mirror of
https://github.com/emmansun/gmsm.git
synced 2025-04-22 02:06:18 +08:00
125 lines
3.5 KiB
Go
125 lines
3.5 KiB
Go
// Package cfca handles cfca issued key and certificate
|
||
package cfca
|
||
|
||
import (
|
||
"crypto/cipher"
|
||
"encoding/asn1"
|
||
"errors"
|
||
"fmt"
|
||
"math/big"
|
||
|
||
"github.com/emmansun/gmsm/padding"
|
||
"github.com/emmansun/gmsm/pkcs"
|
||
"github.com/emmansun/gmsm/pkcs7"
|
||
"github.com/emmansun/gmsm/sm2"
|
||
"github.com/emmansun/gmsm/sm3"
|
||
"github.com/emmansun/gmsm/sm4"
|
||
"github.com/emmansun/gmsm/smx509"
|
||
)
|
||
|
||
// CFCA私有格式，在SADK中把它定义为PKCS12_SM2
|
||
|
||
type cfcaKeyPairData struct {
|
||
Version int `asn1:"default:1"`
|
||
EncryptedKey keyData
|
||
Certificate certData
|
||
}
|
||
|
||
// 被加密的私钥数据
|
||
type keyData struct {
|
||
ContentType asn1.ObjectIdentifier
|
||
Algorithm asn1.ObjectIdentifier
|
||
EncryptedContent asn1.RawValue
|
||
}
|
||
|
||
// 对应的证书
|
||
type certData struct {
|
||
ContentType asn1.ObjectIdentifier
|
||
Content asn1.RawContent
|
||
}
|
||
|
||
var (
|
||
oidSM2Data = pkcs7.SM2OIDData
|
||
oidSM4 = pkcs.SM4.OID()
|
||
oidSM4CBC = pkcs.SM4CBC.OID()
|
||
)
|
||
|
||
// ParseSM2 parses the der data, returns private key and related certificate, it's CFCA private structure.
|
||
func ParseSM2(password, data []byte) (*sm2.PrivateKey, *smx509.Certificate, error) {
|
||
var keys cfcaKeyPairData
|
||
if _, err := asn1.Unmarshal(data, &keys); err != nil {
|
||
return nil, nil, err
|
||
}
|
||
if !keys.Certificate.ContentType.Equal(oidSM2Data) {
|
||
return nil, nil, fmt.Errorf("cfca: unsupported content type oid <%v>", keys.Certificate.ContentType)
|
||
}
|
||
if !keys.EncryptedKey.ContentType.Equal(oidSM2Data) {
|
||
return nil, nil, fmt.Errorf("cfca: unsupported content type oid <%v>", keys.EncryptedKey.ContentType)
|
||
}
|
||
if !keys.EncryptedKey.Algorithm.Equal(oidSM4) && !keys.EncryptedKey.Algorithm.Equal(oidSM4CBC) {
|
||
return nil, nil, fmt.Errorf("cfca: unsupported algorithm <%v>", keys.EncryptedKey.Algorithm)
|
||
}
|
||
ivkey := sm3.Kdf(password, 32)
|
||
marshalledIV, err := asn1.Marshal(ivkey[:16])
|
||
if err != nil {
|
||
return nil, nil, err
|
||
}
|
||
pk, err := pkcs.SM4CBC.Decrypt(ivkey[16:], &asn1.RawValue{FullBytes: marshalledIV}, keys.EncryptedKey.EncryptedContent.Bytes)
|
||
if err != nil {
|
||
return nil, nil, err
|
||
}
|
||
d := new(big.Int).SetBytes(pk) // here we do NOT check if the d is in (0, N) or not
|
||
// Create private key from *big.Int
|
||
prvKey := new(sm2.PrivateKey)
|
||
prvKey.Curve = sm2.P256()
|
||
prvKey.D = d
|
||
prvKey.PublicKey.X, prvKey.PublicKey.Y = prvKey.ScalarBaseMult(prvKey.D.Bytes())
|
||
|
||
cert, err := smx509.ParseCertificate(keys.Certificate.Content)
|
||
if err != nil {
|
||
return nil, nil, err
|
||
}
|
||
|
||
if !prvKey.PublicKey.Equal(cert.PublicKey) {
|
||
return nil, nil, errors.New("cfca: public key and private key do not match")
|
||
}
|
||
return prvKey, cert, nil
|
||
}
|
||
|
||
// MarshalSM2 encodes sm2 private key and related certificate to cfca defined format
|
||
func MarshalSM2(password []byte, key *sm2.PrivateKey, cert *smx509.Certificate) ([]byte, error) {
|
||
if len(password) == 0 {
|
||
return nil, errors.New("cfca: invalid password")
|
||
}
|
||
ivkey := sm3.Kdf(password, 32)
|
||
block, err := sm4.NewCipher(ivkey[16:])
|
||
if err != nil {
|
||
return nil, err
|
||
}
|
||
mode := cipher.NewCBCEncrypter(block, ivkey[:16])
|
||
pkcs7 := padding.NewPKCS7Padding(uint(block.BlockSize()))
|
||
plainText := pkcs7.Pad(key.D.Bytes())
|
||
ciphertext := make([]byte, len(plainText))
|
||
mode.CryptBlocks(ciphertext, plainText)
|
||
|
||
ciphertext, err = asn1.Marshal(ciphertext)
|
||
if err != nil {
|
||
return nil, err
|
||
}
|
||
|
||
keys := cfcaKeyPairData{
|
||
Version: 1,
|
||
EncryptedKey: keyData{
|
||
ContentType: oidSM2Data,
|
||
Algorithm: oidSM4,
|
||
EncryptedContent: asn1.RawValue{FullBytes: ciphertext},
|
||
},
|
||
Certificate: certData{
|
||
ContentType: oidSM2Data,
|
||
Content: cert.Raw,
|
||
},
|
||
}
|
||
|
||
return asn1.Marshal(keys)
|
||
}
|