How to solve 'Cannot add node...Wrong signature'
Under some circumstances, the following error occurs when trying to add a Terminal Server Node to the Enterprise Terminal Server:
NX> 500 ERROR: Cannot add node '<node>:4000'. Wrong signature.
This happens when PAM on the remote is configured to block the nx user, for example with the following PAM configuration:
1) account required pam_access.so is set into /etc/pam.d/nx
2) -: nx:ALL is set into/etc/security/access.conf
Note that the nx is a reserved user created during the installation of NoMachine server, necessary to perform internal operations. For example this user is used to authenticate the server to the node while adding it. When the nx user is blocked, the node cannot be added.
As a workaround, disable the following key in the /usr/NX/etc/server.cfg file on the remote node:
#
# Enable or disable support for PAM account management when public key
# authentication is used in connections by NX protocol.
#
# 1: Enabled. Support for PAM account management is enabled.
#
# 0: Disabled. Support for PAM account management is disabled.
#
#NXKeyBasedUsePAM 1
To disable it, set: NXKeyBasedUsePAM 0
The fix of the following Trouble Report provides a final solution for the problem: