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cfca csr with tmp publickey and parse returned encryption key #286
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@emmansun
emmansun authored Dec 11, 2024
1 parent c6881ae commit 3371b7c
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Showing 5 changed files with 181 additions and 30 deletions.
70 changes: 67 additions & 3 deletions cfca/pkcs10.go
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Original file line number Diff line number Diff line change
Expand Up @@ -5,23 +5,87 @@
package cfca

import (
"bytes"
"crypto/ecdsa"
"crypto/x509"
"encoding/asn1"
"encoding/base64"
"errors"
"io"
"strconv"

"github.com/emmansun/gmsm/sm2"
"github.com/emmansun/gmsm/smx509"
)

type CertificateRequest = smx509.CertificateRequestCFCA

// CreateCertificateRequest creates a new certificate request based on a template.
// The following members of template are used: Subject.
// The certPriv is the private key for the certificate, and the tmpPriv is the temporary private key for returning encryption key decryption.
// The certPriv is the private key for the certificate, and the tmpPub is the temporary public key for returning encryption key decryption.
// The challenge password is basically a shared-secret nonce between you and CFCA, embedded in the CSR.
func CreateCertificateRequest(rand io.Reader, template *x509.CertificateRequest, certPriv, tmpPriv any, challengePassword string) ([]byte, error) {
return smx509.CreateCFCACertificateRequest(rand, template, certPriv, tmpPriv, challengePassword)
func CreateCertificateRequest(rand io.Reader, template *x509.CertificateRequest, certPriv, tmpPub any, challengePassword string) ([]byte, error) {
return smx509.CreateCFCACertificateRequest(rand, template, certPriv, tmpPub, challengePassword)
}

// ParseCertificateRequest parses a certificate request from the given DER data.
func ParseCertificateRequest(der []byte) (*CertificateRequest, error) {
return smx509.ParseCFCACertificateRequest(der)
}

const encryptedEncKeyPrefix = "0000000000000001000000000000000100000000000000000000000000000000"

type encryptedPrivateKeyInfo struct {
Version int `asn1:"default:1"`
EncryptedKey []byte
}

// ParseEncryptionPrivateKey parses an encrypted SM2 private key from the given data.
// The data is expected to be in the format of "0000000000000001000000000000000100000000000000000000000000000000...".
// If the data is not in this format, it will be treated as base64 encoded data directly.
func ParseEncryptionPrivateKey(tmpPriv *sm2.PrivateKey, data []byte) (*sm2.PrivateKey, error) {
if len(data) < 268 {
return nil, errors.New("cfca: invalid encrypted private key data")
}
encodedKeyPart := data
if bytes.HasPrefix(data, []byte(encryptedEncKeyPrefix)) {
retLen, err := strconv.Atoi(string(data[64:80]))
if err != nil {
return nil, err
}
if retLen != len(data[80:]) {
return nil, errors.New("cfca: invalid encrypted private key data")
}
encodedKeyPart = data[80:]
}
// remove all commas ONLY now. If there are other non-base64 characters, the base64 decoder will fail.
encodedKeyPart = bytes.ReplaceAll(encodedKeyPart, []byte{44}, []byte{})
der, err := base64.StdEncoding.DecodeString(string(encodedKeyPart))
if err != nil {
return nil, err
}
var keyInfo encryptedPrivateKeyInfo
if _, err := asn1.Unmarshal(der, &keyInfo); err != nil {
return nil, err
}
var ret []byte
if ret, err = tmpPriv.Decrypt(nil, append([]byte{0x04}, keyInfo.EncryptedKey...), nil); err != nil {
return nil, errors.New("cfca: failed to decrypt the private key, possibly due to incorrect key data")
}
// X || Y || D
if len(ret) != 96 {
return nil, errors.New("cfca: invalid decrypted private key data")
}
var priv *sm2.PrivateKey
if priv, err = sm2.NewPrivateKey(ret[64:]); err != nil {
return nil, err
}
var pub *ecdsa.PublicKey
if pub, err = sm2.NewPublicKey(append([]byte{0x04}, ret[:64]...)); err != nil {
return nil, err
}
if !pub.Equal(&priv.PublicKey) {
return nil, errors.New("cfca: key pair mismatch, possibly due to incorrect key data or corruption")
}
return priv, nil
}
103 changes: 98 additions & 5 deletions cfca/pkcs10_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,7 @@ import (
"crypto/rand"
"crypto/x509"
"crypto/x509/pkix"
"encoding/hex"
"testing"

"github.com/emmansun/gmsm/sm2"
Expand Down Expand Up @@ -41,18 +42,18 @@ func TestCreateCertificateRequest(t *testing.T) {
t.Fatal("certificate private key does not implement crypto.Signer")
}
_, err = CreateCertificateRequest(random, template, certKey, "", "")
if err == nil || err.Error() != "x509: tmp private key does not implement crypto.Signer" {
t.Fatal("tmp private key does not implement crypto.Signer")
if err == nil || err.Error() != "x509: only SM2 public key is supported" {
t.Fatal("only SM2 public key is supported")
}
_, err = CreateCertificateRequest(random, template, certKey, invalidTmpKey, "")
_, err = CreateCertificateRequest(random, template, certKey, invalidTmpKey.Public(), "")
if err == nil || err.Error() != "x509: only SM2 public key is supported" {
t.Fatal("only SM2 public key is supported")
}
_, err = CreateCertificateRequest(random, template, certKey, tmpKey, "")
_, err = CreateCertificateRequest(random, template, certKey, tmpKey.Public(), "")
if err == nil || err.Error() != "x509: challenge password is required" {
t.Fatal("challenge password is required")
}
csrDer, err := CreateCertificateRequest(random, template, certKey, tmpKey, "111111")
csrDer, err := CreateCertificateRequest(random, template, certKey, tmpKey.Public(), "111111")
if err != nil {
t.Fatal(err)
}
Expand All @@ -73,3 +74,95 @@ func TestCreateCertificateRequest(t *testing.T) {
t.Fatal("tmp public key not match")
}
}

func TestParseEncryptionPrivateKey(t *testing.T) {
cases := []struct {
encKeyHex string
tmpKeyHex string
encryptedKey string
wantError bool
errorMsg string
}{
{ // with prefix, without delimiter
"f6e02c941a0dfdac58d8b3b1bc1bd136f179741b7465ebc7b0b25bb381840a3b",
"cacece36cac24aab94e52bcd5c0f552c95028f2856053135a1e47510b4c307ba",
"00000000000000010000000000000001000000000000000000000000000000000000000000000268MIHGAgEBBIHArhtKwTVT8dPEkykVRpvQNMxHv/yeqtaKZiSp2MbjcqMZtPfKW8IatiIPPitNhQtU5C7gMbsUxgf5Yo16vDSXdoWqoOOaes2pEJwmXWZI55lMMWc168WgzQ82fmMi05Vhlw9HNjGI3azE6MS5/ujSNGLZ0qAAmLnBiHlXFAXXAWRiy9MxZKwF4xKn6qMaKmkqbYmTbBbEJEhzJBmu0IJ1kNDcTFirAyapghHSw267erSUwsHjkQis9mKYpzGied0E",
false,
"",
},
{ // without prefix, without delimiter
"f6e02c941a0dfdac58d8b3b1bc1bd136f179741b7465ebc7b0b25bb381840a3b",
"cacece36cac24aab94e52bcd5c0f552c95028f2856053135a1e47510b4c307ba",
"MIHGAgEBBIHArhtKwTVT8dPEkykVRpvQNMxHv/yeqtaKZiSp2MbjcqMZtPfKW8IatiIPPitNhQtU5C7gMbsUxgf5Yo16vDSXdoWqoOOaes2pEJwmXWZI55lMMWc168WgzQ82fmMi05Vhlw9HNjGI3azE6MS5/ujSNGLZ0qAAmLnBiHlXFAXXAWRiy9MxZKwF4xKn6qMaKmkqbYmTbBbEJEhzJBmu0IJ1kNDcTFirAyapghHSw267erSUwsHjkQis9mKYpzGied0E",
false,
"",
},
{ // with prefix, with delimiter
"f6e02c941a0dfdac58d8b3b1bc1bd136f179741b7465ebc7b0b25bb381840a3b",
"cacece36cac24aab94e52bcd5c0f552c95028f2856053135a1e47510b4c307ba",
"00000000000000010000000000000001000000000000000000000000000000000000000000000273MIHGAgEBBIHArhtKwTVT8dPEkykVRpvQNMxHv/yeqtaKZiSp2MbjcqMZtPfKW8Ia,tiIPPitNhQtU5C7gMbsUxgf5Yo16vDSXdoWqoOOaes2pEJwmXWZI55lMMWc168Wg,zQ82fmMi05Vhlw9HNjGI3azE6MS5/ujSNGLZ0qAAmLnBiHlXFAXXAWRiy9MxZKwF,4xKn6qMaKmkqbYmTbBbEJEhzJBmu0IJ1kNDcTFirAyapghHSw267erSUwsHjkQis,9mKYpzGied0E,",
false,
"",
},
{ // too short
"f6e02c941a0dfdac58d8b3b1bc1bd136f179741b7465ebc7b0b25bb381840a3b",
"cacece36cac24aab94e52bcd5c0f552c95028f2856053135a1e47510b4c307ba",
"000000000000000100000000000000010",
true,
"cfca: invalid encrypted private key data",
},
{ // length not match
"f6e02c941a0dfdac58d8b3b1bc1bd136f179741b7465ebc7b0b25bb381840a3b",
"cacece36cac24aab94e52bcd5c0f552c95028f2856053135a1e47510b4c307ba",
"00000000000000010000000000000001000000000000000000000000000000000000000000000273MIHGAgEBBIHArhtKwTVT8dPEkykVRpvQNMxHv/yeqtaKZiSp2MbjcqMZtPfKW8IatiIPPitNhQtU5C7gMbsUxgf5Yo16vDSXdoWqoOOaes2pEJwmXWZI55lMMWc168WgzQ82fmMi05Vhlw9HNjGI3azE6MS5/ujSNGLZ0qAAmLnBiHlXFAXXAWRiy9MxZKwF4xKn6qMaKmkqbYmTbBbEJEhzJBmu0IJ1kNDcTFirAyapghHSw267erSUwsHjkQis9mKYpzGied0E",
true,
"cfca: invalid encrypted private key data",
},
{ // with prefix, with invalid delimiter
"f6e02c941a0dfdac58d8b3b1bc1bd136f179741b7465ebc7b0b25bb381840a3b",
"cacece36cac24aab94e52bcd5c0f552c95028f2856053135a1e47510b4c307ba",
"00000000000000010000000000000001000000000000000000000000000000000000000000000274MIHGAgEBBIHArhtKwTVT8dPEkykVRpvQNMxHv/yeqtaKZiSp2MbjcqMZtPfKW8Ia, tiIPPitNhQtU5C7gMbsUxgf5Yo16vDSXdoWqoOOaes2pEJwmXWZI55lMMWc168Wg,zQ82fmMi05Vhlw9HNjGI3azE6MS5/ujSNGLZ0qAAmLnBiHlXFAXXAWRiy9MxZKwF,4xKn6qMaKmkqbYmTbBbEJEhzJBmu0IJ1kNDcTFirAyapghHSw267erSUwsHjkQis,9mKYpzGied0E,",
true,
"illegal base64 data at input byte 64",
},
{ // invalid base64
"f6e02c941a0dfdac58d8b3b1bc1bd136f179741b7465ebc7b0b25bb381840a3b",
"cacece36cac24aab94e52bcd5c0f552c95028f2856053135a1e47510b4c307ba",
"NIHGAgEBBIHArhtKwTVT8dPEkykVRpvQNMxHv/yeqtaKZiSp2MbjcqMZtPfKW8IatiIPPitNhQtU5C7gMbsUxgf5Yo16vDSXdoWqoOOaes2pEJwmXWZI55lMMWc168WgzQ82fmMi05Vhlw9HNjGI3azE6MS5/ujSNGLZ0qAAmLnBiHlXFAXXAWRiy9MxZKwF4xKn6qMaKmkqbYmTbBbEJEhzJBmu0IJ1kNDcTFirAyapghHSw267erSUwsHjkQis9mKYpzGied0E",
true,
"asn1: structure error: tags don't match (16 vs {class:0 tag:20 length:198 isCompound:true}) {optional:false explicit:false application:false private:false defaultValue:<nil> tag:<nil> stringType:0 timeType:0 set:false omitEmpty:false} encryptedPrivateKeyInfo @3",
},
{ // with prefix, with delimiter, invalid length string
"f6e02c941a0dfdac58d8b3b1bc1bd136f179741b7465ebc7b0b25bb381840a3b",
"cacece36cac24aab94e52bcd5c0f552c95028f2856053135a1e47510b4c307ba",
"00000000000000010000000000000001000000000000000000000000000000000000000000000/73MIHGAgEBBIHArhtKwTVT8dPEkykVRpvQNMxHv/yeqtaKZiSp2MbjcqMZtPfKW8Ia,tiIPPitNhQtU5C7gMbsUxgf5Yo16vDSXdoWqoOOaes2pEJwmXWZI55lMMWc168Wg,zQ82fmMi05Vhlw9HNjGI3azE6MS5/ujSNGLZ0qAAmLnBiHlXFAXXAWRiy9MxZKwF,4xKn6qMaKmkqbYmTbBbEJEhzJBmu0IJ1kNDcTFirAyapghHSw267erSUwsHjkQis,9mKYpzGied0E,",
true,
"strconv.Atoi: parsing \"0000000000000/73\": invalid syntax",
},
}
for _, c := range cases {
encKey, _ := hex.DecodeString(c.encKeyHex)
tmpKey, _ := hex.DecodeString(c.tmpKeyHex)
tmpSM2Key, err := sm2.NewPrivateKey(tmpKey)
if err != nil {
t.Fatal(err)
}
targetEncKey, err := sm2.NewPrivateKey(encKey)
if err != nil {
t.Fatal(err)
}
gotKey, err := ParseEncryptionPrivateKey(tmpSM2Key, []byte(c.encryptedKey))
if c.wantError {
if err == nil || err.Error() != c.errorMsg {
t.Fatalf("expected error %v, got %v", c.errorMsg, err)
}
continue
}
if err != nil {
t.Fatal(err)
}
if !gotKey.Equal(targetEncKey) {
t.Fatalf("decrypted key not match")
}
}
}
9 changes: 4 additions & 5 deletions cfca/pkcs12_sm2.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -70,11 +70,10 @@ func ParseSM2(password, data []byte) (*sm2.PrivateKey, *smx509.Certificate, erro
}
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())

prvKey, err := sm2.NewPrivateKeyFromInt(d)
if err != nil {
return nil, nil, err
}
cert, err := smx509.ParseCertificate(keys.Certificate.Content)
if err != nil {
return nil, nil, err
Expand Down
19 changes: 7 additions & 12 deletions smx509/cfca_csr.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -29,11 +29,11 @@ var (
// - SignatureAlgorithm
// - Subject
//
// The certPriv is the private key for the certificate, and the tmpPriv is the temporary private key for returning encryption key decryption.
// The certPriv is the private key for the certificate, and the tmpPub is the temporary private key for returning encryption key decryption.
// The challenge password is basically a shared-secret nonce between you and CFCA, embedded in the CSR,
// which the issuer may use to authenticate you should that ever be needed.
// The template is the certificate request template, we just use Subject now.
func CreateCFCACertificateRequest(rand io.Reader, template *x509.CertificateRequest, priv, tmpPriv any, challengePassword string) ([]byte, error) {
func CreateCFCACertificateRequest(rand io.Reader, template *x509.CertificateRequest, priv, tmpPub any, challengePassword string) ([]byte, error) {
key, ok := priv.(crypto.Signer)
if !ok {
return nil, errors.New("x509: certificate private key does not implement crypto.Signer")
Expand All @@ -52,8 +52,8 @@ func CreateCFCACertificateRequest(rand io.Reader, template *x509.CertificateRequ

var rawAttributes []asn1.RawValue
// Add the temporary public key and challenge password if requested.
if tmpPriv != nil {
rawAttributes, err = buildTmpPublicKeyAttr(rawAttributes, tmpPriv)
if tmpPub != nil {
rawAttributes, err = buildTmpPublicKeyAttr(rawAttributes, tmpPub)
if err != nil {
return nil, err
}
Expand Down Expand Up @@ -130,18 +130,13 @@ func buildChallengePasswordAttr(rawAttributes []asn1.RawValue, challengePassword
return append(rawAttributes, rawValue), nil
}

func buildTmpPublicKeyAttr(rawAttributes []asn1.RawValue, tmpPriv any) ([]asn1.RawValue, error) {
key, ok := tmpPriv.(crypto.Signer)
if !ok {
return nil, errors.New("x509: tmp private key does not implement crypto.Signer")
}
func buildTmpPublicKeyAttr(rawAttributes []asn1.RawValue, tmpPub crypto.PublicKey) ([]asn1.RawValue, error) {
var publicKeyBytes [136]byte
copy(publicKeyBytes[:], tmpPublicKeyPrefix)
pub := key.Public()
if !sm2.IsSM2PublicKey(pub) {
if !sm2.IsSM2PublicKey(tmpPub) {
return nil, errors.New("x509: only SM2 public key is supported")
}
ecPub, _ := pub.(*ecdsa.PublicKey)
ecPub, _ := tmpPub.(*ecdsa.PublicKey)
ecPub.X.FillBytes(publicKeyBytes[8:40])
ecPub.Y.FillBytes(publicKeyBytes[72:104])
b, _ := asn1.Marshal(publicKeyBytes[:])
Expand Down
10 changes: 5 additions & 5 deletions smx509/cfca_csr_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -41,18 +41,18 @@ func TestCreateCFCACertificateRequest(t *testing.T) {
t.Fatal("certificate private key does not implement crypto.Signer")
}
_, err = CreateCFCACertificateRequest(random, template, certKey, "", "")
if err == nil || err.Error() != "x509: tmp private key does not implement crypto.Signer" {
t.Fatal("tmp private key does not implement crypto.Signer")
if err == nil || err.Error() != "x509: only SM2 public key is supported" {
t.Fatal("only SM2 public key is supported")
}
_, err = CreateCFCACertificateRequest(random, template, certKey, invalidTmpKey, "")
_, err = CreateCFCACertificateRequest(random, template, certKey, invalidTmpKey.Public(), "")
if err == nil || err.Error() != "x509: only SM2 public key is supported" {
t.Fatal("only SM2 public key is supported")
}
_, err = CreateCFCACertificateRequest(random, template, certKey, tmpKey, "")
_, err = CreateCFCACertificateRequest(random, template, certKey, tmpKey.Public(), "")
if err == nil || err.Error() != "x509: challenge password is required" {
t.Fatal("challenge password is required")
}
csrDer, err := CreateCFCACertificateRequest(random, template, certKey, tmpKey, "111111")
csrDer, err := CreateCFCACertificateRequest(random, template, certKey, tmpKey.Public(), "111111")
if err != nil {
t.Fatal(err)
}
Expand Down

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