Generate code for SM2

[emmansun]

First of all thanks for your great project.

SM2 Elliptic Curve Formula

$$ y^2 = x^3 + ax + b $$

SM2 Curve Parameters

p   = FFFFFFFE FFFFFFFF FFFFFFFF FFFFFFFF
      FFFFFFFF 00000000 FFFFFFFF FFFFFFFF
a   = FFFFFFFE FFFFFFFF FFFFFFFF FFFFFFFF
      FFFFFFFF 00000000 FFFFFFFF FFFFFFFC
b   = 28E9FA9E 9D9F5E34 4D5A9E4B CF6509A7
      F39789F5 15AB8F92 DDBCBD41 4D940E93
n   = FFFFFFFE FFFFFFFF FFFFFFFF FFFFFFFF
      7203DF6B 21C6052B 53BBF409 39D54123
x_G = 32C4AE2C 1F198119 5F990446 6A39C994
      8FE30BBF F2660BE1 715A4589 334C74C7
y_G = BC3736A2 F4F6779C 59BDCEE3 6B692153
      D0A9877C C62A4740 02DF32E5 2139F0A0

Reference:

• https://github.com/riboseinc/rfc-crypto-sm2/blob/master/sections/03-sm2.md

[JasonGross]

Shouldn't this be sm2scalar.go?

[emmansun]

oh yes my mistake.

[andres-erbsen]

Thank you for the contribution!