/vmware/applmgmt/backupSchedulerCron.log is filled with warning messages "Blowfish has been deprecated"

Products

• VMware vCenter Server

Issue/Introduction

• We will observe below warning messages under /vmware/applmgmt/backupSchedulerCron.log even if vCenter VAMI backup is not configured in the vCenter.

  • /usr/lib/python3.10/site-packages/paramiko/transport.py:237: CryptographyDeprecationWarning: Blowfish has been deprecated
      "class": algorithms.Blowfish,
    /usr/lib/python3.10/site-packages/paramiko/transport.py:237: CryptographyDeprecationWarning: Blowfish has been deprecated
      "class": algorithms.Blowfish,
    /usr/lib/python3.10/site-packages/paramiko/transport.py:237: CryptographyDeprecationWarning: Blowfish has been deprecated
      "class": algorithms.Blowfish,
    /usr/lib/python3.10/site-packages/paramiko/transport.py:237: CryptographyDeprecationWarning: Blowfish has been deprecated
      "class": algorithms.Blowfish,
    /usr/lib/python3.10/site-packages/paramiko/transport.py:237: CryptographyDeprecationWarning: Blowfish has been deprecated
      "class": algorithms.Blowfish,
    /usr/lib/python3.10/site-packages/paramiko/transport.py:237: CryptographyDeprecationWarning: Blowfish has been deprecated
      "class": algorithms.Blowfish,

Environment

• VMware vCenter server 8.0 U3

Cause

• This comes from Paramiko, which still lists Blowfish as a supported cipher for SSH. The cryptography library, which Paramiko uses under the hood, is warning that Blowfish is deprecated.

Resolution

• Engineering team is aware of this deprecation and it is expected to be addressed in a future release of vCenter or its related components.
• The use of Blowfish is internal to a dependent library (Paramiko), and the deprecation warning is informational only. 
• This warning will not have any impact on the functionality or performance of vCenter.