The current minimum versions are:
- OpenSSL 1.0.2 
- APR 1.4.3

The following version of the libraries are recommended:

- APR 1.7.0 or later, http://apr.apache.org
- OpenSSL 1.1.1k or later, http://www.openssl.org

Older versions should also work but are not as thoroughly tested by the Tomcat
Native team


It is current anticipated that Tomcat Native releases will transition to 1.3.x
after April 2021 when the minimum version will become OpenSSL 1.1.0 and
APR 1.5.2.


The minimum version of OpenSSL is driven by the version of OpenSSL used by
downstream distributions.

The current state of OpenSSL in Debian is:
- OpenSSL 1.1.0l in Debian 9 (EOL in June 2022)
- OpenSSL 1.1.1d in Debian 10

And in Ubuntu:
- OpenSSL 1.0.2g in Ubuntu 16.04 LTS (EOL in April 2021)
- OpenSSL 1.1.1  in Ubuntu 18.04 LTS
- OpenSSL 1.1.1f in Ubuntu 20.04 LTS


The minimum version of APR is driven by the version of APR used by
downstream distributions.

The current state of APR in Debian is:
- APR 1.5.2 in Debian 9 (EOL in June 2022)
- APR 1.6.5 in Debian 10

And in Ubuntu:
- APR 1.5.2 in Ubuntu 16.04 LTS (EOL in April 2021)
- APR 1.6.3 in Ubuntu 18.04 LTS
- APR 1.6.5 in Ubuntu 20.04 LTS
