Symptoms
DRDA client supporting the DB2 connector within Excel cannot connect to DB2 for z/OS through an intermediary IBM DB2 Connect gateway when gateway is configured for encrypted authentication by using Advanced Encryption Standard (AES) instead of Data Encryption Standard (DES), returning an authentication failure error.
Cause
DRDA Client cannot determine correct encryption algorithm at connect time. Use ADO.NET provider for DRDA (DrdaClient) or ADO.NET provider for DB2 (MsDb2Client) connection string argument EncryptionAlgorithm=AES to instruct DRDA Client to utilize DRDA Encryption Algorithm (ENCALG) Advanced Encryption Standard (AES) on DRDA Security Mechanism (SECMEC) when processing DRDA Security Check (SECCHK).
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Resolution
This issue is fixed in the following cumulative update for Host Integration Server:
References
Learn about the terminology that Microsoft uses to describe software updates.
Third-party information disclaimer
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products
