YouChuKoffee/app/utils/postbank/internal/sm2/utils.go

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2024-06-19 18:32:34 +08:00
package sm2
import (
"encoding/hex"
"errors"
"math/big"
)
func ReadPrivateKeyFromHex(Dhex string) (*PrivateKey, error) {
c := P256Sm2()
d, err := hex.DecodeString(Dhex)
if err != nil {
return nil, err
}
k := new(big.Int).SetBytes(d)
params := c.Params()
one := new(big.Int).SetInt64(1)
n := new(big.Int).Sub(params.N, one)
if k.Cmp(n) >= 0 {
return nil, errors.New("privateKey's D is overflow.")
}
priv := new(PrivateKey)
priv.PublicKey.Curve = c
priv.D = k
priv.PublicKey.X, priv.PublicKey.Y = c.ScalarBaseMult(k.Bytes())
return priv, nil
}
func ReadPublicKeyFromHex(Qhex string) (*PublicKey, error) {
q, err := hex.DecodeString(Qhex)
if err != nil {
return nil, err
}
if len(q) == 65 && q[0] == byte(0x04) {
q = q[1:]
}
if len(q) != 64 {
return nil, errors.New("publicKey is not uncompressed.")
}
pub := new(PublicKey)
pub.Curve = P256Sm2()
pub.X = new(big.Int).SetBytes(q[:32])
pub.Y = new(big.Int).SetBytes(q[32:])
return pub, nil
}