Running an Exchange 2003 setup and have been asked by one of our clients to enable TLS. I understand the concept and reasoning for this. However, my question is what consequences making this change to our server will have on all other clients that don't have TLS enabled on client side? Or is this a non issue? Basically will the mail still flow in cases where TLS isn't activated?
Any insight would be appreciated.
TLS will only be enabled on the connection if both sides support it. Otherwise, in most cases, the message will be delivered in plain text, without encryption. However, there are some MTA's that are configured to abort the connection if the other side does not support TLS, or if the certificate check fails.
Related
Converse.js successfully makes requests to Prosody bosh but the chat client never actually connects. In the console I can see it hitting the bosh endpoint and after each request it outputs to the console:
"Server did not yet offer a supported authentication mechanism. Sending a blank poll request."
I can hit the bosh endpoint from my browser as well, the proxy pass appears to be working as intended and bosh is running and responding to requests.
Any insight is much appreciated.
I came across this issue as well while using the fullpage demo. The problem was because Prosody was forcing encrypted authentication only for client side.
I recommend going into the config file /etc/prosody/prosody.cfg.lua
Look for the code
-- Force clients to use encrypted connections? This option will
-- prevent clients from authenticating unless they are using encryption.
c2s_require_encryption = true
By default for me this was set to true, change this to false
c2s_require_encryption = false
save it and reboot Prosody
systemctl restart prosody
you could also do
prosodyctl restart
The error message is quite clear. Prosody is not offering a SASL authentication mechanism supported by Converse.
By default Converse supports SCRAM-SHA1, DIGEST-MD5 and PLAIN.
Your XMPP server needs to support one of these.
Is it possible in SSL/TLS handshake where client only send its certificate. Server need not to send any certificate ?As of now in one way handshake only server send its certificate to client.
As i am aware of that in this scenario server needs to maintain all clients root certificate(if diffrent).This is not practical.If possible what are the security concerns.
Here is context under Use of SSL with socket programming in C# or C++
Thanks for help!
Yes, it is possible to use SSL/TLS without a server certificate. See https://security.stackexchange.com/questions/38589/can-https-server-configured-without-a-server-certificate
You need software that supports at least one of the anonymous cipher suites SSL/TLS supports, such as TLS_DH_anon_WITH_AES_128_CBC_SHA256. Per the OpenSSL Diffie Hellman wiki entry:
Anonymous Diffie-Hellman uses Diffie-Hellman, but without authentication. Because the keys used in the exchange are not
authenticated, the protocol is susceptible to Man-in-the-Middle
attacks. Note: if you use this scheme, a call to
SSL_get_peer_certificate will return NULL because you have selected an
anonymous protocol. This is the only time SSL_get_peer_certificate
is allowed to return NULL under normal circumstances.
You should not use Anonymous Diffie-Hellman. You can prohibit its use
in your code by using "!ADH" in your call to SSL_set_cipher_list.
Note that support for such cipher suites and configurations in most available SSL/TLS software is either non-existent or very limited, as such configurations are vulnerable to man-in-the-middle attacks - one of the very things SSL/TLS is used to prevent. You'd have to compile your own OpenSSL code, for example.
Unless you control the software at both ends of your communication channel(s), effectively there's no way to implement such a system.
And there's no real reason to implement such a system as it's not secure at all.
But you can do it with a lot of effort.
Server Certificate which contains the public key part of its key pair is must. The client may decide to overlook the authenticity of the certificate( Its bad!) but the TLS handshake requires the public key for the generation of pre-master-secret. So no way you can prevent server from sending the certificate.
Server if it wishes can request client for its certificate. This is for authenticating the client.
I need to setup a cron job to run a SOAP client. The customer insists that I connect to their web service (on an https address) from an https address. They insist that if I don't their response to me can't be encrypted.
My first question is, is that true? I thought that as long as I'm connecting to their SOAP service over https, the response back would automatically be encrypted.
If that's true, how can I run a cron job to be as https? My site is on a LAMP setup with cPanel access.
Thank you in advance for your help!
Your customers statement seems to be a little bit unclear in what he/she specifically means by "... connecting from an https adress" as there isn't any notion of the term "https adress" in the specs and https URLS only seem to make sense in the context of Request-URI s given in a https request.
Given this unclarity I'm only wild guessing. Nevertheless to me it seems your clients requirements might most probably not be connected to the http protocol but rather to establishing your TLS connection.
If your client is very sensitive in respect to the security of his system - which in fact if he intends to offer RPC requests might be a very good idea - he might not want to the whole world to be able to connect an encrypted connection to his machines and rely on any secondary authentication mechanism once the connection has been established.
As most users of the public internet don't have any certificates signed by a trusted authority this feature it isn't used out in the open wild but besides server authentication the TLS handshake protocol also provides a means of client authentication via client certificates (the relevant part being section 7 in RFC 5246 here. see: https://www.rfc-editor.org/rfc/rfc5246#section-7)
While in the absence of widely used client certificates web services usually rely on establishing an encryted connection to first to authenticate users by some kind of challange response test like querying for username and password your client might want to either additionally secure access to his machines by additionally requiring a valid client certificate or even - probably not the best idea - replace a second authorization like the one already mentioned above.
Nevertheless all this are nothing but some ideas that I came along with given the riddle in your question.
Most probably the best idea might be to just ask your client what he/she meant when saying "... connecting from an https adress"
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.
Does anyone have an experience or just thoughts about securing MQ TCP
communication channels using stunnel?
I am integration with third party S.W which has MQ support built in but it can not support SSL. So to have some kind of security over the TCP we would like to use stunnel. Does any one have any thoughts how to implement and any best practices
I haven't used stunnel so I'll leave that part of the answer to another responder. With regard to WMQ, keep in mind that this will provide you with data privacy and data integrity over the stunnel link but will not give you channel-level services such as WMQ authentication. True, you will have some level of authentication on the stunnel connection itself, but anyone with a TCP route to the QMgr that does not arrive via stunnel will also be able to start that channel.
Your requirement for security obviously includes data privacy. If it also includes authentication and authorization, you might need to use something like BlockIP2 (from http://mrmq.dk )to filter incoming connections on that channel by IP address to insure they arrive over the stunnel link. Of course, there is nothing to prevent someone at the remote end from specifying any channel name to connect to so if you secure one channel, you need to secure them all - i.e. make sure that SYSTEM.DEF.* and SYSTEM.AUTO.* channels are disabled or that they use SSL and/or an exit to authenticate the inbound connection.
Finally, be aware that if WMQ is configured to accept the ID presented by the client then the connection has full administrative access and that includes remote code execution. To prevent this you must configure all inbound channels (RCVR, RQSTR, CLUSRCVR and SVRCONN) that are not administrative with a low-privileged ID in the channel's MCAUSER. For any channels that are intended for administrators, authenticate these with SSL. (Hopefully your 3rd party SW is an application and not an administrative tool! Any WMQ admin tool must support SSL or else don't use it!)
So by all means use stunnel to secure this link, just be sure to secure the rest of the QMgr or else anyone who can legitimately connect (or even anonymous remote users if you leave MCAUSER blank and aren't using SSL and/or exits) will just bypass the security or disable it.
There's a copy of the IMPACT presentation Hardening WMQ Security at https://t-rob.net/links/ which explains all this in more detail.
Rob - I agree with you. For that only we have MQIPT. Which is much better. For STunnel for MQ i have sloved the problem.
Keys -U need a .pem key (From Key manager you can create .p12 and use open ssl to covert to .PEM).
Client Side: Download and install stunnel have followoling entries in the config file
cert = XXX.pem
client = yes
[MQ]
accept = 1415
connect = DestinationIP:1415
Server Side:
cert = xxx.pem
client = no
[MQ]
accept = 1415
connect = MQIP:1415
Once you do this all you have do is just call the amquputc with the Queue name.