Password Encryption in DB-Nodes failed

I was working with the batchcommands to run knime while I encountered a problem. It worked perfectly but after some days I got these error messages:

WARN DatabaseReaderConnection PreparedStatement not support by database: Input length must be a multiple of 8 when decrypting with padded cipher
WARN Database Connector java.sql.SQLException: javax.crypto.IllegalBlockSizeException: Input length must be a multiple of 8 when decrypting with padded cipher

And I think I discovered why: I switched my workspace during this time and imported some workflows from my old workspace after copying them to new places. While comparing the node.xml of my database connector nodes I discovered that the password was written in plaintext. Then I checked the node.xml of my old workspace and these were encrypted.
After creating new database connector nodes in KNIME I found out, that in my old and first workspace everything was alright, the password was enrypted immediatley after configuring the nodes, and the next time you checked the configuration there were 8 asterisks.
But in my new and second workspace the automatik encryption failed. After configuring and establishing the connection, there were still exactly as much asterisks as the password had characters. And moreover the password was saved in plaintext.

I don’t have a clue what happened here, but maybe, someone can help me. It looks like a programming error. Maybe the developers can fix it.

Kind regards,


Hi Michael, Can you please tell me which version of KNIME you were using together with your old resp. new workspace. My only guess is that the master key in the old workspace has not be defined (correctly) that’s why the encryption fails inside the new workspace. That means, after you have entered a master key for the first time in the new workspace, the encrypted password can’t be decrypted anymore, since the length is invalid. You need to re-enter the password in this case. Regards, Thomas