feat: add support for AuthPrivateKey

config.go

@@ -467,6 +467,16 @@ func AuthCertificate(cert []byte) Option {
 	}
 }
 
+// AuthPrivateKey sets the client's authentication RSA private key
+// Note: PolicyID still needs to be set outside of this method, typically through
+// the SecurityFromEndpoint() Option
+func AuthPrivateKey(key *rsa.PrivateKey) Option {
+	return func(cfg *Config) error {
+		cfg.sechan.UserKey = key
+		return nil
+	}
+}
+
 // AuthIssuedToken sets the client's authentication data based on an externally-issued token
 // Note: PolicyID still needs to be set outside of this method, typically through
 // the SecurityFromEndpoint() Option

config_test.go

@@ -218,6 +218,17 @@ func TestOptions(t *testing.T) {
 				}(),
 			},
 		},
+		{
+			name: `AuthPrivateKey()`,
+			opt:  AuthPrivateKey(cert.PrivateKey.(*rsa.PrivateKey)),
+			cfg: &Config{
+				sechan: func() *uasc.Config {
+					c := DefaultClientConfig()
+					c.UserKey = cert.PrivateKey.(*rsa.PrivateKey)
+					return c
+				}(),
+			},
+		},
 		{
 			name: `AuthIssuedToken()`,
 			opt:  AuthIssuedToken([]byte("a")),

examples/crypto/crypto.go

@@ -125,6 +125,7 @@ func clientOptsFromFlags(endpoints []*ua.EndpointDescription) []opcua.Option {
 	}
 
 	var cert []byte
+	var privateKey *rsa.PrivateKey
 	if *gencert || (*certfile != "" && *keyfile != "") {
 		if *gencert {
 			certPEM, keyPEM, err := uatest.GenerateCert(*appuri, 2048, 24*time.Hour)
@@ -148,6 +149,7 @@ func clientOptsFromFlags(endpoints []*ua.EndpointDescription) []opcua.Option {
 				log.Fatalf("Invalid private key")
 			}
 			cert = c.Certificate[0]
+			privateKey = pk
 			opts = append(opts, opcua.PrivateKey(pk), opcua.Certificate(cert))
 		}
 	}
@@ -167,8 +169,8 @@ func clientOptsFromFlags(endpoints []*ua.EndpointDescription) []opcua.Option {
 	}
 
 	// Select the most appropriate authentication mode from server capabilities and user input
-	authMode, authOption := authFromFlags(cert)
-	opts = append(opts, authOption)
+	authMode, authOptions := authFromFlags(cert, privateKey)
+	opts = append(opts, authOptions...)
 
 	var secMode ua.MessageSecurityMode
 	switch strings.ToLower(*mode) {
@@ -246,15 +248,15 @@ func clientOptsFromFlags(endpoints []*ua.EndpointDescription) []opcua.Option {
 	return opts
 }
 
-func authFromFlags(cert []byte) (ua.UserTokenType, opcua.Option) {
+func authFromFlags(cert []byte, pk *rsa.PrivateKey) (ua.UserTokenType, []opcua.Option) {
 	var err error
 
 	var authMode ua.UserTokenType
-	var authOption opcua.Option
+	var authOptions []opcua.Option
 	switch strings.ToLower(*auth) {
 	case "anonymous":
 		authMode = ua.UserTokenTypeAnonymous
-		authOption = opcua.AuthAnonymous()
+		authOptions = append(authOptions, opcua.AuthAnonymous())
 
 	case "username":
 		authMode = ua.UserTokenTypeUserName
@@ -284,25 +286,28 @@ func authFromFlags(cert []byte) (ua.UserTokenType, opcua.Option) {
 			*password = string(passInput)
 			fmt.Print("\n")
 		}
-		authOption = opcua.AuthUsername(*username, *password)
+		authOptions = append(authOptions, opcua.AuthUsername(*username, *password))
 
 	case "certificate":
 		authMode = ua.UserTokenTypeCertificate
-		authOption = opcua.AuthCertificate(cert)
+		// Note: You should still use these two Config options to load the auth certificate and private key
+		// separately from the secure channel configuration even if the same certificate is used for both purposes
+		authOptions = append(authOptions, opcua.AuthCertificate(cert))
+		authOptions = append(authOptions, opcua.AuthPrivateKey(pk))
 
 	case "issuedtoken":
 		// todo: this is unsupported, fail here or fail in the opcua package?
 		authMode = ua.UserTokenTypeIssuedToken
-		authOption = opcua.AuthIssuedToken([]byte(nil))
+		authOptions = append(authOptions, opcua.AuthIssuedToken([]byte(nil)))
 
 	default:
 		log.Printf("unknown auth-mode, defaulting to Anonymous")
 		authMode = ua.UserTokenTypeAnonymous
-		authOption = opcua.AuthAnonymous()
+		authOptions = append(authOptions, opcua.AuthAnonymous())
 
 	}
 
-	return authMode, authOption
+	return authMode, authOptions
 }
 
 func validateEndpointConfig(endpoints []*ua.EndpointDescription, secPolicy string, secMode ua.MessageSecurityMode, authMode ua.UserTokenType) error {

uasc/config.go

@@ -33,6 +33,10 @@ type Config struct {
 	// messages.  It is the key associated with Certificate
 	LocalKey *rsa.PrivateKey
 
+	// UserKey is a RSA Private Key which will be used to sign the UserTokenSignature.
+	// It is the key associated with AuthCertificate
+	UserKey *rsa.PrivateKey
+
 	// Thumbprint is the thumbprint of the X.509 v3 Certificate assigned to the receiving
 	// application Instance.
 	// The thumbprint is the CertificateDigest of the DER encoded form of the

uasc/secure_channel_crypto.go

@@ -111,7 +111,7 @@ func (s *SecureChannel) NewUserTokenSignature(policyURI string, cert, nonce []by
 	}
 	remoteKey := remoteX509Cert.PublicKey.(*rsa.PublicKey)
 
-	enc, err := uapolicy.Asymmetric(policyURI, s.cfg.LocalKey, remoteKey)
+	enc, err := uapolicy.Asymmetric(policyURI, s.cfg.UserKey, remoteKey)
 	if err != nil {
 		return nil, "", err
 	}