[cm/signed/] with GOST R 34.10-2012.
=> RFC 7091, GOST R 34.10-2012

GOST R 34.10-2012 must be used with Streebog (GOST R 34.11-2012)
hash function. Its digest must be big-endian serialised. Signature
is in "BE(R)||BE(S)" format.
=> RFC 6986, GOST R 34.11-2012

Algorithm identifiers for the signature: "gost3410-256A", "gost3410-512C".