTERNET or NLM_CONNECTIVITY_IPV6_INTERNET in the response.
I am needing to implement email notifications for a C++ project. Basically a user provides all the relevant information for their email account and on certain events this component would fire off an email. Ideally I would like to find a small cross platform open source command line project that I can exec from within my project and parse the output. Something like blat but it would also support SSL connections and can be used in both Windows(XP and 2003) and Linux (Ubuntu 6.06 and 8.04)
I could also use a library if it were simple enough and licensed under a commercial friendly license, but would be open to hearing all suggestions.
Thank you very much in advance for any recommendations
(A) One option is to use XMail:
http://www.xmailserver.org/
The readme file has instructions of how to build it in Linux and Windows:
http://www.xmailserver.org/Readme.html
If you look at the forums:
http://xmailforum.homelinux.net/
or do some Google searches you should be able to find more information on how to use it.
(B) Another, possibly easier option, would be to just make your application connect to and use an external SMTP server to send your notifications.
To compose the email libmime (http://www.mozilla.org/mailnews/arch/libmime-description.html) can be helpful.
To send the mail libsmtp (http://libsmtp.berlios.de/) can be used.
All the protocol and SSL code for my email client is available in Lgi:
http://www.memecode.com/lgi.php
It's LGPL, so you could use it as a DLL/SO. However it's not packaged ready to use binaries, you'd have to build it yourself and write some glue using the SMTP and MIME code. The SSL sockets stuff uses OpenSSL and works on both Linux and Windows.
I ended up using the Perl script sendEmail. A windows binary was available and building a new binary after modifying the Perl script was not too hard to do at all. The script also had no issues running in the LTE Ubuntu environments after the required Debian packages were installed.