Can ssl handshake be established only with client certification validation instead of server certificate validation? - sockets

From my browser I want to communicate to localhost application using ssl. Here browser(which acts as client) will submit the certificate instead of localhost application(which acts as server). Can Ssl be established in this scenario? So finally it boils down to problem statement can a ssl communication be established by server validating the client certificate and client not validating the server certificate.

The SSL/TLS implementation inside the browser do not support this scenario. A server certificate is always required by the browser with SSL/TLS in order to be sure that the browser is communicating with the expected server (as specified in the URL) and not some man in the middle. Apart from that it is not clear what you want to achieve with such a setup in the first place - maybe there is a better design for your unknown use case.

Related

Self-signed certificate for own client

I am developing an app with a server part programmed in Go and a client programmed in C#, the connection between the two is made using TCP socket communication, and to ensure the connection I am using TLS.
My question is whether there would be any security problem in my case when using self-signed certificates for TLS communication.
I understand that for a web server that uses https it is necessary to use certificates signed by a certificate authority (CA) but in my case, when connecting my own client application I don't see why I should use one of these.
If anyone knows anything about it, it would be a great help.
Certificates are used for authenticating the end points, and usually the cert is signed by a certificate authority which your client (such as a web browser) already trusts. Using a self-signed cert in that scenario can lead to problems, as the browser won't trust it, and so will pop a warning box. However, the real issue is that for the typical user, a warning from your server is as good as indistinguishable from an attacker using another self-signed certificate. They'll click-away and KABOOM!
If this is a closed environment, and you control both the server and client, then the self-signed certificate is irrelevant. In fact, you don't even need one at all, and may be better off with one of the alternatives, like TLS-PSK, or TLS-SRP.

creating a tls websocket connection

I have been trying to write a program that is a websocket client connecting to a wss (tls websocket) endpoint. The problem I am having is that I am getting a bad handshake. What all certificate do I need to create a tls connection? I am asking language non specific just mean general authentication needed and possibly how to generate the files.

haproxy require client certificate for specific url?

I want to configure Haproxy so that it only requires client certificate when specific URL accessed? Ex:
www.test.com - it proceeds normally.
www.test.com/secure - haproxy requires the client certificate.
To understand why this isn't directly possible requires an understanding of how TLS (SSL) works. TLS encrypts the connection before the HTTP request is sent (over the now-encrypted connection). By the time the URL is known by HAProxy, the time for requiring a client certificate has already passed.
For practical reasons, an endpoint (HAProxy frontend or listen) needs to either require a certificate for connections, or not... however, using verify optional it might be possible to achieve what you want. Using verify optional means that the proxy will ask for a client cert upon connection, and if either the client offers no cert or if the cert is valid according to the ca-file, the client will be allowed to connect. Invalid certs will result in disconnection.
Then, the ssl_c_used fetch could be used to deny requests for that path for clients who didn't present the "optional" certificate, earlier.
http-request deny if { path_beg /secure } ! { ssl_c_used }
The viability of this solution depends on how gracefully browsers behave when asked for a certificate that they would not have -- and all connecting browsers will be asked for a certificate.
But there is no way of doing exactly what you are asking, either in HAProxy or on any other platform since, by design, the path is unknown until after TLS negotiation is already complete.

REST Service - SSL Implementation (HTTP Error 403.7 - Forbidden)

In order to secure my Rest Services, I have enabled SSL in IIS and Created a Self-Signed Certificate and assigned it to the HTTPS binding in IIS. I exported the same as pfx file and added the same in IE also but when I try to access the Services, I get the following error on Windows 7, Enterprise edition
HTTP Error 403.7 - Forbidden
The page you are attempting to access requires your browser to have a Secure Sockets Layer (SSL) client certificate that the Web server recognizes.
And on Windows Server 2003, this is
HTTP Error 403.7 - Forbidden: SSL client certificate is required.
Internet Information Services (IIS)
I am not sure what shall I do except adding the certificate in IE under “Personal” and “Trusted Root Certification Authorities”? Could you please suggest me some step, in order to make this work.
Note: I have tried with “Self-Signed Certificates” as well as with Certificates generated from Microsoft “Certificate Services” also.
Any help is greatly appreciated.
SSL is used to verify the identity of the server, not the identity of the client. The error suggests (http://support.microsoft.com/kb/199215, "This is used for authenticating you as a valid user of the resource. ") the server wants to identify the client. Which of the two are you trying to do?
Edit: SSL requires the public part of the SSL certificate to be available to the client. Adding it to the trusted root certificates seems to me to be the only way to make the public part of a self-signed certificate available to the browser.

Any way to setup LDAP server over secure connection on Perl?

Currently I am using Net::LDAP::Server to setup my server but it is not secure enough.
Is there any module or method so that I can setup a LDAP server over TLS or other secure connection?
I just found many information about how to connect to a secure ldap server, but cant found how to setup a secure ldap server.
Can anyone give some advices?
How does an LDAPS connection work
LDAPS is an unofficial protocol. It is to LDAP what HTTPS is to HTTP, namely the exact same protocol (but in this case LDAPv2 or LDAPv3) running over a secured SSL ("Secure Socket Layer") connection to port 636 (by default).
Not all servers will be configured to listen for LDAPS connections, but if they do, it will commonly be on a different port from the normal plain text LDAP port.
Using LDAPS can potentially solve the vulnerabilities described above, but you should be aware that simply "using" SSL is not a magic bullet that automatically makes your system "secure".
First of all, LDAPS can solve the problem of verifying that you are connected to the correct server. When the client and server connect, they perform a special SSL 'handshake', part of which involves the server and client exchanging cryptographic keys, which are described using X.509 certificates. If the client wishes to confirm that it is connected to the correct server, all it needs to do is verify the server's certificate which is sent in the handshake. This is done in two ways:
check that the certificate is signed (trusted) by someone that you trust, and that the certificate hasn't been revoked. For instance, the server's certificate may have been signed by Verisign (www.verisign.com), and you decide that you want to trust Verisign to sign legitimate certificates.
check that the least-significant cn RDN in the server's certificate's DN is the fully-qualified hostname of the hostname that you connected to when creating the LDAPS object. For example if the server is , then the RDN to check is cn=ldap.example.com.
You can do this by using the cafile and capath options when creating a Net::LDAPS object, and by setting the verify option to 'require'.
To prevent hackers 'sniffing' passwords and other information on your connection, you also have to make sure the encryption algorithm used by the SSL connection is good enough. This is also something that gets decided by the SSL handshake - if the client and server cannot agree on an acceptable algorithm the connection is not made.
Net::LDAPS will by default use all the algorithms built into your copy of OpenSSL, except for ones considered to use "low" strength encryption, and those using export strength encryption. You can override this when you create the Net::LDAPS object using the 'ciphers' option.
Once you've made the secure connection, you should also check that the encryption algorithm that is actually being used is one that you find acceptable. Broken servers have been observed in the field which 'fail over' and give you an unencrypted connection, so you ought to check for that.
How does LDAP and TLS work
SSL is a good solution to many network security problems, but it is not a standard. The IETF corrected some defects in the SSL mechanism and published a standard called RFC 2246 which describes TLS ("Transport Layer Security"), which is simply a cleaned up and standardized version of SSL.
You can only use TLS with an LDAPv3 server. That is because the standard (RFC 2830) for LDAP and TLS requires that the normal LDAP connection (ie., on port 389) can be switched on demand from plain text into a TLS connection. The switching mechanism uses a special extended LDAP operation, and since these are not legal in LDAPv2, you can only switch to TLS on an LDAPv3 connection.
So the way you use TLS with LDAPv3 is that you create your normal LDAPv3 connection using Net::LDAP::new(), and then you perform the switch using Net::LDAP::start_tls(). The start_tls() method takes pretty much the same arguments as Net::LDAPS::new(), so check above for details.
Well, perhaps LDAPS is not an RFC but to say it is not a standard or secure is certainly a stretch.
LDAPS is supported by ALL LDAP Server Vendors.
LDAPS is at least as secure as HTTPS.
As with ALL SSL (or TLS) the security weak points are how the certificates are handled.
Certainly LDAPS is more supported by LDAP server vendors and clients than is TLS. Active Directory as one example, does not support TLS. Querying the rootDSE for the supportedExtention 1.3.6.1.4.1.1466.20037 will (should) show if TLS is supported on any particular LDAP server.
We have some examples at:
http://ldapwiki.willeke.com/wiki/Perl%20LDAP%20Samples.