Server Certificates

Creating and Loading the Server Certificate in pem Files

Server Certificates

Server certificates are needed when you use secure socket connections - SSL/TLS.

For secure socket connection a proper certificate is needed. You can either generate your own self-signed certificate or obtain certificate from trusted third party organization.

Here are steps how to obtain certificate from a trusted organization.

Generating your Own Certificates

Self-signed certificates can be generated easily on a Linux system. Although it may not be considered a 'trusted' certificate authority, it can be useful to test server installations. We do not recommend regular use of self-signed certificates.

Note

that Tigase v5.0 and later can automatically create self signed PEM files if needed. However we will cover doing this process by hand.

This tutorial assumes you are running a Linux-based operating system with access to command shell, and the 'Openssl' package is installed on the system.

The process takes the following steps: 1. Create a local private key. This file ends with .key extension. It is recommended to create a new private key for the process. 2. Generate a certificate request. This file ends with the .csr extension and is the file sent to the Certificate Authority to be signed. 3. CA signs private key. This can be done by your own computer, but can also be done by private CAs for a fee. 4. Results are obtained from the CA. This is a .crt file which contains a separate public certificate. 5. Combine the .csr and .crt file into a unified .pem file. Tigase requires keys to be non-password protected PEM files.

Generate local private key. 

openssl genrsa -out [domain.com.key] 1024

This command generates a private key using a 1024 bit RSA algorithm. -out designates the name of the file, in this case it will be domain.com.key. The exact name is not important, and the file will be created in whatever directory you are currently in.

Generate a certificate request: 

openssl req -nodes -key domain.com.key -out domain.com.csr

This command generates a certificate request using the file specified after -key, and the result file will be domain.com.csr. You will be asked a series of questions to generate the request.

Country Name (2 letter code) [AU]:AU
State or Province Name (full name) [Some-State]:Somestate
Locality Name (eg, city) []:Your city name
Organization Name (eg, company) [Internet Widgits Pty Ltd]:Company name
Organizational Unit Name (eg, section) []:Department or any unit
Common Name (eg, YOUR name) []:*.yourdomain.com
Email Address []:your_email_address@somedomain.com

Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:

Sign the Certificate Request: Now the .csr file will be signed by a Certificate Authority. In this tutorial, we will be self-signging our certificate. This practice however is generally not recommended, and you will receive notifications that your certificate is not trusted. There are commercial offers from companies to sign your certificate from trusted sources. Please see the Certificate From Other Providers section for more information.

openssl x509 -req -days 365 -in domain.com.csr -signkey domain.com.key -out domain.com.crt

This command signs the certificate for 365 days and generates the domain.com.crt file. You can, of course use any number of days you like.

Generate PEM file. You should now have the following files in the working directory: ..\ domain.com.key domain.com.csr domain.com.crt

cat yourdomain.com.cert.pem intermediate.cert.pem root.cert.pem > yourdomain.com.pem

If the certificate is issued by third-party authority you will have to attach the certificate chain, that being certificate of the authority who has generated your certificate. You normally need to obtain certificates for your chain from the authority who has generated your certificate.

The result file should looks similar to:

-----BEGIN CERTIFICATE-----
MIIG/TCCBeWgAwIBAgIDAOwZMA0GCSqGSIb3DQEBBQUAMIGMMQswCQYDVQQGEwJJ
.
.
.
pSLqw/PmSLSmUNIr8yQnhy4=
-----END CERTIFICATE-----
-----BEGIN RSA PRIVATE KEY-----
WW91J3JlIGtpZGRpbmchISEKSSBkb24ndCBzaG93IHlvdSBvdXIgcHJpdmF0ZSBr
.
.
.
ZXkhISEhCkNyZWF0ZSB5b3VyIG93biA7KSA7KSA7KQo=
-----END RSA PRIVATE KEY-----
-----BEGIN CERTIFICATE-----
MIIHyTCCBbGgAwIBAgIBATANBgkqhkiG9w0BAQUFADB9MQswCQYDVQQGEwJJTDEW
.
.
.
xV/stleh
-----END CERTIFICATE-----

For Tigase server as well as many other servers (Apache 2.x), the order is following; your domain certificate, your private key, authority issuing your certificate, root certificate.

Note! Tigase requires full certificate chain in PEM file (described above)! Different applications may require pem file with certificates and private key in different order. So the same file may not be necessarily used by other services like Web server or e-mail server. Currently, Tigase can automatically sort certificates in PEM file while loading it.

Installing/Loading Certificate To the Tigase Server

Installing and loading certificates is very easy. The server can load all certificates directly from pem files. You just need to create a separate pem file for each of your virtual domains and put the file in a directory accessible by the server. Tigase server can automatically load all pem files found in given directory. By default, and to make things easy, we recommend the Tigase/certs directory.

Certificate From Other Providers

There is number of certificate providers offering certificates either for free or for money. You can use any of them, however you have to be aware that sometimes certificates might not be recognized by all XMPP servers, especially if it’s one from a new provider. Here is an example list of providers:

To obtain certificate from a third party authority you have to go to its website and request the certificate using certificate request generated above. I cannot provide any instructions for this as each of the providers listed have different requirements and interfaces.

We highly recommend using LetsEncrypt keys to self-sign and secure your domain. Instructions are in the next section.

Using one certificate for multiple domains

By default, each virtual hosts will require it’s own certificate. However, if you choose to use one certificate for all virtual hosts, Tigase supports that option. For example, if you have host1.example.net, host2.example.net, and host3.example.net each vhost will need some configuration:

'certificate-container' {
    'custom-certificates' {
        'host1.example.net' = '/home/tigase/certs/host1.pem'
        'host2.example.net' = '/home/tigase/certs/host2.pem'
        'host3.example.net' = '/home/tigase/certs/host3.pem'
    }
}

This may be time consuming if you have many Vhosts, or expect to generate many more. The good news is, now one certificate can be used for ALL Vhosts using the following configuration line:

'certificate-container' {
    'custom-certificates' {
        '*.example.net' = '/home/tigase/certs/certificate.pem'
    }
}

Now any Vhosts created will use the same certificate located at /home/tigase/certs/certificate.pem.

Note

This is an all or nothing option, if you wish to customize each Vhost, you will need to do so individually.

Installing LetsEncrypt Certificates in Your Linux System

LetsEncrypt is a trusted CA that provides free security certificates. Unlike previously self-signed certificates, we can use LetsEncrypt Certificates to certify your domains from a trusted source.

Please refer to official [certbot User Guide](https://certbot.eff.org/docs/using.html) for details how to install and operate the tool, choosing desired method of domain authentication (DNS or webserver). After successful execution the certificate with all related files will be stored under /etc/letsencrypt/live/$domain

$ sudo ls  /etc/letsencrypt/live/$domain
cert.pem  chain.pem  fullchain.pem  privkey.pem  README

In that directory, you will find four files: - privkey.pem - private key for the certificate - cert.pem - contains the server certificate by itself - chain.pem - contains the additional intermediate certificate or certificates - fullchain.pem - all certificates, including server certificate (aka leaf certificate or end-entity certificate). The server certificate is the first one in this file, followed by any intermediates.

For Tigase XMPP Server, we are only concerned with privkey.pem and fullchain.pem.

At this point we will need to obtain the root and intermediate certificates, this can be done by downloading these certificates from the LetsEncrypt website.

Alternatively, you may obtain them using wget:

wget https://letsencrypt.org/certs/isrgrootx1.pem
wget https://letsencrypt.org/certs/letsencryptauthorityx3.pem

These are the root certificate, and the intermediate certificate signed by root certificate.

Note

IdenTrust cross-signed certificate will not function properly.

Take the contents of your privkey.pem, certificate, and combine them with the contents of isrgrootx1.pem and letsencryptauthorityx3.pem into a single pem certificate. You need to name the file after your domain such as mydomain.com.pem and place it under certs/ subdirectory of Tigase XMPP Server installation

If you moved all certs to a single directory, you may combine them using the following command under *nix operating systems:.

cat ./cert.pem ./privkey.pem ./letsencryptauthorityx3.pem ./isrgrootx1.pem > mydomain.com.pem

Your certificate should look something like this:

-----BEGIN PRIVATE KEY-----
MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQDAUAqqKu7Z4odo
...
og89F9AbWr1mNmyRoScyqMXo
-----END PRIVATE KEY-----
-----BEGIN CERTIFICATE-----
cmNoIEdyb3VwMRUwEwYDVQQDEwxJU1JHIFJvb3QgWDEwHhcNMTUwNjA0MTEwNDM4
...
TzELMAkGA1UEBhMCVVMxKTAnBgNVBAoTIEludGVybmV0IFNlY3VyaXR5IFJlc2Vh
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
FhpodHRwOi8vY3BzLmxldHNlbmNyeXB0Lm9yZzCBqwYIKwYBBQUHAgIwgZ4MgZtU
...
bmcgUGFydGllcyBhbmQgb25seSBpbiBhY2NvcmRhbmNlIHdpdGggdGhlIENlcnRp
-----END CERTIFICATE-----

Warning

LetsEncrypt certificates expire 90 days from issue and need to be renewed in order for them to remain valid!