I have an application which statically linked with all dependent libraries and at the end I have a single binary file for Windows and Linux.
Is there a way to set ca certificate at compile time the content wil be included together with binary and it will not be necessary to move it together with application binary.
If you use the native SSL library on Windows (sometimes referred to as winssl), there's no need to ship any CA cert at all since curl will then use the internal one Windows features.
If you built libcurl to use OpenSSL, you can set a callback to verify the CA with a fixed built-in CA store. Showed in the cacertinmem example on the curl web site using the CURLOPT_SSL_CTX_FUNCTION option.
Shipping an app with a fixed internal CA cert storage might be troublesome when the services your app are using update/change their certs along the way, so maybe using an external file that you can update occasionally is still a better idea?
Related
The TL;DR version
I'd like to know:
Where does the specification for the use of ECDHE get defined (in a cert parameter or a server configuration of SSL contexts, or elsewhere)?
In a non-home-rolled certificate setup, who's responsibility is it to define the ECDHE public and private information (the end user or cert provider)?
Can an existing Certificate which does not appear to use ECDHE be made to without causing issues with the Certificate?
Are there any examples of someone using SSL in Boost::ASIO with an ECDHE setup?
The Longer Version
We've been building an application which is using a proper-paid-for certificate from an external Cert Authority. The application uses a home-rolled server setup based off of Boost ASIO and Boost Beast, and we only recently noticed it doesn't play nice with iOS - ASIO says there is no shared cipher.
Reading into how TLS works has led me to the fact that some part of our server was preventing us from serving TLS using the ECDHE-* suite of ciphers (which iOS seems to want) - but I'm having difficulty in figuring out how to wrangle ASIO and our current cert/key into serving ECDHE.
What I've tried:
Using the same cert and key, adding in the results of openssl dhparam into ASIO using set_tmp_dh, then specifying ciphers. Curl reports that this allows a connection using DHE but not ECDHE. Specifying ciphers that only use ECDHE causes errors when connecting.
Trying to pass the output of openssl ecparam to ASIO using a similar method to the above. I've not been able to format something that ASIO accepts.
Trying to see if there is a way you can use the output of openssl ecparam with another combining function to modify the original cert into one that uses ECDHE. I clued onto this one from the OpenSSL wiki suggesting that if the cert does not contain the line ASN1 OID: prime256v1 (or a similar named curve), then it is not suitable for ECDHE usage.
At this point I'm unsure as to where the issue truly lies (in ASIO, in the certificates or in how I'm putting it all together) and most of the information on the internet I can find relates to home-rolling everything from scratch, rather than working with existing certs.
Update 11/05/19
https://github.com/chriskohlhoff/asio/pull/117 pulled in changes for ASIO with ECDHE. Will need to wait a while to see which Boost lib version it makes it into.
Original Answer
I seem to have found an answer for any googlers - ASIO does not appear to support ECDHE natively at the time of writing. This issue from the main repo suggests that ECDHE is on the cards for support but is not yet implemented.
Here is a link to the ECDHE implementation that's been waiting to be merged since 2016: https://github.com/chriskohlhoff/asio/pull/117.
+1 to get the attention of the Boost ASIO maintainer; he's been pretty slow with it.
Novice to Qt and developing a cross platform app, which requires SSL authentication from the server as well as client sides The .pem based encryption is working on Linux, Android, Windows. However there are problems with Mac OSX. Our code looks like below:
QFile privateKeyFile(":/Certificate.pem"); // --> has certificate + key
privateKeyFile.open(QIODevice::ReadOnly | QIODevice::Text);
setLocalCertificateChain(QSslCertificate::fromPath(":/Certificate.pem", QSsl::Pem));
setPrivateKey(QSslKey(privateKeyFile.readAll(), QSsl::Rsa));
In above code privateKey().isNull() returns true for Mac. When we referred this post, it says that Mac doesn't support .pem based encryption.
The Secure Transport back-end to curl only supports client IDs that are in PKCS#12 (P12) format; it does not support client IDs in PEM format because Apple does not allow us to create a security identity from an identity file in PEM format without using a private API. And we can't use the private API, because apps that use private API are not allowed in any of Apple's app stores.
With my limited understanding, I interpreted that .pem is not a good idea for SSL communication with the server. Please stop me if it's wrong!
Hence, we decided to move to .pfx for all the platforms. We already had a .pfx file with a passphrase. We converted above code to be compatible with .pfx (i.e. "Certificate.pfx", we had this old file along with "Certificate.pem"). Instead of QSsl::Pem, we tried QSsl::Der. But as expected, it didn't work. However, there was no encryption error either, but we are sure that we are doing something wrong. :-)
We referred this post and try to regenerate a .pfx from .pem, but that also didn't help.
QSslCertificate::importPkcs12 fails to parse PFX file
In above case, the QSslCertificate::importPkcs12() returns false for the original .pfx file. Even if we generate a new .pfx from the command line, that also fails for the above function.
Question: Can someone help with exact way of performing the .pfx encryption with the server?
.pem authentication is also fine.
Note:
Server supports both .pfx & .pem. That we confirmed with regular C OpenSSL libraries. But we want to achieve it using Qt.
We are open to formats other than .pfx, should they work in all the platforms
DISCLAIMER: I am writing this from the top of my mind, since I don't personally own a Mac and cannot verify it anymore.
We had this exact problem about a year or two ago at my last job.
It all boils down to Apple dropping support for OpenSSL.
Because of that, Qt switched from OpenSSL backend to Secure Transport backend on Mac with Qt5.6. Now the Secure Transport implementation is lacking some features. For example we were not able to load private key pem-files. I think switching from PKCS#8 to PKCS#1 helped, which can both be stored in .pem files and look almost identical, so that took a while to figure out.
We also noticed that a successfully loaded private key will be stored inside the Mac's key store and could be viewed and exported from there by the user, which we also did not want.
We finally went with re-compiling the QtNetwork module to use OpenSSL instead of Secure Transport. You will need to provide OpenSSL for that, since OSX does not include the headers anymore. A homebrew installation was sufficient I think. Other than that the compilation was surprisingly painless and fast, since you just have to compile one small module, not the whole Qt.
The easiest way to do this is:
download the source distribution of the Qt version you are running
./configure it to use OpenSSL (the -openssl switch I believe)
cdinto the network folder
make
copy the generated QtNetwork.framework inside your Qt-Installation and replace the existing one.
With that everything worked as expected.
I'm developing application in C++ (cross-platform; Windows, Mac and Linux) that needs to communicate securely with servers using https protocol with libcurl (built with winssl/darwinssl/openssl on Windows/Mac/Linux respectively). I've changed a curl option, CURLOPT_SSL_VERIFYPEER from 0 to 1 which should help prevent MitM issues.
This has caused issues that an initial search points to turning that option off, but after digging deeper I found:
Get a CA certificate that can verify the remote server and use the proper option to point out this CA cert for verification when connecting. For libcurl hackers: curl_easy_setopt(curl, CURLOPT_CAPATH, capath); from curl docs
and
Get a better/different/newer CA cert bundle! One option is to extract the one a recent Firefox browser uses by running 'make ca-bundle' in the curl build tree root, or possibly download a version that was generated this way for you.
from curl docs
I actually use CURLOPT_CAINFO to the bundle as I had seen some word of issues using CURLOPT_CAPATH on Windows; curl docs. I have downloaded and installed this bundle along with the application on Windows and Mac and I'd like to know if this is the correct way to do it or if there is a better practice.
Initially this caused issues for users of the application running behind some corporate networks or proxy which seemed to get fixed by building libcurl against winssl instead of openssl on Windows; though potentially disguising itself as a firewall issue, still unclear although it seems likely.
Sorry for the length.
Is anything silly about installing the ca-cert-bundle.crt along with the application, and is there anything that should be done differently to communicate securely with the server from this installed application?
A slightly separate, but still very related, issue I have is CURLOPT_CAINFO on Linux giving the error:
error setting certificate verify locations:
CAfile: ../share/my_application/curl-ca-bundle.crt
CApath: none
Though attempting to open the file for reading from within the application does work successfully. Edit: This issue I solved by NOT setting the CURLOPT_CAINFO field on Linux (leaving it blank) and adding the dependency package ca-certificates to the application package. The default path is correctly /etc/ssl/certs/ca-certificates.crt and seems to be working. To me this feels a bit better than installing the bundle with the application.
Edit2: Although solved it appears the ca-certificates package sometimes doesn't install ca-certificates.crt and instead ca-bundle.crt and the locations vary on different distros as this source, happyassassin.net shows that different Linux systems store the CA bundles in different locations. It did not seem to have a clear answer as to HOW to handle this. Should I be using a value in the configuration file that the user can then modify, or any other thoughts on the subject?
Edit3: Some users have pointed out that my name exists in one of the paths curl looks for, I'm not entirely sure how that is possible as the only thing I've specified for curl is where I built openssl/cares libraries...
I realize this is a loaded/multipart question but it is all on the same subject as the title states, I'd appreciate any help.
Thanks.
In my opinion, it is better to use system certificate then package certificates with application (if you are not using some special certs). For the linux it should be easy according to https://serverfault.com/questions/394815/how-to-update-curl-ca-bundle-on-redhat And for windows you can either use winssl or create the file from system https://superuser.com/questions/442793/why-cant-curl-properly-verify-a-certificate-on-windows Configure cURL to use default system cert store
A default libcurl build is setup to attempt to use the "right" CA bundle.
Linux
A libcurl built on Linux will scan and check where the CA store is located on your system and use that. If you install libcurl on a regular Linux distro, it should've been built to use the distro's "typical" CA store.
macOS
If you build libcurl for mac and tell it to use the Secure Transport backend, it will automatically use the macOS CA store. So will the default-installed curl and libcurls that come shipped bundled with macOS from Apple.
Windows
If you build libcurl for Windows to use Schannel (the windows TLS system) it will by default use the Windows CA store.
Other setups
If you deviate from these setups, you basically opt to not use the CA store that comes bundled in the operating system you're using. Then you need to handle and update the CA store yourself.
I wish to verify a server's certificate. I have a boost::asio::ssl::context
This successfully verifies the certificate:
context.load_verify_file("E:\\a\\windows\\Path\\to\\certificate\\9207bca9.0");
However, I do not wish to explicitly specify the files to verify certificates against. I want to be able to put them in one directory, and tell the context to use the files in that folder to verify the certificates. So I do this instead:
context.add_verify_path("E:\\a\\windows\\Path\\to\\certificate");
And verification is unsuccessful
Note: The file name 9207bca9.0: 9207bca9 is the hash of the subject of the CA certificate, and its extension is '.0' to satisfy the requirements of the add_verify_path method found here (also the only contents of this file are the root certificate. Keep in mind I have been successful in verifying certificates with this file):
http://www.boost.org/doc/libs/1_53_0/doc/html/boost_asio/reference/ssl__context/add_verify_path/overload1.html
Any suggestions?
There are only two possibilities that I can think of, the first is that your hash value is incorrect, this can be verified like so:
openssl x509 -noout -hash -in ca-certificate-file
The second is that there is some error in your directory configuration preventing OpenSSL from using the CA directory, for example, permissions and ownership are important on Linux systems, not sure to what extent these matter on Windows platforms. The only way to pinpoint this sort of error is to trace the verification stage via a debugger and observe the code directly as it scans the directory.
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