Client certificate rejected w. 'BadSecurityChecksFailed'

[thomas.koehrsen]

Hi UA Forum.

Our implementation of the OPC UA Server is returning 'BadSecurityCheckFailed' towards a 3rd party OPC UA Client.

Is the client certificate 'Bad' and in what way?

Server log writes the following:

Code: Select all

2024-01-09 11:56:42.6881|0016|01|4|Opening connection '92cad990-bef3-49bd-9aff-35c429c34a34'
2024-01-09 11:56:42.6881|0091|01|4|Connection Hello received '92cad990-bef3-49bd-9aff-35c429c34a34'
2024-01-09 11:56:42.6881|0091|01|1|[BadSecurityChecksFailed] Error processing incoming message. SecureChannelId=0|StatusException|Input buffer needs to be a multiple of the key size.
2024-01-09 11:56:42.6881|0091|01|4|Closing connection '92cad990-bef3-49bd-9aff-35c429c34a34' SCID=0

[Support Team]

Hi,

this is hard to say with such little information. The OpenSecureChannel is not working.

• The third pary client is from which company?

• Is that available for testing?

• Have you been able to connect to any other server with this third party client?

• Have you tested with UaExpert? Does it work when using UaExpert and doing similar scenario?

Our educated guess is, that the client is using the wrong (or no) security algorithm (or padding) for encryption, hence the cypher is of incorrect length, and rejected by the server.