Grasshopper

This project is optimized implementation of Russian ГОСТ Р 34.12-2015 Kuznechik (Grasshopper).

Results:

ECB encryption, Mb/s

	i3-4030u	i5-5200u	i5-7200u	i5-8250u
Baseline	6	8.8	10.2	11.4
With LUT	53	77	99	107
LUT, vector xor	69	99	131	139
Offset precalc	79	113	135	142
AVX2	84	121	150	159

CFB decryption, Mb/s

	i3-4030u	i5-5200u	i5-7200u	i5-8250u
Baseline	5.2	8.7	10.2	9.4
With LUT	50	73	94	103
LUT, vector xor	73	105	131	145
Offset precalc	80	118	135	150
AVX2	82	120	145	159