There was a question: how to implement the GOST algorithm?
What is the GOST algorithm? Only GOSTs are googled.
Answer 1, authority 100%
There are GOST 28147-89 and GOST 34.12-2015. These are GOSTs for cryptographic protection of information.
Answer 2, authority 100%
GOST is a Soviet symmetric block cipher declassified back in the 80s. You can read on Wikipedia there is a new incarnation of it from 2015 known as Grasshopper
There are quite a few of its implementations, in particular, it is implemented in the well-known crypto package Bouncy Castle
Sources in various languages many