func (client *clientImpl) validateTCert(tCertDER []byte) (*x509.Certificate, error) {
client.node.log.Debug("Validating TCert [%s]", utils.EncodeBase64(tCertDER))
// DER to x509
x509Cert, err := utils.DERToX509Certificate(tCertDER)
if err != nil {
client.node.log.Debug("Failed parsing certificate: [%s].", err)
return nil, err
}
// Handle Critical Extension TCertEncTCertIndex
if _, err = utils.GetCriticalExtension(x509Cert, utils.TCertEncTCertIndex); err != nil {
client.node.log.Error("Failed getting extension TCERT_ENC_TCERTINDEX [%s].", err.Error())
return nil, err
}
// Verify certificate against root
if _, err := utils.CheckCertAgainRoot(x509Cert, client.node.tcaCertPool); err != nil {
client.node.log.Warning("Warning verifing certificate [%s].", err.Error())
return nil, err
}
return x509Cert, nil
}
func (validator *validatorImpl) getEnrollmentCert(id []byte) (*x509.Certificate, error) {
sid := utils.EncodeBase64(id)
validator.peer.node.log.Debug("Getting enrollment certificate for [%d]", sid)
if cert := validator.enrollCerts[sid]; cert != nil {
validator.peer.node.log.Debug("Enrollment certificate for [%d] already in memory.", sid)
return cert, nil
}
// Retrieve from the DB or from the ECA in case
validator.peer.node.log.Debug("Retrieve Enrollment certificate for [%d]...", sid)
rawCert, err := validator.peer.node.ks.GetSignEnrollmentCert(id, validator.getEnrollmentCertByHashFromECA)
if err != nil {
validator.peer.node.log.Error("Failed getting enrollment certificate for [%s]: [%s]", sid, err)
}
validator.peer.node.log.Debug("Enrollment certificate for [%s] = [%s]", sid, utils.EncodeBase64(rawCert))
cert, err := utils.DERToX509Certificate(rawCert)
if err != nil {
validator.peer.node.log.Error("Failed parsing enrollment certificate for [%s]: [%s],[%s]", sid, utils.EncodeBase64(rawCert), err)
}
validator.enrollCerts[sid] = cert
return cert, nil
}
func (validator *validatorImpl) getEnrollmentCert(id []byte) (*x509.Certificate, error) {
if len(id) == 0 {
return nil, fmt.Errorf("Invalid peer id. It is empty.")
}
sid := utils.EncodeBase64(id)
validator.debug("Getting enrollment certificate for [%s]", sid)
if cert := validator.enrollCerts[sid]; cert != nil {
validator.debug("Enrollment certificate for [%s] already in memory.", sid)
return cert, nil
}
// Retrieve from the DB or from the ECA in case
validator.debug("Retrieve Enrollment certificate for [%s]...", sid)
rawCert, err := validator.ks.GetSignEnrollmentCert(id, validator.getEnrollmentCertByHashFromECA)
if err != nil {
validator.error("Failed getting enrollment certificate for [%s]: [%s]", sid, err)
return nil, err
}
cert, err := utils.DERToX509Certificate(rawCert)
if err != nil {
validator.error("Failed parsing enrollment certificate for [%s]: [% x],[% x]", sid, rawCert, err)
return nil, err
}
validator.enrollCerts[sid] = cert
return cert, nil
}
func (node *nodeImpl) retrieveTCACertsChain(userID string) error {
// Retrieve TCA certificate and verify it
tcaCertRaw, err := node.getTCACertificate()
if err != nil {
node.log.Error("Failed getting TCA certificate [%s].", err.Error())
return err
}
node.log.Debug("TCA certificate [%s]", utils.EncodeBase64(tcaCertRaw))
// TODO: Test TCA cert againt root CA
_, err = utils.DERToX509Certificate(tcaCertRaw)
if err != nil {
node.log.Error("Failed parsing TCA certificate [%s].", err.Error())
return err
}
// Store TCA cert
node.log.Debug("Storing TCA certificate for validator [%s]...", userID)
err = ioutil.WriteFile(node.conf.getTCACertsChainPath(), utils.DERCertToPEM(tcaCertRaw), 0700)
if err != nil {
node.log.Error("Failed storing tca certificate [%s].", err.Error())
return err
}
return nil
}
func (node *nodeImpl) retrieveECACertsChain(userID string) error {
// Retrieve ECA certificate and verify it
ecaCertRaw, err := node.getECACertificate()
if err != nil {
node.log.Error("Failed getting ECA certificate [%s].", err.Error())
return err
}
node.log.Debug("ECA certificate [%s].", utils.EncodeBase64(ecaCertRaw))
// TODO: Test ECA cert againt root CA
// TODO: check responce.Cert against rootCA
x509ECACert, err := utils.DERToX509Certificate(ecaCertRaw)
if err != nil {
node.log.Error("Failed parsing ECA certificate [%s].", err.Error())
return err
}
// Prepare ecaCertPool
node.ecaCertPool = x509.NewCertPool()
node.ecaCertPool.AddCert(x509ECACert)
// Store ECA cert
node.log.Debug("Storing ECA certificate for [%s]...", userID)
if err := node.ks.storeCert(node.conf.getECACertsChainFilename(), ecaCertRaw); err != nil {
node.log.Error("Failed storing eca certificate [%s].", err.Error())
return err
}
return nil
}
func (client *clientImpl) getTCertFromExternalDER(der []byte) (tCert, error) {
// DER to x509
x509Cert, err := utils.DERToX509Certificate(der)
if err != nil {
client.debug("Failed parsing certificate [% x]: [%s].", der, err)
return nil, err
}
// Handle Critical Extension TCertEncTCertIndex
if _, err = utils.GetCriticalExtension(x509Cert, utils.TCertEncTCertIndex); err != nil {
client.error("Failed getting extension TCERT_ENC_TCERTINDEX [% x]: [%s].", der, err)
return nil, err
}
// Verify certificate against root
if _, err := utils.CheckCertAgainRoot(x509Cert, client.tcaCertPool); err != nil {
client.warning("Warning verifing certificate [% x]: [%s].", der, err)
return nil, err
}
return &tCertImpl{client, x509Cert, nil}, nil
}
func (node *nodeImpl) retrieveTCACertsChain(userID string) error {
// Retrieve TCA certificate and verify it
tcaCertRaw, err := node.getTCACertificate()
if err != nil {
node.error("Failed getting TCA certificate [%s].", err.Error())
return err
}
node.debug("TCA certificate [% x]", tcaCertRaw)
// TODO: Test TCA cert againt root CA
_, err = utils.DERToX509Certificate(tcaCertRaw)
if err != nil {
node.error("Failed parsing TCA certificate [%s].", err.Error())
return err
}
// Store TCA cert
node.debug("Storing TCA certificate for [%s]...", userID)
if err := node.ks.storeCert(node.conf.getTCACertsChainFilename(), tcaCertRaw); err != nil {
node.error("Failed storing tca certificate [%s].", err.Error())
return err
}
return nil
}
func (node *nodeImpl) getTLSCertificateFromTLSCA(id, affiliation string) (interface{}, []byte, error) {
node.log.Info("getTLSCertificate...")
priv, err := utils.NewECDSAKey()
if err != nil {
node.log.Error("Failed generating key: %s", err)
return nil, nil, err
}
uuid, err := util.GenerateUUID()
if err != nil {
node.log.Error("Failed generating uuid: %s", err)
return nil, nil, err
}
// Prepare the request
pubraw, _ := x509.MarshalPKIXPublicKey(&priv.PublicKey)
now := time.Now()
timestamp := google_protobuf.Timestamp{int64(now.Second()), int32(now.Nanosecond())}
req := &obcca.TLSCertCreateReq{
×tamp,
&obcca.Identity{Id: id + "-" + uuid},
&obcca.Password{Pw: ""},
&obcca.PublicKey{
Type: obcca.CryptoType_ECDSA,
Key: pubraw,
}, nil}
rawreq, _ := proto.Marshal(req)
r, s, err := ecdsa.Sign(rand.Reader, priv, utils.Hash(rawreq))
if err != nil {
panic(err)
}
R, _ := r.MarshalText()
S, _ := s.MarshalText()
req.Sig = &obcca.Signature{obcca.CryptoType_ECDSA, R, S}
pbCert, err := node.callTLSCACreateCertificate(context.Background(), req)
if err != nil {
node.log.Error("Failed requesting tls certificate: %s", err)
return nil, nil, err
}
node.log.Info("Verifing tls certificate...")
tlsCert, err := utils.DERToX509Certificate(pbCert.Cert)
certPK := tlsCert.PublicKey.(*ecdsa.PublicKey)
utils.VerifySignCapability(priv, certPK)
node.log.Info("Verifing tls certificate...done!")
return priv, pbCert.Cert, nil
}
func (client *clientImpl) signUsingTCertDER(tCertDER []byte, msg []byte) ([]byte, error) {
// Parse the DER
tCert, err := utils.DERToX509Certificate(tCertDER)
if err != nil {
client.node.log.Error("Failed parsing TCert DER [%s].", err.Error())
return nil, err
}
return client.signUsingTCertX509(tCert, msg)
}
func (validator *validatorImpl) verifyValidityPeriod(tx *obc.Transaction) (*obc.Transaction, error) {
if tx.Cert != nil && tx.Signature != nil {
// Unmarshal cert
cert, err := utils.DERToX509Certificate(tx.Cert)
if err != nil {
validator.peer.node.log.Error("verifyValidityPeriod: failed unmarshalling cert %s:", err)
return tx, err
}
cid := viper.GetString("pki.validity-period.chaincodeHash")
ledger, err := ledger.GetLedger()
if err != nil {
validator.peer.node.log.Error("verifyValidityPeriod: failed getting access to the ledger %s:", err)
return tx, err
}
vp_bytes, err := ledger.GetState(cid, "system.validity.period", true)
if err != nil {
validator.peer.node.log.Error("verifyValidityPeriod: failed reading validity period from the ledger %s:", err)
return tx, err
}
i, err := strconv.ParseInt(string(vp_bytes[:]), 10, 64)
if err != nil {
validator.peer.node.log.Error("verifyValidityPeriod: failed to parse validity period %s:", err)
return tx, err
}
vp := time.Unix(i, 0)
var errMsg string = ""
// Verify the validity period of the TCert
switch {
case cert.NotAfter.Before(cert.NotBefore):
errMsg = "verifyValidityPeriod: certificate validity period is invalid"
case vp.Before(cert.NotBefore):
errMsg = "verifyValidityPeriod: certificate validity period is in the future"
case vp.After(cert.NotAfter):
errMsg = "verifyValidityPeriod: certificate validity period is in the past"
}
if errMsg != "" {
validator.peer.node.log.Error(errMsg)
return tx, errors.New(errMsg)
}
}
return tx, nil
}
func (handler *tCertHandlerImpl) initDER(client *clientImpl, tCertDER []byte) error {
// Parse the DER
tCert, err := utils.DERToX509Certificate(tCertDER)
if err != nil {
client.node.log.Error("Failed parsing TCert DER [%s].", err.Error())
return err
}
handler.initX509(client, tCert)
return nil
}
// TransactionPreValidation verifies that the transaction is
// well formed with the respect to the security layer
// prescriptions (i.e. signature verification).
func (peer *peerImpl) TransactionPreValidation(tx *obc.Transaction) (*obc.Transaction, error) {
if !peer.isInitialized {
return nil, utils.ErrNotInitialized
}
// peer.debug("Pre validating [%s].", tx.String())
peer.debug("Tx confdential level [%s].", tx.ConfidentialityLevel.String())
if tx.Cert != nil && tx.Signature != nil {
// Verify the transaction
// 1. Unmarshal cert
cert, err := utils.DERToX509Certificate(tx.Cert)
if err != nil {
peer.error("TransactionPreExecution: failed unmarshalling cert [%s] [%s].", err.Error())
return tx, err
}
// TODO: verify cert
// 3. Marshall tx without signature
signature := tx.Signature
tx.Signature = nil
rawTx, err := proto.Marshal(tx)
if err != nil {
peer.error("TransactionPreExecution: failed marshaling tx [%s] [%s].", err.Error())
return tx, err
}
tx.Signature = signature
// 2. Verify signature
ok, err := peer.verify(cert.PublicKey, rawTx, tx.Signature)
if err != nil {
peer.error("TransactionPreExecution: failed marshaling tx [%s] [%s].", err.Error())
return tx, err
}
if !ok {
return tx, utils.ErrInvalidTransactionSignature
}
} else {
if tx.Cert == nil {
return tx, utils.ErrTransactionCertificate
}
if tx.Signature == nil {
return tx, utils.ErrTransactionSignature
}
}
return tx, nil
}
func (validator *validatorImpl) getEnrollmentCertByHashFromECA(id []byte) ([]byte, []byte, error) {
// Prepare the request
validator.peer.node.log.Debug("Reading certificate for hash [%s]", utils.EncodeBase64(id))
req := &obcca.Hash{Hash: id}
responce, err := validator.peer.node.callECAReadCertificateByHash(context.Background(), req)
if err != nil {
validator.peer.node.log.Error("Failed requesting enrollment certificate [%s].", err.Error())
return nil, nil, err
}
validator.peer.node.log.Debug("Certificate for hash [%s] = [%s][%s]", utils.EncodeBase64(id), utils.EncodeBase64(responce.Sign), utils.EncodeBase64(responce.Enc))
// Verify responce.Sign
x509Cert, err := utils.DERToX509Certificate(responce.Sign)
if err != nil {
validator.peer.node.log.Error("Failed parsing signing enrollment certificate for encrypting: [%s]", err)
return nil, nil, err
}
// Check role
roleRaw, err := utils.GetCriticalExtension(x509Cert, ECertSubjectRole)
if err != nil {
validator.peer.node.log.Error("Failed parsing ECertSubjectRole in enrollment certificate for signing: [%s]", err)
return nil, nil, err
}
role, err := strconv.ParseInt(string(roleRaw), 10, len(roleRaw)*8)
if err != nil {
validator.peer.node.log.Error("Failed parsing ECertSubjectRole in enrollment certificate for signing: [%s]", err)
return nil, nil, err
}
if obcca.Role(role) != obcca.Role_VALIDATOR {
validator.peer.node.log.Error("Invalid ECertSubjectRole in enrollment certificate for signing. Not a validator: [%s]", err)
return nil, nil, err
}
return responce.Sign, responce.Enc, nil
}
// CheckTransaction is used to verify that a transaction
// is well formed with the respect to the security layer
// prescriptions. To be used for internal verifications.
func (client *clientImpl) checkTransaction(tx *obc.Transaction) error {
if !client.isInitialized {
return utils.ErrNotInitialized
}
if tx.Cert == nil && tx.Signature == nil {
return utils.ErrTransactionMissingCert
}
if tx.Cert != nil && tx.Signature != nil {
// Verify the transaction
// 1. Unmarshal cert
cert, err := utils.DERToX509Certificate(tx.Cert)
if err != nil {
client.node.log.Error("Failed unmarshalling cert [%s].", err.Error())
return err
}
// TODO: verify cert
// 3. Marshall tx without signature
signature := tx.Signature
tx.Signature = nil
rawTx, err := proto.Marshal(tx)
if err != nil {
client.node.log.Error("Failed marshaling tx [%s].", err.Error())
return err
}
tx.Signature = signature
// 2. Verify signature
ver, err := client.node.verify(cert.PublicKey, rawTx, tx.Signature)
if err != nil {
client.node.log.Error("Failed marshaling tx [%s].", err.Error())
return err
}
if ver {
return nil
}
return utils.ErrInvalidTransactionSignature
}
return utils.ErrTransactionMissingCert
}
func (validator *validatorImpl) getEnrollmentCert(id []byte) (*x509.Certificate, error) {
sid := utils.EncodeBase64(id)
if cert := validator.enrollCerts[sid]; cert != nil {
return cert, nil
}
// Retrieve from the DB or from the ECA in case
rawCert, err := validator.peer.node.ks.GetEnrollmentCert(id, validator.getEnrollmentCertByHashFromECA)
if err != nil {
validator.peer.node.log.Error("Failed getting enrollment certificate for ", sid, err)
}
cert, err := utils.DERToX509Certificate(rawCert)
if err != nil {
validator.peer.node.log.Error("Failed parsing enrollment certificate for ", sid, utils.EncodeBase64(rawCert))
}
validator.enrollCerts[sid] = cert
return cert, nil
}
func (client *clientImpl) getTCertFromDER(der []byte) (tCert tCert, err error) {
if client.tCertOwnerKDFKey == nil {
return nil, fmt.Errorf("KDF key not initialized yet")
}
TCertOwnerEncryptKey := utils.HMACTruncated(client.tCertOwnerKDFKey, []byte{1}, utils.AESKeyLength)
ExpansionKey := utils.HMAC(client.tCertOwnerKDFKey, []byte{2})
// DER to x509
x509Cert, err := utils.DERToX509Certificate(der)
if err != nil {
client.debug("Failed parsing certificate [% x]: [%s].", der, err)
return
}
// Handle Critical Extenstion TCertEncTCertIndex
tCertIndexCT, err := utils.GetCriticalExtension(x509Cert, utils.TCertEncTCertIndex)
if err != nil {
client.error("Failed getting extension TCERT_ENC_TCERTINDEX [%s].", err.Error())
return
}
// Verify certificate against root
if _, err = utils.CheckCertAgainRoot(x509Cert, client.tcaCertPool); err != nil {
client.warning("Warning verifing certificate [%s].", err.Error())
return
}
// Verify public key
// 384-bit ExpansionValue = HMAC(Expansion_Key, TCertIndex)
// Let TCertIndex = Timestamp, RandValue, 1,2,…
// Timestamp assigned, RandValue assigned and counter reinitialized to 1 per batch
// Decrypt ct to TCertIndex (TODO: || EnrollPub_Key || EnrollID ?)
pt, err := utils.CBCPKCS7Decrypt(TCertOwnerEncryptKey, tCertIndexCT)
if err != nil {
client.error("Failed decrypting extension TCERT_ENC_TCERTINDEX [%s].", err.Error())
return
}
// Compute ExpansionValue based on TCertIndex
TCertIndex := pt
// TCertIndex := []byte(strconv.Itoa(i))
client.debug("TCertIndex: [% x].", TCertIndex)
mac := hmac.New(utils.NewHash, ExpansionKey)
mac.Write(TCertIndex)
ExpansionValue := mac.Sum(nil)
// Derive tpk and tsk accordingly to ExapansionValue from enrollment pk,sk
// Computable by TCA / Auditor: TCertPub_Key = EnrollPub_Key + ExpansionValue G
// using elliptic curve point addition per NIST FIPS PUB 186-4- specified P-384
// Compute temporary secret key
tempSK := &ecdsa.PrivateKey{
PublicKey: ecdsa.PublicKey{
Curve: client.enrollPrivKey.Curve,
X: new(big.Int),
Y: new(big.Int),
},
D: new(big.Int),
}
var k = new(big.Int).SetBytes(ExpansionValue)
var one = new(big.Int).SetInt64(1)
n := new(big.Int).Sub(client.enrollPrivKey.Params().N, one)
k.Mod(k, n)
k.Add(k, one)
tempSK.D.Add(client.enrollPrivKey.D, k)
tempSK.D.Mod(tempSK.D, client.enrollPrivKey.PublicKey.Params().N)
// Compute temporary public key
tempX, tempY := client.enrollPrivKey.PublicKey.ScalarBaseMult(k.Bytes())
tempSK.PublicKey.X, tempSK.PublicKey.Y =
tempSK.PublicKey.Add(
client.enrollPrivKey.PublicKey.X, client.enrollPrivKey.PublicKey.Y,
tempX, tempY,
)
// Verify temporary public key is a valid point on the reference curve
isOn := tempSK.Curve.IsOnCurve(tempSK.PublicKey.X, tempSK.PublicKey.Y)
if !isOn {
client.error("Failed temporary public key IsOnCurve check.")
return nil, fmt.Errorf("Failed temporary public key IsOnCurve check.")
}
// Check that the derived public key is the same as the one in the certificate
certPK := x509Cert.PublicKey.(*ecdsa.PublicKey)
if certPK.X.Cmp(tempSK.PublicKey.X) != 0 {
client.error("Derived public key is different on X")
return nil, fmt.Errorf("Derived public key is different on X")
}
if certPK.Y.Cmp(tempSK.PublicKey.Y) != 0 {
client.error("Derived public key is different on Y")
return nil, fmt.Errorf("Derived public key is different on Y")
}
// Verify the signing capability of tempSK
err = utils.VerifySignCapability(tempSK, x509Cert.PublicKey)
if err != nil {
client.error("Failed verifing signing capability [%s].", err.Error())
return
}
// Marshall certificate and secret key to be stored in the database
if err != nil {
client.error("Failed marshalling private key [%s].", err.Error())
return
}
if err = utils.CheckCertPKAgainstSK(x509Cert, interface{}(tempSK)); err != nil {
client.error("Failed checking TCA cert PK against private key [%s].", err.Error())
return
}
tCert = &tCertImpl{client, x509Cert, tempSK}
return
}
func (node *nodeImpl) getEnrollmentCertificateFromECA(id, pw string) (interface{}, []byte, []byte, error) {
// Get a new ECA Client
sock, ecaP, err := node.getECAClient()
defer sock.Close()
// Run the protocol
signPriv, err := utils.NewECDSAKey()
if err != nil {
node.log.Error("Failed generating ECDSA key [%s].", err.Error())
return nil, nil, nil, err
}
signPub, err := x509.MarshalPKIXPublicKey(&signPriv.PublicKey)
if err != nil {
node.log.Error("Failed mashalling ECDSA key [%s].", err.Error())
return nil, nil, nil, err
}
encPriv, err := utils.NewECDSAKey()
if err != nil {
node.log.Error("Failed generating Encryption key [%s].", err.Error())
return nil, nil, nil, err
}
encPub, err := x509.MarshalPKIXPublicKey(&encPriv.PublicKey)
if err != nil {
node.log.Error("Failed marshalling Encryption key [%s].", err.Error())
return nil, nil, nil, err
}
req := &obcca.ECertCreateReq{&protobuf.Timestamp{Seconds: time.Now().Unix(), Nanos: 0},
&obcca.Identity{id},
&obcca.Token{Tok: []byte(pw)},
&obcca.PublicKey{obcca.CryptoType_ECDSA, signPub},
&obcca.PublicKey{obcca.CryptoType_ECDSA, encPub},
nil}
resp, err := ecaP.CreateCertificatePair(context.Background(), req)
if err != nil {
node.log.Error("Failed invoking CreateCertficatePair [%s].", err.Error())
return nil, nil, nil, err
}
//out, err := rsa.DecryptPKCS1v15(rand.Reader, encPriv, resp.Tok.Tok)
spi := ecies.NewSPI()
eciesKey, err := spi.NewPrivateKey(nil, encPriv)
if err != nil {
node.log.Error("Failed parsing decrypting key [%s].", err.Error())
return nil, nil, nil, err
}
ecies, err := spi.NewAsymmetricCipherFromPublicKey(eciesKey)
if err != nil {
node.log.Error("Failed creating asymmetrinc cipher [%s].", err.Error())
return nil, nil, nil, err
}
out, err := ecies.Process(resp.Tok.Tok)
if err != nil {
node.log.Error("Failed decrypting toke [%s].", err.Error())
return nil, nil, nil, err
}
req.Tok.Tok = out
req.Sig = nil
hash := utils.NewHash()
raw, _ := proto.Marshal(req)
hash.Write(raw)
r, s, err := ecdsa.Sign(rand.Reader, signPriv, hash.Sum(nil))
if err != nil {
node.log.Error("Failed signing [%s].", err.Error())
return nil, nil, nil, err
}
R, _ := r.MarshalText()
S, _ := s.MarshalText()
req.Sig = &obcca.Signature{obcca.CryptoType_ECDSA, R, S}
resp, err = ecaP.CreateCertificatePair(context.Background(), req)
if err != nil {
node.log.Error("Failed invoking CreateCertificatePair [%s].", err.Error())
return nil, nil, nil, err
}
// Verify response
// Verify cert for signing
node.log.Debug("Enrollment certificate for signing [%s]", utils.EncodeBase64(utils.Hash(resp.Certs.Sign)))
x509SignCert, err := utils.DERToX509Certificate(resp.Certs.Sign)
if err != nil {
node.log.Error("Failed parsing signing enrollment certificate for signing: [%s]", err)
return nil, nil, nil, err
}
_, err = utils.GetCriticalExtension(x509SignCert, ECertSubjectRole)
if err != nil {
node.log.Error("Failed parsing ECertSubjectRole in enrollment certificate for signing: [%s]", err)
return nil, nil, nil, err
}
err = utils.CheckCertAgainstSKAndRoot(x509SignCert, signPriv, node.ecaCertPool)
if err != nil {
node.log.Error("Failed checking signing enrollment certificate for signing: [%s]", err)
return nil, nil, nil, err
}
// Verify cert for encrypting
node.log.Debug("Enrollment certificate for encrypting [%s]", utils.EncodeBase64(utils.Hash(resp.Certs.Enc)))
x509EncCert, err := utils.DERToX509Certificate(resp.Certs.Enc)
if err != nil {
node.log.Error("Failed parsing signing enrollment certificate for encrypting: [%s]", err)
return nil, nil, nil, err
}
_, err = utils.GetCriticalExtension(x509EncCert, ECertSubjectRole)
if err != nil {
node.log.Error("Failed parsing ECertSubjectRole in enrollment certificate for encrypting: [%s]", err)
return nil, nil, nil, err
}
err = utils.CheckCertAgainstSKAndRoot(x509EncCert, encPriv, node.ecaCertPool)
if err != nil {
node.log.Error("Failed checking signing enrollment certificate for encrypting: [%s]", err)
return nil, nil, nil, err
}
// END
return signPriv, resp.Certs.Sign, resp.Chain.Tok, nil
}
func (client *clientImpl) signWithTCert(tCertDER []byte, msg []byte) ([]byte, error) {
// Extract the signing key from the tCert
// client.node.log.Debug("TCertOwnerKDFKey [%s].", utils.EncodeBase64(client.tCertOwnerKDFKey))
TCertOwnerEncryptKey := utils.HMACTruncated(client.tCertOwnerKDFKey, []byte{1}, utils.AESKeyLength)
ExpansionKey := utils.HMAC(client.tCertOwnerKDFKey, []byte{2})
tCert, err := utils.DERToX509Certificate(tCertDER)
if err != nil {
client.node.log.Error("Failed parsing key [%s].", err.Error())
return nil, err
}
// TODO: retrieve TCertIndex from the ciphertext encrypted under the TCertOwnerEncryptKey
ct, err := utils.GetExtension(tCert, utils.TCertEncTCertIndex)
if err != nil {
client.node.log.Error("Failed getting extension TCERT_ENC_TCERTINDEX [%s].", err.Error())
return nil, err
}
// Decrypt ct to TCertIndex (TODO: || EnrollPub_Key || EnrollID ?)
decryptedTCertIndex, err := utils.CBCPKCS7Decrypt(TCertOwnerEncryptKey, ct)
if err != nil {
client.node.log.Error("Failed decrypting extension TCERT_ENC_TCERTINDEX [%s].", err.Error())
return nil, err
}
// Compute ExpansionValue based on TCertIndex
TCertIndex := decryptedTCertIndex
client.node.log.Debug("TCertIndex [%s].", utils.EncodeBase64(TCertIndex))
mac := hmac.New(utils.NewHash, ExpansionKey)
mac.Write(TCertIndex)
ExpansionValue := mac.Sum(nil)
// Derive tpk and tsk accordingly to ExapansionValue from enrollment pk,sk
// Computable by TCA / Auditor: TCertPub_Key = EnrollPub_Key + ExpansionValue G
// using elliptic curve point addition per NIST FIPS PUB 186-4- specified P-384
// Compute temporary secret key
tempSK := &ecdsa.PrivateKey{
PublicKey: ecdsa.PublicKey{
Curve: client.node.enrollPrivKey.Curve,
X: new(big.Int),
Y: new(big.Int),
},
D: new(big.Int),
}
var k = new(big.Int).SetBytes(ExpansionValue)
var one = new(big.Int).SetInt64(1)
n := new(big.Int).Sub(client.node.enrollPrivKey.Params().N, one)
k.Mod(k, n)
k.Add(k, one)
tempSK.D.Add(client.node.enrollPrivKey.D, k)
tempSK.D.Mod(tempSK.D, client.node.enrollPrivKey.PublicKey.Params().N)
// Compute temporary public key
tempX, tempY := client.node.enrollPrivKey.PublicKey.ScalarBaseMult(k.Bytes())
tempSK.PublicKey.X, tempSK.PublicKey.Y =
tempSK.PublicKey.Add(
client.node.enrollPrivKey.PublicKey.X, client.node.enrollPrivKey.PublicKey.Y,
tempX, tempY,
)
return client.node.sign(tempSK, msg)
}
func (client *clientImpl) getTCertsFromTCA(num int) ([][]byte, error) {
client.node.log.Debug("Get [%d] certificates from the TCA...", num)
// Contact the TCA
TCertOwnerKDFKey, certDERs, err := client.callTCACreateCertificateSet(num)
if err != nil {
client.node.log.Debug("Failed contacting TCA [%s].", err.Error())
return nil, err
}
// client.node.log.Debug("TCertOwnerKDFKey [%s].", utils.EncodeBase64(TCertOwnerKDFKey))
// Store TCertOwnerKDFKey and checks that every time it is always the same key
if client.tCertOwnerKDFKey != nil {
// Check that the keys are the same
equal := bytes.Equal(client.tCertOwnerKDFKey, TCertOwnerKDFKey)
if !equal {
return nil, errors.New("Failed reciving kdf key from TCA. The keys are different.")
}
} else {
client.tCertOwnerKDFKey = TCertOwnerKDFKey
// TODO: handle this situation more carefully
if err := client.storeTCertOwnerKDFKey(); err != nil {
client.node.log.Error("Failed storing TCertOwnerKDFKey [%s].", err.Error())
return nil, err
}
}
// Validate the Certificates obtained
TCertOwnerEncryptKey := utils.HMACTruncated(TCertOwnerKDFKey, []byte{1}, utils.AESKeyLength)
ExpansionKey := utils.HMAC(TCertOwnerKDFKey, []byte{2})
resCert := make([][]byte, num)
j := 0
for i := 0; i < num; i++ {
client.node.log.Debug("Validating certificate [%d], [%s]", i, utils.EncodeBase64(certDERs[i]))
// DER to x509
x509Cert, err := utils.DERToX509Certificate(certDERs[i])
if err != nil {
client.node.log.Debug("Failed parsing certificate: [%s].", err)
continue
}
// Handle Critical Extenstion TCertEncTCertIndex
tCertIndexCT, err := utils.GetCriticalExtension(x509Cert, utils.TCertEncTCertIndex)
if err != nil {
client.node.log.Error("Failed getting extension TCERT_ENC_TCERTINDEX [%s].", err.Error())
continue
}
// Verify certificate against root
if _, err := utils.CheckCertAgainRoot(x509Cert, client.node.tcaCertPool); err != nil {
client.node.log.Warning("Warning verifing certificate [%s].", err.Error())
continue
}
// Verify public key
// 384-bit ExpansionValue = HMAC(Expansion_Key, TCertIndex)
// Let TCertIndex = Timestamp, RandValue, 1,2,…
// Timestamp assigned, RandValue assigned and counter reinitialized to 1 per batch
// Decrypt ct to TCertIndex (TODO: || EnrollPub_Key || EnrollID ?)
pt, err := utils.CBCPKCS7Decrypt(TCertOwnerEncryptKey, tCertIndexCT)
if err != nil {
client.node.log.Error("Failed decrypting extension TCERT_ENC_TCERTINDEX [%s].", err.Error())
continue
}
// Compute ExpansionValue based on TCertIndex
TCertIndex := pt
// TCertIndex := []byte(strconv.Itoa(i))
client.node.log.Debug("TCertIndex: [%s].", utils.EncodeBase64(TCertIndex))
mac := hmac.New(utils.NewHash, ExpansionKey)
mac.Write(TCertIndex)
ExpansionValue := mac.Sum(nil)
// Derive tpk and tsk accordingly to ExapansionValue from enrollment pk,sk
// Computable by TCA / Auditor: TCertPub_Key = EnrollPub_Key + ExpansionValue G
// using elliptic curve point addition per NIST FIPS PUB 186-4- specified P-384
// Compute temporary secret key
tempSK := &ecdsa.PrivateKey{
PublicKey: ecdsa.PublicKey{
Curve: client.node.enrollPrivKey.Curve,
X: new(big.Int),
Y: new(big.Int),
},
D: new(big.Int),
}
var k = new(big.Int).SetBytes(ExpansionValue)
var one = new(big.Int).SetInt64(1)
n := new(big.Int).Sub(client.node.enrollPrivKey.Params().N, one)
k.Mod(k, n)
k.Add(k, one)
tempSK.D.Add(client.node.enrollPrivKey.D, k)
tempSK.D.Mod(tempSK.D, client.node.enrollPrivKey.PublicKey.Params().N)
// Compute temporary public key
tempX, tempY := client.node.enrollPrivKey.PublicKey.ScalarBaseMult(k.Bytes())
tempSK.PublicKey.X, tempSK.PublicKey.Y =
tempSK.PublicKey.Add(
client.node.enrollPrivKey.PublicKey.X, client.node.enrollPrivKey.PublicKey.Y,
tempX, tempY,
)
// Verify temporary public key is a valid point on the reference curve
isOn := tempSK.Curve.IsOnCurve(tempSK.PublicKey.X, tempSK.PublicKey.Y)
if !isOn {
client.node.log.Error("Failed temporary public key IsOnCurve check.")
continue
}
// Check that the derived public key is the same as the one in the certificate
certPK := x509Cert.PublicKey.(*ecdsa.PublicKey)
cmp := certPK.X.Cmp(tempSK.PublicKey.X)
if cmp != 0 {
client.node.log.Error("Derived public key is different on X")
continue
}
cmp = certPK.Y.Cmp(tempSK.PublicKey.Y)
if cmp != 0 {
client.node.log.Error("Derived public key is different on Y")
continue
}
// Verify the signing capability of tempSK
err = utils.VerifySignCapability(tempSK, x509Cert.PublicKey)
if err != nil {
client.node.log.Error("Failed verifing signing capability [%s].", err.Error())
continue
}
// Marshall certificate and secret key to be stored in the database
resCert[j] = certDERs[i]
if err != nil {
client.node.log.Error("Failed marshalling private key [%s].", err.Error())
continue
}
if err := utils.CheckCertPKAgainstSK(x509Cert, interface{}(tempSK)); err != nil {
client.node.log.Error("Failed checking TCA cert PK against private key [%s].", err.Error())
continue
}
client.node.log.Debug("Sub index [%d]", j)
j++
client.node.log.Debug("Certificate [%d] validated.", i)
}
if j == 0 {
client.node.log.Error("No valid TCert was sent")
return nil, errors.New("No valid TCert was sent.")
}
return resCert[:j], nil
}