OPC-UA certificate issues - qt

Question

I'm using Qt qtopcuaviewer example to test the connection to a PLC.
Usually it works fine and I can retrieve the variables. With this specific PLC I get the following output:
"Creating PKI path '/home/user/bin/pki/trusted/certs': SUCCESS."
"Creating PKI path '/home/user/bin/pki/trusted/crl': SUCCESS."
"Creating PKI path '/home/user/bin/pki/issuers/certs': SUCCESS."
"Creating PKI path '/home/user/bin/pki/issuers/crl': SUCCESS."
Discovering servers on "opc.tcp://192.168.1.50:4840"
qt.opcua.plugins.open62541.sdk.userland: "AcceptAll Certificate Verification. Any remote certificate will be accepted."
qt.opcua.plugins.open62541.sdk.securechannel: "Connection 11 | SecureChannel 3778283009 | Opened SecureChannel with SecurityPolicy http://opcfoundation.org/UA/SecurityPolicy#None"
qt.opcua.plugins.open62541.sdk.client: "Client Status: ChannelState: Open, SessionState: Closed, ConnectStatus: Good"
qt.opcua.plugins.open62541.sdk.client: "Client Status: ChannelState: Closed, SessionState: Closed, ConnectStatus: Good"
qt.opcua.plugins.open62541.sdk.userland: "AcceptAll Certificate Verification. Any remote certificate will be accepted."
qt.opcua.plugins.open62541.sdk.securechannel: "Connection 11 | SecureChannel 3778283010 | Opened SecureChannel with SecurityPolicy http://opcfoundation.org/UA/SecurityPolicy#None"
qt.opcua.plugins.open62541.sdk.client: "Client Status: ChannelState: Open, SessionState: Closed, ConnectStatus: Good"
qt.opcua.plugins.open62541.sdk.client: "Client Status: ChannelState: Closed, SessionState: Closed, ConnectStatus: Good"
qt.opcua.plugins.open62541: Directory is empty
Client state changed QOpcUaClient::Connecting
qt.opcua.plugins.open62541: Directory is empty
qt.opcua.plugins.open62541.sdk.userland: "AcceptAll Certificate Verification. Any remote certificate will be accepted."
qt.opcua.plugins.open62541.sdk.securitypolicy: "The Basic128Rsa15 security policy with openssl is added."
qt.opcua.plugins.open62541.sdk.securitypolicy: "The basic256 security policy with openssl is added."
qt.opcua.plugins.open62541.sdk.securitypolicy: "The basic256sha256 security policy with openssl is added."
qt.opcua.plugins.open62541.sdk.client: "The configured ApplicationURI does not match the URI specified in the certificate for the SecurityPolicy http://opcfoundation.org/UA/SecurityPolicy#None"
qt.opcua.plugins.open62541.sdk.securechannel: "Connection 11 | SecureChannel 3778283011 | Opened SecureChannel with SecurityPolicy http://opcfoundation.org/UA/SecurityPolicy#None"
qt.opcua.plugins.open62541.sdk.client: "Client Status: ChannelState: Open, SessionState: Closed, ConnectStatus: Good"
qt.opcua.plugins.open62541.sdk.client: "Rejecting UserTokenPolicy 0 (username) in endpoint 0: configuration doesn't match"
qt.opcua.plugins.open62541.sdk.client: "Rejecting endpoint 1: security mode doesn't match"
qt.opcua.plugins.open62541.sdk.client: "Rejecting endpoint 2: security policy doesn't match"
qt.opcua.plugins.open62541.sdk.client: "Rejecting endpoint 3: security mode doesn't match"
qt.opcua.plugins.open62541.sdk.client: "Rejecting endpoint 4: security policy doesn't match"
qt.opcua.plugins.open62541.sdk.client: "Rejecting endpoint 5: security mode doesn't match"
qt.opcua.plugins.open62541.sdk.client: "No suitable UserTokenPolicy found for the possible endpoints"
qt.opcua.plugins.open62541.sdk.client: "Client Status: ChannelState: Closed, SessionState: Closed, ConnectStatus: BadInternalError"
qt.opcua.plugins.open62541: Open62541: Failed to connect
Client error changed QOpcUaClient::UnknownError
Client state changed QOpcUaClient::Disconnected
The PLC's developer says there are no certificates required - still I'm not sure to understand the root cause of the refused connection.
Is anything I can do to debug this issue? Or it's so clear and my limited knowledge is preventing me to fix it?
EDIT
In the getEndpoints() function I added the following debug calls:
void MainWindow::getEndpoints()
{
ui->endpoints->clear();
updateUiState();
if (ui->servers->currentIndex() >= 0) {
const QString serverUrl = ui->servers->currentText();
createClient();
mOpcUaClient->requestEndpoints(serverUrl);
qDebug() << mOpcUaClient->supportedSecurityPolicies();
qDebug() << mOpcUaClient->supportedUserTokenTypes();
}
}
This is the output:
QList("http://opcfoundation.org/UA/SecurityPolicy#None", "http://opcfoundation.org/UA/SecurityPolicy#Basic128Rsa15", "http://opcfoundation.org/UA/SecurityPolicy#Basic256", "http://opcfoundation.org/UA/SecurityPolicy#Basic256Sha256")
QList(0, 1)
Here the enumeration for TokenType:
enum TokenType {
Anonymous = 0,
Username = 1,
Certificate = 2,
IssuedToken = 3
};
Q_ENUMS(TokenType)
May this help?
UPDATE
With the application mentioned above I find these endpoints:
From my understanding it appears as a request of certificates.
Instead, other machines (the ones that work) show this other endpoint:
So, is it true that the first machine "does not require any security certificate" as stated by the manufacturer?

Answer 1

192.168.1.50 seems to only support Secure communication (None is not present). 192.168.1.12 support only Unsecure communication. I guess your OPC UA Client is not configured to connect to a Secure Server. Check with another OPC UA Client supporting Secure communication ( ie: UA Expert)