These are useful open source project sites.

OpenSSL

http://www.openssl.org

This is very  powerful PKI library.

 

OpenSSL wiki

https://wiki.openssl.org/index.php/Main_Page

There is example and description about OpenSSL

 

OpenSSL cmp patch

https://github.com/mpeylo/cmpossl

You can download Openssl project to support CMP.

 

mbedTLS

http://tls.mbed.org

This is very light PKI library.

 

 

QT

https://www.qt.io

This is cross platform C++ framework.

 

Git usage (korean)

https://rogerdudler.github.io/git-guide/index.ko.html

 

libKMIP

https://libkmip.readthedocs.io/en/latest/index.html

 

PyKMIP

https://pykmip.readthedocs.io/en/latest/index.html