Reviewed-by: Richard Levitte <levitte@openssl.org>
Based on code from Matthias Ballreich, Steve Henson, and Wolf Tobias. Reviewed-by: Matt Caswell <matt@openssl.org> (Merged from https://github.com/openssl/openssl/pull/4724)
Reviewed-by: Stephen Henson <steve@openssl.org> Reviewed-by: Rich Salz <rsalz@openssl.org> (Merged from https://github.com/openssl/openssl/pull/2759)