OpenSSL since version 1.0.0 supports the Russian cryptographic standard algorithms, commonly called GOST algorithms. Use of GOST in SSL/TLS is standardized by the IETF, thus openvpn is the VPN software of choice for Russian users when constrained to use GOST algorithms.
With this patch series, users can choose to use GOST by using the algorithms in the X.509 PKI and configuring openvpn with, e.g. --engine gost --auth gost-mac --cipher gost89 --tls-cipher GOST2001-GOST89-GOST89 More information about the GOST algorithms can be found in IETF RFCs: 4357 Additional Cryptographic Algorithms for Use with GOST Algorithms 4490 GOST Algorithms with the Cryptographic Message Syntax (CMS) 4491 GOST Algorithms with the Internet X.509 Public Key Infrastructure (PKI) 5830 GOST 28147-89 Block Cipher and MAC Algorithms 5831 GOST R 34.11-94 Hash Function Algorithm 5832 GOST R 34.10-2001 Digital Signature Algorithm
