trying to connect to remote Exchange server 2007 from powershell - powershell

Am getting SSL error while connecting to remote exchange server.
Can any one help me.

Taking a completely random guess at this near-empty question, I'd say your exchange server is using a privately issued SSL certificate and the workstation that you are trying to connect to it from doesn't have the Root CA (it doesn't trust the remote SSL cert)

Try connecting with something like WFetch. This will help you get a meaningful response from Exchange when attempting to connect. Also i agree with x0n , it sounds like you are missing certificate which is required when connecting over SSL.

Related

SSL TLS Version issue in BigQuery Linked Service in ADF

I am creating a Linked Service to connect to BigQuery with Service Account authentication and p12 file has already been placed in IR VM directory.
Receiving following error:
ERROR [HY000] [Microsoft][DriverSupport] (1160) Cannot enable SSL for the connection when connecting to a server that has not enabled SSL. If the server has SSL enabled, please check if it has been configured to use a SSL protocol version that is lower than what is allowed for the connection. The minimum SSL protocol version allowed for the connection is: TLS 1.2.
But when i place p12 file in another IR VM, linked service is working correctly.
Tried to check TLS version in both VM's and everything looks same.
Please suggest ways to check SSL and TLS version in VM's and how to resolve this issue.
Based on the error message it seems the issue might be w.r.t SSL certificate so 1st step would be to compare the SSL/TLS across both the servers
In case if they are same, would suggest to monitor the traffic across both the server when trying to access GCP Big Query.
You might get the exact cause of failure which can be like :
Firewall blockage
some missing set up like Big query need Google_base set up as a signature
etc.
You could create a PowerShell script that checks the TLS & SSL registry entries mentioned in the following documentation:
https://learn.microsoft.com/en-us/windows-server/security/tls/tls-registry-settings
Even if after enabling TLS/SSL settings the same issue arises then please try re-installing IR in the VM

SSL_accept error in log while using Postfix

So I set up a mail server on my VPS with cyberpanel and I can send emails manually through rainloop. I also have a program based on the lettre crate for Rust which runs perfectly fine on my own devices and correctly sends emails out through code. However when I try to run the program on my VPS, I get the following messages in my syslog.
globalfun postfix/smtps/smtpd[24656]: connect from localhost[::1]
globalfun postfix/smtps/smtpd[24656]: SSL_accept error from localhost[::1]: -1
globalfun postfix/smtps/smtpd[24656]: warning TLS library problem: error 14094418:SSL routines:ssl3_resl3_read_bytes: tlsv1 alert unknown ca:../ssl/rec/layer_s3.c:1543:SSL alert number 48:
globalfun postfix/smtps/smtpd[24656]: lost connection after CONNECT from localhost[::1]
globalfun postfix/smtps/smtpd[24656]: disconnect from localhost[::1] commands=0/0
I don't really understand why I can't send out emails through my program but it seems to have something to do with SSL. For reference, I have two servers on the same domain - one for my website which has an SSL installed through Let's Encrypt and another for the mail server which doesn't have SSL on it. That said, I don't think that's the issue as I can send emails through the mail server manually completely fine. Does anyone have any ideas as to what's wrong? Thanks in advance.
globalfun postfix/smtps/smtpd[24656]: warning TLS library problem: error 14094418:SSL routines:ssl3_resl3_read_bytes: tlsv1 alert unknown ca:../ssl/rec/layer_s3.c:1543:SSL alert number 48:
Your client refuses to connect to your mail server since it does not trust the CA which issued the mail servers certificate. It notifies the server about this problem by sending a unknown ca TLS alert.
There can be various reasons for this. Typically it is either the use of a CA which is not trusted by the client which need to be fixed at the client (trust this CA) or at the server (use a certificate from a CA trusted by the client). Or the root CA is actually trusted but the server is not sending the intermediate certificates needed by the client to build the trust chain to this trusted root CA. This need to be fixed at the server.

SSL for mail server

I don't know if I am asking this in the right place.
I have an SSL cert for my website, and I am trying to setup a mail server (same domain) using the same cert.
I am using Postfix and Dovecot. When I try logging in from Evolution mail client, I get an error "Peer failed to perform TLS handshake". When I try an online service to verify I get "Recipient address rejected: User unknown in local recipient table."
I guess my actual question is, can I actually use the same SSL cert for my website and my email server?
What do I do to debug next?
You can use a certificate you have for the web server also for your mail server as long as it matches the hostname you use to access your mail server. Of course the certificate need to properly setup at the mail server, i.e. include the necessary intermediate certificates similar to how it is (hopefully) setup on the web server.
I am using Postfix and Dovecot.
This means you need to take care of multiple configurations, both for SMTP in Postfix and IMAP/POP3 (whatever you use) in Dovecot. And in all cases the certificates subject/SAN must match the hostname you use to connect to the server.
When I try logging in from Evolution mail client, I get an error "Peer failed to perform TLS handshake".
There are not enough information about this setup to find out what exactly is causing the TLS error. It is not even clear if the error is caused when retrieving mail (IMAP/POP3, i.e. Dovecot) or while sending (Postfix).
When I try an online service to verify I get "Recipient address rejected: User unknown in local recipient table."
This has nothing to do with TLS at all. The test server simply tried to use a recipient which your mail server (Postfix) will not accept.
What do I do to debug next?
The next steps would probably be to check if the certificate matches the names you use in the first place and to look into log files for error messages or warnings. Following steps depend on what the result of these steps is.

Connect to ejabberd server using a certificate

I want to connect to my ejabberd server from another machine using a certificate instead of a login/password. I've looked for authentication client-to-server with a certificate for ejabberd, but i couldn't find something helpfull.
If anyone has any ideas how it cas be done, I'm taking..
As of version 16.02, ejabberd Community Server does not yet support client cert authentication.
However, if your questions is about communication encryption, you can indeed configure ejabberd with Starttls support to use TLS between client and server. A service like Let's encrypt can provide such certificates for free: https://letsencrypt.org/

Does Exchange server uses Certificate to validate client?

I am creating an EWS service which will connect to the Exchange server 2007. I am using Autodiscover service of Exchange server.I need to understand following:
How can I validate the SSL/TSL certificates for my service.
I need to know conventional way how outlook communicate with Exchange server.
How to Detect the specific certificate is installed for authentication.
I had written the code to connect to the Exchange server.But I am facing issues with the Certificate part.I am totally confused with the proper handshake with help of certificate.
In my code I had used X509Store to get the certificate stores and then validate from the server,but the certificate may differ from server to server (Exchange).Is there any way around.