One of the QMAIL server installs, I have installed very long time ago. I've been notified by clients, that the certificate of the mail server has expired and therefore I had to quickly renew the certificate.
This qmail installation, SSL certificates were located in /var/qmail/control under the names servercert.key and cervercert.pem
Renewing the certificates with a new self signed ones is pretty straight forward, to renew them I had to issue the following commands:
1. Generate servercert encoded key with 1024 bit encoding
debian:~# cd /var/qmail/control
debian:/var/qmail/control# openssl genrsa -des3 -out servercert.key.enc 1024
Generating RSA private key, 1024 bit long modulus
...........++++++
.........++++++
e is 65537 (0x10001)
Enter pass phrase for servercert.key.enc:
Verifying - Enter pass phrase for servercert.key.enc:
In the Enter pass phrase for servercert.key.enc I typed twice my encoded key password, any password is good, here though using a stronger one is better.
2. Generate the servercert.key file
debian:/var/qmail/control# openssl rsa -in servercert.key.enc -out servercert.key
Enter pass phrase for servercert.key.enc:
writing RSA key
3. Generate the certificate request
debian:/var/qmail/control# openssl req -new -key servercert.key -out servercert.csr
debian:/var/qmail/control# openssl rsa -in servercert.key.enc -out servercert.key
Enter pass phrase for servercert.key.enc:writing RSA key
root@soccerfame:/var/qmail/control# openssl req -new -key servercert.key -out servercert.csr
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [AU]:UK
State or Province Name (full name) [Some-State]:London
Locality Name (eg, city) []:London
Organization Name (eg, company) [Internet Widgits Pty Ltd]:My Company
Organizational Unit Name (eg, section) []:My Org
Common Name (eg, YOUR name) []:
Email Address []:admin@adminmail.com
Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:
In the above prompts its necessery to fill in the company name and location, as each of the prompts clearly states.
4. Sign the just generated certificate request
debian:/var/qmail/control# openssl x509 -req -days 9999 -in servercert.csr -signkey servercert.key -out servercert.crt
Notice the option -days 9999 this option instructs the newly generated self signed certificate to be valid for 9999 days which is quite a long time, the reason why the previous generated self signed certificate expired was that it was built for only 365 days
5. Fix the newly generated servercert.pem permissions debian:~# cd /var/qmail/control
debian:/var/qmail/control# chmod 640 servercert.pem
debian:/var/qmail/control# chown vpopmail:vchkpw servercert.pem
debian:/var/qmail/control# cp -f servercert.pem clientcert.pem
debian:/var/qmail/control# chown root:qmail clientcert.pem
debian:/var/qmail/control# chmod 640 clientcert.pem
Finally to load the new certificate, restart of qmail is required:
6. Restart qmail server
debian:/var/qmail/control# qmailctl restart
Restarting qmail:
* Stopping qmail-smtpd.
* Sending qmail-send SIGTERM and restarting.
* Restarting qmail-smtpd.
Test the newly installed certificate
To test the newly installed SSL certificate use the following commands:
debian:~# openssl s_client -crlf -connect localhost:465 -quiet
depth=0 /C=UK/ST=London/L=London/O=My Org/OU=My Company/emailAddress=admin@adminmail.com
verify error:num=18:self signed certificate
verify return:1
...
debian:~# openssl s_client -starttls smtp -crlf -connect localhost:25 -quiet
depth=0 /C=UK/ST=London/L=London/O=My Org/OU=My Company/emailAddress=admin@adminmail.com
verify error:num=18:self signed certificate
verify return:1
250 AUTH LOGIN PLAIN CRAM-MD5
...
If an error is returned like 32943:error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol:s23_clnt.c:607: this means that SSL variable in the qmail-smtpdssl/run script is set to 0.
To solve this error, change SSL=0 to SSL=1 in /var/qmail/supervise/qmail-smtpdssl/run and do qmailctl restart
The error verify return:1 displayed is perfectly fine and it's more of a warning than an error as it just reports the certificate is self signed.
